WorldWideScience

Sample records for carboxylic groups activation

  1. Ovalbumin with Glycated Carboxyl Groups Shows Membrane-Damaging Activity

    Directory of Open Access Journals (Sweden)

    Ching-Chia Tang

    2017-02-01

    Full Text Available The aim of the present study was to investigate whether glycated ovalbumin (OVA showed novel activity at the lipid-water interface. Mannosylated OVA (Man-OVA was prepared by modification of the carboxyl groups with p-aminophenyl α-dextro (d-mannopyranoside. An increase in the number of modified carboxyl groups increased the membrane-damaging activity of Man-OVA on cell membrane-mimicking vesicles, whereas OVA did not induce membrane permeability in the tested phospholipid vesicles. The glycation of carboxyl groups caused a notable change in the gross conformation of OVA. Moreover, owing to their spatial positions, the Trp residues in Man-OVA were more exposed, unlike those in OVA. Fluorescence quenching studies suggested that the Trp residues in Man-OVA were located on the interface binds with the lipid vesicles, and their microenvironment was abundant in positively charged residues. Although OVA and Man-OVA showed a similar binding affinity for lipid vesicles, the lipid-interacting feature of Man-OVA was distinct from that of OVA. Chemical modification studies revealed that Lys and Arg residues, but not Trp residues, played a crucial role in the membrane-damaging activity of Man-OVA. Taken together, our data suggest that glycation of carboxyl groups causes changes in the structural properties and membrane-interacting features of OVA, generating OVA with membrane-perturbing activities at the lipid-water interface.

  2. Interaction of 1-iodochlordecone, as radioactive tracer, with the carboxylate group on activated carbon

    International Nuclear Information System (INIS)

    Gamboa-Carballo, Juan José; Melchor-Rodríguez, Kenia; Hernández-Valdés, Daniel; Jáuregui-Haza, Ulises Javier

    2016-01-01

    Chlordecone is a synthetic organo chlorinated compound that has been used as pesticide. It has been identified and listed as persistent organic pollutant by the Stockholm Convention. The use of activated carbon filters is one of the most widely popular solutions for water decontamination. The chlordecone labeled with radioactive iodine (1-iodochordecone) is a potential radioactive tracer for studying adsorption, environmental availability and bio-distribution of chlordecone. The selection of the best suited activation carbon for this type of contaminants is mainly an empiric process, increasing the costs of research. A simplified activation carbon model, consisting of a seven ring graphene sheet with a functional group (carboxylate) was used to assess the interaction of chlordecone and 1-iodochlordecone with this surface group under neutral pH conditions over the adsorption process. The Multiple Minima Hypersurface methodology with the semiempirical Hamiltonian PM7 was used. The results indicate that for carboxylate, in neutral conditions, significant associations appear which suggest chemisorption in activated carbon. No significant differences were observed for the interactions of chlordecone and 1 iodochlordecone with carboxylate, making 1-iodochlordecone a good candidate as a radioactive tracer in medical research. (author)

  3. Carboxyl group reactivity in actin

    Energy Technology Data Exchange (ETDEWEB)

    Elzinga, M.

    1986-01-01

    While earlier work showed that the carboxyl groups of proteins could be quantitatively coupled to amino groups at pH 4.75 in the presence of EDC and a denaturing agent, the work presented here indicates that under milder conditions the modification of sidechain carboxyls is limited and somewhat specific. Most of the incorporated glycine ethyl ester (GEE) is apparently bound to five carboxyls. The total GEE incorporated was 3 to 4 moles/mole of protein as measured by an increase in Gly upon acid hydrolysis and amino acid analysis, as well as total radioactivity. 3.55 residues were found in peptides, 2.75 bound to residues 1 to 4, and 0.8 bound to Gly-100. 9 refs., 2 figs., 2 tabs.

  4. Carboxyl group reactivity in actin

    International Nuclear Information System (INIS)

    Elzinga, M.

    1986-01-01

    While earlier work showed that the carboxyl groups of proteins could be quantitatively coupled to amino groups at pH 4.75 in the presence of EDC and a denaturing agent, the work presented here indicates that under milder conditions the modification of sidechain carboxyls is limited and somewhat specific. Most of the incorporated glycine ethyl ester (GEE) is apparently bound to five carboxyls. The total GEE incorporated was 3 to 4 moles/mole of protein as measured by an increase in Gly upon acid hydrolysis and amino acid analysis, as well as total radioactivity. 3.55 residues were found in peptides, 2.75 bound to residues 1 to 4, and 0.8 bound to Gly-100. 9 refs., 2 figs., 2 tabs

  5. The Activity of [60]Fullerene Derivatives Bearing Amine and Carboxylic Solubilizing Groups against Escherichia coli: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Dmitry G. Deryabin

    2014-01-01

    Full Text Available We report a comparative investigation of the antibacterial activity of two water-soluble fullerene derivatives bearing protonated amine (AF and deprotonated carboxylic (CF groups appended to the fullerene cage via organic linkers. The negatively charged fullerene derivative CF showed no tendency to bind to the bacterial cells and, consequently, no significant antibacterial activity. In contrast, the compound AF loaded with cationic groups showed strong and partially irreversible binding to the negatively charged Escherichia coli K12 TG1 cells and to human erythrocytes, also possessing negative zeta potential. Adsorption of AF on the bacterial surface was visualized by atomic force microscopy revealing the formation of specific clusters (AF aggregates surrounding the bacterial cell. Incubation of E. coli K12 TG1 with AF led to a dose-dependent bactericidal effect with LD50 = 79.1 µM. The presence of human erythrocytes in the test medium decreased the AF antibacterial activity. Thus we reveal that the water-soluble cationic fullerene derivative AF possesses promising antibacterial activity, which might be utilized in the development of novel types of chemical disinfectants.

  6. Biological activities of new monohydroxylated brassinosteroid analogues with a carboxylic group in the side chain

    Czech Academy of Sciences Publication Activity Database

    Kvasnica, Miroslav; Oklešťková, Jana; Bazgier, Václav; Rárová, Lucie; Berka, K.; Strnad, Miroslav

    2014-01-01

    Roč. 85, JUL 2014 (2014), s. 58-64 ISSN 0039-128X R&D Projects: GA MŠk LK21306; GA MŠk(CZ) LO1204 Grant - others:GA MŠk ED2.1.00/03.0058 Program:ED Institutional support: RVO:61389030 Keywords : Anticancer activity * Brassinosteroids * Organic synthesis Subject RIV: EF - Botanics Impact factor: 2.639, year: 2014 http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Alerting&SrcApp=Alerting&DestApp=CCC&DestLinkType=FullRecord&UT=000337652700008

  7. Preparation, Characterization, and In Vitro and Vivo Antitumor Activity of Oridonin-Conjugated Multiwalled Carbon Nanotubes Functionalized with Carboxylic Group

    Directory of Open Access Journals (Sweden)

    Chuanjin Wang

    2016-01-01

    Full Text Available Carbon nanotubes have shown great potential in tumor therapy. Oridonin (ORI is a poorly water-soluble diterpenoid compound (C20H28O6 used in the treatment of esophageal and hepatic carcinoma for decades. For the purpose of enhancing the antitumor potency and reducing cytotoxicity of ORI, multiwalled carbon nanotubes functionalized with carboxylic group (MWCNTs-COOH were used as ORI carrier. ORI was noncovalently encapsulated into (or onto the functionalized carbon nanotubes (MWCNTs-ORI. The obtained MWCNTs-ORI has been characterized. The ORI loading efficiency in MWCNTs-COOH carrier was studied to be about 82.6% (w/w. In vitro cytotoxicity assay on MWCNTs-ORI gave IC50 of 7.29±0.5 μg/mL and ORI-F gave IC50 of 14.5±1.4 μg/mL. The antitumor effect studies in vivo showed that MWCNTs-ORI improved antitumor activity of ORI in comparison with ORI-F. The tumor inhibition ratio for MWCNTs-ORI (1.68×10-2 g·Kg−1·d−1 was 86.4%, higher than that of ORI-F (1.68×10-2 g·Kg−1·d−1 which was 39.2%. This can greatly improve the pharmaceutical efficiency and reduce potential side effects.

  8. Synthesis and bioactivities of Phenazine-1-carboxylic acid derivatives based on the modification of PCA carboxyl group.

    Science.gov (United States)

    Xiong, Zhipeng; Niu, Junfan; Liu, Hao; Xu, Zhihong; Li, Junkai; Wu, Qinglai

    2017-05-01

    Phenazine-1-carboxylic acid (PCA) as a natural product widely exists in microbial metabolites of Pseudomonads and Streptomycetes and has been registered for the fungicide against rice sheath blight in China. To find higher fungicidal activities compounds and study the effects on fungicidal activities after changing the carboxyl group of PCA, we synthesized a series of PCA derivatives by modifying the carboxyl group of PCA and their structures were confirmed by 1 H NMR and HRMS. Most compounds exhibited significant fungicidal activities in vitro. In particular, compound 6 exhibited inhibition effect against Rhizoctonia solani with EC 50 values of 4.35mg/L and compound 3b exhibited effect against Fusarium graminearum with EC 50 values of 8.30mg/L, compared to the positive control PCA with its EC 50 values of 7.88mg/L (Rhizoctonia solani) and 127.28mg/L (Fusarium graminearum), respectively. The results indicated that the carboxyl group of PCA could be modified to be amide group, acylhydrazine group, ester group, methyl, hydroxymethyl, chloromethyl and ether group etc. And appropriate modifications on carboxyl group of PCA were useful to extend the fungicidal scope. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Rhodium-catalyzed regioselective olefination directed by a carboxylic group.

    Science.gov (United States)

    Mochida, Satoshi; Hirano, Koji; Satoh, Tetsuya; Miura, Masahiro

    2011-05-06

    The ortho-olefination of benzoic acids can be achieved effectively through rhodium-catalyzed oxidative coupling with alkenes. The carboxylic group is readily removable to allow ortho-olefination/decarboxylation in one pot. α,β-Unsaturated carboxylic acids such as methacrylic acid also undergo the olefination at the β-position. Under the rhodium catalysis, the cine-olefination of heteroarene carboxylic acids such as thiophene-2-carboxylic acid proceeds smoothly accompanied by decarboxylation to selectively produce the corresponding vinylheteroarene derivatives. © 2011 American Chemical Society

  10. Electrochemical impedance and spectroscopy study of the EDC/NHS activation of the carboxyl groups on poly(ε-caprolactone/poly(m-anthranilic acid nanofibers

    Directory of Open Access Journals (Sweden)

    Z. Guler

    2016-02-01

    Full Text Available Electrochemical impedance spectroscopy (EIS and spectroscopy was applied to investigate the surface activation of carboxyl group (–COOH containing nanofibers by the reaction of 1-ethyl-3-(dimethyl-aminopropyl carbodiimide hydrochloride (EDC/N-hydroxyl succinimide (NHS in different concentrations. Poly(!-caprolactone/poly(m-anthranilic acid (PCL/P3ANA nanofibers were fabricated by electrospinning and were activated with 5/0.5, 0.5/5, 5/5 and 50/50 mM of EDC/NHS. The surface activation was investigated by Attenuated Total Reflectance Fourier transform infrared spectroscopy (FTIR-ATR and activation yield was estimated. Albumin was immobilized after surface activation and the amount of covalently immobilized protein was determined by bicinchoninic acid (BCA assay. Morphology and composition of albumin immobilized nanofibers were characterized by Scanning Electron Microscopy/Energy-Dispersive X-ray Spectroscopy (SEM/EDX and Atomic force microscope (AFM. EIS measurements indicated that nanofibers become resistant after albumin immobilization. The obtained data revealed that the highest amount of albumin bound to nanofibers activated with 50/50 mM of EDC/NHS which was found to be the optimum concentration for the activation of PCL/P3ANA nanofibers.

  11. Cyclodextrin derivatives with cyanohydrin and carboxylate groups as artificial glycosidases

    DEFF Research Database (Denmark)

    Bols, Mikael; Ortega-Caballero, Fernando

    2006-01-01

    Two cyclodextrin derivatives (1 and 2) were prepared in an attempt to create glycosidase mimics with a general acid catalyst and a nucleophilic carboxylate group. The catalysts 1 and 2 were found to catalyse the hydrolysis of 4-nitrophenyl beta-D-glucopyranoside at pH 8.0, but rapidly underwent...... decomposition with loss of hydrogen cyanide to convert the cyanohydrin to the corresponding aldehyde. The initial rate of the catalysis shows that the cyanohydrin group in these molecules functions as a good catalyst, but that the carboxylate has no positive effect. The decomposition product aldehydes display...

  12. Determination of carboxyl groups in wood fibers by headspace gas chromatography

    Science.gov (United States)

    X.-S. Chai; Q.X. Hou; J.Y. Zhu; S.-L. Chen; S.F. Wang; L. Lucia

    2003-01-01

    The phase reaction conversion (PRC) headspace gas chromatographic (HSGC) technique was employed to develop a method for the determination of the content of carboxyl groups in wood fibers. Acid treatment of the wood fibers using hydrochloric was applied to convert carboxyl groups to carboxyl acids. Bicarbonate solution is then used to react with carboxyl acids on the...

  13. Confinement effect of protonation/deprotonation of carboxylic group modified in nanochannel

    International Nuclear Information System (INIS)

    Gao, Hong-Li; Zhang, Hui; Li, Cheng-Yong; Xia, Xing-Hua

    2013-01-01

    Protonation and deprotonation processes are the key step of acid–base reaction and occur in many biological processes. Study on the deprotonation process of molecules and/or functional groups in confined conditions would help us understand the acid–base theory and confinement effect of biomolecules. In this paper, we use a recently established approach to the study of protonation and deprotonation processes of functional groups in porous anodic alumina array nanochannels by measuring the flux of electrochemical active probes (ferricyanide ions) using an Au film electrochemical detector sputtered at the end of nanochannels. The protonation and deprotonation processes of surface functional groups in nanochannels will change the surface charges and in turn modulate the transportation of charged electroactive probes through nanochannels. The titration curve for the deprotonation of carboxylic groups in nanochannel confined conditions is obtained by measuring the current signal of ferricyanide probe flowing through an carboxylic-anchored PAA nanochannels array at different solution pH. Results show that the deprotonation of carboxylic group in nanochannel occurs in one step with a pK 1/2 = 6.2. The present method provides an effective tool to study the deprotonation processes of various functional groups and biomolecules under confined conditions

  14. Two types of essential carboxyl groups in Rhodospirillum rubrum proton ATPase

    International Nuclear Information System (INIS)

    Ceccarelli, E.; Vallejos, R.H.

    1983-01-01

    Two different types of essential carboxyl groups were detected in the extrinsic component of the proton ATPase of Rhodospirillum rubrum. Chemical modification of R. rubrum chromatophores or its solubilized ATPase by Woodward's reagent K resulted in inactivation of photophosphorylating and ATPase activities. The apparent order of reaction was nearly 1 with respect to reagent concentration and similar K1 were obtained for the soluble and membrane-bound ATPases suggesting that inactivation was associated with modification of one essential carboxyl group located in the soluble component of the proton ATPase. Inactivation was prevented by adenine nucleotides but not by divalent cations. Dicyclohexylcarbodiimide completely inhibited the solubilized ATPase with a K1 of 5.2 mM and a K2 of 0.81 min-1. Mg2+ afforded nearly complete protection with a Kd of 2.8 mM. Two moles of [14C]dicyclohexylcarbodiimide were incorporated per mole of enzyme for complete inactivation but in the presence of 30 mM MgCl2 only one mole was incorporated and there was no inhibition. The labeling was recovered mostly from the beta subunit. The incorporation of the labeled reagent into the ATPase was not prevented by previous modification with Woodward's reagent K. It is concluded that both reagents modified two different essential carboxyl groups in the soluble ATPase from R. rubrum

  15. Adsorption of UO2+2 by polyethylene adsorbents with amidoxime, carboxyl, and amidoxime/carboxyl group

    International Nuclear Information System (INIS)

    Choi, Seong-Ho; Nho, Young Chang

    2000-01-01

    The polyethylene (PE) adsorbents were prepared by a radiation-induced grafting of acrylonitrile (AN), acrylic acid (AA), and the mixture of AN/AA onto PE film, and by subsequent amidoximation of cyano groups of poly-AN graft chains. With an increase of AA composition in AN/AA monomer mixture, the water uptake of the grafted polyethylene film increased. In AN/AA mixture, the maximum adsorption of UO 2+ 2 was observed in the adsorbent with a ratio of AN/AA (50/50, mol%) in copolymer. The amidoxime, carboxyl, and amidoxime/carboxyl groups onto PE acted as a chelating site for the selected UO 2+ 2 . The complex structure of polyethylene with three functional groups and UO 2+ 2 was confirmed by Fourier Transform Infrared (FTIR) spectroscopy. (author)

  16. Multi-walled carbon nanotubes functionalized by carboxylic groups: Activation of TiO{sub 2} (anatase) and phosphate olivines (LiMnPO{sub 4}; LiFePO{sub 4}) for electrochemical Li-storage

    Energy Technology Data Exchange (ETDEWEB)

    Kavan, Ladislav; Zukalova, Marketa [J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-18223 Prague 8 (Czech Republic); Bacsa, Revathi; Tunckol, Meltem; Serp, Philippe [Laboratoire de Chimie de Coordination, UPR CNRS 8241, composante ENSIACET, Universite de Toulouse UPS-INP-LCC 4, Allee Emile Monso, BP 74233, 31432, Toulouse (France); Zakeeruddin, Shaik M.; Le Formal, Florian; Graetzel, Michael [Laboratoire de Photonique et Interfaces, EPFL, Ecublens, CH-1015 Lausanne (Switzerland)

    2010-08-15

    Multi-walled carbon nanotubes functionalized by carboxylic groups, exhibit better affinity towards TiO{sub 2} (P90, Degussa) as compared to that of pristine nanotubes. Also the electrochemical performance of TiO{sub 2} is improved by nanotube networking, but the Li-storage capacity of TiO{sub 2} is unchanged. Whereas the composite of TiO{sub 2} with non-functionalized nanotubes demonstrates simple superposition of the behavior of pure components, the composite with functionalized nanotubes shows unique faradaic pseudocapacitance which is specific for this composite only. The surface functionalization of nanotubes enhances charge storage capacity and reversibility of a composite with LiMnPO{sub 4} (olivine), but mediates also the electrolyte breakdown at potentials >4.2 V. Whereas the electrochemical activation of LiMnPO{sub 4} (olivine) by functionalized nanotubes is quite modest, excellent performance was found for LiFePO{sub 4} (olivine) in composite materials containing only 2 wt% of functionalized nanotubes. (author)

  17. New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2011-09-01

    Full Text Available We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl, Br, NO3, HSO4, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization

  18. Enrichment of Nanodiamond Surfaces with Carboxyl Groups for Doxorubicin Loading and Release

    Science.gov (United States)

    Astuti, Y.; Saputra, F. D.; Wuning, S.; Arnelli; Bhaduri, G.

    2017-02-01

    In their pristine state, nanodiamond crystals produced via detonation techniques containing several functional groups present on the surface including amine, amide, alcohol, carbonyl, and carboxyl. These functional groups facilitate nanodiamond to interact drugs so as to nanodiamond is potential for medical application such as drug delivery. Even though research on t he use of nanodiamond for this application has been conducted widely, research on the effect of enrichment of nanodiamond surface with carboxyl functional groups for drug loading and release has not been explored extensively. Therefore, in this paper, the effect of carboxyl-terminated nanodiamond (ND-COOH) on drug loading and release will be presented. The enrichment of nanodiamond with carboxyl groups was undertaken by treating nanodiamond with sulphuric acid and nitric acid. The results show that the doxorubicin (DOX) loading and release efficiencies of ND pristine are higher than that of ND-COOH.

  19. Photoacidic and Photobasic Behavior of Transition Metal Compounds with Carboxylic Acid Group(s)

    Energy Technology Data Exchange (ETDEWEB)

    O’Donnell, Ryan M. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Sampaio, Renato N. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Li, Guocan [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Johansson, Patrik G. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Ward, Cassandra L. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Meyer, Gerald J. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States

    2016-03-10

    Excited state proton transfer studies of six Ru polypyridyl compounds with carboxylic acid/carboxylate group(s) revealed that some were photoacids and some were photobases. The compounds [RuII(btfmb)2(LL)]2+, [RuII(dtb)2(LL)]2+, and [RuII(bpy)2(LL)]2+, where bpy is 2,2'-bipyridine, btfmb is 4,4'-(CF3)2-bpy, and dtb is 4,4'-((CH3)3C)2-bpy, and LL is either dcb = 4,4'-(CO2H)2-bpy or mcb = 4-(CO2H),4'-(CO2Et)-2,2'-bpy, were synthesized and characterized. The compounds exhibited intense metal-to-ligand charge-transfer (MLCT) absorption bands in the visible region and room temperature photoluminescence (PL) with long τ > 100 ns excited state lifetimes. The mcb compounds had very similar ground state pKa’s of 2.31 ± 0.07, and their characterization enabled accurate determination of the two pKa values for the commonly utilized dcb ligand, pKa1 = 2.1 ± 0.1 and pKa2 = 3.0 ± 0.2. Compounds with the btfmb ligand were photoacidic, and the other compounds were photobasic. Transient absorption spectra indicated that btfmb compounds displayed a [RuIII(btfmb–)L2]2+* localized excited state and a [RuIII(dcb–)L2]2+* formulation for all the other excited states. Time dependent PL spectral shifts provided the first kinetic data for excited state proton transfer in a transition metal compound. PL titrations, thermochemical cycles, and kinetic analysis (for the mcb compounds) provided self-consistent pKa* values. The ability to make a single ionizable group photobasic or photoacidic through ligand design was unprecedented and was understood based on the orientation of the lowest-lying MLCT excited state dipole relative to the ligand that contained the carboxylic acid group(s).

  20. Carboxylic acid functional group analysis using constant neutral loss scanning-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dron, Julien [Laboratoire de Chimie et Environnement, Marseille Universites (case 29), 3 place Victor Hugo, 13331 Marseille Cedex 3 (France)], E-mail: julien.dron@up.univ-mrs.fr; Eyglunent, Gregory; Temime-Roussel, Brice; Marchand, Nicolas; Wortham, Henri [Laboratoire de Chimie et Environnement, Marseille Universites (case 29), 3 place Victor Hugo, 13331 Marseille Cedex 3 (France)

    2007-12-12

    The present study describes the development of a new analytical technique for the functional group determination of the carboxylic moiety using atmospheric pressure chemical ionization-mass spectrometry (APCI-MS/MS) operated in the constant neutral loss scanning (CNLS) mode. Carboxylic groups were first derivatized into their corresponding methyl esters by reacting with BF{sub 3}/methanol mix and the reaction mixture was then directly injected into the APCI chamber. The loss of methanol (m/z = 32 amu) resulting from the fragmentation of the protonated methyl esters was then monitored. Applying this method together with a statistical approach to reference mixtures containing 31 different carboxylic acids at randomly calculated concentrations demonstrated its suitability for quantitative functional group measurements with relative standard deviations below 15% and a detection limit of 0.005 mmol L{sup -1}. Its applicability to environmental matrices was also shown through the determination of carboxylic acid concentrations inside atmospheric aerosol samples. To the best of our knowledge, it is the first time that the tandem mass spectrometry was successfully applied to functional group analysis, offering great perspectives in the characterization of complex mixtures which are prevailing in the field of environmental analysis as well as in the understanding of the chemical processes occurring in these matrices.

  1. Carboxylic acid functional group analysis using constant neutral loss scanning-mass spectrometry

    International Nuclear Information System (INIS)

    Dron, Julien; Eyglunent, Gregory; Temime-Roussel, Brice; Marchand, Nicolas; Wortham, Henri

    2007-01-01

    The present study describes the development of a new analytical technique for the functional group determination of the carboxylic moiety using atmospheric pressure chemical ionization-mass spectrometry (APCI-MS/MS) operated in the constant neutral loss scanning (CNLS) mode. Carboxylic groups were first derivatized into their corresponding methyl esters by reacting with BF 3 /methanol mix and the reaction mixture was then directly injected into the APCI chamber. The loss of methanol (m/z = 32 amu) resulting from the fragmentation of the protonated methyl esters was then monitored. Applying this method together with a statistical approach to reference mixtures containing 31 different carboxylic acids at randomly calculated concentrations demonstrated its suitability for quantitative functional group measurements with relative standard deviations below 15% and a detection limit of 0.005 mmol L -1 . Its applicability to environmental matrices was also shown through the determination of carboxylic acid concentrations inside atmospheric aerosol samples. To the best of our knowledge, it is the first time that the tandem mass spectrometry was successfully applied to functional group analysis, offering great perspectives in the characterization of complex mixtures which are prevailing in the field of environmental analysis as well as in the understanding of the chemical processes occurring in these matrices

  2. Influence of carboxyl group formation on ammonia adsorption of NiO-templated nanoporous carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Long-Yue [Department of Chemistry, Inha University, 100 Inharo, Nam-gu, Incheon 402-751 (Korea, Republic of); Park, Soo-Jin, E-mail: sjpark@inha.ac.kr [Department of Chemistry, Inha University, 100 Inharo, Nam-gu, Incheon 402-751 (Korea, Republic of)

    2012-11-15

    The scope of this work was to control the surface functional groups of nanoporous carbons (NPs) by oxidizing agents (nitric acid and hydrogen peroxide) treatments and to investigate the relation between carboxyl group and ammonia removal efficiency. The NPs were directly prepared from a cation exchange resin by the carbonization of a mixture with Ni acetate at 900 Degree-Sign C. N{sub 2}/-196 Degree-Sign C adsorption, Boehm's titrations, and X-ray photoelectron spectroscopy (XPS) analyzes were employed to confirm the physicochemical properties of NPs. The ammonia removal efficiency was confirmed by temperature programmed desorption (TPD) technique. In the result, the oxygen content of NPs increased after various treatments and the highest content of carboxyl group formation appeared at a 2:3 volume ratio of HNO{sub 3}/H{sub 2}O{sub 2}. It was also found that the oxidation treatment led to an increase in ammonia removal efficiency of NPs, mainly due to an increase of acid oxygen functional groups (such as carboxyl) on NPs surfaces. -- Graphical abstract: The nanoporous carbons were prepared from an exchange resin by the carbonization of a mixture with Ni acetate for ammonia adsorption. Highlights: Black-Right-Pointing-Pointer The carbons were prepared from an exchange resin by the carbonization of a mixture with Ni acetate. Black-Right-Pointing-Pointer The carbon surfaces were modified with HNO{sub 3}/H{sub 2}O{sub 2} solution at different volume radio. Black-Right-Pointing-Pointer The highest content of carboxyl group formation appeared at a 2:3 volume ratio of HNO{sub 3}/H{sub 2}O{sub 2}. Black-Right-Pointing-Pointer The acid oxygen functional groups (such as carboxyl) on carbon surfaces led to an increase in ammonia adsorption.

  3. Measuring the concentration of carboxylic acid groups in torrefied spruce wood.

    Science.gov (United States)

    Khazraie Shoulaifar, Tooran; Demartini, Nikolai; Ivaska, Ari; Fardim, Pedro; Hupa, Mikko

    2012-11-01

    Torrefaction is moderate thermal treatment (∼200-300°C) to improve the energy density, handling and storage properties of biomass fuels. In biomass, carboxylic sites are partially responsible for its hygroscopic. These sites are degraded to varying extents during torrefaction. In this paper, we apply methylene blue sorption and potentiometric titration to measure the concentration of carboxylic acid groups in spruce wood torrefied for 30min at temperatures between 180 and 300°C. The results from both methods were applicable and the values agreed well. A decrease in the equilibrium moisture content at different humidity was also measured for the torrefied wood samples, which is in good agreement with the decrease in carboxylic acid sites. Thus both methods offer a means of directly measuring the decomposition of carboxylic groups in biomass during torrefaction as a valuable parameter in evaluating the extent of torrefaction which provides new information to the chemical changes occurring during torrefaction. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Controlled surface functionalization of silica-coated magnetic nanoparticles with terminal amino and carboxyl groups

    International Nuclear Information System (INIS)

    Kralj, Slavko; Drofenik, Miha; Makovec, Darko

    2011-01-01

    General and versatile methods for the functionalization of superparamagnetic, silica-coated, maghemite nanoparticles by surface amino and/or carboxyl groups have been established. The nanoparticles were synthesized using co-precipitation from aqueous solutions and coated with a thin layer of silica using the hydrolysis and condensation of tetraethoxysilane (TEOS). For the amino functionalization, 3-(2-aminoethylamino)propylmethyldimethoxysilane (APMS) was grafted onto the nanoparticle surfaces in their aqueous suspensions. The grafting process was followed by measurements of the ζ-potential and a determination of the concentration of the surface amino groups with conductometric titrations. The surface concentration of the amino groups could be varied by increasing the amount of APMS in the grafting process up to approximately 2.3 –NH 2 groups per nm 2 . The carboxyl functionalization was obtained in two ways: (i) by a ring-opening linker elongation reaction of the surface amines at the functionalized nanoparticles with succinic anhydride (SA) in non-aqueous medium, and (ii) by reacting the APMS and SA first, followed by grafting of the carboxyl-terminated reagent onto the nanoparticle surfaces. Using the first method, the SA only reacted with the terminal primary amino groups (–NH 2 ) of the surface-grafted APMS molecules. Infra-red spectroscopy (ATR FTIR) and mass spectrometry (HRMS) showed that the second method enables the bonding of up to two SA molecules per one APMS molecule, since the SA reacted with both the primary (–NH 2 ) and secondary amino (–NH–) groups of the APMS molecule. When using both methods, the ratio between the surface amino and carboxyl groups can be controlled.

  5. Coupling of carboxylic groups onto the surface of polystyrene parts during fused filament fabrication

    Science.gov (United States)

    Nagel, Jürgen; Zimmermann, Philipp; Schubert, Oliver; Simon, Frank; Schlenstedt, Kornelia

    2017-11-01

    A method for the fabrication of polystyrene parts, modified with carboxylic groups during Fused Filament Fabrication (FFF), is being introduced. This method is based on the application of a thin layer of a reactive polymer carrying carboxylic groups on a substrate surface. A polystyrene film is printed on top of this layer. During contact between the hot melt and the reactive layer, a Friedel-Crafts type acylation using a green catalyst takes place, which attaches the reactive polymer to the polystyrene surface. The modified surface is homogeneous, hydrophilic and able to bind copper ions. The method could be used to fabricate unique parts of polystyrene with tailored surface functionalisation. It could be applied for laboratory use, e.g. for the manufacture of lab-on-a-chip devices.

  6. Carboxyl group modification significantly altered the kinetic properties of purified carboxymethylcellulase from Aspergillus niger.

    Science.gov (United States)

    Siddiqui; Saqib; Rashid; Rajoka

    2000-10-01

    Carboxymethylcellulase (CMCase) from Aspergillus niger NIAB280 was purified by a combination of ammonium sulphate precipitation, ion-exchange, hydrophobic interaction and gel filtration chromatography on FPLC with 9-folds increase in specific activity. Native and subunit molecular weights were found to be 36 kDa each. The purified CMCase was modified by 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) in the presence of glycinamide for 15 min (GAM15) and glycinamide plus cellobiose for 75 min (GAM75). Similarly, the enzyme was modified by EDC in the presence of ethylenediamine dihydrochloride plus cellobiose for 75 min (EDAM75). The neutralization (GAM15 and GAM75) and reversal (EDAM75) of negative charges of carboxyl groups of CMCase had profound effect on the specificity constant (k(cat)/K(m)), pH optima, pK(a)'s of the active-site residues and thermodynamic parameters of activation. The specificity constants of native, GAM15, GAM75, and EDAM75 were 143, 340, 804, and 48, respectively. The enthalpy of activation (DeltaH(#)) of Carboxymethylcellulose (CMC) hydrolysis of native (50 and 15 kJ mol(-1)) and GAM15 (41 and 16 kJ mol(-1)) were biphasic whereas those of GAM75 (43 kJ mol(-1)) and EDAM75 (41 k J mol(-1)) were monophasic. Similarly, the entropy of activation (DeltaS(#)) of CMC hydrolysis of native (-61 and -173 J mol(-1) K(-1)) and GAM15 (-91 and -171 J mol(-1) K(-1)) were biphasic whereas those of GAM75 (-82 J mol(-1) K(-1)) and EDAM75 (-106 J mol(-1) K(-1)) were monophasic. The pH optima/pK(a)'s of both acidic and basic limbs of charge neutralized CMCases increased compared with those of native enzyme. The CMCase modification in the presence of glycinamide and absence of cellobiose at different pH's periodically activated and inhibited the enzyme activity indicating conformational changes. We believe that the alteration of the surface charges resulted in gross movement of loops that surround the catalytic pocket, thereby inducing changes in the vicinity

  7. Dancing multiplicity states supported by a carboxylated group in dicopper structures bonded to O2

    KAUST Repository

    Poater, Albert

    2013-01-29

    The present study pretends to assign the correct multiplicity state to dinuclear copper complexes when interacting with free molecular oxygen. Recently, the formation of a bridge butterfly μ-η2: η2-peroxo dicopper core structure stabilized by the direct interaction of the counterion, a carboxylate group that allows the double bridge linking both metal-centre atoms, was characterized by crystallography. This system was assigned as a diradical singlet with Ms = 0. However, after new calculations it has turned out to be triplet (Ms = 1) despite the stabilization for this latter multiplicity state is not high. Here, the factors that contribute to make this structure display a multiplicity different with respect to the previously expected diradical singlet are described. In the present theoretical study, the roles of the αSp ligand constraints and the counterion are unravelled. On the other hand, the relative stability between the butterfly μ-η2: η2-peroxo structure and the isomeric bis(μ-oxo) species is also on discussion. Despite the relative stabilities of all these either structural or electronic isomeric species are supposed to depend on the computational method, which is a difficulty to reach a definite conclusion about the nature of the active species, all DFT methods using either pure or not pure DFT functionals here reach the same conclusion, favoring the triplet as the ground state for the butterfly μ-η2: η2-peroxo dicopper core structure, and the bis(μ-oxo) species when removing the benzoate counterion. © Springer-Verlag Berlin Heidelberg 2013.

  8. Rational design of carboxyl groups perpendicularly attached to a graphene sheet: a platform for enhanced biosensing applications.

    Science.gov (United States)

    Bonanni, Alessandra; Chua, Chun Kiang; Pumera, Martin

    2014-01-03

    Graphene oxide (GO)-based materials offer great potential for biofunctionalization with applications ranging from biosensing to drug delivery. Such biofunctionalization utilizes specific functional groups, typically a carboxyl moiety, as anchoring points for biomolecule. However, due to the fact that the exact chemical structure of GO is still largely unknown and poorly defined (it was postulated to consist of various oxygen-containing groups, such as epoxy, hydroxyl, carboxyl, carbonyl, and peroxy in varying ratios), it is challenging to fabricate highly biofunctionalized GO surfaces. The predominant anchoring sites (i.e., carboxyl groups) are mainly present as terminal groups on the edges of GO sheets and thus account for only a fraction of the oxygen-containing groups on GO. Herein, we suggest a direct solution to the long-standing problem of limited abundance of carboxyl groups on GO; GO was first reduced to graphene and consequently modified with only carboxyl groups grafted perpendicularly to its surface by a rational synthesis using free-radical addition of isobutyronitrile with subsequent hydrolysis. Such grafted graphene oxide can contain a high amount of carboxyl groups for consequent biofunctionalization, at which the extent of grafting is limited only by the number of carbon atoms in the graphene plane; in contrast, the abundance of carboxyl groups on "classical" GO is limited by the amount of terminal carbon atoms. Such a graphene platform embedded with perpendicularly grafted carboxyl groups was characterized in detail by X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy, and its application was exemplified with single-nucleotide polymorphism detection. It was found that the removal of oxygen functionalities after the chemical reduction enhanced the electron-transfer rate of the graphene. More importantly, the introduction of carboxyl groups promoted a more efficient immobilization of DNA probes on the

  9. Intramolecular electron transfer through a bridging carboxylate group coordinated to two cobalt(III)-ions

    International Nuclear Information System (INIS)

    Wieghardt, K.

    1978-01-01

    Reduction of the binuclear μ-p-nitrobenzoato -di-μ-hydroxo -bis[triammine cobalt(III)] cation with (CH 3 ) 2 COH radicals yields a radical cation with the p-nitrobenzoato radical being coordinated to two cobalt(III) ions at the carboxylic group. The unprotonated form of this species undergoes intramolecular electron transfer producing Co(II) (k = (3.3 +- 0.3). x 10 3 s -1 ). The role of the carboxylate group in the intramolecular electron transfer process is tentatively assessed in terms of an intramolecular outer-sphere reaction because of lack of overlap of the donor orbitals (π) and the acceptor orbital (sigma). The protonated form of the radical cation (pKsub(a) = 2.5) disproportionates via a bimolecular process without production of Co(II). The effect of two coordinated Co(III) ions as compared to only one on the properties of the nitrobenzoate radical anion are discussed. (orig.) 891 HK 892 GM [de

  10. Separation of Trace Amount Zn (II Using Additional Carbonyl and Carboxyl Groups Functionalized-Nano Graphene

    Directory of Open Access Journals (Sweden)

    A. Moghimi

    2013-01-01

    Full Text Available A novel and selective method for the fast determination of trace amounts of Zn(IIions in water samples has been developed.  The first additional carbonyl and carboxyl functionalized-nano graphene (SPFNano graphene. The presence of additional carbonyl and carboxyl groups located at the edge of the sheets makes GO sheets strongly hydrophilic, allowing them to readily swell and disperse in water. Based on these oxygen functionalities, different model structures of GO were used as absorbent for extraction of Zn (II   ions by solid phase extraction method. The complexes were eluted with HNO3 (2M10% V.V-1 methanol in acetone and determined the analyte by flame atomic absorption spectrometry.  The procedure is based on the selective formation of Zn (II at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISKTM disks modified carbonyl and carboxyl functionalized-nano graphene oxide molecules covalently bonded together followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, SPFNano graphene, amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be 456± 3 µg for Zn2+.The limit of detection of the proposed method is 5ng per 1000mL.The method was applied to the extraction and recovery of Zn in different water samples.

  11. Preparation of carboxyl group-modified palladium nanoparticles in an aqueous solution and their conjugation with DNA

    Science.gov (United States)

    Wang, Zhifei; Li, Hongying; Zhen, Shuang; He, Nongyue

    2012-05-01

    The use of nanomaterials in biomolecular labeling and their corresponding detection has been attracting much attention, recently. There are currently very few studies on palladium nanoparticles (Pd NPs) due to their lack of appropriate surface functionalities for conjugation with DNA. In this paper, we thus firstly present an approach to prepare carboxyl group-modified Pd NPs (with an average size of 6 nm) by the use of 11-mercaptoundecanoic acid (MUDA) as a stabilizer in the aqueous solution. The effect of the various reducing reaction conditions on the morphology of the Pd NPs was investigated. The particles were further characterized by TEM, UV-vis, FT-IR and XPS techniques. DNA was finally covalently conjugated to the surface of the Pd NPs through the activation of the carboxyl group, which was confirmed by agarose gel electrophoresis and fluorescence analysis. The resulting Pd NPs-DNA conjugates show high single base pair mismatch discrimination capabilities. This work therefore sets a good foundation for further applications of Pd NPs in bio-analytical research.

  12. Ru(II)-Catalyzed Oxidative Heck-Type Olefination of Aromatic Carboxylic Acids with Styrenes through Carboxylate-Assisted C-H Bond Activation.

    Science.gov (United States)

    Dana, Suman; Mandal, Anup; Sahoo, Harekrishna; Mallik, Sumitava; Grandhi, Gowri Sankar; Baidya, Mahiuddin

    2018-02-02

    A straightforward synthesis of 2-styrylbenzoic acids from aryl carboxylic acids is disclosed through a carboxylate-assisted coupling under Ru(II) catalysis. This protocol is simple and exhibits broad scope with high tolerance of common organic functional groups, providing good to excellent yields of diverse olefinated products. The efficacy of this protocol has been showcased through sequential syntheses of isochromanone, isocoumarin, and formal synthesis of anacardic acid derivative in good yields.

  13. Multiple functionalization of multi-walled carbon nanotubes with carboxyl and amino groups

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhiyuan [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Yang, Zhanhong, E-mail: zhongnan320@gmail.com [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha 410083 (China); Hu, Youwang; Li, Jianping [College of Mechanical and Electrical Engineering, Central South University, Changsha 410083 (China); Fan, Xinming [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2013-07-01

    In this paper, carboxyl and amino groups have been introduced onto the surface of the multi-walled carbon nanotubes (MWCNTs) by the mixed acid treatment and the diazonium reaction, respectively. The presence of multifunctionality groups on the MWCNTs has been characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TGA) analysis, Raman spectra, scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS). The multifunctionalized carbon nanotubes were further utilized to react with acetyl chloride and ethylenediamine (EDA). The formation of the amide bond in the grafting reaction has been confirmed by FT-IR spectroscopy. The result indicates that the further grafting is successful. The multifunctionalized MWCNTs can be a new versatile platform for many interesting applications.

  14. Electrochemical properties of polyolefin nonwoven fabric modified with carboxylic acid group for battery separator

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seong-Ho; Kang, Hae-Jeong; Ryu, Eun-Nyoung; Lee, Kwang-Pill E-mail: kplee@kyungpook.ac.kr

    2001-07-01

    Carboxylic acid group was introduced by radiation-induced grafting of acrylic acid (AAc) onto polyolefine nonwoven fabric (PNF), wherein the PNF comprises at least about 60% of a polyethylene having a melting temperature at {approx}132 deg. C and no more than about 40% of a second polypropylene having a lower melting temperature at {approx}162 deg. C, for a battery separator. The AAc-grafted PNF was characterized by XPS, SEM, DSC, TGA and porosimeter. The wetting speed, electrolyte retention, electrical resistance, and tensile strength were evaluated after grafting of AAc. It was found that the wetting speed, electrolyte retention, thickness, and ion-exchange capacity increased, whereas the electrical resistance decreased with increasing grafting yield. The tensile strength decreased with increasing grafting yield, whereas the elongation decreased with increasing grafting yield. (author)

  15. Electrochemical properties of polyolefine nonwoven fabric modified with carboxylic acid group for battery separator

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seong-Ho; Park, Keung-Shik; Kang, Hae-Jeong; Ryu, Eun-Nyoung; Lee, Pill-Kwang [Department of Chemistry Graduate School, Kyungpook National University, Taegu (Korea)

    2000-07-01

    Carboxylic acid group was introduced by radiation-induced grafting of acrylic acid (AAc) onto polyolefine nonwoven fabric (PNF), wherein the PNF comprises at least about 60% of a polyethylene having a melting temperature at {approx}132degC and no more than about 40% of a second polypropylene having a lower melting temperature at {approx}162degC, for a battery separator. The AAc-grafted PNF was characterized by XPS, SEM, DSC, TGA and porosimeter. The wetting speed, electrolyte retention, electrical resistance, and tensile strength were evaluated after grafting of AAc. It was found that the wetting speed, electrolyte retention, thickness, and ion-exchange capacity increased, whereas the electrical resistance decreased with increasing grafting yield. The tensile strength decreased with increasing grafting yield, whereas the elongation decreased with increasing grafting yield. (author)

  16. Biosynthesis of quinoxaline antibiotics: Purification and characterization of the quinoxaline-2-carboxylic acid activating enzyme from Streptomyces triostinicus

    International Nuclear Information System (INIS)

    Glund, K.; Schlumbohm, W.; Bapat, M.; Keller, U.

    1990-01-01

    A quinoxaline-2-carboxylic acid activating enzyme was purified to homogeneity from triostin-producing Streptomyces triostinicus. It could also be purified from quinomycin-producing Streptomyces echinatus. Triostins and quinomycins are peptide lactones that contain quinoxaline-2-carboxylic acid as chromophoric moiety. The enzyme catalyzes the ATP-pyrophosphate exchange reaction dependent on quinoxaline-2-carboxylic acid and the formation of the corresponding adenylate. Besides quinoxaline-2-carboxylic acid, the enzyme also catalyzes the formation of adenylates from quinoline-2-carboxylic acid and thieno[3,2-b]pyridine-5-carboxylic acid. No adenylates were seen from quinoline-3-carboxylic acid, quinoline-4-carboxylic acid, pyridine-2-carboxylic acid, and 2-pyrazinecarboxylic acid. Previous work revealed that quinoline-2-carboxylic acid and thieno[3,2-b]pyridine-5-carboxylic acid became efficiently incorporated into the corresponding quinoxaline antibiotic analogues in vivo. Together with the data described here, this suggests that the enzyme is part of the quinoxaline antibiotics synthesizing enzyme system. The enzyme displays a native molecular weight of 42,000, whereas in its denatured form it is a polypeptide of Mr 52,000-53,000. It resembles in its behavior actinomycin synthetase I, the chromophore activating enzyme involved in actinomycin biosynthesis

  17. Surface grafting of carboxylic groups onto thermoplastic polyurethanes to reduce cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Alves, P., E-mail: palves@eq.uc.pt [CIEPQPF, Departamento de Engenharia Química, Universidade de Coimbra, Polo II, Pinhal de Marrocos, 3030-790 Coimbra (Portugal); Ferreira, P. [CIEPQPF, Departamento de Engenharia Química, Universidade de Coimbra, Polo II, Pinhal de Marrocos, 3030-790 Coimbra (Portugal); Kaiser, Jean-Pierre [EMPA, St. Gallen, Lerchenfeldstrasse 5, CH-9014 St. Gallen (Switzerland); Salk, Natalie [Mikrofertigung – Micro Engineering, Fraunhofer IFAM, Wiener Strasse 12, D-288359 Bremen (Germany); Bruinink, Arie [EMPA, St. Gallen, Lerchenfeldstrasse 5, CH-9014 St. Gallen (Switzerland); Sousa, Hermínio C. de; Gil, M.H. [CIEPQPF, Departamento de Engenharia Química, Universidade de Coimbra, Polo II, Pinhal de Marrocos, 3030-790 Coimbra (Portugal)

    2013-10-15

    The interaction of polymers with other materials is an important issue, being their surface properties clearly crucial. For some important polymer applications, their surfaces have to be modified. Surface modification aims to tailor the surface characteristics of a material for a specific application without affecting its bulk properties. Materials can be surface modified by using biological, chemical or physical methods. The aim of this work was to improve the reactivity of the thermoplastic polyurethane (TPU) material (Elastollan{sup ®}) surface and to make its surface cell repellent by grafting carboxylic groups onto its surface. Two TPU materials were studied: a polyether-based TPU and a polyester-based TPU. The grafting efficiency was evaluated by contact angle measurements and by analytical determination of the COOH groups. Scanning electron microscopy (SEM) of the membranes surface was performed as well as cell adhesion tests. It was proved that the surfaces of the TPUs membranes were successfully modified and that cell adhesion was remarkably reduced.

  18. Phase behavior and micellar properties of carboxylic acid end group modified pluronic surfactants

    NARCIS (Netherlands)

    Custers, J.P.A.; Broeke, van den L.J.P.; Keurentjes, J.T.F.

    2007-01-01

    The micellar behavior of three different carboxylic acid end standing (CAE) surfactants has been characterized using conductometry, differential scanning calorimetry, isothermal titration calorimetry, and dynamic light scattering. The CAE surfactants are modified high molecular weight Pluronic

  19. Carboxylic acid effects on the size and catalytic activity of magnetite nanoparticles.

    Science.gov (United States)

    Hosseini-Monfared, Hassan; Parchegani, Fatemeh; Alavi, Sohaila

    2015-01-01

    Magnetite nanoparticles (Fe3O4-NPs) were successfully synthesized in diethylene glycol in the presence of carboxylic acids. They were characterized using XRD, SEM and FTIR. Carboxylic acid plays a critical role in determining the morphology, particle size and size distribution of the resulting particles. The results show that as-prepared magnetite nanoparticles are monodisperse and highly crystalline. The nanoparticles can be easily dispersed in aqueous media and other polar solvents due to coated by a layer of hydrophilic polyol and carboxylic acid ligands in situ. Easily prepared Fe3O4-NPs have been shown to be an active, recyclable, and highly selective catalyst for the epoxidation of cyclic olefins with aqueous 30% H2O2. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Protic ammonium carboxylate ionic liquids: insight into structure, dynamics and thermophysical properties by alkyl group functionalization.

    Science.gov (United States)

    Reddy, Th Dhileep N; Mallik, Bhabani S

    2017-04-19

    This study is aimed at characterising the structure, dynamics and thermophysical properties of five alkylammonium carboxylate ionic liquids (ILs) from classical molecular dynamics simulations. The structural features of these ILs were characterised by calculating the site-site radial distribution functions, g(r), spatial distribution functions and structure factors. The structural properties demonstrate that ILs show greater interaction between cations and anions when alkyl chain length increases on the cation or anion. In all ILs, spatial distribution functions show that the anion is close to the acidic hydrogen atoms of the ammonium cation. We determined the role of alkyl group functionalization of the charged entities, cations and anions, in the dynamical behavior and the transport coefficients of this family of ionic liquids. The dynamics of ILs are described by studying the mean square displacement (MSD) of the centres of mass of the ions, diffusion coefficients, ionic conductivities and hydrogen bonds as well as residence dynamics. The diffusion coefficients and ionic conductivity decrease with an increase in the size of the cation or anion. The effect of alkyl chain length on ionic conductivity calculated in this article is consistent with the findings of other experimental studies. Hydrogen bond lifetimes and residence times along with structure factors were also calculated, and are related to alkyl chain length.

  1. Substituted Amides of Pyrazine-2-carboxylic acids: Synthesis and Biological Activity

    Directory of Open Access Journals (Sweden)

    Katarina Kralova

    2002-03-01

    Full Text Available Condensation of 6-chloro-, 5-tert-butyl- or 6-chloro-5-tert-butylpyrazine-2-carboxylic acid chloride with ring substituted anilines yielded a series of amides, which were tested for their in vitro antimycobacterial, antifungal and photosynthesis-inhibiting activities. The highest antituberculotic activity (72% inhibition against Mycobacterium tuberculosis and the highest lipophilicity (log P = 6.85 were shown by the 3,5-bistrifluoromethylphenyl amide of 5-tert-butyl-6-chloropyrazine-2-carboxylic acid (2o. The 3-methylphenyl amides of 6-chloro- and 5-tert-butyl-6-chloro-pyrazine-2-carboxylic acid (2d and 2f exhibited only a poor in vitro antifungal effect (MIC = 31.25-500 μmol·dm-3 against all strains tested, although the latter was the most active antialgal compound (IC50 = 0.063 mmol·dm-3. The most active inhibitor of oxygen evolution rate in spinach chloroplasts was the (3,5-bis-trifluoromethylphenylamide of 6-chloropyrazine-2-carboxylic acid (2m, IC50 = 0.026 mmol·dm-3.

  2. Synthesis and antifungal activity of the derivatives of novel pyrazole carboxamide and isoxazolol pyrazole carboxylate.

    Science.gov (United States)

    Sun, Jialong; Zhou, Yuanming

    2015-03-09

    A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy). Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani) using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  3. Synthesis and Antifungal Activity of the Derivatives of Novel Pyrazole Carboxamide and Isoxazolol Pyrazole Carboxylate

    Directory of Open Access Journals (Sweden)

    Jialong Sun

    2015-03-01

    Full Text Available A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy. Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  4. Synthesis and Biological Evaluation of Ru(II) and Pt(II) Complexes Bearing Carboxyl Groups as Potential Anticancer Targeted Drugs.

    Science.gov (United States)

    Martínez, Ma Ángeles; Carranza, M Pilar; Massaguer, Anna; Santos, Lucia; Organero, Juan A; Aliende, Cristina; de Llorens, Rafael; Ng-Choi, Iteng; Feliu, Lidia; Planas, Marta; Rodríguez, Ana M; Manzano, Blanca R; Espino, Gustavo; Jalón, Félix A

    2017-11-20

    The synthesis and characterization of Pt(II) (1 and 2) and Ru(II) arene (3 and 4) or polypyridine (5 and 6) complexes is described. With the aim of having a functional group to form bioconjugates, one uncoordinated carboxyl group has been introduced in all complexes. Some of the complexes were selected for their potential in photodynamic therapy (PDT). The molecular structures of complexes 2 and 5, as well as that of the sodium salt of the 4'-(4-carboxyphenyl)-2,2':6',2″-terpyridine ligand (cptpy), were determined by X-ray diffraction. Different techniques were used to evaluate the binding capacity to model DNA molecules, and MTT cytotoxicity assays were performed against four cell lines. Compounds 3, 4, and 5 showed little tendency to bind to DNA and exhibited poor biological activity. Compound 2 behaves as bonded to DNA probably through a covalent interaction, although its cytotoxicity was very low. Compound 1 and possibly 6, both of which contain a cptpy ligand, were able to intercalate with DNA, but toxicity was not observed for 6. However, compound 1 was active in all cell lines tested. Clonogenic assays and apoptosis induction studies were also performed on the PC-3 line for 1. The photodynamic behavior for complexes 1, 5, and 6 indicated that their nuclease activity was enhanced after irradiation at λ = 447 nm. The cell viability was significantly reduced only in the case of 5. The different behavior in the absence or presence of light makes complex 5 a potential prodrug of interest in PDT. Molecular docking studies followed by molecular dynamics simulations for 1 and the counterpart without the carboxyl group confirmed the experimental data that pointed to an intercalation mechanism. The cytotoxicity of 1 and the potential of 5 in PDT make them good candidates for subsequent conjugation, through the carboxyl group, to "selected peptides" which could facilitate the selective vectorization of the complex toward receptors that are overexpressed in

  5. Effect of the number of phenyl groups per molecule on the reactivity of hydroxyl or carboxyl group in hydrogen-isotope exchange reaction

    International Nuclear Information System (INIS)

    Okada, Minoru; Imaizumi, Hiroshi; Oguma, Shuichi

    1989-01-01

    Hydrogen-exchange reactions in solid alcohols (or solid carboxylic acids) which contain phenyl group(s) in each molecule have been observed in a gas-solid system or liquid-solid system at 40 ≅ 80deg C. The data thus obtained have been analyzed by using the A''-McKay plot method, and 'the acidities based on kinetic logic' have been obtained for those compounds. From the acidities the following four characteristics have been determined. (1) The acidity increases with increases of temperature. (2) The reactivities of carboxylic acids are larger than those of alcohols at any temperature. (3) The effect of the number of phenyl groups on the reactivity of the functional group in the molecule in question is fairly large. (4) Acidity based on kinetic logic can be applied not only to gas-solid reactions, but also to liquid-solid reactions. (orig.)

  6. Treatment of sewage from iodo-bromine industrial plants from the second group cations using carboxyl cationnites

    International Nuclear Information System (INIS)

    Kononova, G.N.; Dolbysheva, A.G.; Ksenzenko, V.I.; Ryazantseva, Zh.I.

    1977-01-01

    Effectiveness has been shown of purifying sewage from iodo-bromine plants from the second Group cations on a carboxyl cationite KB-4P. For strongly mineralized waters as industrial waters from iodo-bromine plants, the selectivity decreases in the series: Ca 2+ > Sr 2+ > Mg 2+ . It has been shown that the determining stage is an outside diffusion. SH nitric acid has been used for regeneration of cationite. The second Group cations are washed off with nitric acid simultaneously and at a high rate. Strontium can be separated from the eluate obtained by the halurgical method

  7. Localized conformational interrogation of antibody and antibody-drug conjugates by site-specific carboxyl group footprinting.

    Science.gov (United States)

    Pan, Lucy Yan; Salas-Solano, Oscar; Valliere-Douglass, John F

    Establishing and maintaining conformational integrity of monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) during development and manufacturing is critical for ensuring their clinical efficacy. As presented here, we applied site-specific carboxyl group footprinting (CGF) for localized conformational interrogation of mAbs. The approach relies on covalent labeling that introduces glycine ethyl ester tags onto solvent-accessible side chains of protein carboxylates. Peptide mapping is used to monitor the labeling kinetics of carboxyl residues and the labeling kinetics reflects the conformation or solvent-accessibility of side chains. Our results for two case studies are shown here. The first study was aimed at defining the conformational changes of mAbs induced by deglycosylation. We found that two residues in C H 2 domain (D268 and E297) show significantly enhanced side chain accessibility upon deglycosylation. This site-specific result highlighted the advantage of monitoring the labeling kinetics at the amino acid level as opposed to the peptide level, which would result in averaging out of highly localized conformational differences. The second study was designed to assess conformational effects brought on by conjugation of mAbs with drug-linkers. All 59 monitored carboxyl residues displayed similar solvent-accessibility between the ADC and mAb under native conditions, which suggests the ADC and mAb share similar side chain conformation. The findings are well correlated and complementary with results from other assays. This work illustrated that site-specific CGF is capable of pinpointing local conformational changes in mAbs or ADCs that might arise during development and manufacturing. The methodology can be readily implemented within the industry to provide comprehensive conformational assessment of these molecules.

  8. The Distant Double Bond Determines the Fate of the Carboxylic Group in the Dissociative Photoionization of Oleic Acid.

    Science.gov (United States)

    Heringa, Maarten F; Slowik, Jay G; Goldmann, Maximilian; Signorell, Ruth; Hemberger, Patrick; Bodi, Andras

    2017-12-15

    The valence threshold photoionization of oleic acid has been studied using synchrotron VUV radiation and imaging photoelectron photoion coincidence (iPEPICO) spectroscopy. An oleic acid aerosol beam was impacted on a copper thermodesorber, heated to 130 °C, to evaporate the particles quantitatively. Upon threshold photoionization, oleic acid produces the intact parent ion first, followed by dehydration at higher energies. Starting at ca. 10 eV, a large number of fragment ions slowly rise suggesting several fragmentation coordinates with quasi-degenerate activation energies. However, water loss is the dominant low-energy dissociation channel, and it is shown to be closely related to the unsaturated carbon chain. In the lowest-barrier process, one of the four allylic hydrogen atoms is transferred to the carboxyl group to form the leaving water molecule and a cyclic ketone fragment ion. A statistical model to analyze the breakdown diagram and measured rate constants yields a 0 K appearance energy of 9.77 eV, which can be compared with the density functional theory result of 9.19 eV. Alternative H-transfer steps yielding a terminal C=O group are ruled out based on energetics and kinetics arguments. Some of the previous photoionization mass spectrometric studies also reported 2 amu and 26 amu loss fragment ions, corresponding to hydrogen and acetylene loss. We could not identify such peaks in the mass spectrum of oleic acid. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. ATR-FTIR Spectroscopic Evidence for Biomolecular Phosphorus and Carboxyl Groups Facilitating Bacterial Adhesion to Iron Oxides

    Science.gov (United States)

    Parikh, Sanjai J.; Mukome, Fungai N.D.; Zhang, Xiaoming

    2014-01-01

    Attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy has been used to probe the binding of bacteria to hematite (α-Fe2O3) and goethite (α-FeOOH). In situ ATR-FTIR experiments with bacteria (Pseudomonas putida, P. aeruginosa, Escherichia coli), mixed amino acids, polypeptide extracts, deoxyribonucleic acid (DNA), and a suite of model compounds were conducted. These compounds represent carboxyl, catecholate, amide, and phosphate groups present in siderophores, amino acids, polysaccharides, phospholipids, and DNA. Due in part to the ubiquitous presence of carboxyl groups in biomolecules, numerous IR peaks corresponding to outer-sphere or unbound (1400 cm−1) and inner-sphere (1310-1320 cm−1) coordinated carboxyl groups are noted following reaction of bacteria and biomolecules with α-Fe2O3 and α-FeOOH. However, the data also reveal that the presence of low-level amounts (i.e., 0.45-0.79%) of biomolecular phosphorous groups result in strong IR bands at ~1043 cm−1, corresponding to inner-sphere Fe-O-P bonds, underscoring the importance of bacteria associated P-containing groups in biomolecule and cell adhesion. Spectral comparisons also reveal slightly greater P-O-Fe contributions for bacteria (Pseudomonad, E. coli) deposited on α-FeOOH, as compared to α-Fe2O3. This data demonstrates that slight differences in bacterial adhesion to Fe oxides can be attributed to bacterial species and Fe-oxide minerals. However, more importantly, the strong binding affinity of phosphate in all bacteria samples to both Fe-oxides results in the formation of inner-sphere Fe-O-P bonds, signifying the critical role of biomolecular P in the initiation of bacterial adhesion. PMID:24859052

  10. A new fluorinated urethane dimethacrylate with carboxylic groups for use in dental adhesive compositions

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, Tinca, E-mail: tbur@icmpp.ro [Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Melinte, Violeta [Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Aldea, Horia [Gr. T. Popa University of Medicine and Pharmacy, Faculty of Dentistry, 16 University Str., 700115 Iasi (Romania); Pelin, Irina M.; Buruiana, Emil C. [Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi (Romania)

    2016-05-01

    A urethane macromer containing hexafluoroisopropylidene, poly(ethylene oxide) and carboxylic moieties (UF-DMA) was synthesized and used in proportions varying between 15 and 35 wt.% (F1–F3) in dental adhesive formulations besides BisGMA, triethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate. The FTIR and {sup 1}H ({sup 13}C) NMR spectra confirmed the chemical structure of the UF-DMA. The experimental adhesives were characterized with regard to the degree of conversion, water sorption/solubility, contact angle, diffusion coefficient, Vickers hardness, and morphology of the crosslinked networks and compared with the specimens containing 10 wt.% hydroxyapatite (HAP) or calcium phosphate (CaP). The conversion degree (after 180 s of irradiation with visible light) ranged from 59.5% (F1) to 74.8% (F3), whereas the water sorption was between 23.15 μg mm{sup −3} (F1) and 40.52 μg mm{sup −3} (F3). Upon the addition of HAP or CaP this parameter attained values of 37.82–49.14 μg mm{sup −3} (F1–F3-HAP) and 34.58–45.56 μg mm{sup −3}, respectively. Also, the formation of resin tags through the infiltration of a dental composition (F3) was visualized by SEM analysis. The results suggest that UF-DMA taken as co-monomer in dental adhesives of acrylic type may provide improved properties in the moist environment of the mouth. - Highlights: • Fluorinated urethane dimethacrylate with carboxylic units (UF-DMA) was proposed as co-monomer in dental adhesives. • UF-DMA exhibits good photoreactivity in mixture with commercial dental monomers. • Water sorption/solubility and diffusion coefficient depend on the amount of UF-DMA. • The infiltration of adhesive mixture into the dentin tubules was evidenced by SEM.

  11. Antioxidant activity of hydrated carboxylated nanodiamonds and its influence on water γ-radiolysis

    Science.gov (United States)

    Santacruz-Gomez, Karla; Sarabia-Sainz, A.; Acosta-Elias, M.; Sarabia-Sainz, M.; Janetanakit, Woraphong; Khosla, Nathan; Melendrez, R.; Pedroza Montero, Martin; Lal, Ratnesh

    2018-03-01

    Water radiolysis involves chemical decomposition of the water molecule into free radicals after exposure to ionizing radiation. These free radicals have deleterious effects on normal cell physiology. Carboxylated nanodiamonds (cNDs) appear to modulate the deleterious effects of γ-irradiation on the pathophysiology of red blood cells (RBCs). In the present work, the antioxidant activity of hydrated cNDs (h-cNDs) on limiting oxidative damage (the water radiolysis effect) by γ-irradiation was confirmed. Our results show that h-cNDs have remarkable free radical scavenging ability and preserve the enzymatic activity of catalase after γ-irradiation. The underlying mechanism through which nanodiamonds exhibit antioxidant activity appears to depend on their colloidal stability. This property of detonation synthesized nanodiamonds is improved after carboxylation, which in turn influences changes in the hydrogen bond strength in water. The observed stability of h-cNDs in water and their antioxidant activity correlates with their protective effect on RBCs against γ-irradiation.

  12. Carboxylate and amino group coated silver nanoparticles as joining materials for copper-to-copper silver joints.

    Science.gov (United States)

    Oestreicher, A; Röhrich, T; Lerch, M

    2012-12-01

    Organic silver complexes are introduced where silver is linked either with a carboxyl group or with an amino group. Upon heating, nanoparticles are generated if the respective ligands are long enough to act as stabilizing agents in the nanoparticulate regime. With decomposition and volatilization of the organic material, the sintering of silver occurs. The thermal characteristics of the carboxylates silver-n-octanoate, silver-n-decanoate, and AgOOC(CH2OCH2)2CH2OCH3 are compared with silver-n-alkylamines (n = 8, 9, and 12), and their thermal behavior is discussed based on thermogravimetry (TG) measurements. The consecutive stages of a metallization process are addressed based on the properties of AgOOC(CH2OCH2)2CH2OCH3, and the usable effects of the individual phases of this metal organic compound are analyzed by cross-sectional scanning electron microscope (SEM) images of silver joints. Selection criteria are addressed based on the thermal behavior. A mechanism for the joining process is proposed, considering formation and sintering of the nanoparticles. It was found that the bulk material can be used for low-temperature joining processes. Strong adherence to copper as a basic material can be achieved.

  13. Determining the selectivity of divalent metal cations for the carboxyl group of alginate hydrogel beads during competitive sorption.

    Science.gov (United States)

    An, Byungryul; Lee, Healim; Lee, Soonjae; Lee, Sang-Hyup; Choi, Jae-Woo

    2015-11-15

    To investigate the competitive sorption of divalent metal ions such as Ca(2+), Cu(2+), Ni(2+), and Pb(2+) on alginate hydrogel beads, batch and column tests were conducted. The concentration of carboxyl group was found to be limited in the preparation of spherical hydrogel beads. From kinetic test results, 80% of sorption was observed within 4h, and equilibrium was attained in 48 h. According to the comparison of the total uptake and release, divalent metal ions were found to stoichiometrically interact with the carboxyl group in the alginate polymer chain. From the Langmuir equation, the maximum capacities of Pb(2+), Cu(2+), and Ni(2+) were calculated to be 1.1, 0.48, and 0.13 mmol/g, respectively. The separation factor (α) values for αPb/Cu, αPb/Ni, and αCu/Ni were 14.0, 98.9, and 7.1, respectively. The sorption capacity of Pb(2+) was not affected by the solution pH; however, the sorption capacities of Cu(2+) and Ni(2+) decreased with increasing solution pH, caused by competition with hydrogen. According to the result from the fixed column test, Pb(2+) exhibited the highest affinity, followed by Cu(2+) and Ni(2+), which is in exact agreement with those of kinetic and isotherm tests. The sorbent could be regenerated using 4% HCl, and the regenerated sorbent exhibited 90% capacity upto 9 cycles. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Effect of carboxyl anchoring groups in asymmetric zinc phthalocyanine with large steric hindrance on the dye-sensitized solar cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wenye; Peng, Bosi; Lin, Li; Li, Renjie; Zhang, Jing, E-mail: jzhang03@whu.edu.cn; Peng, Tianyou, E-mail: typeng@whu.edu.cn

    2015-08-01

    Asymmetric zinc phthalocyanines containing tribenzonaphtho-condensed porphyrazine with six bulky diphenylphenoxy and one or two carboxyl groups are used as sensitizers for dye-sensitized solar cells (DSSCs). It is found that Zn-tri-PcNc-4 having two carboxyl groups shows a slight redshift in the Q-band absorption but a significantly decreased absorbance as compared with Zn-tri-PcNc-8 having one carboxyl group, and Zn-tri-PcNc-4 can be more stably and perpendicularly grafted onto the TiO{sub 2} surface than Zn-tri-PcNc-8, which further leads to the differences in the interfacial charge transfer dynamics and dye-loaded amount. Zn-tri-PcNc-4 with two carboxyl groups grafted onto the TiO{sub 2} electrode surface of DSSC results in a photovoltaic conversion efficiency of 3.22%, higher than that (3.01%) of the analog with one carboxyl group (Zn-tri-PcNc-8), which exhibits a lower short-circuit current but much higher open-circuit voltage. The additional carboxyl group in Zn-tri-PcNc-4 leads to the enhanced dye-loaded amount and the molecular orbital energy level shift toward positive direction, causing more efficient electron injection and higher short-circuit current than Zn-tri-PcNc-8; while the two carboxyl groups of Zn-tri-PcNc-4 would cause more protonation of TiO{sub 2} surface, which possibly leads to the downward shift of TiO{sub 2} conduction band edge, and then to the decreased open-circuit voltage. The present results demonstrate the molecular engineering aspect of ZnPc dyes in which the fine tuning of the energy levels and molecular structures is crucial for high conversion efficiency of DSSCs. - Highlights: • ZnPcs with six diphenylphenoxy and one/two carboxyl groups are used as dyes for DSSCs. • Effect of carboxyl group number on the ZnPc-sensitized cell property are scrutinized. • Grafting two carboxyl groups on ZnPc leads to the enhanced photocurrent and efficiency. • ZnPc with one COOH has a higher open-circuit voltage than its analog with two

  15. Matrix-Assisted Laser Desorption Ionization Mass Spectrometry of Compounds Containing Carboxyl Groups Using CdTe and CuO Nanoparticles

    OpenAIRE

    Megumi Sakurai; Taro Sato; Jiawei Xu; Soichi Sato; Tatsuya Fujino

    2018-01-01

    Matrix-assisted laser desorption ionization mass spectrometry of compounds containing carboxyl groups was carried out by using semiconductor nanoparticles (CdTe and CuO) as the matrix. Salicylic acid (Sal), glucuronic acid (Glu), ibuprofen (Ibu), and tyrosine (Tyr) were ionized as deprotonated species (carboxylate anions) by using electrons ejected from CdTe after the photoexcitation. When CuO was used as the matrix, the peak intensity of Tyr became high compared with that obtained with CdTe....

  16. Calculating the Ionization Constant of Functional Groups of Carboxyl Ion Exchangers

    Science.gov (United States)

    Meychik, N. R.; Stepanov, S. I.; Nikolaeva, Yu. I.

    2018-02-01

    The potentiometric titration of a weakly basic carboxyl cation exchanger, obtained via alkaline hydrolysis of an acrylonitrile copolymer with divinyl benzene (degree of crosslinking, 12%) in a wide range of variation in a solution of pH (2-12) and NaCl (concentration 0.01, 0.1, 0.5, 1 M), is considered. The maximum ion-exchange capacity of the ion exchanger for Na+ is determined (10.10 ± 0.088 mmol/g of the dry mass) and found to be independent of the solution's ionic strength. It is established that in the investigated range of NaCl concentrations and pH, the acid-base balance is adequately described by Gregor's equation. The parameters of this equation are calculated as a function of the NaCl concentration: p K a = 8.13 ± 0.04, n = 1.50 ± 0.02 for 0.01 M; p K a = 6.56 ± 0.04, n = 2.60 ± 0.07 for 0.1 M; and p K a = 5.66 ± 0.6, n = 2.62 ± 0.06 for 0.5 and 1 M. It is shown that to describe the acid-base balance correctly within the proposed model we must estimate the adequacy of the experimental and calculated values of the ion exchanger's capacity at each pH value according to the calculated parameters of Gregor's equation.

  17. Acid-Base Behavior of Carboxylic Acid Groups Covalently Attached at the Surface of Polyethylene: The Usefulness of Contact Angle in Following the Ionization of Surface Functionality

    Science.gov (United States)

    1985-08-01

    additional check, we converted granular PE-CO 2H to granular PE-CO 2CH3 by acid -catalyzed esterification. This material had no titrable groups. Upon...Task No. NR-631-840 TECHNICAL REPORT NO. 85-1 Acid -Base Behavior of Carboxylic Acid Groups Covalently Attached at the Surface of Polyethylene: The...34I Acid -Base Behavior K-142 ofCarboxylicAcidGroupsAttached...______________________ 12. PERSIIMAL AUTHOR IS) S.R. Holmes-Farly., R.H. Reamey, T.J

  18. Polymethyl methacrylate-co-methacrylic acid coatings with controllable concentration of surface carboxyl groups: A novel approach in fabrication of polymeric platforms for potential bio-diagnostic devices

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Samira; Ibrahim, Fatimah [Center for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Djordjevic, Ivan, E-mail: ivan.djordjevic@um.edu.my [Center for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Koole, Leo H. [Center for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Biomedical Engineering, Faculty of Health. Medicine and Life Science, Maastricht University, PO Box 616, NL 6200 MD Maastricht (Netherlands)

    2014-05-01

    Highlights: • Synthesis and processing of PMMA-co-MAA spin-coatings on silicon wafers. • Surface chemistry and morphology as a function of tailored co-polymer structure. • Polymer coatings with controlled number of surface carboxyl groups. - Abstract: The generally accepted strategy in development of bio-diagnostic devices is to immobilize proteins on polymeric surfaces as a part of detection process for diseases and viruses through antibody/antigen coupling. In that perspective, polymer surface properties such as concentration of functional groups must be closely controlled in order to preserve the protein activity. In order to improve the surface characteristics of transparent polymethacrylate plastics that are used for diagnostic devices, we have developed an effective fabrication procedure of polymethylmetacrylate-co-metacrylic acid (PMMA-co-MAA) coatings with controlled number of surface carboxyl groups. The polymers were processed effectively with the spin-coating technique and the detailed control over surface properties is here by demonstrated through the variation of a single synthesis reaction parameter. The chemical structure of synthesized and processed co-polymers has been investigated with nuclear magnetic resonance spectroscopy (NMR) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-ToF-MS). The surface morphology of polymer coatings have been analyzed with atomic force microscopy (AFM) and scanning electron microscopy (SEM). We demonstrate that the surface morphology and the concentration of surface –COOH groups (determined with UV–vis surface titration) on the processed PMMA-co-MAA coatings can be precisely controlled by variation of initial molar ratio of reactants in the free-radical polymerization reaction. The wettability of developed polymer surfaces also varies with macromolecular structure.

  19. Polymethyl methacrylate-co-methacrylic acid coatings with controllable concentration of surface carboxyl groups: A novel approach in fabrication of polymeric platforms for potential bio-diagnostic devices

    International Nuclear Information System (INIS)

    Hosseini, Samira; Ibrahim, Fatimah; Djordjevic, Ivan; Koole, Leo H.

    2014-01-01

    Highlights: • Synthesis and processing of PMMA-co-MAA spin-coatings on silicon wafers. • Surface chemistry and morphology as a function of tailored co-polymer structure. • Polymer coatings with controlled number of surface carboxyl groups. - Abstract: The generally accepted strategy in development of bio-diagnostic devices is to immobilize proteins on polymeric surfaces as a part of detection process for diseases and viruses through antibody/antigen coupling. In that perspective, polymer surface properties such as concentration of functional groups must be closely controlled in order to preserve the protein activity. In order to improve the surface characteristics of transparent polymethacrylate plastics that are used for diagnostic devices, we have developed an effective fabrication procedure of polymethylmetacrylate-co-metacrylic acid (PMMA-co-MAA) coatings with controlled number of surface carboxyl groups. The polymers were processed effectively with the spin-coating technique and the detailed control over surface properties is here by demonstrated through the variation of a single synthesis reaction parameter. The chemical structure of synthesized and processed co-polymers has been investigated with nuclear magnetic resonance spectroscopy (NMR) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-ToF-MS). The surface morphology of polymer coatings have been analyzed with atomic force microscopy (AFM) and scanning electron microscopy (SEM). We demonstrate that the surface morphology and the concentration of surface –COOH groups (determined with UV–vis surface titration) on the processed PMMA-co-MAA coatings can be precisely controlled by variation of initial molar ratio of reactants in the free-radical polymerization reaction. The wettability of developed polymer surfaces also varies with macromolecular structure

  20. Cellulose bearing Schiff base and carboxylic acid chelating groups: a low cost and green adsorbent for heavy metal ion removal from aqueous solution.

    Science.gov (United States)

    Saravanan, R; Ravikumar, L

    2016-10-01

    Chemically modified cellulose bearing metal binding sites like Schiff base and carboxylic acid groups was synthesized and characterized through Fourier transform infrared and solid state 13 C-nuclear magnetic resonance (NMR) analysis. The chemically modified cellulose (Cell-PA) adsorbent was examined for its metal ion uptake ability for Cu(II) and Pb(II) ions from aqueous solution. Kinetic and isotherm studies were carried out under optimum conditions. Pseudo-second-order kinetics and Langmuir isotherm fit well with the experimental data. Thermodynamic studies were also performed along with adsorption regeneration performance studies. The adsorbent (Cell-PA) shows high potential for the removal of Cu(II) and Pb(II) metal ions, and it shows antibacterial activity towards selected microorganisms.

  1. Spectroscopic and first principles investigation on 4-[(4-pyridinylmethylene)amino]-benzoic acid bearing pyridyl and carboxyl anchoring groups

    Science.gov (United States)

    Zhang, Lei; Wang, Qiaoyi

    2018-03-01

    We report a combined experimental and computational investigation on the structure and photophysics of 4-[(4-pyridinylmethylene)amino]-benzoic acid, a functional molecule bearing two anchoring groups for attachment onto a TiO2 surface and perovskite surface, for potential solar cell application. This molecule possesses interesting adsorption properties in perovskite solar cell because the pyridyl group serves as the Lewis base and targets Lewis acidic sites in the perovskite surface, while the carboxyl group targets TiO2 surface, improving the coupling between the perovskite surface and the TiO2 surface. The electronic structures of the molecule and its photochemistry are revealed by the UV-vis absorption spectra and the fluorescence spectra under visible light irradiation, which are combined with density functional theory (DFT) and time-dependent density functional theory (TDDFT) analysis. Considering the bi-anchoring groups and the conjugated π system embedded in the molecule, we anticipate it can molecular engineer the TiO2/perovskite interface in perovskite solar cell.

  2. Synthesis, Antifungal Activity and QSAR of Some Novel Carboxylic Acid Amides

    Directory of Open Access Journals (Sweden)

    Shijie Du

    2015-03-01

    Full Text Available A series of novel aromatic carboxylic acid amides were synthesized and tested for their activities against six phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to good activity. Among them N-(2-(1H-indazol-1-ylphenyl-2-(trifluoromethylbenzamide (3c exhibited the highest antifungal activity against Pythium aphanidermatum (EC50 = 16.75 µg/mL and Rhizoctonia solani (EC50 = 19.19 µg/mL, compared to the reference compound boscalid with EC50 values of 10.68 and 14.47 µg/mL, respectively. Comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA were employed to develop a three-dimensional quantitative structure-activity relationship model for the activity of the compounds. In the molecular docking, a fluorine atom and the carbonyl oxygen atom of 3c formed hydrogen bonds toward the hydroxyl hydrogens of TYR58 and TRP173.

  3. Water-soluble Manganese and Iron Mesotetrakis(carboxyl)porphyrin: DNA Binding, Oxidative Cleavage, and Cytotoxic Activities.

    Science.gov (United States)

    Shi, Lei; Jiang, Yi-Yu; Jiang, Tao; Yin, Wei; Yang, Jian-Ping; Cao, Man-Li; Fang, Yu-Qi; Liu, Hai-Yang

    2017-06-29

    Two new water-soluble metal carboxyl porphyrins, manganese (III) meso -tetrakis (carboxyl) porphyrin and iron (III) meso -tetrakis (carboxyl) porphyrin, were synthesized and characterized. Their interactions with ct-DNA were investigated by UV-Vis titration, fluorescence spectra, viscosity measurement and CD spectra. The results showed they can strongly bind to ct-DNA via outside binding mode. Electrophoresis experiments revealed that both complexes can cleave pBR322 DNA efficiently in the presence of hydrogen peroxide, albeit 2-Mn exhibited a little higher efficiency. The inhibitor tests suggest the oxidative DNA cleavage by these two complexes may involve hydroxyl radical active intermediates. Notably, 2-Mn exhibited considerable photocytotoxicity against Hep G2 cell via triggering a significant generation of ROS and causing disruption of MMP after irradiation.

  4. Anti-Inflammatory and Antinociceptive Activities of Anthraquinone-2-Carboxylic Acid.

    Science.gov (United States)

    Park, Jae Gwang; Kim, Seung Cheol; Kim, Yun Hwan; Yang, Woo Seok; Kim, Yong; Hong, Sungyoul; Kim, Kyung-Hee; Yoo, Byong Chul; Kim, Shi Hyung; Kim, Jong-Hoon; Cho, Jae Youl

    2016-01-01

    Anthraquinone compounds are one of the abundant polyphenols found in fruits, vegetables, and herbs. However, the in vivo anti-inflammatory activity and molecular mechanisms of anthraquinones have not been fully elucidated. We investigated the activity of anthraquinones using acute inflammatory and nociceptive experimental conditions. Anthraquinone-2-carboxylic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA), one of the major anthraquinones identified from Brazilian taheebo, ameliorated various inflammatory and algesic symptoms in EtOH/HCl- and acetylsalicylic acid- (ASA-) induced gastritis, arachidonic acid-induced edema, and acetic acid-induced abdominal writhing without displaying toxic profiles in body and organ weight, gastric irritation, or serum parameters. In addition, AQCA suppressed the expression of inflammatory genes such as cyclooxygenase- (COX-) 2 in stomach tissues and lipopolysaccharide- (LPS-) treated RAW264.7 cells. According to reporter gene assay and immunoblotting analyses, AQCA inhibited activation of the nuclear factor- (NF-) κB and activator protein- (AP-) 1 pathways by suppression of upstream signaling involving interleukin-1 receptor-associated kinase 4 (IRAK1), p38, Src, and spleen tyrosine kinase (Syk). Our data strongly suggest that anthraquinones such as AQCA act as potent anti-inflammatory and antinociceptive components in vivo, thus contributing to the immune regulatory role of fruits and herbs.

  5. Complexation of vanadium with amidoxime and carboxyl groups. Uncovering the competitive role of vanadium in uranium extraction from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cong-Zhi; Wu, Qun-Yan; Lan, Jian-Hui; Shi, Wei-Qun [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Chai, Zhi-Fang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Soochow Univ., Suzhou (China). School of Radiological and Interdisciplinary Sciences (RAD-X); Wu, Guo-Zhong [Chinese Academy of Sciences, Shanghai (China). Shanghai Inst. of Applied Physics

    2017-09-01

    At present, amidoxime-based adsorbents are considered to be the most promising materials for extraction of uranium from seawater. However, the high concentrations of transition metals especially vanadium strongly compete with uranium in the sequestration process, which is extremely limited the commercial use of amidoxime-based adsorbents. In this work, the coordination modes, bonding nature, and stabilities of possible vanadium(IV) (VO{sup 2+}) and (V) (VO{sub 2}{sup +}, VO{sup 3+}, V{sup 5+}) complexes with amidoximate (AO{sup -}), carboxyl (Ac{sup -}), glutarimidedioximate (HA{sup -}) and deprotonated glutarimidedioximate (A{sup 2-}) on single and double alkyl chains (R=C{sub 13}H{sub 26}) are systematically explored by quantum chemical calculations. Different from the uranyl (UO{sub 2}{sup 2+}) complexes, the AO{sup -} groups of the vanadium(IV) and (V) complexes prefer to coordinate as monodentate and chelate ligands, while few species with AO{sup -} groups in η{sup 2}-binding mode have been observed in the vanadium complexes. Besides, the vanadium complexes are predicted to have obvious covalent metal-ligand bonds. According to thermodynamic stability analysis, all the vanadium complexes with AO{sup -}, Ac{sup -}, HA{sup -} and A{sup 2-} ligands on double alkyl chains are found to be more stable than corresponding complexes with ligands on a single chain. The synergistic effect of the amidoxime and carboxyl groups can be observed in most of VO{sub 2}{sup +} and VO{sup 3+} complexes with mixed ligands (AO{sup -}/Ac{sup -}). The vanadium(IV) and (V) complexes are more stable than the corresponding uranyl complexes, and the adsorption capability of the amidoxime-based adsorbents toward vanadium(V) ions decrease in the order of VO{sub 2}{sup +}>VO{sup 3+}> V{sup 5+}. The dioxovanadium cation VO{sub 2}{sup +} is predicted to form multinuclear vanadium complex in the sequestration process, possibly resulting in higher stable VO{sub 2}{sup +} complexes. Therefore

  6. Lipid oxidation. Part. 1. Effect of free carboxyl group on the decomposition of lipid hydroperoxide.

    Science.gov (United States)

    Pokorný, J; Rzepa, J; Janícek, G

    1976-01-01

    Hydroperoxido butyl oleate was decomposed by heating in excess palmitic acid at 60-120 degrees C. The decomposition followed the kinetics of a first order reaction with formation of both monomeric and oligomeric secondary products. The proportions of oligomers slightly increased with increasing reaction temperature and decreased with increasing concentration of hydroperoxide. The activation energy was 70.4 kJ/mol +/- 4.7 kJ/mol. The decomposition of hydroperoxides proceeded partially by monomolecular cleavage, partially by formation of esters with palmitic acid.

  7. Direct Carboxylation of the Diazo Group ipso-C(sp2)-H bond with Carbon Dioxide: Access to Unsymmetrical Diazomalonates and Derivatives.

    Science.gov (United States)

    Liu, Qianyi; Li, Man; Xiong, Rui; Mo, Fanyang

    2017-12-15

    The direct carboxylation of the ipso-C(sp 2 )-H bond of a diazo compound with carbon dioxide under mild reaction conditions is described. This method is transition-metal-free, uses a weak base, and proceeds at ambient temperature under atmospheric pressure in carbon dioxide. The carboxylation exhibits high reactivity and is amenable to subsequent diversification. A series of unsymmetrical 1,3-diester/keto/amide diazo compounds are obtained with moderate to excellent yields (up to 99%) with good functional group compatibility.

  8. Enhancement of carboxylic acid degradation with sulfate radical generated by persulfate activation.

    Science.gov (United States)

    Criquet, J; Nebout, P; Karpel Vel Leitner, N

    2010-01-01

    The aim of this work was to investigate the generation of sulfate radical for the removal of two carboxylic acids in aqueous solution: acetic and citric acids. From photochemical and radiolytic processes, kinetics of the degradation of these two carboxylic acids was studied as a function of the pH of the solution. It was shown that the maximum of acetic acid degradation occurred at pH 5. Above this pH, competitive reactions with the carbon mineralized inhibit the reaction of with the solute. In the case of citric acid, pH has only a little effect on the kinetic of citric acid degradation. The determination of mineralization yields shows several differences depending on carboxylic acids and pH. The degradation of both carboxylic acids was also studied in the radiolysis process whether with or without persulfate addition. A comparison of the processes of sulfate radical production is presented.

  9. Synthesis, Characterization and catalytic activity of triorganotin(IV) carboxylates for the production of biodiesel from rocket seed oil

    International Nuclear Information System (INIS)

    Tariq, M.; Ali, S.

    2013-01-01

    Organotin(IV) carboxylates have a wide range of industrial applications such as antifouling paints, PVC stabilization, ion carries in electrochemical membranes and homogeneous catalysts. The catalytic application of organotin carboxylates are in the field of silicone curing, polyurethane formation and esterification. Only a limited literature is available regarding the use of organotin carboxylates in the transesterification of vegetable oil to produce biodiesel . The present study deals with the synthesis of some new triorganotin(IV) carboxylates for their subsequent use as catalyst for transesterification of rocket seed oil to produce biodiesel. The three new triorganotin(IV) i.e. (Me/sub 3/SnL) (1),(Bu/sub 3/Snl) (2) and (Ph/sub 3/SnL) (3), were synthesized by refluxing sodium salt of ligand (NaL), where L=O/sub 2/C(CH/sub 3/)C=CHC/sub 6/H/sub 4/F with trimethyl, tributyl and triphenyl tin(IV) chlorides, respectively for 10 hrs. The synthesized compounds were characterized by instrumental techniques like FT-IR and NMR (1H, 13C). The catalytic activity of these compounds was assessed for transesterification of triglycerides in rocket seed oil to produce biodiesel. All the tested compounds showed good catalytic activity in the order 1> 2 > 3. (author)

  10. Characterization and sequencing of the active site of 1-aminocyclopropane-1-carboxylate synthase

    International Nuclear Information System (INIS)

    Yip, Wing-Kin; Dong, Jian-Guo; Yang, S.F.; Kenny, J.W.; Thompson, G.A.

    1990-01-01

    The pyridoxal phosphate (PLP)-dependent 1-aminocyclopropane-1-carboxylic acid (ACC) synthase the key enzyme in ethylene biosynthesis, is inactivated by its substrate S-adenosylmethionine (AdoMet). Apple ACC synthase was purified with an immunoaffinity gel, and its active site was probed with NaB 3 H 4 or Ado[ 14 C]Met. Peptide sequencing of both 3 H- and 14 C-labeled peptides revealed a common dodecapeptide of Ser-Leu-Ser-Xaa-Asp-Leu-Gly-Leu-Pro-Gly-Phe-Arg, where Xaa was the modified, radioactive residue in each case. Acid hydrolysis of the 3 H-labeled enzyme released radioactive N-pyridoxyllysine, indicating that the active-site peptide contained lysine at position 4. Mass spectrometry of the 14 C-labeled peptide indicated a protonated molecular ion at m/z 1390.6, from which the mass of Xaa was calculated to be 229, a number that is equivalent to the mass of a lysine residue alkylated by the 2-aminobutyrate portion of AdoMet, as we previously proposed. These results indicate that the same active-site lysine binds the PLP and convalently links to the 2-aminobutyrate portion of AdoMet during inactivation. The active site of tomato ACC synthase was probed in the same manner with Ado [ 14 C]Met. Sequencing of the tomato active-site peptide revealed two highly conserved dodecapeptides; the minor peptide possessed a sequence identical to that of the apple enzyme, whereas the major peptide differed from the minor peptide in that methionine replaced leucine at position 6

  11. Carboxyl-terminal Truncations of ClC-Kb Abolish Channel Activation by Barttin Via Modified Common Gating and Trafficking*

    Science.gov (United States)

    Stölting, Gabriel; Bungert-Plümke, Stefanie; Franzen, Arne; Fahlke, Christoph

    2015-01-01

    ClC-K chloride channels are crucial for auditory transduction and urine concentration. Mutations in CLCNKB, the gene encoding the renal chloride channel hClC-Kb, cause Bartter syndrome type III, a human genetic condition characterized by polyuria, hypokalemia, and alkalosis. In recent years, several Bartter syndrome-associated mutations have been described that result in truncations of the intracellular carboxyl terminus of hClC-Kb. We here used a combination of whole-cell patch clamp, confocal imaging, co-immunoprecipitation, and surface biotinylation to study the functional consequences of a frequent CLCNKB mutation that creates a premature stop codon at Trp-610. We found that W610X leaves the association of hClC-Kb and the accessory subunit barttin unaffected, but impairs its regulation by barttin. W610X attenuates hClC-Kb surface membrane insertion. Moreover, W610X results in hClC-Kb channel opening in the absence of barttin and prevents further barttin-mediated activation. To describe how the carboxyl terminus modifies the regulation by barttin we used V166E rClC-K1. V166E rClC-K1 is active without barttin and exhibits prominent, barttin-regulated voltage-dependent gating. Electrophysiological characterization of truncated V166E rClC-K1 demonstrated that the distal carboxyl terminus is necessary for slow cooperative gating. Since barttin modifies this particular gating process, channels lacking the distal carboxyl-terminal domain are no longer regulated by the accessory subunit. Our results demonstrate that the carboxyl terminus of hClC-Kb is not part of the binding site for barttin, but functionally modifies the interplay with barttin. The loss-of-activation of truncated hClC-Kb channels in heterologous expression systems fully explains the reduced basolateral chloride conductance in affected kidneys and the clinical symptoms of Bartter syndrome patients. PMID:26453302

  12. A soft biomolecule actuator based on a highly functionalized bacterial cellulose nano-fiber network with carboxylic acid groups.

    Science.gov (United States)

    Wang, Fan; Jeon, Jin-Han; Park, Sukho; Kee, Chang-Doo; Kim, Seong-Jun; Oh, Il-Kwon

    2016-01-07

    Upcoming human-related applications such as soft wearable electronics, flexible haptic systems, and active bio-medical devices will require bio-friendly actuating materials. Here, we report a soft biomolecule actuator based on carboxylated bacterial cellulose (CBC), ionic liquid (IL), and poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) ( PSS) electrodes. Soft and biocompatible polymer-IL composites were prepared via doping of CBC with ILs. The highly conductive PSS layers were deposited on both sides of the CBC-IL membranes by a dip-coating technique to yield a sandwiched actuator system. Ionic conductivity and ionic exchange capacity of the CBC membrane can be increased up to 22.8 times and 1.5 times compared with pristine bacterial cellulose (BC), respectively, resulting in 8 times large bending deformation than the pure BC actuators with metallic electrodes in an open air environment. The developed CBC-IL actuators show significant progress in the development of biocompatible and soft actuating materials with quick response, low operating voltage and comparatively large bending deformation.

  13. Role of Carboxylate ligands in the Synthesis of AuNPs: Size Control, Molecular Interaction and Catalytic Activity

    KAUST Repository

    Aljohani, Hind Abdullah

    2016-05-22

    Nanoparticles (NPs) are the basis of nanotechnology and finding numerous applications in various fields such as health, electronics, environment, personal care products, transportation, and catalysis. To fulfill these functions, the nanoparticles must be synthesized, passivated to control their chemical reactivity, stabilized against aggregation and functionalized to achieve specific performances. The chemistry of metal nanoparticles especially that of noble metals (Gold, Platinum…) is a growing field. The nanoparticles have indeed different properties from those of the corresponding bulk material. These properties are largely influenced by several parameters; the most important are the size, shape, and the local environment of the nanoparticles. One of the most common synthetic methods for the preparation of gold nanoparticles (AuNPs) is based on stabilization by citrate. Since it was reported first by Turkevich et al. in 1951, this synthetic scheme has been widely used, studied and a substantial amount of important information regarding this system has been reported in the literature. The most popular method developed by Frens for controlling the size of the noble gold nanoparticles based on citrate was achieved by varying the concentration of sodium citrate. Despite a large number of investigations focused on utilizing Cit-AuNPs, the structural details of citrate anions adsorbed on the AuNP surface are still unknown. It is known only that citrate anions “coordinate” to the metal surface by inner sphere complexation of the carboxylate groups and there are trace amounts of AuCl4−, Cl−, and OH− on the metal surface. Moreover, it is generally accepted that the ligand shell morphology of Au nanoparticles can be partly responsible for important properties such as oxidation of carbon monoxide. The use of Au-NPs in heterogeneous catalysis started mostly with Haruta who discovered the effect of particle size on the activity for carbon monoxide oxidation at

  14. Characterization of Lactobacillus salivarius alanine racemase: short-chain carboxylate-activation and the role of A131.

    Science.gov (United States)

    Kobayashi, Jyumpei; Yukimoto, Jotaro; Shimizu, Yasuhiro; Ohmori, Taketo; Suzuki, Hirokazu; Doi, Katsumi; Ohshima, Toshihisa

    2015-01-01

    Many strains of lactic acid bacteria produce high concentrations of d-amino acids. Among them, Lactobacillus salivarius UCC 118 produces d-alanine at a relative concentration much greater than 50 % of the total d, l-alanine (100d/d, l-alanine). We characterized the L. salivarius alanine racemase (ALR) likely responsible for this d-alanine production and found that the enzyme was activated by carboxylates, which is an unique characteristic among ALRs. In addition, alignment of the amino acid sequences of several ALRs revealed that A131 of L. salivarius ALR is likely involved in the activation. To confirm that finding, an L. salivarius ALR variant with an A131K (ALR(A131K)) substitution was prepared, and its properties were compared with those of ALR. The activity of ALR(A131K) was about three times greater than that of ALR. In addition, whereas L. salivarius ALR was strongly activated by low concentrations (e.g., 1 mM) of short chain carboxylates, and was inhibited at higher concentrations (e.g., 10 mM), ALR(A131K) was clearly inhibited at all carboxylate concentrations tested (1-40 mM). Acetate also increased the stability of ALR such that maximum activity was observed at 35 °C and pH 8.0 without acetate, but at 50 °C in the presence of 1 mM acetate. On the other hand, maximum ALR(A131K) activity was observed at 45 °C and around pH 9.0 with or without acetate. It thus appears that A131 mediates the activation and stabilization of L. salivarius ALR by short chain carboxylates.

  15. A stereospecific carboxyl esterase from Bacillus coagulans hosting nonlipase activity within a lipase-like fold.

    Science.gov (United States)

    De Vitis, Valerio; Nakhnoukh, Cristina; Pinto, Andrea; Contente, Martina L; Barbiroli, Alberto; Milani, Mario; Bolognesi, Martino; Molinari, Francesco; Gourlay, Louise J; Romano, Diego

    2018-03-01

    Microbial carboxylesterases are important biocatalysts that selectively hydrolyze an extensive range of esters. Here, we report the biochemical and structural characterization of an atypical carboxylesterase from Bacillus coagulans (BCE), endowed with high enantioselectivity toward different 1,2-O-isopropylideneglycerol (IPG or solketal) esters. BCE efficiently catalyzes the production of enantiopure (S)-IPG, a chiral building block for the synthesis of β-blockers, glycerophospholipids, and prostaglandins; efficient hydrolysis was observed up to 65 °C. To gain insight into the mechanistic bases of such enantioselectivity, we solved the crystal structures of BCE in apo- and glycerol-bound forms at resolutions of 1.9 and 1.8 Å, respectively. In silico docking studies on the BCE structure confirmed that IPG esters with small acyl chains (≤ C6) were easily accommodated in the active site pocket, indicating that small conformational changes are necessary to accept longer substrates. Furthermore, docking studies suggested that enantioselectivity may be due to an improved stabilization of the tetrahedral reaction intermediate for the S-enantiomer. Contrary to the above functional data implying nonlipolytic functions, BCE displays a lipase-like 3D structure that hosts a "lid" domain capping the main entrance to the active site. In lipases the lid mediates catalysis through interfacial activation, a process that we did not observe for BCE. Overall, we present the functional-structural properties of an atypical carboxyl esterase that has nonlipase-like functions, yet possesses a lipase-like 3D fold. Our data provide original enzymatic information in view of BCE applications as an inexpensive, efficient biocatalyst for the production of enantiopure (S)-IPG. Coordinates and structure factors have been deposited in the Protein Data Bank (www.rcsb.org) under accession numbers 5O7G (apo-BCE) and 5OLU (glycerol-bound BCE). © 2017 Federation of European Biochemical

  16. Structure-Activity Relationship Study of Ionotropic Glutamate Receptor Antagonist (2S,3R)-3-(3-Carboxyphenyl)pyrrolidine-2-carboxylic Acid

    DEFF Research Database (Denmark)

    Krogsgaard-Larsen, Niels; Storgaard, Morten; Møller, Charlotte

    2015-01-01

    Herein we describe the first structure-activity relationship study of the broad-range iGluR antagonist (2S,3R)-3-(3-carboxyphenyl)pyrrolidine-2-carboxylic acid (1) by exploring the pharmacological effect of substituents in the 4, 4', or 5' positions and the bioisosteric substitution of the distal...... carboxylic acid for a phosphonic acid moiety. Of particular interest is a hydroxyl group in the 4' position 2a which induced a preference in binding affinity for homomeric GluK3 over GluK1 (Ki = 0.87 and 4.8 μM, respectively). Two X-ray structures of ligand binding domains were obtained: 2e in GluA2-LBD...... and 2f in GluK1-LBD, both at 1.9 Å resolution. Compound 2e induces a D1-D2 domain opening in GluA2-LBD of 17.3-18.8° and 2f a domain opening in GluK1-LBD of 17.0-17.5° relative to the structures with glutamate. The pyrrolidine-2-carboxylate moiety of 2e and 2f shows a similar binding mode as kainate...

  17. Effects of carboxyl and ester anchoring groups on solar conversion efficiencies of TiO2 dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sepehrifard, A.; Stublla, A.; Haftchenary, S.; Chen, S.; Potvin, P.; Morin, S. [York Univ., Toronto, ON (Canada). Dept. of Chemistry

    2008-07-01

    This paper reported on a study in which 2 new Ruthenium (Ru(2)) dyes bearing different anchoring groups were applied to sensitize TiO2 for dye-sensitized solar cells (DSSCs). The solar conversion efficiencies were measured. Results for 2 of the dyes which carried ester and carboxyl anchoring groups were presented. The extent and nature of the surface binding was studied using electrochemical, UV-visible, fluorescence and FTIR measurements. Solar cell performance was discussed in terms of surface concentration of chemisorbed dyes, electronic properties of the photoanodes and electrochemical properties of adsorbed dyes. The study showed that carboxylic acid groups offer better dye adsorption than ester groups. However, sensitization with warm solutions improved the adsorption of the esterified dye, most likely through transesterification. It was concluded that this may be a useful means of improving solar conversion efficiencies of ester-bearing dyes. 6 refs., 1 tab., 2 figs.

  18. Recovery of carboxylic acids produced during dark fermentation of food waste by adsorption on Amberlite IRA-67 and activated carbon.

    Science.gov (United States)

    Yousuf, Ahasa; Bonk, Fabian; Bastidas-Oyanedel, Juan-Rodrigo; Schmidt, Jens Ejbye

    2016-10-01

    Amberlite IRA-67 and activated carbon were tested as promising candidates for carboxylic acid recovery by adsorption. Dark fermentation was performed without pH control and without addition of external inoculum at 37°C in batch mode. Lactic, acetic and butyric acids, were obtained, after 7days of fermentation. The maximum acid removal, 74%, from the Amberlite IRA-67 and 63% from activated carbon was obtained from clarified fermentation broth using 200gadsorbent/Lbroth at pH 3.3. The pH has significant effect and pH below the carboxylic acids pKa showed to be beneficial for both the adsorbents. The un-controlled pH fermentation creates acidic environment, aiding in adsorption by eliminating use of chemicals for efficient removal. This study proposes simple and easy valorization of waste to valuable chemicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A Concise Synthesis and the Antibacterial Activity of 5,6-Dimethoxynaphthalene-2-carboxylic Acid

    OpenAIRE

    GÖKSU, Süleyman; UĞUZ, Metin Tansu

    2014-01-01

    5,6-Dimethoxynaphthalene-2-carboxylic acid was synthesized in 7 steps and with an overall yield of 46%. Bromination of 2-naphthol, and methylation with dimethyl sulfate followed by Friedel-Crafts acylation with AcCl gave 2-acetyl-5-bromo-6-methoxynaphthalene. 2-Acetyl-5-bromo-6-methoxynaphthalene was converted to 5-bromo-6- methoxynaphthalene-2-carboxylic acid by a haloform reaction. The esterification of the acid with methanol, methoxylation with NaOCH3 in the presence of CuI and s...

  20. Synthesis and Characterization of PEDOT Derivative with Carboxyl Group and Its Chemo/Bio Sensing Application as Nanocomposite, Immobilized Biological and Enhanced Optical Materials

    International Nuclear Information System (INIS)

    Zhang, Long; Wen, Yangping; Yao, Yuanyuan; Xu, Jingkun; Duan, Xuemin; Zhang, Ge

    2014-01-01

    indicate that chemo/bio-sensors based on PC4 possess excellent chemo/bio sensing performance and enhanced optical response, and its carboxylic group can realize the immobilization of biologically active species, self-assembly of inorganic nanomaterials

  1. Optimization of polycrystalline platinum catalytic activity opposite to carboxylic acids oxidation

    International Nuclear Information System (INIS)

    Le Naour, C.; Moisy, P.; Blanc, P.; Madic, C.

    1994-01-01

    In electro nuclear industry, in the aim to reduce the quantity of wastes coming from the spent fuels reprocessing, the use of reagents as some carboxylic acids is considered: after use, these reagents are completely decomposed in gaseous products, which can be filtered and released in environment

  2. A rapid and sensitive method for the simultaneous analysis of aliphatic and polar molecules containing free carboxyl groups in plant extracts by LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Bonaventure Gustavo

    2009-11-01

    Full Text Available Abstract Background Aliphatic molecules containing free carboxyl groups are important intermediates in many metabolic and signalling reactions, however, they accumulate to low levels in tissues and are not efficiently ionized by electrospray ionization (ESI compared to more polar substances. Quantification of aliphatic molecules becomes therefore difficult when small amounts of tissue are available for analysis. Traditional methods for analysis of these molecules require purification or enrichment steps, which are onerous when multiple samples need to be analyzed. In contrast to aliphatic molecules, more polar substances containing free carboxyl groups such as some phytohormones are efficiently ionized by ESI and suitable for analysis by LC-MS/MS. Thus, the development of a method with which aliphatic and polar molecules -which their unmodified forms differ dramatically in their efficiencies of ionization by ESI- can be simultaneously detected with similar sensitivities would substantially simplify the analysis of complex biological matrices. Results A simple, rapid, specific and sensitive method for the simultaneous detection and quantification of free aliphatic molecules (e.g., free fatty acids (FFA and small polar molecules (e.g., jasmonic acid (JA, salicylic acid (SA containing free carboxyl groups by direct derivatization of leaf extracts with Picolinyl reagent followed by LC-MS/MS analysis is presented. The presence of the N atom in the esterified pyridine moiety allowed the efficient ionization of 25 compounds tested irrespective of their chemical structure. The method was validated by comparing the results obtained after analysis of Nicotiana attenuata leaf material with previously described analytical methods. Conclusion The method presented was used to detect 16 compounds in leaf extracts of N. attenuata plants. Importantly, the method can be adapted based on the specific analytes of interest with the only consideration that the

  3. Synthesis of new oxovanadium (IV) complexes of potential insulinmimetic activity with coumarin-3-carboxylic acid ligands and substituted derivatives

    International Nuclear Information System (INIS)

    Salas Fernandez, Paloma; Alvino de la Sota, Nora; Galli Rigo-Righi, Carla

    2013-01-01

    This work comprises the design and synthesis of four new oxovanadium (IV) complexes, a metal which possesses insulin-mimetic action. Coumarin-3-carboxylic acid and three of its 6 -and 6,8- derivatives were used as ligands. Coumarins are of interest due to their well-known biological properties and pharmacological applications; these include the insulino-sensibilizing effect of certain alcoxy-hydroxy-derivatives which might lead to the eventual existence of a synergetic effect with the active metal center. The synthesis of the vanadyl complexes was preceded by the synthesis of the coumarin-3-carboxylic acid and its 6-bromo- derivative, as well as the syntheses of three derivatives not previously reported: 6-bromo-8-metoxi-, 6-bromo-8-nitro-, and 6-bromo-8-hydroxy-, which were prepared by a Knoevenagel condensation reaction. The complexes, on their part, were prepared by a metathesis reaction between VOSO 4 and the corresponding ligands, on the basis of methods reported for other vanadyl complexes and under strict pH control. The coumarin-3-carboxylic ligands and the derivatives were characterized by 1 H-NMR-, FTIR- and UV-Vis-spectroscopy. In the case of the complexes, their paramagnetic character did not allow for NMR characterization, being thus identified by FT-IR-spectroscopy and by the quantitative determination of their vanadium contents. (author)

  4. Carboxyl-terminal Truncations of ClC-Kb Abolish Channel Activation by Barttin Via Modified Common Gating and Trafficking.

    Science.gov (United States)

    Stölting, Gabriel; Bungert-Plümke, Stefanie; Franzen, Arne; Fahlke, Christoph

    2015-12-18

    ClC-K chloride channels are crucial for auditory transduction and urine concentration. Mutations in CLCNKB, the gene encoding the renal chloride channel hClC-Kb, cause Bartter syndrome type III, a human genetic condition characterized by polyuria, hypokalemia, and alkalosis. In recent years, several Bartter syndrome-associated mutations have been described that result in truncations of the intracellular carboxyl terminus of hClC-Kb. We here used a combination of whole-cell patch clamp, confocal imaging, co-immunoprecipitation, and surface biotinylation to study the functional consequences of a frequent CLCNKB mutation that creates a premature stop codon at Trp-610. We found that W610X leaves the association of hClC-Kb and the accessory subunit barttin unaffected, but impairs its regulation by barttin. W610X attenuates hClC-Kb surface membrane insertion. Moreover, W610X results in hClC-Kb channel opening in the absence of barttin and prevents further barttin-mediated activation. To describe how the carboxyl terminus modifies the regulation by barttin we used V166E rClC-K1. V166E rClC-K1 is active without barttin and exhibits prominent, barttin-regulated voltage-dependent gating. Electrophysiological characterization of truncated V166E rClC-K1 demonstrated that the distal carboxyl terminus is necessary for slow cooperative gating. Since barttin modifies this particular gating process, channels lacking the distal carboxyl-terminal domain are no longer regulated by the accessory subunit. Our results demonstrate that the carboxyl terminus of hClC-Kb is not part of the binding site for barttin, but functionally modifies the interplay with barttin. The loss-of-activation of truncated hClC-Kb channels in heterologous expression systems fully explains the reduced basolateral chloride conductance in affected kidneys and the clinical symptoms of Bartter syndrome patients. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Group Activities for Math Enthusiasts

    Science.gov (United States)

    Holdener, J.; Milnikel, R.

    2016-01-01

    In this article we present three group activities designed for math students: a balloon-twisting workshop, a group proof of the irrationality of p, and a game of Math Bingo. These activities have been particularly successful in building enthusiasm for mathematics and camaraderie among math faculty and students at Kenyon College.

  6. “Fifty Shades” of Black and Red or How Carboxyl Groups Fine Tune Eumelanin and Pheomelanin Properties

    Directory of Open Access Journals (Sweden)

    Raffaella Micillo

    2016-05-01

    Full Text Available Recent advances in the chemistry of melanins have begun to disclose a number of important structure-property-function relationships of crucial relevance to the biological role of human pigments, including skin (photo protection and UV-susceptibility. Even slight variations in the monomer composition of black eumelanins and red pheomelanins have been shown to determine significant differences in light absorption, antioxidant, paramagnetic and redox behavior, particle morphology, surface properties, metal chelation and resistance to photo-oxidative wear-and-tear. These variations are primarily governed by the extent of decarboxylation at critical branching points of the eumelanin and pheomelanin pathways, namely the rearrangement of dopachrome to 5,6-dihydroxyindole (DHI and 5,6-dihydroxyindole-2-carboxylic acid (DHICA, and the rearrangement of 5-S-cysteinyldopa o-quinoneimine to 1,4-benzothiazine (BTZ and its 3-carboxylic acid (BTZCA. In eumelanins, the DHICA-to-DHI ratio markedly affects the overall antioxidant and paramagnetic properties of the resulting pigments. In particular, a higher content in DHICA decreases visible light absorption and paramagnetic response relative to DHI-based melanins, but markedly enhances antioxidant properties. In pheomelanins, likewise, BTZCA-related units, prevalently formed in the presence of zinc ions, appear to confer pronounced visible and ultraviolet A (UVA absorption features, accounting for light-dependent reactive oxygen species (ROS production, whereas non-carboxylated benzothiazine intermediates seem to be more effective in inducing ROS production by redox cycling mechanisms in the dark. The possible biological and functional significance of carboxyl retention in the eumelanin and pheomelanin pathways is discussed.

  7. Concomitant carboxylate and oxalate formation from the activation of CO{sub 2} by a thorium(III) complex

    Energy Technology Data Exchange (ETDEWEB)

    Formanuik, Alasdair; Ortu, Fabrizio; Mills, David P. [School of Chemistry, The University of Manchester (United Kingdom); Inman, Christopher J. [Department of Chemistry and Biochemistry, School of Life Sciences, University of Sussex, Brighton (United Kingdom); Kerridge, Andrew [Department of Chemistry, Lancaster University (United Kingdom); Castro, Ludovic; Maron, Laurent [LPCNO, CNRA et INSA, Universite Paul Sabatier, Toulouse (France)

    2016-12-12

    Improving our comprehension of diverse CO{sub 2} activation pathways is of vital importance for the widespread future utilization of this abundant greenhouse gas. CO{sub 2} activation by uranium(III) complexes is now relatively well understood, with oxo/carbonate formation predominating as CO{sub 2} is readily reduced to CO, but isolated thorium(III) CO{sub 2} activation is unprecedented. We show that the thorium(III) complex, [Th(Cp''){sub 3}] (1, Cp''={C_5H_3(SiMe_3)_2-1,3}), reacts with CO{sub 2} to give the mixed oxalate-carboxylate thorium(IV) complex [{Th(Cp'')_2[κ"2-O_2C{C_5H_3-3,3'-(SiMe_3)_2}]}{sub 2}(μ-κ{sup 2}:κ{sup 2}-C{sub 2}O{sub 4})] (3). The concomitant formation of oxalate and carboxylate is unique for CO{sub 2} activation, as in previous examples either reduction or insertion is favored to yield a single product. Therefore, thorium(III) CO{sub 2} activation can differ from better understood uranium(III) chemistry. (copyright 2016 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  8. Quantification of functional groups and modeling of their ionization behavior in the active layer of FT30 reverse osmosis membrane.

    Science.gov (United States)

    Coronell, Orlando; Mariñas, Benito J; Zhang, Xijing; Cahill, David G

    2008-07-15

    A new experimental approach was developed to measure the concentration of charged functional groups (FGs) in the active layer of thin-film composite reverse osmosis (RO) and nanofiltration (NF) membranes as a function of solution pH. FT30 RO membrane, with a fully aromatic polyamide (PA) active layer sandwiched between a polysulfone support and a coating layer, was used. The experiments consisted of saturating charged FGs with heavy ion probes, and determining the ion probe concentration by Rutherford backscattering spectrometry (RBS). Deprotonated carboxylic groups were saturated with Ag+, and protonated amine groups with W04(2-). The ionization behavior of carboxylic and amine groups was modeled based on acid-base equilibrium theory. While the ionization behavior of amine groups was satisfactorily described by one dissociation constant (pKa = 4.74), two pKa values (5.23 and 8.97) were necessary to describe the titration curve of carboxylic groups. These results were consistent with the bimodal pore size distribution (PSD) of FT30 active layer reported in the literature. The calculated total concentrations of carboxylic and amine groups in the active layer of the FT30 RO membrane studied were 0.432 and 0.036 M, respectively, and the isoelectric point (IEP) was 4.7. The total concentration of carboxylic and amine groups revealed that the degree of cross-linking of the PA active layer of the FT30 RO membrane studied was 94%.

  9. Synthesis and pharmacological characterization of novel xanthine carboxylate amides as A2A adenosine receptor ligands exhibiting bronchospasmolytic activity.

    Science.gov (United States)

    Yadav, Rakesh; Bansal, Ranju; Rohilla, Suman; Kachler, Sonja; Klotz, Karl-Norbert

    2016-04-01

    The carboxylate amides of 8-phenyl-1,3-dimethylxanthine described herein represent a new series of selective ligands of the adenosine A2A receptors exhibiting bronchospasmolytic activity. The effects of location of 8-phenyl substitutions on the adenosine receptor (AR) binding affinities of the newly synthesized xanthines have also been studied. The compounds displayed moderate to potent binding affinities toward various adenosine receptor subtypes when evaluated through radioligand binding studies. However, most of the compounds showed the maximum affinity for the A2A subtype, some with high selectivity versus all other subtypes. Xanthine carboxylate amide 13b with a diethylaminoethylamino moiety at the para-position of the 8-phenylxanthine scaffold was identified as the most potent A2A adenosine receptor ligand with Ki=0.06μM. Similarly potent and highly A2A-selective are the isovanillin derivatives 16a and 16d. In addition, the newly synthesized xanthine derivatives showed good in vivo bronchospasmolytic activity when tested in guinea pigs. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Comparisons of the spectroscopic and microbiological activities among coumarin-3-carboxylate, o-phenanthroline and zinc(II) complexes

    Science.gov (United States)

    Islas, María S.; Martínez Medina, Juan J.; Piro, Oscar E.; Echeverría, Gustavo A.; Ferrer, Evelina G.; Williams, Patricia A. M.

    2018-06-01

    Coumarins (2H-chromen-2-one) are oxygen-containing heterocyclic compounds that belong to the benzopyranones family. In this work we have synthesized different coordination complexes with coumarin-3-carboxylic acid (HCCA), o-phenanthroline (phen) and zinc(II). In the reported [Zn(CCA)2(H2O)2] complex, coumarin-3-carboxylate (CCA) is acting as a bidentate ligand while in the two prepared complexes, [Zn(phen)3]CCA(NO3) (obtained as a single crystal) and [Zn(CCA)2phen].4H2O, CCA is acting as a counterion of the complex cation [Zn(phen)3]+2 or coordinated to the metal center along with phen, respectively. These compounds were characterized on the basis of elemental analysis and thermogravimetry. NMR, FTIR and Raman spectroscopies of the compounds and the CCA potassium salt (KCCA) allow to determine several similarities and differences among them. Finally, their behavior against alkaline phosphatase enzyme and their antimicrobial activities were also measured.

  11. 1-Azaniumylcyclobutane-1-carboxylate monohydrate

    Directory of Open Access Journals (Sweden)

    Ray J. Butcher

    2014-02-01

    Full Text Available In the title compound, C5H9NO2·H2O, the amino acid is in the usual zwitterionic form involving the α-carboxylate group. The cyclobutane backbone of the amino acid is disordered over two conformations, with occupancies of 0.882 (7 and 0.118 (7. In the crystal, N—H...O and O—H...O hydrogen bonds link the zwitterions [with the water molecule involved as both acceptor (with the NH3+ and donor (through a single carboxylate O from two different aminocyclobutane carboxylate moities], resulting in a two-dimensional layered structure lying parallel to (100.

  12. 1-(3-aminopropyl)-3-butylimidazolium bromide for carboxyl group derivatization: potential applications in high sensitivity peptide identification by mass spectrometry.

    Science.gov (United States)

    Qiao, Xiaoqiang; Zhou, Yuan; Hou, Chunyan; Zhang, Xiaodan; Yang, Kaiguang; Zhang, Lihua; Zhang, Yukui

    2013-03-01

    The cationic reagent 1-(3-aminopropyl)-3-butylimidazolium bromide (BAPI) was exploited for the derivatization of carboxyl groups on peptides. Nearly 100% derivatization efficiency was achieved with the synthetic peptide RVYVHPI (RI-7). Furthermore, the peptide derivative was stable in a 0.1% TFA/water solution or a 0.1% (v/v) TFA/acetonitrile/water solution for at least one week. The effect of BAPI derivatization on the ionization of the peptide RI-7 was further investigated, and the detection sensitivity was improved >42-fold via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), thus outperforming the commercial piperazine derivatization approach. Moreover, the charge states of the peptide were largely increased via BAPI derivatization by electrospray ionization (ESI) MS. The results indicate the potential merits of BAPI derivatization for high sensitivity peptide analysis by MS.

  13. Control of Surface Functional Groups on Pertechnetate Sorption on Activated Carbon

    International Nuclear Information System (INIS)

    Y. Wang; H. Gao; R. Yeredla; H. Xu; M. Abrecht; G.D. Stasio

    2006-01-01

    99 Tc is highly soluble and poorly adsorbed by natural materials under oxidizing conditions, thus being of particular concern for radioactive waste disposal. Activated carbon can potentially be used as an adsorbent for removing Tc from aqueous solutions. We have tested six commercial activated carbon materials for their capabilities for sorption of pertechnetate (TcO 4 - ). The tested materials can be grouped into two distinct types: Type I materials have high sorption capabilities with the distribution coefficients (K d ) varying from 9.5 x 10 5 to 3.2 x 10 3 mL/g as the pH changes from 4.5 to 9.5, whereas type II materials have relatively low sorption capabilities with K d remaining more or less constant (1.1 x 10 3 - 1.8 x 10 3 mL/g) over a similar pH range. The difference in sorption behavior between the two types of materials is attributed to the distribution of surface functional groups. The predominant surface groups are identified to be carboxylic and phenolic groups. The carboxylic group can be further divided into three subgroups A, B, and C in the order of increasing acidity. The high sorption capabilities of type I materials are found to be caused by the presence of a large fraction of carboxylic subgroups A and B, while the low sorption capabilities of type II materials are due to the exclusive presence of phenolic and carboxylic subgroup C. Therefore, the performance of activated carbon for removing TcO 4 - can be improved by enhancing the formation of carboxylic subgroups A and B during material processing

  14. Single amino acids in the carboxyl terminal domain of aquaporin-1 contribute to cGMP-dependent ion channel activation

    Directory of Open Access Journals (Sweden)

    Yool Andrea J

    2003-10-01

    Full Text Available Abstract Background Aquaporin-1 (AQP1 functions as an osmotic water channel and a gated cation channel. Activation of the AQP1 ion conductance by intracellular cGMP was hypothesized to involve the carboxyl (C- terminus, based on amino acid sequence alignments with cyclic-nucleotide-gated channels and cGMP-selective phosphodiesterases. Results Voltage clamp analyses of human AQP1 channels expressed in Xenopus oocytes demonstrated that the nitric oxide donor, sodium nitroprusside (SNP; 3–14 mM activated the ionic conductance response in a dose-dependent manner. Block of soluble guanylate cyclase prevented the response. Enzyme immunoassays confirmed a linear dose-dependent relationship between SNP and the resulting intracellular cGMP levels (up to 1700 fmol cGMP /oocyte at 14 mM SNP. Results here are the first to show that the efficacy of ion channel activation is decreased by mutations of AQP1 at conserved residues in the C-terminal domain (aspartate D237 and lysine K243. Conclusions These data support the idea that the limited amino acid sequence similarities found between three diverse classes of cGMP-binding proteins are significant to the function of AQP1 as a cGMP-gated ion channel, and provide direct evidence for the involvement of the AQP1 C-terminal domain in cGMP-mediated ion channel activation.

  15. 6-Substituted 3,4-dihydro-naphthalene-2-carboxylic acids: synthesis and structure-activity studies in a novel class of human 5alpha reductase inhibitors.

    Science.gov (United States)

    Baston, Eckhard; Salem, Ola I A; Hartmann, Rolf W

    2002-10-01

    Novel 3,4-dihydro-naphthalene-2-carboxylic acids were synthesized and evaluated for 5alpha reductase inhibitory activity. This enzyme exists in two isoforms and is a pharmacological target for the treatment of benign prostatic hyperplasia, male pattern baldness and acne. In the present study non-steroidal compounds capable of mimicking the transition state of the steroidal substrates were prepared. The synthetic strategy for the preparation of compounds 1-6 consisted of triflation followed by subsequent Heck-type carboxylation or methoxy carbonylation for 6-phenyl-3,4-dihydronaphthalen-2(1H)-one 1c. A Negishi-type coupling reaction between 6-(trifluoro-methanesulfonyloxy)-3,4-dihydro-naphthalene-2-carboxylic acid methyl ester 7b and various aryl bromides led, after further transformations, to 6-substituted 3,4-dihydro-naphthalene-2-carboxylic acids 7-15. In a similar way the corresponding naphthalene-2-carboxylic acids 16 and 17 were obtained. The DU 145 cell line and prostate homogenates served as enzyme sources for the human type 1 and type 2 isozymes, whereas ventral prostate was employed to evaluate rat isozyme inhibitory potency. The most active inhibitors identified in this study were 6-[4-(N,N-dicyclohexylaminocarbonyl)phenyl]-3,4-dihydro-naphthalene-2-carboxylic acid (3) (IC50 = 0.09 microM, rat type 1), 6-[3-(N,N-dicyclohexylaminocarbonyl)phenyl]-3,4-dihydro-naphthalene-2-carboxylic acid (13) (IC50 = 0.75 microM, human type 2; IC50 = 0.81 microM, human type 1) and 6-[4-(N,N-diisopropylamino-carbonyl)phenyl]naphthalene-2-carboxylic acid (16) (IC50 = 0.2 microM, human type 2). The latter compound was shown to deactivate the enzyme in an uncompetitive manner (Ki = 90 nM; Km, Testosterone = 0.8-1.0 microM) similar to the steroidal inhibitor Epristeride. Select inhibitors (13 and 16) were tested in vivo using testosterone propionate-treated, juvenile, orchiectomized SD-rats. None of the compounds was active at a dose of 25 mg/kg. This result might in part be

  16. Covalent immobilization of porcine pancreatic lipase on carboxyl-activated magnetic nanoparticles: Characterization and application for enzymatic inhibition assays

    International Nuclear Information System (INIS)

    Zhu, Yuan-Ting; Ren, Xiao-Yun; Liu, Yi-Ming; Wei, Ying; Qing, Lin-Sen; Liao, Xun

    2014-01-01

    Using carboxyl functionalized silica-coated magnetic nanoparticles (MNPs) as carrier, a novel immobilized porcine pancreatic lipase (PPL) was prepared through the 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. Transmission electron microscopic images showed that the synthesized nanoparticles (Fe 3 O 4 –SiO 2 ) possessed three dimensional core–shell structures with an average diameter of ∼ 20 nm. The effective enzyme immobilization onto the nanocomposite was confirmed by atomic force microscopic (AFM) analysis. Results from Fourier-transform infrared spectroscopy (FT-IR), Bradford protein assay, and thermo-gravimetric analysis (TGA) indicated that PPL was covalently attached to the surface of magnetic nanoparticles with a PPL immobilization yield of 50 mg enzyme/g MNPs. Vibrating sample magnetometer (VSM) analysis revealed that the MNPs-PPL nanocomposite had a high saturation magnetization of 42.25 emu·g −1 . The properties of the immobilized PPL were investigated in comparison with the free enzyme counterpart. Enzymatic activity, reusability, thermo-stability, and storage stability of the immobilized PPL were found significantly superior to those of the free one. The K m and the V max values (0.02 mM, 6.40 U·mg −1 enzyme) indicated the enhanced activity of the immobilized PPL compared to those of the free enzyme (0.29 mM, 3.16 U·mg −1 enzyme). Furthermore, at an elevated temperature of 70 °C, immobilized PPL retained 60% of its initial activity. The PPL-MNPs nanocomposite was applied in the enzyme inhibition assays using orlistat, and two natural products isolated from oolong tea (i.e., EGCG and EGC) as the test compounds. - Highlights: • Porcine pancreatic lipase was firstly covalently immobilized onto carboxylated MNPs. • Immobilized porcine pancreatic lipase (PPL) was characterized by various techniques. • MNPs-PPL showed higher activity, reusability, and thermo-stability than

  17. Covalent immobilization of porcine pancreatic lipase on carboxyl-activated magnetic nanoparticles: Characterization and application for enzymatic inhibition assays

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuan-Ting [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ren, Xiao-Yun [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China); Liu, Yi-Ming [Department of Chemistry and Biochemistry, Jackson State University, 1400 Lynch St., Jackson, MS 39217 (United States); Wei, Ying [Changzhi Medical College, Changzhi 046000 (China); Qing, Lin-Sen [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China); Liao, Xun, E-mail: liaoxun@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China)

    2014-05-01

    Using carboxyl functionalized silica-coated magnetic nanoparticles (MNPs) as carrier, a novel immobilized porcine pancreatic lipase (PPL) was prepared through the 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. Transmission electron microscopic images showed that the synthesized nanoparticles (Fe{sub 3}O{sub 4}–SiO{sub 2}) possessed three dimensional core–shell structures with an average diameter of ∼ 20 nm. The effective enzyme immobilization onto the nanocomposite was confirmed by atomic force microscopic (AFM) analysis. Results from Fourier-transform infrared spectroscopy (FT-IR), Bradford protein assay, and thermo-gravimetric analysis (TGA) indicated that PPL was covalently attached to the surface of magnetic nanoparticles with a PPL immobilization yield of 50 mg enzyme/g MNPs. Vibrating sample magnetometer (VSM) analysis revealed that the MNPs-PPL nanocomposite had a high saturation magnetization of 42.25 emu·g{sup −1}. The properties of the immobilized PPL were investigated in comparison with the free enzyme counterpart. Enzymatic activity, reusability, thermo-stability, and storage stability of the immobilized PPL were found significantly superior to those of the free one. The K{sub m} and the V{sub max} values (0.02 mM, 6.40 U·mg{sup −1} enzyme) indicated the enhanced activity of the immobilized PPL compared to those of the free enzyme (0.29 mM, 3.16 U·mg{sup −1} enzyme). Furthermore, at an elevated temperature of 70 °C, immobilized PPL retained 60% of its initial activity. The PPL-MNPs nanocomposite was applied in the enzyme inhibition assays using orlistat, and two natural products isolated from oolong tea (i.e., EGCG and EGC) as the test compounds. - Highlights: • Porcine pancreatic lipase was firstly covalently immobilized onto carboxylated MNPs. • Immobilized porcine pancreatic lipase (PPL) was characterized by various techniques. • MNPs-PPL showed higher activity

  18. Effect of Nd3+ ion on carboxylation activity of ribulose-1,5-bisphosphate carboxylase/oxygenase of spinach

    International Nuclear Information System (INIS)

    Liu Chao; Hong Fashui; Wu Kang; Ma, Hong-bing; Zhang Xueguang; Hong Chengjiao; Wu Cheng; Gao Fengqing; Yang Fan; Zheng Lei; Wang Xuefeng; Liu Tao; Xie Yaning; Xu Jianhua; Li Zhongrui

    2006-01-01

    Neodymium (Nd), as a member of rare earth elements, proved to enhance the photosynthesis rate and organic substance accumulation of spinach through the increase in carboxylation activity of Rubisco. Although the oxygenase activity of spinach Rubisco was slightly changed with the Nd 3+ treatment, the specific factor of Rubisco was greatly increased. It was partially due to the promotion of Rubisco activase (R-A) activity but mainly to the formation of Rubisco-Rubisco activase super-complex, a heavier molecular mass protein (about 1200 kD) comprising both Rubisco and Rubisco activase. This super-complex was found during the extraction procedure of Rubisco by the gel electrophoresis and Western-blot studies. The formation of Rubisco-R-A super-complex suggested that the secondary structure of the protein purified from the Nd 3+ -treated spinach was different from that of the control. Extended X-ray absorption fine structure study of the 'Rubisco' purified from the Nd 3+ -treated spinach revealed that Nd was bound with four oxygen atoms and two sulfur atoms of amino acid residues at the Nd-O and Nd-S bond lengths of 2.46 and 2.89 A, respectively

  19. Ubiquitin carboxyl terminal hydrolase L1 negatively regulates TNFα-mediated vascular smooth muscle cell proliferation via suppressing ERK activation

    International Nuclear Information System (INIS)

    Ichikawa, Tomonaga; Li, Jinqing; Dong, Xiaoyu; Potts, Jay D.; Tang, Dong-Qi; Li, Dong-Sheng; Cui, Taixing

    2010-01-01

    Deubiquitinating enzymes (DUBs) appear to be critical regulators of a multitude of processes such as proliferation, apoptosis, differentiation, and inflammation. We have recently demonstrated that a DUB of ubiquitin carboxyl terminal hydrolase L1 (UCH-L1) inhibits vascular lesion formation via suppressing inflammatory responses in vasculature. However, the precise underlying mechanism remains to be defined. Herein, we report that a posttranscriptional up-regulation of UCH-L1 provides a negative feedback to tumor necrosis factor alpha (TNFα)-mediated activation of extracellular signal-regulated kinases (ERK) and proliferation in vascular smooth muscle cells (VSMCs). In rat adult VSMCs, adenoviral over-expression of UCH-L1 inhibited TNFα-induced activation of ERK and DNA synthesis. In contrast, over-expression of UCH-L1 did not affect platelet derived growth factor (PDGF)-induced VSMC proliferation and activation of growth stimulating cascades including ERK. TNFα hardly altered UCH-L1 mRNA expression and stability; however, up-regulated UCH-L1 protein expression via increasing UCH-L1 translation. These results uncover a novel mechanism by which UCH-L1 suppresses vascular inflammation.

  20. [Isolation and identification of hydrogen-oxidizing bacteria producing 1-aminocyclopropane-1-carboxylate deaminase and the determination of enzymatic activity].

    Science.gov (United States)

    Fu, Bo; Wang, Weiwei; Tang, Ming; Chen, Xingdu

    2009-03-01

    We used Medicago sativa rhizosphere in Shaanxi province of China to isolate and identify hydrogen-oxidizing bacteria that produced ACC (1-aminocyclopropane-1-carboxylate) deaminase, and then studied the mechanism why they can promote the growth of plants. Hydrogen-oxidizing bacteria were isolated by gas-cycle incubation system. We studied the morphological character, physiological characteristics, 16S rDNA sequence analysis and built the phylogenic tree. Thin layer chromatography was used to isolate the strain that produced ACC deaminase. Ninhydrin reaction was used to test the enzyme activity. In total 37 strains were isolated, 8 of which could oxidize H2 strongly and grow chemolithoautotrophically. We initially identified them as hydrogen-oxidizing bacteria. Only strain WMQ-7 produced ACC deaminase among these 8 strains. Morphological and physiological characteristics analysis showed that strain WMQ-7 was essentially consistent with Pseudomonas putida. The 16S rDNA sequence analysis (GenBank accession number EU807744) suggested that strain WMQ-7 was clustered together with Pseudomonas putida in phylogenetic tree, with the sequence identity of 99%. Based on all these results, strain WMQ-7 was identified as Pseudomonas putida. The enzyme activity of strain WMQ-7 was 0.671 U/microg. A strain producing ACC deaminase was identified and tested.

  1. Microwave-assisted synthesis, structural characterization, DFT studies, antibacterial and antioxidant activity of 2-methyl-4-oxo-1,2,3,4-tetrahydroquinazoline-2-carboxylic acid

    Science.gov (United States)

    Obafemi, Craig A.; Fadare, Olatomide A.; Jasinski, Jerry P.; Millikan, Sean P.; Obuotor, Efere M.; Iwalewa, Ezekiel O.; Famuyiwa, Samson O.; Sanusi, Kayode; Yilmaz, Yusuf; Ceylan, Ümit

    2018-03-01

    In the present study a new tetrahydroquinazoline-2-carboxylic, C10H10N2O3, 1‧, was synthesized and its structure was characterized by elemental analysis, IR, 1H NMR, 13C NMR data and high-resolution mass spectrometry. The spectral results are in line with the proposed structure. Single crystal X-ray structural analysis of the compound showed that the crystal structure adopts a monoclinic space group P21/c, with the packing of the molecule stabilized by Cdbnd O … …Hsbnd O, Nsbnd H … ….Odbnd Csbnd Osbnd intermolecular hydrogen bonding. The theoretical geometrical parameters of the compound have been calculated using density functional (DFT) and time-dependent density functional (TD-DFT) theory methods and have been used to predict the thermodynamic one-electron redox potential and the electronic absorption property of the compound. The theoretical characterization matched the experimental measurements, showing a good correlation. The calculated HOMO-LUMO gap (4.79 eV) suggests that compound 1‧ could be a potential antioxidant. The synthesized compound was screened for its in vitro antimicrobial activity against selected bacterial strains and antioxidant activity using the TAC, FRAP, NO and ABTS models. In vitro antioxidant activity of 1' showed a moderate activity, but weaker scavenging activity than the standards of ascorbic acid and trolox. Results of the antibacterial activity of the tested compound showed that it possesses a higher activity against Bacillus anthracis, Bacillus cereus, Bacillus polymyxa, Bacillus subtilis and Staphylococcus aureus than the two standard drugs, streptomycin and tetracycline, and better activity than tetracycline against Escherichia coli.

  2. High-performance supercapacitors of carboxylate-modified hollow carbon nanospheres coated on flexible carbon fibre paper: Effects of oxygen-containing group contents, electrolytes and operating temperature

    International Nuclear Information System (INIS)

    Phattharasupakun, Nutthaphon; Wutthiprom, Juthaporn; Suktha, Phansiri; Iamprasertkun, Pawin; Chanlek, Narong; Shepherd, Celine; Hadzifejzovic, Emina; Moloney, Mark G.; Foord, John S.; Sawangphruk, Montree

    2017-01-01

    Although functionalized carbon-based materials have been widely used as the supercapacitor electrodes, the optimum contents of the functional groups, the charge storage mechanisms, and the effects of electrolytes and operating temperature have not yet been clearly investigated. In this work, carboxylate-modified hollow carbon nanospheres (c-HCN) with different functional group contents synthesized by an oxidation process of carbon nanospheres with nitric acid were coated on flexible carbon fibre paper and used as the supercapacitor electrodes. An as-fabricated supercapacitor of the c-HCN with a finely tuned 6.2 atomic % of oxygen of the oxygen-containing groups in an ionic liquid electrolyte exhibits a specific capacitance of 390 F g"−"1, a specific energy of 115 Wh kg"−"1, and a maximum specific power of 13548 W kg"−"1 at 70 °C. The charge storage mechanism investigated is based on the chemical adsorption of the ionic liquid electrolyte on the c-HCN electrode. This process is highly reversible leading to high capacity retention. The supercapacitor in this work may be practically used in many high energy and power applications.

  3. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid Amides.

    Science.gov (United States)

    Du, Shijie; Tian, Zaimin; Yang, Dongyan; Li, Xiuyun; Li, Hong; Jia, Changqing; Che, Chuanliang; Wang, Mian; Qin, Zhaohai

    2015-05-08

    A series of novel 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-yl)phenyl)-3-(difluoro-methyl)-1-methyl-1H-pyrazole-4-carboxamide (9m) exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  4. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic Acid Amides

    Directory of Open Access Journals (Sweden)

    Shijie Du

    2015-05-01

    Full Text Available A series of novel 3-(difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-ylphenyl-3-(difluoro-methyl-1-methyl-1H-pyrazole-4-carboxamide (9m exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  5. Kinetics of the esterification of active pharmaceutical ingredients containing carboxylic Acid functionality in polyethylene glycol

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie V; Hansen, Steen Honoré; Moesgaard, Birthe

    2014-01-01

    Polyethylene glycols (PEGs) are attractive as excipients in the manufacture of drug products because they are water soluble and poorly immunogenic. They are used in various pharmaceutical preparations. However, because of their terminal hydroxyl groups, PEGs can participate in esterification reac......, it is important to be aware of this drug-excipient interaction, as it can reduce the shelf-life of a low-average molecular weight PEG formulation considerably. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2424-2433, 2014....

  6. Identification of a Potent Phosphoinositide 3-Kinase Pan Inhibitor Displaying a Strategic Carboxylic Acid Group and Development of Its Prodrugs.

    Science.gov (United States)

    Pirali, Tracey; Ciraolo, Elisa; Aprile, Silvio; Massarotti, Alberto; Berndt, Alex; Griglio, Alessia; Serafini, Marta; Mercalli, Valentina; Landoni, Clarissa; Campa, Carlo Cosimo; Margaria, Jean Piero; Silva, Rangel L; Grosa, Giorgio; Sorba, Giovanni; Williams, Roger; Hirsch, Emilio; Tron, Gian Cesare

    2017-09-21

    Activation of the phosphoinositide 3-kinase (PI3K) pathway is a key signaling event in cancer, inflammation, and other proliferative diseases. PI3K inhibitors are already approved for some specific clinical indications, but their systemic on-target toxicity limits their larger use. In particular, whereas toxicity is tolerable in acute treatment of life-threatening diseases, this is less acceptable in chronic conditions. In the past, the strategy to overcome this drawback was to block selected isoforms mainly expressed in leukocytes, but redundancy within the PI3K family members challenges the effectiveness of this approach. On the other hand, decreasing exposure to selected target cells represents a so-far unexplored alternative to circumvent systemic toxicity. In this manuscript, we describe the generation of a library of triazolylquinolones and the development of the first prodrug pan-PI3K inhibitor. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Degradation of chitosan hydrogel dispersed in dilute carboxylic acids by solution plasma and evaluation of anticancer activity of degraded products

    Science.gov (United States)

    Chokradjaroen, Chayanaphat; Rujiravanit, Ratana; Theeramunkong, Sewan; Saito, Nagahiro

    2018-01-01

    Chitosan is a polysaccharide that has been extensively studied in the field of biomedicine, especially its water-soluble degraded products called chitooligosaccharides (COS). In this study, COS were produced by the degradation of chitosan hydrogel dispersed in a dilute solution (i.e., 1.55 mM) of various kinds of carboxylic acids using a non-thermal plasma technology called solution plasma (SP). The degradation rates of chitosan were influenced by the type of carboxylic acids, depending on the interaction between chitosan and each carboxylic acid. After SP treatment, the water-soluble degraded products containing COS could be easily separated from the water-insoluble residue of chitosan hydrogel by centrifugation. The production yields of the COS were mostly higher than 55%. Furthermore, the obtained COS products were evaluated for their inhibitory effect as well as their selectivity against human lung cancer cells (H460) and human lung normal cells (MRC-5).

  8. Electrical properties of SAM-modified ITO surface using aromatic small molecules with double bond carboxylic acid groups for OLED applications

    International Nuclear Information System (INIS)

    Can, Mustafa; Havare, Ali Kemal; Aydın, Hasan; Yagmurcukardes, Nesli; Demic, Serafettin; Icli, Sıddık; Okur, Salih

    2014-01-01

    Graphical abstract: - Highlights: • We report that the performance of OLED consist of aromatic small molecules with double bond carboxylic acid groups on ITO surface. • The OLED devices were tested in terms of electrical and optical characteristics. • The I–V results show that OLEDs with SAM-modified ITO surface have lower turn on voltages than OLED configurations without SAMs. - Abstract: 5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space–charge-limited current measurements (SCLC)

  9. Effects of alkyl chain length and solvents on thermodynamic dissociation constants of the ionic liquids with one carboxyl group in the alkyl chain of imidazolium cations.

    Science.gov (United States)

    Chen, Yuehua; Wang, Huiyong; Wang, Jianji

    2014-05-01

    Thermodynamic dissociation constants of the Brønsted acidic ionic liquids (ILs) are important for their catalytic and separation applications. In this work, a series of imidazolium bromides with one carboxylic acid substitute group in their alkyl chain ([{(CH2)nCOOH}mim]Br, n = 1,3,5,7) have been synthesized, and their dissociation constants (pKa) at different ionic strengths have been determined in aqueous and aqueous organic solvents at 0.1 mole fraction (x) of ethanol, glycol, iso-propanol, and dimethyl sulfoxide by potentiometric titrations at 298.2 K. The standard thermodynamic dissociation constants (pKa(T)) of the ILs in these solvents were calculated from the extended Debye-Hückel equation. It was found that the pKa values increased with the increase of ionic strength of the media and of the addition of organic solvent in water. The pKa(T) values also increased with the increase of the alkyl chain length of cations of the ILs. In addition, the effect of solvent nature on pKa(T) values is interpreted from solvation of the dissociation components and their Gibbs energy of transfer from water to aqueous organic solutions.

  10. Electrical properties of SAM-modified ITO surface using aromatic small molecules with double bond carboxylic acid groups for OLED applications

    Energy Technology Data Exchange (ETDEWEB)

    Can, Mustafa [Izmir Katip Celebi University, Faculty of Engineering, Department of Engineering Sciences, Çiğli, Izmir (Turkey); Havare, Ali Kemal [Toros University, Faculty of Engineering, Electric and Electronic Department, Mersin (Turkey); Aydın, Hasan; Yagmurcukardes, Nesli [Izmir Institute of Technology, Material Science and Engineering, Izmir (Turkey); Demic, Serafettin [Izmir Katip Celebi University, Faculty of Engineering, Department of Material Science and Engineering, Çiğli, Izmir (Turkey); Icli, Sıddık [Ege University, Solar Energy Institute, Izmir (Turkey); Okur, Salih, E-mail: salih.okur@ikc.edu.tr [Izmir Katip Celebi University, Faculty of Engineering, Department of Material Science and Engineering, Çiğli, Izmir (Turkey)

    2014-09-30

    Graphical abstract: - Highlights: • We report that the performance of OLED consist of aromatic small molecules with double bond carboxylic acid groups on ITO surface. • The OLED devices were tested in terms of electrical and optical characteristics. • The I–V results show that OLEDs with SAM-modified ITO surface have lower turn on voltages than OLED configurations without SAMs. - Abstract: 5-[(3-Methylphenyl)(phenyl)amino]isophthalic acid (5-MePIFA) and 5-(diphenyl)amino]isophthalic acid (5-DPIFA) organic molecules were synthesized to form self-assembled monolayer on indium tin oxide (ITO) anode to enhance hole transport from ITO to organic hole transport layers such as TPD. The modified surface was characterized by scanning tunneling microscopy (STM). The change in the surface potential was measured by Kelvin probe force microscopy (KPFM). Our Kelvin probe force microscopy (KPFM) measurements showed that the surface potentials increased more than 100 mV with reference to bare indium tin-oxide. The results show that the threshold voltage on OLEDs with modified ITO is lowered significantly compared to OLEDs with unmodified ITO. The hole mobility of TPD has been estimated using space–charge-limited current measurements (SCLC)

  11. Copper- and copper–N-heterocyclic carbene-catalyzed C─H activating carboxylation of terminal alkynes with CO2 at ambient conditions

    Science.gov (United States)

    Yu, Dingyi; Zhang, Yugen

    2010-01-01

    The use of carbon dioxide as a renewable and environmentally friendly source of carbon in organic synthesis is a highly attractive approach, but its real world applications remain a great challenge. The major obstacles for commercialization of most current protocols are their low catalytic performances, harsh reaction conditions, and limited substrate scope. It is important to develop new reactions and new protocols for CO2 transformations at mild conditions and in cost-efficient ways. Herein, a copper-catalyzed and copper–N-heterocyclic carbene-cocatalyzed transformation of CO2 to carboxylic acids via C─H bond activation of terminal alkynes with or without base additives is reported. Various propiolic acids were synthesized in good to excellent yields under ambient conditions without consumption of any organometallic or organic reagent additives. This system has a wide scope of substrates and functional group tolerances and provides a powerful tool for the synthesis of highly functionalized propiolic acids. This catalytic system is a simple and economically viable protocol with great potential in practical applications. PMID:21059950

  12. Identification of 2-aminothiazole-4-carboxylate derivatives active against Mycobacterium tuberculosis H37Rv and the beta-ketoacyl-ACP synthase mtFabH.

    Directory of Open Access Journals (Sweden)

    Qosay Al-Balas

    Full Text Available BACKGROUND: Tuberculosis (TB is a disease which kills two million people every year and infects approximately over one-third of the world's population. The difficulty in managing tuberculosis is the prolonged treatment duration, the emergence of drug resistance and co-infection with HIV/AIDS. Tuberculosis control requires new drugs that act at novel drug targets to help combat resistant forms of Mycobacterium tuberculosis and reduce treatment duration. METHODOLOGY/PRINCIPAL FINDINGS: Our approach was to modify the naturally occurring and synthetically challenging antibiotic thiolactomycin (TLM to the more tractable 2-aminothiazole-4-carboxylate scaffold to generate compounds that mimic TLM's novel mode of action. We report here the identification of a series of compounds possessing excellent activity against M. tuberculosis H(37R(v and, dissociatively, against the beta-ketoacyl synthase enzyme mtFabH which is targeted by TLM. Specifically, methyl 2-amino-5-benzylthiazole-4-carboxylate was found to inhibit M. tuberculosis H(37R(v with an MIC of 0.06 microg/ml (240 nM, but showed no activity against mtFabH, whereas methyl 2-(2-bromoacetamido-5-(3-chlorophenylthiazole-4-carboxylate inhibited mtFabH with an IC(50 of 0.95+/-0.05 microg/ml (2.43+/-0.13 microM but was not active against the whole cell organism. CONCLUSIONS/SIGNIFICANCE: These findings clearly identify the 2-aminothiazole-4-carboxylate scaffold as a promising new template towards the discovery of a new class of anti-tubercular agents.

  13. A Dynamic Policy for Grouping Maintenance Activities

    NARCIS (Netherlands)

    R.E. Wildeman (Ralph); R. Dekker (Rommert); A.C.J.M. Smit

    1995-01-01

    textabstractA maintenance activity carried out on a technical system often involves a system-dependent set-up cost that is the same for all maintenance activities carried out on that system. Grouping activities thus saves costs since execution of a group of activities requires only one set-up. Many

  14. Alteration of the carboxyl-terminal domain of Ada protein influences its inducibility, specificity, and strength as a transcriptional activator.

    OpenAIRE

    Shevell, D E; LeMotte, P K; Walker, G C

    1988-01-01

    The ada gene of Escherichia coli K-12 encodes the regulatory protein for the adaptive response to alkylating agents. A set of plasmids carrying ordered deletions from the 3' end of the ada gene were isolated and characterized. These ada deletions encode fusion proteins that derive their amino termini from ada and their carboxyl termini from the downstream vector sequence that occurs before an in-frame stop codon. Several of these ada deletions encode Ada derivatives that constitutively activa...

  15. Synthesis and Antitumor Activity of 3-Methyl-4-oxo-3,4-dihydroimidazo [5,1-d][1,2,3,5]tetrazine-8-carboxylates and -carboxamides

    Directory of Open Access Journals (Sweden)

    Lin-Xiang Zhao

    2010-12-01

    Full Text Available Seventeen novel 3-methyl-4-oxo-3,4-dihydroimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxylate and -carboxamide derivatives were synthesized and evaluated for their growth inhibition in seven human solid tumor and a human leukemia HL-60 cell lines. Compound IVa showed more activity than the other compounds and the positive control temozolomide. In the presence of 40 mg/mL of IVa, the survival rate of all tested tumor cells was less than 10%. Esters displayed more potent antitumour activity than amides and temozolomide against HL-60 cells. These compounds also exhibited considerably enhanced water-solubility.

  16. Reaction of Nα-acetyl-L-histidine with diazomethane: A model esterification reaction of carboxylic groups in the presence of imidazole rings

    Directory of Open Access Journals (Sweden)

    Zamora, R.

    1996-10-01

    Full Text Available The reaction of Nα-acetyl-L-histidine with diazomethane was studied in order to analyze the esterification reaction of a carboxylic group in the presence of an imidazole ring. The reaction produced the expected Nα-acetyl-L-histidine methyl ester (1 as a major product. However, important amounts of [S]-acetyl-1-methylimidazole-4-alanine methyl ester (2 and [S]-acetyl-1-methylimidazole-5-alanine methyl ester (3 were also produced. These compounds, which could be detected by capillary electrophoresis (HPCE and thin layer chromatography, were fractionated by column chromatography and identified by gas chromatography coupled with mass spectrometry (GC-MS, and 1H and 13C nuclear magnetic resonance spectroscopy. Structures for compounds 1-3 were confirmed by HPCE after acid hydrolysis. These results indicated that the use of diazomethane produces the methyl derivative of the heterocyclic ring in addition to the methyl ester. This reaction should be considered when preparing derivatives for GC-MS analysis.

    La reacción de la Nα-acetil-L-histidina con diazometano fue estudiada con objeto de conocer el comportamiento de la reacción de esterificación de un grupo carboxílico en presencia de un anillo de imidazol. La reacción produjo el esperado éster metílico de la Nα-acetil-L-histidina (1 como producto mayoritario. Sin embargo, también se observó la formación de cantidades importantes de los esteres metílicos de la [S]-acetil-1-metilimidazol- 4-alanina (2 y la [S]-acetil-1-metilimidazol-5-alanina (3. Estos compuestos que pudieron ser detectados por electroforesis capilar y cromatografía en capa fina, fueron separados por cromatografía en columna e identificados por cromatografía de gases acoplada a espectrometría de masas, y por espectroscopia de resonancia magnética nuclear de 1H y 13C. Las estructuras de los compuestos

  17. Simultaneous Decolorization and Biohydrogen Production from Xylose by Klebsiella oxytoca GS-4-08 in the Presence of Azo Dyes with Sulfonate and Carboxyl Groups

    Science.gov (United States)

    Cao, Ming-yue; Wang, Peng-tao; Wang, Shi; Yue, Ying-rong; Yuan, Wen-duo; Qiao, Wei-chuan; Wang, Fei

    2017-01-01

    ABSTRACT Biohydrogen production from the pulp and paper effluent containing rich lignocellulosic material could be achieved by the fermentation process. Xylose, an important hemicellulose hydrolysis product, is used less efficiently as a substrate for biohydrogen production. Moreover, azo dyes are usually added to fabricate anticounterfeiting paper, which further increases the complexity of wastewater. This study reports that xylose could serve as the sole carbon source for a pure culture of Klebsiella oxytoca GS-4-08 to achieve simultaneous decolorization and biohydrogen production. With 2 g liter−1 of xylose as the substrate, a maximum xylose utilization rate (URxyl) and a hydrogen molar yield (HMY) of 93.99% and 0.259 mol of H2 mol of xylose−1, respectively, were obtained. Biohydrogen kinetics and electron equivalent (e− equiv) balance calculations indicated that methyl red (MR) penetrates and intracellularly inhibits both the pentose phosphate pathway and pyruvate fermentation pathway, while methyl orange (MO) acted independently of the glycolysis and biohydrogen pathway. The data demonstrate that biohydrogen pathways in the presence of azo dyes with sulfonate and carboxyl groups were different, but the azo dyes could be completely reduced during the biohydrogen production period in the presence of MO or MR. The feasibility of hydrogen production from industrial pulp and paper effluent by the strain if the xylose is sufficient was also proved and was not affected by toxic substances which usually exist in such wastewater, except for chlorophenol. This study offers a promising energy-recycling strategy for treating pulp and paper wastewaters, especially for those containing azo dyes. IMPORTANCE The pulp and paper industry is a major industry in many developing countries, and the global market of pulp and paper wastewater treatment is expected to increase by 60% between 2012 and 2020. Such wastewater contains large amounts of refractory contaminants, such

  18. A spin-crossover complex based on a 2,6-bis(pyrazol-1-yl)pyridine (1-bpp) ligand functionalized with a carboxylate group.

    Science.gov (United States)

    Abhervé, Alexandre; Clemente-León, Miguel; Coronado, Eugenio; Gómez-García, Carlos J; López-Jordà, Maurici

    2014-07-07

    Combining Fe(ii) with the carboxylate-functionalized 2,6-bis(pyrazol-1-yl)pyridine (bppCOOH) ligand results in the spin-crossover compound [Fe(bppCOOH)2](ClO4)2 which shows an abrupt spin transition with a T1/2 of ca. 380 K and a TLIESST of 60 K due to the presence of a hydrogen-bonded linear network of complexes.

  19. Synthesis and characterization of carboxylic acid functionalized silicon nanoparticles

    Science.gov (United States)

    Shaner, Ted V.

    Silicon nanoparticles are of great interest in a great number of fields. Silicon nanoparticles show great promise particularly in the field of bioimaging. Carboxylic acid functionalized silicon nanoparticles have the ability to covalently bond to biomolecules through the conjugation of the carboxylic acid to an amine functionalized biomolecule. This thesis explores the synthesis of silicon nanoparticles functionalized by both carboxylic acids and alkenes and their carboxylic acid functionality. Also discussed is the characterization of the silicon nanoparticles by the use of x-ray spectroscopy. Finally, the nature of the Si-H bond that is observed on the surface of the silicon nanoparticles will be investigated using photoassisted exciton mediated hydrosilation reactions. The silicon nanoparticles are synthesized from both carboxylic acids and alkenes. However, the lack of solubility of diacids is a significant barrier to carboxylic acid functionalization by a mixture of monoacids and diacids. A synthesis route to overcome this obstacle is to synthesize silicon nanoparticles with terminal vinyl group. This terminal vinyl group is distal to the surface of the silicon nanoparticle. The conversion of the vinyl group to a carboxylic acid is accomplished by oxidative cleavage using ozonolysis. The carboxylic acid functionalized silicon nanoparticles were then successfully conjugated to amine functionalized DNA strand through an n-hydroxy succinimide ester activation step, which promotes the formation of the amide bond. Conjugation was characterized by TEM and polyacrylamide gel electrophoresis (PAGE). The PAGE results show that the silicon nanoparticle conjugates move slower through the polyacrylamide gel, resulting in a significant separation from the nonconjugated DNA. The silicon nanoparticles were then characterized by the use of x-ray absorption near edge spectroscopy (Xanes) and x-ray photoelectron spectroscopy (XPS) to investigate the bonding and chemical

  20. New derivatives of 3,4-dihydroisoquinoline-3-carboxylic acid with free-radical scavenging, D-amino acid oxidase, acetylcholinesterase and butyrylcholinesterase inhibitory activity.

    Science.gov (United States)

    Solecka, Jolanta; Guśpiel, Adam; Postek, Magdalena; Ziemska, Joanna; Kawęcki, Robert; Lęczycka, Katarzyna; Osior, Agnieszka; Pietrzak, Bartłomiej; Pypowski, Krzysztof; Wyrzykowska, Agata

    2014-09-30

    A series of 3,4-dihydroisoquinoline-3-carboxylic acid derivatives were synthesised and tested for their free-radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS·+), superoxide anion radical (O2·-) and nitric oxide radical (·NO) assays. We also studied d-amino acid oxidase (DAAO), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity. Almost each of newly synthesised compounds exhibited radical scavenging capabilities. Moreover, several compounds showed moderate inhibitory activities against DAAO, AChE and BuChE. Compounds with significant free-radical scavenging activity may be potential candidates for therapeutics used in oxidative-stress-related diseases.

  1. Dual role of the carboxyl-terminal region of pig liver L-kynurenine 3-monooxygenase: mitochondrial-targeting signal and enzymatic activity.

    Science.gov (United States)

    Hirai, Kumiko; Kuroyanagi, Hidehito; Tatebayashi, Yoshitaka; Hayashi, Yoshitaka; Hirabayashi-Takahashi, Kanako; Saito, Kuniaki; Haga, Seiich; Uemura, Tomihiko; Izumi, Susumu

    2010-12-01

    l-kynurenine 3-monooxygenase (KMO) is an NAD(P)H-dependent flavin monooxygenase that catalyses the hydroxylation of l-kynurenine to 3-hydroxykynurenine, and is localized as an oligomer in the mitochondrial outer membrane. In the human brain, KMO may play an important role in the formation of two neurotoxins, 3-hydroxykynurenine and quinolinic acid, both of which provoke severe neurodegenerative diseases. In mosquitos, it plays a role in the formation both of eye pigment and of an exflagellation-inducing factor (xanthurenic acid). Here, we present evidence that the C-terminal region of pig liver KMO plays a dual role. First, it is required for the enzymatic activity. Second, it functions as a mitochondrial targeting signal as seen in monoamine oxidase B (MAO B) or outer membrane cytochrome b(5). The first role was shown by the comparison of the enzymatic activity of two mutants (C-terminally FLAG-tagged KMO and carboxyl-terminal truncation form, KMOΔC50) with that of the wild-type enzyme expressed in COS-7 cells. The second role was demonstrated with fluorescence microscopy by the comparison of the intracellular localization of the wild-type, three carboxyl-terminal truncated forms (ΔC20, ΔC30 and ΔC50), C-terminally FLAG-tagged wild-type and a mutant KMO, where two arginine residues, Arg461-Arg462, were replaced with Ser residues.

  2. Small Group Activities for Introductory Business Classes.

    Science.gov (United States)

    Mundrake, George

    1999-01-01

    Describes numerous small-group activities for the following areas of basic business education: consumer credit, marketing, business organization, entrepreneurship, insurance, risk management, economics, personal finance, business careers, global markets, and government regulation. (SK)

  3. Are carboxyl groups the most acidic sites in amino acids? Gas-phase acidities, photoelectron spectra, and computations on tyrosine, p-hydroxybenzoic acid, and their conjugate bases.

    Science.gov (United States)

    Tian, Zhixin; Wang, Xue-Bin; Wang, Lai-Sheng; Kass, Steven R

    2009-01-28

    Deprotonation of tyrosine in the gas phase was found to occur preferentially at the phenolic site, and the conjugate base consists of a 70:30 mixture of phenoxide and carboxylate anions at equilibrium. This result was established by developing a chemical probe for differentiating these two isomers, and the presence of both ions was confirmed by photoelectron spectroscopy. Equilibrium acidity measurements on tyrosine indicated that deltaG(acid)(o) = 332.5 +/- 1.5 kcal mol(-1) and deltaH(acid)(o) = 340.7 +/- 1.5 kcal mol(-1). Photoelectron spectra yielded adiabatic electron detachment energies of 2.70 +/- 0.05 and 3.55 +/- 0.10 eV for the phenoxide and carboxylate anions, respectively. The H/D exchange behavior of deprotonated tyrosine was examined using three different alcohols (CF3CH2OD, C6H5CH2OD, and CH3CH2OD), and incorporation of up to three deuterium atoms was observed. Two pathways are proposed to account for these results, and all of the experimental findings are supplemented with B3LYP/aug-cc-pVDZ and G3B3 calculations. In addition, it was found that electrospray ionization of tyrosine from a 3:1 (v/v) CH3OH/H2O solution using a commercial source produces a deprotonated [M-H]- anion with the gas-phase equilibrium composition rather than the structure of the ion that exists in aqueous media. Electrospray ionization from acetonitrile, however, leads largely to the liquid-phase (carboxylate) structure. A control molecule, p-hydroxybenzoic acid, was found to behave in a similar manner. Thus, the electrospray conditions that are employed for the analysis of a compound can alter the isomeric composition of the resulting anion.

  4. Highly Carboxylated Cellulose Nanofibers via Succinic Anhydride Esterification of Wheat Fibers and Facile Mechanical Disintegration.

    Science.gov (United States)

    Sehaqui, H; Kulasinski, K; Pfenninger, N; Zimmermann, T; Tingaut, P

    2017-01-09

    We report herein the preparation of 4-6 nm wide carboxyl-functionalized cellulose nanofibers (CNF) via the esterification of wheat fibers with cyclic anhydrides (maleic, phtalic, and succinic) followed by an energy-efficient mechanical disintegration process. Remarkable results were achieved via succinic anhydride esterification that enabled CNF isolation by a single pass through the microfluidizer yielding a transparent and thick gel. These CNF carry the highest content of carboxyl groups ever reported for native cellulose nanofibers (3.8 mmol g -1 ). Compared to conventional carboxylated cellulose nanofibers prepared via Tempo-mediated oxidation of wheat fibers, the present esterified CNF display a higher molar-mass and a better thermal stability. Moreover, highly carboxylated CNF from succinic anhydride esterification were effectively integrated into paper filters for the removal of lead from aqueous solution and are potentially of interest as carrier of active molecules or as transparent films for packaging, biomedical or electronic applications.

  5. A Group Recommender System for Tourist Activities

    Science.gov (United States)

    Garcia, Inma; Sebastia, Laura; Onaindia, Eva; Guzman, Cesar

    This paper introduces a method for giving recommendations of tourist activities to a group of users. This method makes recommendations based on the group tastes, their demographic classification and the places visited by the users in former trips. The group recommendation is computed from individual personal recommendations through the use of techniques such as aggregation, intersection or incremental intersection. This method is implemented as an extension of the e-Tourism tool, which is a user-adapted tourism and leisure application, whose main component is the Generalist Recommender System Kernel (GRSK), a domain-independent taxonomy-driven search engine that manages the group recommendation.

  6. Decarboxylative Trifluoromethylation of Aliphatic Carboxylic Acids.

    Science.gov (United States)

    Kautzky, Jacob A; Wang, Tao; Evans, Ryan W; MacMillan, David W C

    2018-05-14

    Herein we disclose an efficient method for the conversion of carboxylic acids to trifluoromethyl groups via the combination of photoredox and copper catalysis. This transformation tolerates a wide range of functionality including heterocycles, olefins, alcohols, and strained ring systems. To demonstrate the broad potential of this new methodology for late-stage functionalization, we successfully converted a diverse array of carboxylic acid-bearing natural products and medicinal agents to the corresponding trifluoromethyl analogues.

  7. Design and synthesis of a tetradentate '3-amine-1-carboxylate' ligand to mimic the metal binding environment at the non-heme iron(II) oxidase active site.

    Science.gov (United States)

    Dungan, Victoria J; Ortin, Yannick; Mueller-Bunz, Helge; Rutledge, Peter J

    2010-04-07

    Non-heme iron(II) oxidases (NHIOs) catalyse a diverse array of oxidative chemistry in Nature. As part of ongoing efforts to realize biomimetic, iron-mediated C-H activation, we report the synthesis of a new 'three-amine-one-carboxylate' ligand designed to complex with iron(II) and mimic the NHIO active site. The tetradentate ligand has been prepared as a single enantiomer in nine synthetic steps from N-Cbz-L-alanine, pyridine-2,6-dimethanol and diphenylamine, using Seebach oxazolidinone chemistry to control the stereochemistry. X-Ray crystal structures are reported for two important intermediates, along with variable temperature NMR experiments to probe the hindered interconversion of conformational isomers of several key intermediates, 2,6-disubstituted pyridine derivatives. The target ligand and an N-Cbz-protected precursor were each then complexed with iron(II) and tested for their ability to promote alkene dihydroxylation, using hydrogen peroxide as the oxidant.

  8. Catalytic ozonation not relying on hydroxyl radical oxidation: A selective and competitive reaction process related to metal-carboxylate complexes

    KAUST Repository

    Zhang, Tao

    2014-01-01

    Catalytic ozonation following non-hydroxyl radical pathway is an important technique not only to degrade refractory carboxylic-containing organic compounds/matter but also to avoid catalyst deactivation caused by metal-carboxylate complexation. It is unknown whether this process is effective for all carboxylates or selective to special molecule structures. In this work, the selectivity was confirmed using O3/(CuO/CeO2) and six distinct ozone-resistant probe carboxylates (i.e., acetate, citrate, malonate, oxalate, pyruvate and succinate). Among these probe compounds, pyruvate, oxalate, and citrate were readily degraded following the rate order of oxalate>citrate>pyruvate, while the degradation of acetate, malonate, and succinate was not promoted. The selectivity was independent on carboxylate group number of the probe compounds and solution pH. Competitive degradation was observed for carboxylate mixtures following the preference order of citrate, oxalate, and finally pyruvate. The competitive degradation was ascribed to competitive adsorption on the catalyst surface. It was revealed that the catalytically degradable compounds formed bidentate chelating or bridging complexes with surface copper sites of the catalyst, i.e., the active sites. The catalytically undegradable carboxylates formed monodentate complexes with surface copper sites or just electrostatically adsorbed on the catalyst surface. The selectivity, relying on the structure of surface metal-carboxylate complex, should be considered in the design of catalytic ozonation process. © 2013 Elsevier B.V.

  9. Carboxylic acid-grafted mesoporous material and its high catalytic activity in one-pot three-component coupling reaction

    Directory of Open Access Journals (Sweden)

    Ruth Gomes

    2014-11-01

    Full Text Available A new carboxylic acid functionalized mesoporous organic polymer has been synthesized via in situ radical polymerization of divinylbenzene and acrylic acid using a mesoporous silica as a seed during the polymerization process under solvothermal conditions. The mesoporous material MPDVAA-1 has been thoroughly characterized employing powder XRD, solid state 13C cross polarization magic angle spinning-nuclear magnetic resonance, FT-IR spectroscopy, N2 sorption, HR-TEM, and NH3 temperature programmed desorption-thermal conductivity detector (TPD-TCD analysis to understand its porosity, chemical environment, bonding, and surface properties. The mesoporous polymer was used as a catalyst for a three comp onent Biginelli condensation between various aldehydes, β-keto esters, and urea/thioureas to give 3,4-dihydropyrimidine-2(1H-ones. The reactions were carried out under conventional heating as well as solvent-free microwave irradiation of solid components, and in both the cases, the mesoporous polymer MPDVAA-1 proved to be a powerful, robust, and reusable catalyst with high catalytic efficiency.

  10. Determination of surface functional groups on mechanochemically activated carbon cloth by Boehm method

    Directory of Open Access Journals (Sweden)

    Đukić Anđelka B.

    2014-01-01

    Full Text Available In order to improve sorption properties of activated carbon cloth that can be used for wastewater purification, mechanochemical activation was performed in both inert and air atmosphere. Boehm method was used to follow the changes in the number and types of surface groups induced by mechanical milling. The number of the base groups of 0,2493 mmol/g is significantly smaller than the total amount of acidic functional groups, 2,5093 mmol/g. Among the acidic groups present on the surface, the most represented are phenolic groups (2.3846 mmol/g , ie . > 95 % , the carboxylic groups are present far less (0.1173 mmol /g, ie. 4.5 %, while the presence of the lactone group on the surface of ACC is negligible (0.0074 mmol/g ie. under 0.3 %. Mechanochemical activation lead to an increase in the number of acidic and basic groups on the surface of the ACC. The milling in inert atmosphere has dominant effect with respect to the changes in the total number of basic functional groups (compared to milling in an air atmosphere: the number of basic groups of the ACC was 0.8153 mmol/g milled under argon, 0.7933 mmol/g in the air; the number of acidic groups is 2.9807 mmol/g for a sample milled under argon and 3.5313 mmol/g for one milled in the air.

  11. An investigation of the functional groups on the surface of activated carbons

    Directory of Open Access Journals (Sweden)

    MARYTE DERVINYTE

    2004-05-01

    Full Text Available Activated carbons were produced in the laboratory from wood using a 20-run Plackett–Burman experimental design for 19 factors. The obtained batches of activated carbon were analysed by potentiometric titration and FTIR spectroscopy to determine the surface functional groups. The results obtained by potentiometric titration displayed the distribution of individual acidity constants of those groups in the pK range. Considering this parameter, the surface functional groups were divided into carboxyl, lactone and phenol. The linear regression equations reflecting the influence of each operation used for the synthesis on the amount of these functional groups in the obtained activated carbons were generated. The FTIR spectra were used in parallel for the evaluation of the amount and the type of the surface functional groups. Relationships between the two data sets obtained by potentiometric titration and FTIR spectroscopy were evaluated by correlation analysis. It was established that the amount of surface functional groups determined by potentiometric titration positively correlates with the intensity of the peaks of hydrophilic functional groups in the FTIR spectra. At the same time, the negative correlation between potentiometrically determined amount of surface functional groups and the intensity of peaks of hydrophobic functional groups was observed. Most probably, these non-polar formations can take part in the interaction of carbon surface with H+/OH- ions and diminish the strength of existent functional groups.

  12. Synthesis, crystal structures, molecular docking, and in vitro biological activities evaluation of transition metal complexes with 4-(3,4-dichlorophenyl) piperazine-1-carboxylic acid

    Science.gov (United States)

    Chen, Zhi-Jian; Chen, Ya-Na; Xu, Chun-Na; Zhao, Shan-Shan; Cao, Qi-Yue; Qian, Shao-Song; Qin, Jie; Zhu, Hai-Liang

    2016-08-01

    Three novel mononuclear complexes, [MⅡ(L)2·2H2O], (M = Cu, Ni or Cd; HL = 4-(3,4-dichlorophenyl)piperazine-1-carboxylic acid)were synthesized and structurally determined by single-crystal X-ray diffraction. Molecular docking study preliminarily revealed that complex 1 had potential urease inhibitory activity. In accordance with the result of calculation, in vitro tests of the inhibitory activities of complexes 1-3 against jack bean urease showed complex 1 (IC50 = 8.17 ± 0.91 μM) had better inhibitory activities than the positive reference acetohydroxamic acid (AHA) (IC50 = 26.99 ± 1.43 μM), while complexes 2 and 3 showed no inhibitory activities., kinetics study was carried out to explore the mechanism of the inhibiting of the enzyme, and the result indicated that complex 1 was a competitive inhibitor of urease. Albumin binding experiment and in vitro toxicity evaluation of complex 1 were implemented to explore its Pharmacological properties.

  13. Uranium (IV) carboxylates - I

    Energy Technology Data Exchange (ETDEWEB)

    Satpathy, K C; Patnaik, A K [Sambalpur Univ. (India). Dept. of Chemistry

    1975-11-01

    A few uranium(IV) carboxylates with monochloro and trichloro acetic acid, glycine, malic, citric, adipic, o-toluic, anthranilic and salicylic acids have been prepared by photolytic methods. The I.R. spectra of these compounds are recorded and basing on the spectral data, structure of the compounds have been suggested.

  14. Synthesis, crystal structure, spectral analysis, dft studies and antimicrobial activity of ethyl 6-(4-(ethoxycarbonyl)-1h-1,2,3-triazol-1-yl)pyridine-3-carboxylate

    International Nuclear Information System (INIS)

    Ahmed, M.N.; Yasin, K.A.; Khan, R.A.H.; Mahmood, T.; Ayub, K.; Malik, D.

    2017-01-01

    Ethyl-6-(4-(ethoxycarbonyl)-1H-1,2,3-triazol-1-yl)pyridine-3-carboxylate (1), was synthesized via click reaction between ethyl tetrazolo[1,5-a]pyridine-6-carboxylate and ethyl propiolate in tetrahydrofuran (THF) in the presence of catalytic amount of a copper acetate. The structure was confirmed by single-crystal X-ray diffraction, NMR, FT-IR and MS. The compound crystallizes in the triclinic system, space group P-1 with a = 4.9122 (5), b = s9.5891 (11), c = 15.4851 (18) Å, a = 92.371 (5), beta = 90.015 (4), gamma = 101.722 (5) Z = 2 and V (Å /sup 3/) = 713.55 (14). Packing diagram indicates that there is dimeric interaction between two units via N(2)H(7). The crystal structure of the title compound 1 is stabilized by several nonboding interactions. Space filling model also revealed C-H...π and the π-π interactions in the molecule. Theoretical investigations were executed by using the Gaussian 09 software to enable comparison with X-ray structure as well as spectroscopic results, and to further probe the structural properties. The molecular electrostatic potential (MEP) analysis gave the idea about chemical reactivity and the Mulliken charge analysis gave quantitative estimate of the charges on the atoms. Frontier molecular orbitals analysis (electronic properties) was used to find the energy gap between the HOMO and the LUMO. The target compound was screened against three different bacterial strains like S. typhimurium, M. luteus and B. bronchiseptica as well as three different fungal strains i.e Aspergilus niger, Mucor specie and Aspergilus flavus. Moderate activities have been displayed by the target compound against tested strains. (author)

  15. Mass spectrometric behaviour of carboxylated polyethylene glycols and carboxylated octylphenol ethoxylates.

    Science.gov (United States)

    Frańska, Magdalena; Zgoła, Agnieszka; Rychłowska, Joanna; Szymański, Andrzej; Łukaszewski, Zenon; Frański, Rafał

    2003-01-01

    Mass spectrometric behaviour of mono- and di-carboxylated polyethylene glycols (PEGCs and CPEGCs) and carboxylated octylphenol ethoxylates (OPECs) are discussed. The tendency for ionisation (deprotonation, protonation and cationisation by alkali metal cations) of carboxylated PEGs was compared with that of non-carboxylated correspondents by using both secondary ion mass spectrometry (SIMS) and electrospray ionisation (ESI). The fragmentation of the PEGCs and CPEGCs is discussed and also compared with their neutral correspondents, PEGs. The B/E mass spectra were recorded, using secondary ion mass spectrometry as a method for generation, for deprotonated and protonated molecules and molecules cationised by alkali metal cations. The fragmentation behaviour of PEGs is found to be different from that of CPEGCs, The presence of carboxylic groups may be confirmed not only by the determination of molecular weights of the ethoxylates studied, but also on the basis of the fragment ions formed. The metastable decomposition of the [OPEC-H](-) ions proceed through the cleavage of the bond between the octylphenol moiety and the ethoxylene chain leading to the octylphenoxy anions. It permits determination of the mass of the hydrophobic moiety of the studied carboxylated alkylphenol ethoxylate. ESI mass spectra recorded in the negative ion mode were found to be more suitable for the determination of the average molecular weight of carboxylated ethoxylates than SI mass spectra.

  16. From Cannibalism to Active Motion of Groups

    Science.gov (United States)

    Romanczuk, Pawel; Schimansky-Geier, Lutz

    2008-03-01

    The detailed mechanisms leading to collective dynamics in groups of animals and insect are still poorly understood. A recent study by Simpson et. al. suggests cannibalism as a driving mechanism for coordinated migration of mormon crickets [1]. Based on this result we propose a simple generic model of brownian particles interacting by asymmetric, non-conservative collisions accounting for cannibalistic behavior and the corresponding avoidance strategy. We discuss our model in one and two dimensions and show that a certain type of collisions drives the system out of equilibrium and leads to coordinated active motion of groups.[1] Stephen J. Simpson, Gregory A. Sword, Patrick D. Lorch and Iain D. Couzin: Cannibal crickets on a forced march for protein and salt, PNAS, 103:4152-4156, 2006

  17. Novel Polymers with Carboxylic Acid Loading

    DEFF Research Database (Denmark)

    Thomsen, Anders Daugaard; Malmström, Eva; Hvilsted, Søren

    2006-01-01

    Click chemistry has been used to prepare a range of novel polymers with pendant carboxylic acid side groups. Four azido carboxylic acids, either mono- or difunctional and aliphatic or aromatic, have been prepared and thoroughly characterized. Extensive model reactions with 1-ethyl-4-hydroxybenzene......, the simplest model for poly(4-hydroxystyrene), and the four azido carboxylic acids have been conducted to establish the proper reaction conditions and provide an analytical frame for the corresponding polymers. Poly(4-hydroxystyrene) moieties in three different polymers—poly(4-hydroxystyrene), poly(4...... the polymers in general exhibit [when poly(4-hydroxystyrene) is a substantial part] significant changes in the glass-transition temperature from the polar poly(4-hydroxystyrene) (120–130 °C) to the much less polar alkyne polymers (46–60 °C). A direct correlation between the nature of the pendant groups...

  18. Activities of Gaz de France Group

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    The Board of Directors of Gaz de France approved the Group's consolidated accounts for 2004. In a more dynamic economic environment than in 2003, the Gaz de France Group reports enhanced results and has continued to pursue its growth in Europe. Increase in net sales driven by sustained growth in sales (+ 8.9%): In 2004, net sales rose 8.9% compared with the 2003 financial year to reach a total of euro 18,129 m. This strong increase in business activities was driven by sustained growth in sales volumes both in France and Europe. Total Group sales volumes amounted to 730 TWh (approximately 66 billion cubic metres), equal to growth of 10.3%. Natural gas sales volumes increased by approximately 10% in France, and are almost 18% higher in Europe, notably in the United Kingdom, Italy, Belgium and the Netherlands. The Group has pursued the profitable development of its activities outside France. As a result, international activities account for 29% of total sales in 2004, against 23% in 2003. The contribution made by international subsidiaries - particularly those specializing in exploration and production - grew by a very substantial 44.3% to reach a total of euro 502 m in 2004. Energy and Services Offering Branch: this core business line, which includes natural gas and oil exploration and production, energy trading and sales, and services associated with the supply of energy, boasts net sales of euro 16,498 m, equal to growth of 10.8% compared with 2003. Infrastructures Branch: this division, which groups together all activities related to the management of transmission and distribution infrastructures in both the French domestic and international markets, generated net sales of euro 6,794 m in 2004, virtually unchanged from the previous year. This situation is the result of higher sales generated by the distribution subsidiaries operating outside France (+9.2%) offset by a decline in the sales performance of the Transmission, Storage and Distribution in France

  19. cDNA cloning of human DNA topoisomerase I. Catalytic activity of a 67.7-kDa carboxyl-terminal fragment

    International Nuclear Information System (INIS)

    D'Arpa, P.; Machlin, P.S.; Ratrie, H. III; Rothfield, N.F.; Cleveland, D.W.; Earnshaw, W.C.

    1988-01-01

    cDNA clones encoding human topoisomerase I were isolated from an expression vector library (λgt11) screened with autoimmune anti-topoisomerase I serum. One of these clones has been expressed as a fusion protein comprised of a 32-kDa fragment of the bacterial TrpE protein linked to 67.7 kDa of protein encoded by the cDNA. Three lines of evidence indicate that the cloned cDNA encodes topoisomerase I. (i) Proteolysis maps of the fusion protein and human nuclear topoisomerase I are essentially identical. (ii) The fusion protein relaxes supercoiled DNA, an activity that can be immunoprecipitated by anti-topoisomerase I serum. (iii) Sequence analysis has revealed that the longest cDNA clone (3645 base pairs) encodes a protein of 765 amino acids that shares 42% identity with Saccharomyces cerevisiae topoisomerase I. The sequence data also show that the catalytically active 67.7-kDa fragment is comprised of the carboxyl terminus

  20. Substituted 2-Acylaminocycloalkylthiophene-3-carboxylic Acid Arylamides as Inhibitors of the Calcium-Activated Chloride Channel Transmembrane Protein 16A (TMEM16A).

    Science.gov (United States)

    Truong, Eric C; Phuan, Puay W; Reggi, Amanda L; Ferrera, Loretta; Galietta, Luis J V; Levy, Sarah E; Moises, Alannah C; Cil, Onur; Diez-Cecilia, Elena; Lee, Sujin; Verkman, Alan S; Anderson, Marc O

    2017-06-08

    Transmembrane protein 16A (TMEM16A), also called anoctamin 1 (ANO1), is a calcium-activated chloride channel expressed widely mammalian cells, including epithelia, vascular smooth muscle tissue, electrically excitable cells, and some tumors. TMEM16A inhibitors have been proposed for treatment of disorders of epithelial fluid and mucus secretion, hypertension, asthma, and possibly cancer. Herein we report, by screening, the discovery of 2-acylaminocycloalkylthiophene-3-carboxylic acid arylamides (AACTs) as inhibitors of TMEM16A and analysis of 48 synthesized analogs (10ab-10bw) of the original AACT compound (10aa). Structure-activity studies indicated the importance of benzene substituted as 2- or 4-methyl, or 4-fluoro, and defined the significance of thiophene substituents and size of the cycloalkylthiophene core. The most potent compound (10bm), which contains an unusual bromodifluoroacetamide at the thiophene 2-position, had IC 50 of ∼30 nM, ∼3.6-fold more potent than the most potent previously reported TMEM16A inhibitor 4 (Ani9), and >10-fold improved metabolic stability. Direct and reversible inhibition of TMEM16A by 10bm was demonstrated by patch-clamp analysis. AACTs may be useful as pharmacological tools to study TMEM16A function and as potential drug development candidates.

  1. 5,10,15,20-Tetrakis(4-carboxyl phenyl)porphyrin–CdS nanocomposites with intrinsic peroxidase-like activity for glucose colorimetric detection

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qingyun, E-mail: qyliu@sdust.edu.cn [School of Chemistry and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266510 (China); Jia, Qingyan; Zhu, Renren; Shao, Qian; Wang, Dongmei; Cui, Peng [School of Chemistry and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266510 (China); Ge, Jiechao, E-mail: jchge2010@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-09-01

    Here, we describe the design of a novel mimic peroxidase, nanocomposites composed by 5,10,15,20-tetrakis(4-carboxyl phenyl)-porphyrin (H{sub 2}TCPP) and cadmium sulfide (CdS). The H{sub 2}TCPP–CdS nanocomposites can catalyze oxidation of substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H{sub 2}O{sub 2} and form a blue product which can be seen by the naked eye in 5 min. The mechanism of the catalytic reaction originated from the generation of hydroxyl radical (·OH), which is a powerful oxidizing agent to oxidize TMB to produce a blue product. Then, we developed a colorimetric method that is highly sensitive and selective to detect glucose, combined with glucose oxidase (GOx). The proposed method allowed the detection of H{sub 2}O{sub 2} concentration in the range of 4 × 10{sup −6}–1.4 × 10{sup −5} M and glucose in the range of 1.875 × 10{sup −5}–1 × 10{sup −4} M with detectable H{sub 2}O{sub 2} concentration as low as 4.6 × 10{sup −7} M and glucose as low as 7.02 × 10{sup −6} M, respectively. The results provided the theoretical basis of practical application in glucose detecting and peroxidase mimetic enzymes. - Graphical abstract: 5,10,15,20-tetrakis(4-carboxyl phenyl)-porphyrin (H{sub 2}TCPP)–CdS nanohybrids were demonstrated to possess intrinsic peroxidase-like activity and used for a glucose colorimetric sensor. - Highlights: • H{sub 2}TCPP–CdS nanocomposites were synthesized by a facile one step under mild condition. • H{sub 2}TCPP–CdS nanocomposites possess excellent intrinsic peroxidase-like activity. • A sensitive and selective colorimetric sensor for glucose is provided based on H{sub 2}TCPP–CdS nanocomposites. • The generation of hydroxyl radical (·OH) decomposed from H{sub 2}O{sub 2} is contributed to efficient catalytic.

  2. Efficient, regioselective ring-opening of activated aziridine-2-carboxylates with [18F]fluoride

    DEFF Research Database (Denmark)

    Schjøth-Eskesen, Christina; Hansen, Paul Robert; Kjær, Andreas

    2015-01-01

    Aziridines can undergo a range of ring-opening reactions with nucleophiles. The regio- and stereochemistry of the products depend on the substituents on the aziridine. Aziridine ring-opening reactions have rarely been used in radiosynthesis. Herein we report the ring opening of activated aziridine...

  3. Atom-Economical Dimerization Strategy by the Rhodium-Catalyzed Addition of Carboxylic Acids to Allenes: Protecting-Group-Free Synthesis of Clavosolide A and Late-Stage Modification.

    Science.gov (United States)

    Haydl, Alexander M; Breit, Bernhard

    2015-12-14

    Natural products of polyketide origin with a high level of symmetry, in particular C2 -symmetric diolides as a special macrolactone-based product class, often possess a broad spectrum of biological activity. An efficient route to this important structural motif was developed as part of a concise and highly convergent synthesis of clavosolide A. This strategy features an atom-economic "head-to-tail" dimerization by the stereoselective rhodium-catalyzed addition of carboxylic acids to terminal allenes with the simultaneous construction of two new stereocenters. The excellent efficiency and selectivity with which the C2 -symmetric core structures were obtained are remarkable considering the outcome under classical dimerization conditions. Furthermore, this approach facilitates late-stage modification and provides ready access to potential new lead structures. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. CatB is Critical for Total Catalase Activity and Reduces Bactericidal Effects of Phenazine-1-Carboxylic Acid on Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola.

    Science.gov (United States)

    Pan, Xiayan; Wu, Jian; Xu, Shu; Duan, Yabing; Zhou, Mingguo

    2017-02-01

    Rice bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae, and rice bacterial leaf streak, caused by X. oryzae pv. oryzicola, are major diseases of rice. Phenazine-1-carboxylic acid (PCA) is a natural product that is isolated from Pseudomonas spp. and is used to control many important rice diseases in China. We previously reported that PCA disturbs the redox balance, which results in the accumulation of reactive oxygen species in X. oryzae pv. oryzae. In this study, we found that PCA significantly upregulated the transcript levels of catB and katE, which encode catalases, and that PCA sensitivity was reduced when X. oryzae pvs. oryzae and oryzicola were cultured with exogenous catalase. Furthermore, catB deletion mutants of X. oryzae pvs. oryzae and oryzicola showed dramatically decreased total catalase activity, increased sensitivity to PCA, and reduced virulence in rice. In contrast, deletion mutants of srpA and katG, which also encode catalases, exhibited little change in PCA sensitivity. The results indicate that catB in both X. oryzae pvs. oryzae and oryzicola encodes a catalase that helps protect the bacteria against PCA-induced stress.

  5. 2-Isopropyl-5-methylcyclohexyl quinoline-2-carboxylate

    Directory of Open Access Journals (Sweden)

    E. Fazal

    2014-01-01

    Full Text Available In the title compound, C20H25NO2, the cyclohexyl ring adopts a slightly disordered chair conformation. The dihedral angle between the mean planes of the quinoline ring and the carboxylate group is 22.2 (6°. In the crystal, weak C—H...N interactions make chains along [010].

  6. Cationic mononuclear ruthenium carboxylates as catalyst prototypes for self-induced hydrogenation of carboxylic acids.

    Science.gov (United States)

    Naruto, Masayuki; Saito, Susumu

    2015-08-28

    Carboxylic acids are ubiquitous in bio-renewable and petrochemical sources of carbon. Hydrogenation of carboxylic acids to yield alcohols produces water as the only byproduct, and thus represents a possible next generation, sustainable method for the production of these alternative energy carriers/platform chemicals on a large scale. Reported herein are molecular insights into cationic mononuclear ruthenium carboxylates ([Ru(OCOR)](+)) as prototypical catalysts for the hydrogenation of carboxylic acids. The substrate-derived coordinated carboxylate was found to function initially as a proton acceptor for the heterolytic cleavage of dihydrogen, and subsequently also as an acceptor for the hydride from [Ru-H](+), which was generated in the first step (self-induced catalysis). The hydrogenation proceeded selectively and at high levels of functional group tolerance, a feature that is challenging to achieve with existing heterogeneous/homogeneous catalyst systems. These fundamental insights are expected to significantly benefit the future development of metal carboxylate-catalysed hydrogenation processes of bio-renewable resources.

  7. Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2'-Bipyridine.

    Science.gov (United States)

    Vasile Scăețeanu, Gina; Chifiriuc, Mariana Carmen; Bleotu, Coralia; Kamerzan, Crina; Măruţescu, Luminiţa; Daniliuc, Constantin G; Maxim, Cătălin; Calu, Larisa; Olar, Rodica; Badea, Mihaela

    2018-01-12

    The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2'-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn₃(2,2'-bipy)₂(C₃H₃O₂)₆] ( 1 ), meanwhile complexes with general formula [M(2,2'-bipy)(C₃H₃O₂)₂(H₂O) x ]∙ y H₂O (( 2 ) M: Ni, x = 1, y = 0; ( 3 ) M: Cu, x = 1, y = 0; ( 4 ) M: Zn, x = 0, y = 1; 2,2'-bipy: 2,2'-bipyridine; C₃H₃O₂: acrylate anion) were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC) of 128 μg mL -1 was recorded for all four tested complexes against Candida albicans , for complex ( 3 ) against Escherichia coli , and for complex ( 4 ) against Staphylocococcus aureus . Compounds ( 3 ) and ( 4 ) were also potent efflux pumps activity inhibitors (EPI), proving their potential for use in synergistic combinations with antibiotics. Complexes ( 1 )-( 4 ) revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

  8. Test Blanket Working Group's recent activities

    International Nuclear Information System (INIS)

    Vetter, J.E.

    2001-01-01

    The ITER Test Blanket Working Group (TBWG) has continued its activities during the period of extension of the EDA with a revised charter on the co-ordination of the development work performed by the Parties and by the JCT leading to a co-ordinated test programme on ITER for a DEMO-relevant tritium breeding blanket. This follows earlier work carried out until July 1998, which formed part of the ITER Final Design Report (FDR), completed in 1998. Whilst the machine parameters for ITER-FEAT have been significantly revised compared to the FDR, testing of breeding blanket modules remains a main objective of the test programme and the development of a reactor-relevant breeding blanket to ensure tritium fuel self-sufficiency is recognized a key issue for fusion. Design work and R and D on breeding blanket concepts, including co-operation with the other Contacting Parties of the ITER-EDA for testing these concepts in ITER, are included in the work plans of the Parties

  9. AER Working Group B activities in 2001

    International Nuclear Information System (INIS)

    Darilek, P.

    2001-01-01

    Review of AER Working Group B Meeting in Czech Republic - Plzen is given. Regular meeting of Core Design Group was organized by SKODA JS, Inc. and held at Plzen-Bolevec, Czech Republic, May 21+22, 2001, together with Working Group A (Authors)

  10. AER Working Group B activities in 2010

    International Nuclear Information System (INIS)

    Darilek, P.

    2010-01-01

    Review of AER Working Group B Meeting in Modra - Harmonia, Slovakia is given. Regular meeting of Core Design Group was organized by VUJE, Inc. and held at Modra - pension Harmonia, Slovakia, April 20-22, 2010, together with Working Group A. Presented papers (see List of papers and List of participants) covered topics as follows. (Author)

  11. Promoting physical activity in socially vulnerable groups

    NARCIS (Netherlands)

    Herens, M.C.

    2016-01-01

    Background: In the Netherlands, inequalities in physical activity behaviour go hand in hand with socioeconomic inequalities in health. To promote physical activity effectively and equitably, participatory community-based physical activity interventions seem promising and are

  12. A novel carboxyl-terminal protease derived from Paenibacillus lautus CHN26 exhibiting high activities at multiple sites of substrates

    DEFF Research Database (Denmark)

    Li, Yunxia; Pan, Yingjie; She, Qunxin

    2013-01-01

    Carboxyl-terminal protease (CtpA) plays essential functions in posttranslational protein processing in prokaryotic and eukaryotic cells. To date, only a few bacterial ctpA genes have been characterized. Here we cloned and characterized a novel CtpA. The encoding gene, ctpAp (ctpA of Paenibacillus...

  13. EDF Group: activity and sustainable development 2010

    International Nuclear Information System (INIS)

    2010-01-01

    After a map illustrating the worldwide dimension of EDF, and an interview of the EDF's chairman, this report presents and comments some sustainable development indicators for EDF activity in 2010. Then, after a presentation of the world energy context, it presents and comments EDF's main activities: energy production and engineering, network management, trading. It presents and comments the operational performance of the company in different countries (France, United Kingdom, Italy, and other countries) and evokes additional activities. The next chapter deals with human resources and with innovation and R and D activities. The last chapter presents governance structures and financial results

  14. Liquid effluent processing group. Activity details 1963

    International Nuclear Information System (INIS)

    1964-08-01

    This report first gives a quantitative overview of volumes of effluents of high activity, medium activity and low activity which passed through the department for effluent processing. It also makes the distinction between the shape or type of container of these effluents. A table indicates their origin and another indicates their destination. The β and α decontamination rates are determined, and the assessment of stored aqueous and organic effluents on the 31 December 1963 is given. The next part proposes an assessment of laboratory activities: control operations (input controls, control of processed effluent before discarding), controls related to processing (processing types, radiochemical and chemical dosing performed on effluent mixes before processing). Tables indicate the characteristics of medium activity effluents collected in 1963, the results of high activity liquid analysis, and Beryllium dosing results. A summary of ALEA processing, a table of the characteristics of stored oils and solvents are given. The third part reports data related to transport activities, and various works performed in the Saclay plant to improve exploitation conditions and results

  15. Modification of polysulfone with pendant carboxylic acid functionality ...

    Indian Academy of Sciences (India)

    polysulfone (PSF) by in situ generated chloromethyl radical in presence of stannic chloride in tetrachloroethane and .... vert the nitrile group to carboxylic acid was reported (Reddy ..... PEG molecular weight vs rejection at 35 psi pressure.

  16. Japan Flavour and Fragrance Materials Association's (JFFMA) safety assessment of food-flavouring substances uniquely used in Japan that belong to the class of aliphatic primary alcohols, aldehydes, carboxylic acids, acetals and esters containing additional oxygenated functional groups.

    Science.gov (United States)

    Saito, Kenji; Hasegawa-Baba, Yasuko; Sekiya, Fumiko; Hayashi, Shim-Mo; Mirokuji, Yoshiharu; Okamura, Hiroyuki; Maruyama, Shinpei; Ono, Atsushi; Nakajima, Madoka; Degawa, Masakuni; Ozawa, Shogo; Shibutani, Makoto; Maitani, Tamio

    2017-09-01

    We performed a safety evaluation using the procedure devised by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) of the following four flavouring substances that belong to the class of 'aliphatic primary alcohols, aldehydes, carboxylic acids, acetals, and esters containing additional oxygenated functional groups' and are uniquely used in Japan: butyl butyrylacetate, ethyl 2-hydroxy-4-methylpentanoate, 3-hydroxyhexanoic acid and methyl hydroxyacetate. Although no genotoxicity study data were found in the published literature, none of the four substances had chemical structural alerts predicting genotoxicity. All four substances were categorised as class I by using Cramer's classification. The estimated daily intake of each of the four substances was determined to be 0.007-2.9 μg/person/day by using the maximised survey-derived intake method and based on the annual production data in Japan in 2001, 2005 and 2010, and was determined to be 0.250-600.0 μg/person/day by using the single-portion exposure technique and based on average-use levels in standard portion sizes of flavoured foods. Both of these estimated daily intake ranges were below the threshold of toxicological concern for class I substances, which is 1800 μg/person/day. Although no information from in vitro and in vivo toxicity studies for the four substances was available, these substances were judged to raise no safety concerns at the current levels of intake.

  17. Mountain Biking with Groups: A "Safe" Activity?

    Science.gov (United States)

    Allen, Terry

    2001-01-01

    A survey mailed to 200 British mountain bike leaders found that rates of cycling accidents and injuries were greater in forests and woodlands than on terrain where a license is required to lead groups of young cyclists. Excessive speed was mentioned in most accidents, coupled with poor use of breaks in many cases. (SV)

  18. Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

    International Nuclear Information System (INIS)

    Elhadi, S. A.

    2004-09-01

    Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, 1 H-and 13 C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

  19. Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Elhadi, S A [Department of Chemistry, Faculty of Education, University of Khartoum, Khartoum (Sudan)

    2004-09-01

    Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, {sup 1}H-and {sup 13}C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

  20. AER Working Group B activities in 2009

    International Nuclear Information System (INIS)

    Darilek, P.

    2009-01-01

    Regular meeting of Core Design Group was organized by SKODA JS a.s. in Plzen (Czech Republic) during the period of 4 to 6 May 2009. There were presented altogether 17 participants from 7 member organizations and 7 presentations were read. Presented papers covered topics as follows: 1) Two presentations dealt with upgrade of calculation and display tools. 2) Three presentations were devoted to benchmark calculations. 3) Two presentations informed about gradual improvement of fuel assembly and cycle for VVER-440 reactors

  1. DOING Physics--Physics Activities for Groups.

    Science.gov (United States)

    Zwicker, Earl, Ed.

    1984-01-01

    Describes an activity in which two pulleys are connected by a wire loop; when the bottom pulley is dipped into hot water, the pulleys rotate. Also suggests that students design/build a machine to propel a bean; the machine must use materials including one bean, two plastic straws, and two rubber bands. (JN)

  2. Carboxylated Polyurethanes Containing Hyperbranched Polyester Soft Segments

    Directory of Open Access Journals (Sweden)

    Žigon, M.

    2006-09-01

    Full Text Available hyperbranched polyester soft segments (HB PU with functional carboxylic groups in order to enable the preparation of stable HB PU dispersions. Carboxylated hyperbranched polyurethanes were synthesized using a hyperbranched polyester based on 2,2-bis(methylolpropionic acid of the fourth pseudo-generation (Boltorn H40 and hexamethylene (HDI or isophorone diisocyanate (IPDI. The reactivity of hyperbranched polyester with HDI was lower than expected, possibly due to the presence of less reactive hydroxyl groups in the linear repeat units. A gel was formed at mole ratios rNCO/OH = 1:2 or 1:4. The synthesis of HB PU was performed with partly esterified hyperbranched polyester with lowered hydroxyl functionality. The carboxyl groups were incorporated in the HB PU backbone by reaction of residual hydroxyl groups with cis-1,2-cyclohexanedicarboxylic anhydride. HB PU aqueous dispersions were stable at least for two months, although their films were brittle. The tensile strength and Young's modulus of blends of linear and HB PU decreased with increasing content of HB PU whereas elongation at break remained nearly constant, which was explained in terms of looser chain packing due to more open tree-like hyperbranched structures.

  3. Activities of covariance utilization working group

    International Nuclear Information System (INIS)

    Tsujimoto, Kazufumi

    2013-01-01

    During the past decade, there has been a interest in the calculational uncertainties induced by nuclear data uncertainties in the neutronics design of advanced nuclear system. The covariance nuclear data is absolutely essential for the uncertainty analysis. In the latest version of JENDL, JENDL-4.0, the covariance data for many nuclides, especially actinide nuclides, was substantialy enhanced. The growing interest in the uncertainty analysis and the covariance data has led to the organisation of the working group for covariance utilization under the JENDL committee. (author)

  4. Individual and group dynamics in purchasing activity

    Science.gov (United States)

    Gao, Lei; Guo, Jin-Li; Fan, Chao; Liu, Xue-Jiao

    2013-01-01

    As a major part of the daily operation in an enterprise, purchasing frequency is in constant change. Recent approaches on the human dynamics can provide some new insights into the economic behavior of companies in the supply chain. This paper captures the attributes of creation times of purchase orders to an individual vendor, as well as to all vendors, and further investigates whether they have some kind of dynamics by applying logarithmic binning to the construction of distribution plots. It’s found that the former displays a power-law distribution with approximate exponent 2.0, while the latter is fitted by a mixture distribution with both power-law and exponential characteristics. Obviously, two distinctive characteristics are presented for the interval time distribution from the perspective of individual dynamics and group dynamics. Actually, this mixing feature can be attributed to the fitting deviations as they are negligible for individual dynamics, but those of different vendors are cumulated and then lead to an exponential factor for group dynamics. To better describe the mechanism generating the heterogeneity of the purchase order assignment process from the objective company to all its vendors, a model driven by product life cycle is introduced, and then the analytical distribution and the simulation result are obtained, which are in good agreement with the empirical data.

  5. Theoretical study of chlordecone and surface groups interaction in an activated carbon model under acidic and neutral conditions.

    Science.gov (United States)

    Gamboa-Carballo, Juan José; Melchor-Rodríguez, Kenia; Hernández-Valdés, Daniel; Enriquez-Victorero, Carlos; Montero-Alejo, Ana Lilian; Gaspard, Sarra; Jáuregui-Haza, Ulises Javier

    2016-04-01

    Activated carbons (ACs) are widely used in the purification of drinking water without almost any knowledge about the adsorption mechanisms of the persistent organic pollutants. Chlordecone (CLD, Kepone) is an organochlorinated synthetic compound that has been used mainly as agricultural insecticide. CLD has been identified and listed as a persistent organic pollutant by the Stockholm Convention. The selection of the best suited AC for this type of contaminants is mainly an empirical and costly process. A theoretical study of the influence of AC surface groups (SGs) on CLD adsorption is done in order to help understanding the process. This may provide a first selection criteria for the preparation of AC with suitable surface properties. A model of AC consisting of a seven membered ring graphene sheet (coronene) with a functional group on the edge was used to evaluate the influence of the SGs over the adsorption. Multiple Minima Hypersurface methodology (MMH) coupled with PM7 semiempirical Hamiltonian was employed in order to study the interactions of the chlordecone with SGs (hydroxyl and carboxyl) at acidic and neutral pH and different hydration conditions. Selected structures were re-optimized using CAM-B3LYP to achieve a well-defined electron density to characterize the interactions by the Quantum Theory of Atoms in Molecules approach. The deprotonated form of surface carboxyl and hydroxyl groups of AC models show the strongest interactions, suggesting a chemical adsorption. An increase in carboxylic SGs content is proposed to enhance CLD adsorption onto AC at neutral pH conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Kinetic analysis of the reactivity of aliphatic cyclic alcohols and carboxylic acids in the T-for-H exchange reaction

    International Nuclear Information System (INIS)

    Tamura, Kiyoshi; Imaizumi, Hiroshi; Kano, Naoki

    2007-01-01

    In order to quantitatively evaluate the influence of tritium ( 3 He or T) on various functional groups in environment, the hydrogen isotope exchange reaction (T-for-H exchange reaction) between tritium-labeled poly-(vinyl alcohol) and each aliphatic cyclic alcohol (or carboxylic acid) has been dynamically observed in the range of 50 to 90degC. Consequently, the activities of the aliphatic cyclic alcohol and carboxylic acid increased with increasing reaction time. Applying in A''-McKay plot method to the observed data, the rate constants (k) for these materials were obtained. Using the k, the relation between the number of carbon atoms in the ring in each alcohol and the reactivity of the alcohol was quantitatively compared. Then, to clarify the effect of relative atomic charge of O atom (connected with the H atom in the hydroxy (or carboxy) group in the material) on the reactivity of the material, the MOPAC method was used. From both the above-mentioned and the obtained previously, the following nine items were found as to aliphatic cyclic alcohols (and carboxylic acids) in the T-for-H exchange reaction. (1) The reactivity of aliphatic cyclic alcohols (and carboxylic acids) depends on the temperature. (2) The reactivity of the cyclic materials decreases with increasing number of carbon atoms in the ring. (3) The reactivity of the aliphatic cyclic carboxylic acid seems to be smaller than that of aliphatic cyclic alcohol, and be larger than that of aliphatic cyclic amine. (4) For aliphatic cyclic alcohols, correlation exists between k and relative atomic charges of O atom obtained by the MOPAC method, but the tendency for aliphatic cyclic carboxylic acid is not clear. (5) As to having the same number of carbon atoms in each ring, the reactivity of the aliphatic cyclic carboxylic acid including the side chain is smaller than of the aliphatic cyclic carboxylic acid including no side chain. (6) The reactivity of aliphatic cyclic carboxylic acid is larger than that of

  7. Theoretical study of γ-hexachlorocyclohexane and β-hexachlorocyclohexane isomers interaction with surface groups of activated carbon model.

    Science.gov (United States)

    Enriquez-Victorero, Carlos; Hernández-Valdés, Daniel; Montero-Alejo, Ana Lilian; Durimel, Axelle; Gaspard, Sarra; Jáuregui-Haza, Ulises

    2014-06-01

    Activated carbon (AC) is employed in drinking water purification without almost any knowledge about the adsorption mechanism of persistent organic pollutants (POPs) onto it. Hexachlorocyclohexane (HCH) is an organochlorinated contaminant present in water and soils of banana crops production zones of the Caribbean. The most relevant isomers of HCH are γ-HCH and β-HCH, both with great environmental persistence. A theoretical study of the influence of AC surface groups (SGs) on HCH adsorption is done in order to help to understand the process and may lead to improve the AC selection process. A simplified AC model consisting of naphthalene with a functional group was used to assess the influence of SGs over the adsorption process. The Multiple Minima Hypersurface (MMH) methodology was employed to study γ-HCH and β-HCH interactions with different AC SGs (hydroxyl and carboxyl) under different hydration and pH conditions. The results obtained showed that association of HCH with SGs preferentially occurs between the axial protons of HCH and SG's oxygen atom, and the most favorable interactions occurring with charged SGs. An increase in carboxylic SGs content is proposed to enhance HCH adsorption onto AC under neutral pH conditions. Finally, this work presents an inexpensive computer aided methodology for preselecting activated carbon SGs content for the removal of a given compound. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Applied nuclear physics group - activities report. 1977-1997

    International Nuclear Information System (INIS)

    Appoloni, Carlos Roberto

    1998-06-01

    This report presents the activities conducted by the Applied Nuclear Physics group of the Londrina State University - Applied Nuclear Physics Laboratory - Brazil, from the activities beginning (1977) up to the end of the year 1997

  9. On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

    Energy Technology Data Exchange (ETDEWEB)

    Navarrete-Encina, Patricio A.; Vega-Retter, Christian, E-mail: pnavarre@vtr.ne [Universidad de Chile, Santiago (Chile). Facultad de Ciencias Quimicas y Farmaceuticas. Lab. de Sintesis Organica y Fisicoquimica; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J. [Universidad de Chile, Santiago (Chile). Fac. de Ciencias Quimicas y Farmaceuticas. Lab. de Bioelectroquimica

    2010-07-01

    Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

  10. On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

    International Nuclear Information System (INIS)

    Navarrete-Encina, Patricio A.; Vega-Retter, Christian; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J.

    2010-01-01

    Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

  11. Group-Based Active Learning of Classification Models.

    Science.gov (United States)

    Luo, Zhipeng; Hauskrecht, Milos

    2017-05-01

    Learning of classification models from real-world data often requires additional human expert effort to annotate the data. However, this process can be rather costly and finding ways of reducing the human annotation effort is critical for this task. The objective of this paper is to develop and study new ways of providing human feedback for efficient learning of classification models by labeling groups of examples. Briefly, unlike traditional active learning methods that seek feedback on individual examples, we develop a new group-based active learning framework that solicits label information on groups of multiple examples. In order to describe groups in a user-friendly way, conjunctive patterns are used to compactly represent groups. Our empirical study on 12 UCI data sets demonstrates the advantages and superiority of our approach over both classic instance-based active learning work, as well as existing group-based active-learning methods.

  12. Teaching Group Interdependence: A Campus Murder Mystery Activity

    Science.gov (United States)

    Minei, Elizabeth M.; Shearer Dunn, Karen

    2017-01-01

    Courses: Introduction to Communication; small group; interpersonal. Objectives: This single activity demonstrates: (1) how interdependence can lead to better group outcomes than individual outcomes can; (2) how diversity of knowledge from multiple contributors helps group functioning; and (3) how students can be introduced to members of the…

  13. A high-throughput screen against pantothenate synthetase (PanC identifies 3-biphenyl-4-cyanopyrrole-2-carboxylic acids as a new class of inhibitor with activity against Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Anuradha Kumar

    Full Text Available The enzyme pantothenate synthetase, PanC, is an attractive drug target in Mycobacterium tuberculosis. It is essential for the in vitro growth of M. tuberculosis and for survival of the bacteria in the mouse model of infection. PanC is absent from mammals. We developed an enzyme-based assay to identify inhibitors of PanC, optimized it for high-throughput screening, and tested a large and diverse library of compounds for activity. Two compounds belonging to the same chemical class of 3-biphenyl-4- cyanopyrrole-2-carboxylic acids had activity against the purified recombinant protein, and also inhibited growth of live M. tuberculosis in manner consistent with PanC inhibition. Thus we have identified a new class of PanC inhibitors with whole cell activity that can be further developed.

  14. A high-throughput screen against pantothenate synthetase (PanC) identifies 3-biphenyl-4-cyanopyrrole-2-carboxylic acids as a new class of inhibitor with activity against Mycobacterium tuberculosis.

    Science.gov (United States)

    Kumar, Anuradha; Casey, Allen; Odingo, Joshua; Kesicki, Edward A; Abrahams, Garth; Vieth, Michal; Masquelin, Thierry; Mizrahi, Valerie; Hipskind, Philip A; Sherman, David R; Parish, Tanya

    2013-01-01

    The enzyme pantothenate synthetase, PanC, is an attractive drug target in Mycobacterium tuberculosis. It is essential for the in vitro growth of M. tuberculosis and for survival of the bacteria in the mouse model of infection. PanC is absent from mammals. We developed an enzyme-based assay to identify inhibitors of PanC, optimized it for high-throughput screening, and tested a large and diverse library of compounds for activity. Two compounds belonging to the same chemical class of 3-biphenyl-4- cyanopyrrole-2-carboxylic acids had activity against the purified recombinant protein, and also inhibited growth of live M. tuberculosis in manner consistent with PanC inhibition. Thus we have identified a new class of PanC inhibitors with whole cell activity that can be further developed.

  15. Synthesis, crystal structure, DFT studies, acid dissociation constant, and antimicrobial activity of methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate

    Science.gov (United States)

    Nural, Yahya; Gemili, Muge; Seferoglu, Nurgul; Sahin, Ertan; Ulger, Mahmut; Sari, Hayati

    2018-05-01

    A novel bicyclic thiohydantoin fused to pyrrolidine compound, methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate, was synthesized by the cyclization reaction of dimethyl 5,5-diphenylpyrrolidine-2,4-dicarboxylate and 4-chlorophenyl isothiocyanate in the presence of 4-(dimethylamino)pyridine to form methyl 2-(4-chlorophenyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate with concomitant addition reaction of the 4-chlorophenyl isothiocyanate in 79% yield. The structural characterization was performed by NMR, FT-IR, MS and HRMS techniques, and the stereochemistry of the compound was determined by single crystal X-ray diffraction study. In addition, the molecular structure and 1H and 13C NMR chemical shifts of the compound were obtained with the density functional theory and Hartree-Fock calculations. Acid dissociation constants of the compound were determined using potentiometric titration method in 25% (v/v) dimethyl sulfoxide-water hydroorganic solvent at 25 ± 0.1 °C, at an ionic background of 0.1 mol/L of NaCl using the HYPERQUAD computer program. Four acid dissociation constants were obtained for the compound, and we suggest that these acid dissociation constants are related to the NH, for two groups of enthiols and enol groups. Antimicrobial activity study was performed against S. aureus, B. subtilis, A. hydrophila, E. coli and A. baumannii as bacterial standard strains, and against M. tuberculosis H37Rv as mycobacterial strain. The compound exhibited antibacterial activity in the range of 31.25-62.5 μg/mL, and antimycobacterial activity with a MIC value of 40 μg/mL against the indicated strains.

  16. ETSON strategic orientations on research activities. ETSON research group activity

    Energy Technology Data Exchange (ETDEWEB)

    Van Dorseelaere, J.P.; Barrachin, M. [IRSN, Saint Paul les Durance (France). Centre de Cadarache; Millington, D. [Wood RSD, Warrington (United Kingdom); and others

    2018-01-15

    In 2011, ETSON published the ''Position Paper of the Technical Safety Organizations: Research Needs in Nuclear Safety for Gen 2 and Gen 3 NPPs''. This paper, published only a few months after the Fukushima-Daiichi severe accidents, presented the priorities for R and D on the main pending safety issues. It was produced by the ETSON Research Group (ERG) that has the mandate of identifying and prioritizing safety research needs, sharing information on research projects in which ETSON members are involved, defining and launching new research projects and disseminating knowledge among ETSON members. Six years after this publication, many R and D international projects finished in diverse frames, and other ones have started. In particular a lot of work was done (and is going on..) on the analysis of the Fukushima-Daiichi severe accidents. Meanwhile a roadmap on research on Gen. 2 and 3 nuclear power plants (NPP), including safety aspects, was produced by the NUGENIA association, followed by a more detailed document as ''NUGENIA global vision''. It was also demonstrated that the ETSON R and D priorities were consistent with the implementation of the 2014 Euratom Directive on safety of nuclear installations.

  17. Methyl (Sp-2-(diphenylphosphinoferrocene-1-carboxylate

    Directory of Open Access Journals (Sweden)

    Petr Štěpnička

    2009-10-01

    Full Text Available The title compound, [Fe(C5H5(C19H16O2P], obtained serendipitously during recrystallization of 1-hydroxybenzotriazolyl (Sp-2-(diphenylphosphinoferrocene-1-carboxylate from methanol, crystallizes in the chiral space group P212121. Its crystal structure not only confirms the anticipated absolute configuration but also establishes a rather regular geometry for the ferrocene unit, devoid of any significant deformation due to the attached substituents. In the crystal, symmetry-related molecules are linked via weak C—H...O interactions.

  18. Sustainable Transportation Systems Research Group: Ongoing and Past Activities

    OpenAIRE

    Gkritza, Konstantina "Nadia"; Hurtado, Davis Chacon; Gkartzonikas, Christos; Ke, Yue; Losada, Lisa L

    2017-01-01

    This presentation describes the ongoing and past activities of the Sustainable Transportation Systems Research (STSR) group at Purdue University (https://engineering.purdue.edu/STSRG). The STSR group aims to achieve green, safe, efficient, and equitable transportation systems by studying and modeling transportation externalities, using state of the art statistical, econometric, and economic analysis tools.

  19. Controlled Electrochemical Carboxylation of Graphene To Create a Versatile Chemical Platform for Further Functionalization

    DEFF Research Database (Denmark)

    Bjerglund Pedersen, Emil; Kongsfelt, Mikkel; Shimizu, Kyoko

    2014-01-01

    An electrochemical approach is introduced for the versatile carboxylation of multi-layered graphene in 0.1 M Bu4NBF4/MeCN. First, the graphene substrate (i.e., graphene chemically vapor-deposited on Ni) is negatively charged at -1.9 V versus Ag/AgI in a degassed solution to allow for intercalation...... of Bu4N+ and, thereby, separation of the individual graphene sheets. In the next step, the strongly activated and nucleophilic graphene is allowed to react with added carbon dioxide in an addition reaction, introducing carboxylate groups stabilized by Bu4N+ already present. This procedure may be carried...... solution at the graphene electrode for a given time. The same functionalization degree is obtained for all multi-layered regions, independent of the number of graphene sheets, which is due to the fact that the entire graphene structure is opened in response to the intercalation of Bu4N+. Hence...

  20. Applying an Activity System to Online Collaborative Group Work Analysis

    Science.gov (United States)

    Choi, Hyungshin; Kang, Myunghee

    2010-01-01

    This study determines whether an activity system provides a systematic framework to analyse collaborative group work. Using an activity system as a unit of analysis, the research examined learner behaviours, conflicting factors and facilitating factors while students engaged in collaborative work via asynchronous computer-mediated communication.…

  1. Problem-Based Group Activities for Teaching Sensation and Perception

    Science.gov (United States)

    Kreiner, David S.

    2009-01-01

    This article describes 14 problem-based group activities for a sensation and perception course. The intent was to provide opportunities for students to practice applying their knowledge to real-world problems related to course content. Student ratings of how effectively the activities helped them learn were variable but relatively high. Students…

  2. Blood-group-Ii-active gangliosides of human erythrocyte membranes

    International Nuclear Information System (INIS)

    Feizi, T.; Childs, R.A.; Hakomori, S.-I.; Powell, M.E.

    1978-01-01

    More than ten new types of gangliosides, in addition to haematoside and sialosylparagloboside, were isolated from human erythrocyte membranes. These were separated by successive chromatographies on DAEA-Sephadex, on porous silica-gel columns and on thin-layer silica gel as acetylated compounds. Highly potent blood-group-Ii and moderate blood-group-H activities were demonstrated in some of the ganglioside fractions. The gangliosides incorporated into chlolesterol/phosphatidylcholine liposomes stoicheiometrically inhibited binding of anti-(blood-group-I and i) antibodies to a radioiodinated blood-group-Ii-active glycoprotein. The fraction with the highest blood-group-I activity, I(g) fraction, behaved like sialosyl-deca- to dodeca-glycosylceramides on t.l.c. Certain blood-group-I and most of the i-determinants were in partially or completely cryptic form and could be unmasked by sialidase treatment. Thus the I and i antigens, which are known to occur on internal structures of blood-group-ABH-active glycoproteins in secretions, also occur in the interior of the carbohydrate chains of erythrocyte gangliosides. (author)

  3. Hidden Markov models for the activity profile of terrorist groups

    OpenAIRE

    Raghavan, Vasanthan; Galstyan, Aram; Tartakovsky, Alexander G.

    2012-01-01

    The main focus of this work is on developing models for the activity profile of a terrorist group, detecting sudden spurts and downfalls in this profile, and, in general, tracking it over a period of time. Toward this goal, a $d$-state hidden Markov model (HMM) that captures the latent states underlying the dynamics of the group and thus its activity profile is developed. The simplest setting of $d=2$ corresponds to the case where the dynamics are coarsely quantized as Active and Inactive, re...

  4. Discriminative latent models for recognizing contextual group activities.

    Science.gov (United States)

    Lan, Tian; Wang, Yang; Yang, Weilong; Robinovitch, Stephen N; Mori, Greg

    2012-08-01

    In this paper, we go beyond recognizing the actions of individuals and focus on group activities. This is motivated from the observation that human actions are rarely performed in isolation; the contextual information of what other people in the scene are doing provides a useful cue for understanding high-level activities. We propose a novel framework for recognizing group activities which jointly captures the group activity, the individual person actions, and the interactions among them. Two types of contextual information, group-person interaction and person-person interaction, are explored in a latent variable framework. In particular, we propose three different approaches to model the person-person interaction. One approach is to explore the structures of person-person interaction. Differently from most of the previous latent structured models, which assume a predefined structure for the hidden layer, e.g., a tree structure, we treat the structure of the hidden layer as a latent variable and implicitly infer it during learning and inference. The second approach explores person-person interaction in the feature level. We introduce a new feature representation called the action context (AC) descriptor. The AC descriptor encodes information about not only the action of an individual person in the video, but also the behavior of other people nearby. The third approach combines the above two. Our experimental results demonstrate the benefit of using contextual information for disambiguating group activities.

  5. Activity report of the Neutrino Research Group. Year 2006

    International Nuclear Information System (INIS)

    2007-01-01

    For the last two decades, neutrino physics has been producing major discoveries including neutrino oscillations. These results gave clear confirmation that active neutrinos oscillate and therefore have mass with three different mass states. This is a very important result showing that the Minimal Standard Model is incomplete and requires an extension which is not yet known. The neutrino research field is very broad and active, at the frontier of today's particle physics. The Neutrino Research Group (GDR) was created in January 2005 with the aim of gathering CEA and CNRS research teams working on Neutrino Physics on experimental or theoretical level. This document is the 2006 activity report of the research group, two years after its creation. It presents the results of the 5 working groups: 1 - Determination of neutrino parameters; 2 - Physics beyond the standard model; 3 - Neutrinos in the universe; 4 - Accelerators, detection means, R and D and valorisation; 5 - Common tools to all working groups. The proposed neutrino physics road-map and the actual and future short-, medium- and long-term projects are presented in appendixes. The Neutrino research group organization, the Memphys specific mission group, the research group participating laboratories and teams, as well as the Memphys project are presented too

  6. Background and future activities of PBNCC's nuclear training working group

    International Nuclear Information System (INIS)

    Chong Hun Rieh; Kunmo Chung; Hamlin, K.W.

    1987-01-01

    This paper presents a review of the background and activities of the nuclear training working group of the Pacific Basin Nuclear Cooperation Committee. The working group has examined various mechanisms for regional cooperation including the development of aregional catalog of training programs and the conceptualization of sharing training facilities among nuclear operators in the region. The working group has focused its attention on the exchange of information on the on-going training programs, operator training facilities, available resources for training assistance and proposed cooperative schemes. These activities are expected to continue and will provide invaluable information for nuclear power programs in the Pacific Basin region. The group also reviewed problems and issues associated with developing regional cooperation. (author)

  7. Background and future activities of PBNCC's nuclear training working group

    International Nuclear Information System (INIS)

    Rieh, C.H.; Chung, K.; Hamlin, K.W.

    1988-01-01

    This paper presents a review of the background and activities of the nuclear training working group of the Pacific Basin Nuclear Cooperation Committee. The working group has examined various mechanisms for regional cooperation including the development of a regional catalog of training programs and the conceptualization of sharing training facilities among nuclear operators in the region. The working group has focused its attention on the exchange of information on the on-going training programs, operator training facilities, available resources for training assistance and proposed cooperative schemes. These activities are expected to continue and will provide invaluable information for nuclear power programs in the Pacific Basin region. The group also reviewed problems and issues associated with developing regional cooperation

  8. Variation in the activities of late stage filaggrin processing enzymes, calpain-1 and bleomycin hydrolase, together with pyrrolidone carboxylic acid levels, corneocyte phenotypes and plasmin activities in non-sun-exposed and sun-exposed facial stratum corneum of different ethnicities.

    Science.gov (United States)

    Raj, N; Voegeli, R; Rawlings, A V; Summers, B; Munday, M R; Lane, M E

    2016-12-01

    Knowledge of the ethnic differences and effects of photodamage on the relative amounts of natural moisturizing factor (NMF) together with filaggrin processing enzymes in facial stratum corneum is limited. Our aim was to characterize the activities of calpain-1 (C-1), bleomycin hydrolase (BH) and the levels of pyrrolidone carboxylic acid (PCA) as a marker for total NMF levels and to relate them to plasmin activities and corneocyte maturation. Enzyme activities, PCA levels and corneocyte maturation were determined from facial tape strippings of photoexposed cheek and photoprotected post-auricular areas (PA) of healthy Caucasian (C), Black African (BA) and albino African (AA) female subjects living in South Africa. PCA concentration levels were of the order AA > BA > C subjects, and the highest activities of BH were present in the AA subjects. BH activities were greater on the photoexposed sites for the BA and C subjects, but they were only numerically elevated in the AA subjects. Photoprotected sites had an increase in C-1 activity in pigmented groups (C and BA), whereas in the AA subjects, the opposite was measured. Plasmin activities were greater on the cheek compared with the PA site for the AA and C subjects, but the activity was low in the BA subjects. In both test sites, the AA, but not the BA and C subjects, had smaller, parakeratotic and less mature corneocytes. Variation in PCA levels has been found for different ethnic groups in this study (AA > BA > C subjects). The values in the AA subjects are surprising as one might expect that the lack of pigmentation, and thereby increased photodamage, might lead to lower levels. Increased BH, but not C-1 activity, was observed in the AA subjects indicating that BH is associated with PCA production to a greater extent. Surprisingly, corneocyte maturation is still impaired with elevated PCA levels in AA subjects. The higher levels of plasmin and BH activities on the cheeks, especially for AA and C subjects, suggest

  9. 2017 Military Services Gender Relations Focus Groups: Active Duty

    Science.gov (United States)

    2018-04-30

    Office of People Analytics Office of People Analytics (OPA) Defense Research, Surveys, and Statistics Center 4800 Mark Center Drive, Suite 06E22...Relations (2017 MSGR) Focus Groups among active duty members. This is the third6 administration of gender relations focus groups. This introductory ...Enlisted, Male “It is true statistically , a majority of sexual assaults there is alcohol or drugs. In the military, it’s into the alcohol more than

  10. Synthesis and study of dioxouranium (6) carboxylate complexes with ammonia

    International Nuclear Information System (INIS)

    Spitsyn, V.I.; Mazo, G.N.; Dunaev, K.M.; Santalova, N.A.

    1980-01-01

    Heterophase synthesis of a series of ammonia complexes of dioxouranium (6) carboxylates namely, UO 2 (HCOO) 2 x2NH 3 , UO 2 (CH 3 COO) 2 x2NH 3 , UO 2 (CH 3 CH 2 OO) 2 x2NH 3 is presented and their properties and structure are studied. Comparison of infrared spectra of dioxouranium (6) carboxylates and their ammonia complexes has shown that NH 3 molecule introduction changes in principle the coordination of azidoligand turning out bridge carboxylate groups into island ones and weakening their bonds with central cations. In spectra of all diammiacates the shift of bands of deformational and valent oscillations of N-H bond in comparison with spectrum of pure ammonia tells about NH 3 coordination with metal. Complexes thermolysis has been studied under iso- and polythermal conditions. General diagram of thermal decay is presented [ru

  11. Non-routine activities in RP Group in 1998

    International Nuclear Information System (INIS)

    Hoefert, M.; Foerkel-Wirth, D.; Otto, T.; Silari, M.; Stevenson, G.R.

    1999-01-01

    This chapter describes activities not directly concerned with the daily routine. These activities are nevertheless an important part of the Group's work as they encompass new projects and developments that require, in most cases, profound studies to prove their feasibility with respect to the radiation protection issues involved. In addition, there are technical and organizational developments in a quest not only to keep the standard of radiation protection at CERN high, but to ensure its constant improvement. All these activities are documented in Divisional Reports, Internal Reports and Technical Memoranda, and are listed in the tables of this chapter

  12. Neutrino Research Group. 2011-2014 activity report

    International Nuclear Information System (INIS)

    2014-01-01

    For the last two decades, neutrino physics has been producing major discoveries including neutrino oscillations. These results gave clear confirmation that active neutrinos oscillate and therefore have mass with three different mass states. This is a very important result showing that the Minimal Standard Model is incomplete and requires an extension which is not yet known. The neutrino research field is very broad and active, at the frontier of today's particle physics. The Neutrino Research Group (GDR) was created in January 2005 with the aim of gathering CEA and CNRS research teams working on Neutrino Physics on experimental or theoretical level. This document is the 2011-2014 activity report of the research group, ten years after its creation. It presents the results of the 5 working groups: 1 - Determination of neutrino parameters; 2 - Physics beyond the standard model; 3 - Neutrinos in the universe; 4 - Accelerators, detection means, R and D and valorisation; 5 - Common tools to all working groups. The research group structure, participating laboratories and teams and the neutrino physics road-map are presented in appendixes

  13. Teacher educators' design and implementation of group learning activities

    NARCIS (Netherlands)

    De Hei, Miranda S.A.; Sjoer, Ellen; Admiraal, Wilfried; Strijbos, J.W.

    2016-01-01

    Group Learning Activities (GLAs) are a key ingredient of course designs in higher education. Various approaches for designing GLAs have been developed, featuring different design components. However, this has not yet resulted in clear guidelines for teachers on how to design GLAs. The purpose of

  14. The Impact of Militancy and Cult Groups' Activities on Rundele ...

    African Journals Online (AJOL)

    The study adopted expectancy theory as its theoretical framework of analysis, emphasizing that the cult groups and militants were motivated in their activities due to the expected rewards from their actions. The findings showed that Rundele as one of the communities in the Niger Delta region had intensive militants' and cult ...

  15. Kinetics study of thermal decomposition of calcium carboxylate salts

    International Nuclear Information System (INIS)

    Landoll, Michael P.; Holtzapple, Mark T.

    2013-01-01

    The MixAlco™ process ferments lignocellulosic biomass to carboxylate salts that are thermally decomposed into ketones, which are then chemically converted to a wide variety of chemicals and fuels. To perform these decompositions, suitable reaction models are necessary to properly design, scale, and optimize commercial reactors. For three salt types (calcium acetate, and two types of mixed calcium carboxylate salts), activation energy was determined using three isoconversional methods that employed TGA curves at different heating rates. For all three salt types, activation energy varied significantly with conversion. The average activation energy for calcium acetate was 556.75 kJ mol −1 , and the activation energies for the two mixed calcium carboxylate salts were 232.87, and 176.55 kJ mol −1 . In addition, three functions of conversion were employed to see which one best modeled the experimental data. The Sestak–Berggren model provides the best universal fit for all three salt types. -- Highlights: •Calcium carboxylate salts from fermentation broth thermally decompose to ketones. •Activation energy varies with conversion for all three salt types. •Sestak–Berggren model provides best fit overall for all three salt types

  16. Kinetics study of thermal decomposition of sodium carboxylate salts

    International Nuclear Information System (INIS)

    Landoll, Michael P.; Holtzapple, Mark T.

    2012-01-01

    The MixAlco™ process ferments lignocellulosic biomass to carboxylate salts that are thermally decomposed into ketones, which are then chemically converted to a wide variety of chemicals and fuels. To perform these decompositions, suitable reaction models are necessary to properly design, scale, and optimize commercial reactors. For three salt types (sodium acetate, and two types of mixed sodium carboxylate salts), activation energy was determined using three isoconversional methods that employed TGA curves at different heating rates. For all three salt types, activation energy varied significantly with conversion. The average activation energy for sodium acetate was 226.65 kJ/mol, and the activation energies for the two mixed sodium carboxylate salts were 195.61, and 218.18 kJ/mol. In addition, three functions of conversion were employed to see which one best modeled the experimental data. The Sestak-Berggren model fits all three salt types best. -- Highlights: ► Sodium carboxylate salts from fermentation broth thermally decompose to ketones. ► Activation energy varies with conversion for all three salt types. ► Sestak-Berggren model provides best fit for all three salt types.

  17. Learners’ views about cloud computing-based group activities

    Directory of Open Access Journals (Sweden)

    Yildirim Serkan

    2017-01-01

    Full Text Available Thanks to its use independently of time and place during the process of software development and by making it easier to access to information with mobile technologies, cloud based environments attracted the attention of education world and this technology started to be used in various activities. In this study, for programming education, the effects of extracurricular group assignments in cloud based environments on learners were evaluated in terms of group work satisfaction, ease of use and user satisfaction. Within the scope of computer programming education lasting eight weeks, a total of 100 students participated in the study including 34 men and 66 women. Participants were divided into groups of at least three people considering the advantages of cooperative learning in programming education. In this study carried out in both conventional and cloud based environments, between groups factorial design was used as research design. The data collected by questionnaires of opinions of group work were examined with quantitative analysis method. According to the study results extracurricular learning activities as group activity created satisfaction. However, perceptions of easy use of the environment and user satisfaction were partly positive. Despite the similar understandings; male participants were easier to perceive use of cloud computing based environments. Some variables such as class level, satisfaction, computer and internet usage time do not have any effect on satisfaction and perceptions of ease of use. Evening class students stated that they found it easy to use cloud based learning environments and became more satisfied with using these environments besides being happier with group work than daytime students.

  18. Protein kinase C activation decreases cell surface expression of the GLT-1 subtype of glutamate transporter. Requirement of a carboxyl-terminal domain and partial dependence on serine 486.

    Science.gov (United States)

    Kalandadze, Avtandil; Wu, Ying; Robinson, Michael B

    2002-11-29

    Na(+)-dependent glutamate transporters are required for the clearance of extracellular glutamate and influence both physiological and pathological effects of this excitatory amino acid. In the present study, the effects of a protein kinase C (PKC) activator on the cell surface expression and activity of the GLT-1 subtype of glutamate transporter were examined in two model systems, primary co-cultures of neurons and astrocytes that endogenously express GLT-1 and C6 glioma cells transfected with GLT-1. In both systems, activation of PKC with phorbol ester caused a decrease in GLT-1 cell surface expression. This effect is opposite to the one observed for the EAAC1 subtype of glutamate transporter (Davis, K. E., Straff, D. J., Weinstein, E. A., Bannerman, P. G., Correale, D. M., Rothstein, J. D., and Robinson, M. B. (1998) J. Neurosci. 18, 2475-2485). Several recombinant chimeric proteins between GLT-1 and EAAC1 transporter subtypes were generated to identify domains required for the subtype-specific redistribution of GLT-1. We identified a carboxyl-terminal domain consisting of 43 amino acids (amino acids 475-517) that is required for PKC-induced GLT-1 redistribution. Mutation of a non-conserved serine residue at position 486 partially attenuated but did not completely abolish the PKC-dependent redistribution of GLT-1. Although we observed a phorbol ester-dependent incorporation of (32)P into immunoprecipitable GLT-1, mutation of serine 486 did not reduce this signal. We also found that chimeras containing the first 446 amino acids of GLT-1 were not functional unless amino acids 475-517 of GLT-1 were also present. These non-functional transporters were not as efficiently expressed on the cell surface and migrated to a smaller molecular weight, suggesting that a subtype-specific interaction is required for the formation of functional transporters. These studies demonstrate a novel effect of PKC on GLT-1 activity and define a unique carboxyl-terminal domain as an

  19. Standardization activities of the Euratom Neutron Radiography Working Group

    International Nuclear Information System (INIS)

    Domanus, J.

    1982-06-01

    In 1979 a working group on neutron radiography was formed at Euratom. The purpose of this group is the standardization of neutron radiographic methods in the field of nuclear fuel. Activities of this Neutron Radiography Working Group are revised. Classification of defects revealed by neutron radiography is illustrated in a special atlas. Beam purity and sensitivity indicators are tested together with a special calibration fuel pin. All the Euratom neutron radiography centers will perform comparative neutron radiography with those items. The measuring results obtained, using various measuring aparatus will form the basis to formulate conclusions about the best measuring methods and instruments to be used in that field. Besides the atlas of neutron radiographic findings in light water reactor fuel, the Euratom Neutron Radiogrphy Working Group has published a neutron radiography handbook in which the neutron radiography installations in the European Community are also described. (author)

  20. Approaching an experimental electron density model of the biologically active trans -epoxysuccinyl amide group-Substituent effects vs. crystal packing

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Ming W.; Stewart, Scott G.; Sobolev, Alexandre N.; Dittrich, Birger; Schirmeister, Tanja; Luger, Peter; Hesse, Malte; Chen, Yu-Sheng; Spackman, Peter R.; Spackman, Mark A.; Grabowsky, Simon (Heinrich-Heine); (Freie); (UC); (Bremen); (JG-UM); (UWA)

    2017-01-24

    The trans-epoxysuccinyl amide group as a biologically active moiety in cysteine protease inhibitors such as loxistatin acid E64c has been used as a benchmark system for theoretical studies of environmental effects on the electron density of small active ingredients in relation to their biological activity. Here, the synthesis and the electronic properties of the smallest possible active site model compound are reported to close the gap between the unknown experimental electron density of trans-epoxysuccinyl amides and the well-known function of related drugs. Intramolecular substituent effects are separated from intermolecular crystal packing effects on the electron density, which allows us to predict the conditions under which an experimental electron density investigation on trans-epoxysuccinyl amides will be possible. In this context, the special importance of the carboxylic acid function in the model compound for both crystal packing and biological activity is revealed through the novel tool of model energy analysis.

  1. Rapid and selective derivatizatin method for the nitrogen-sensitive detection of carboxylic acids in biological fluids prior to gas chromatographic analysis

    NARCIS (Netherlands)

    Lingeman, H.; Haan, H.B.P.; Hulshoff, A.

    1984-01-01

    A rapid and selective derivatization procedure is described for the pre-column labelling of carboxylic acids with a nitrogen-containing label. The carboxylic acid function is activated with 2-bromo-1-methylpyridinium iodide and the activated carboxylic acid function reacts with a primary or a

  2. COSPAR/PRBEM international working group activities report

    Science.gov (United States)

    Bourdarie, S.; Blake, B.; Cao, J. B.; Friedel, R.; Miyoshi, Y.; Panasyuk, M.; Underwood, C.

    It is now clear to everybody that the current standard AE8 AP8 model for ionising particle specification in the radiation belts must be updated But such an objective is quite difficult to reach just as a reminder to develop AE8 AP8 model in the seventies was 10 persons full time for ten years It is clear that world-wide efforts must be combined because not any individual group has the human resource to perform these new models by themselves Under COSPAR umbrella an international group of expert well distributed around the world has been created to set up a common framework for everybody involved in this field Planned activities of the international group of experts are to - Define users needs - Provide guidelines for standard file format for ionising measurements - Set up guidelines to process in-situ data on a common basis - Decide in which form the new models will have to be - Centralise all progress done world-wide to advise the community - Try to organise world-wide activities as a project to ensure complementarities and more efficiencies between all efforts done Activities of this working group since its creation will be reported as well as future plans

  3. Activity report of the Neutrino Research Group. Year 2010

    International Nuclear Information System (INIS)

    2011-01-01

    For the last two decades, neutrino physics has been producing major discoveries including neutrino oscillations. These results gave clear confirmation that active neutrinos oscillate and therefore have mass with three different mass states. This is a very important result showing that the Minimal Standard Model is incomplete and requires an extension which is not yet known. The neutrino research field is very broad and active, at the frontier of today's particle physics. The Neutrino Research Group (GDR) was created in January 2005 with the aim of gathering CEA and CNRS research teams working on Neutrino Physics on experimental or theoretical level. This document is the 2010 activity report of the research group, six years after its creation. It presents the results of the 5 working groups: 1 - Determination of neutrino parameters; 2 - Physics beyond the standard model; 3 - Neutrinos in the universe; 4 - Accelerators, detection means, R and D and valorisation; 5 - Common tools to all working groups. The proposed neutrino physics road-map and the actual and future short-, medium- and long-term projects are presented in appendixes

  4. [Health education for varicose ulcer patients through group activities].

    Science.gov (United States)

    da Silva, Jodo Luis Almeida; Lopes, Marta Julia Marques

    2006-06-01

    It is a report on the group activities carried out with carriers of varicose ulcer in a health unit in Porto Alegre, Rio Grande do Sul, Brazil. The varicose ulcer presents factors, besides the biological ones, which interfere in the cicatrization, in the relapse cases and in its effective resolution. The proposed activities aimed at producing behavior changes with the intention of achieving self-care, providing information, socializing the participants, and stimulating cooperation, searching for joint solutions, aggregating interdisciplinary spirit and improving the care. Two groups have been formed and a thematic schedule established. The results have showed higher adhesion to the treatment, behavioral changes, and adapted and more effective attitudes of the health team.

  5. 7,8,15,16-tetraoxa-dispiro[5.2.5.2]hexadecane-3-carboxylic acid derivatives and their antimalarial activity

    Directory of Open Access Journals (Sweden)

    BOGDAN SOLAJA

    2004-11-01

    Full Text Available Several C2 symmetrical mixed tetraoxanes were prepared starting from a gemdihydroperoxide and a ketone. The obtained tetraoxanes showed pronounced antimalarial activity against P. falciparum chloroquine resistant W2 and chloroquine susceptible D6 strains, with N-(2-dimethylaminoethyl-7,8,15,16-tetraoxa-dispiro[5.2.5.2] hexadecane-3-carboxamide being as active as artemisinin.

  6. 3-Carboxyquinolin-1-ium-2-carboxylate monohydrate

    Directory of Open Access Journals (Sweden)

    Qing Zhang

    2012-03-01

    Full Text Available The title compound, C11H7NO4·H2O, contains a 3-carboxyquinolin-1-ium-2-carboxylate (qda zwitterion and one water molecule. In the crystal, pairs of N—H...O hydrogen bonds link the molecules into inversion dimers, and these dimers are further connected by O—H...O hydrogen bonds into a three-dimensional supramolecular architecture. In addition, π–π interactions occur between pyridine and benzene rings from different qda ligands [centroid–centroid distance = 3.749 (1 Å] and the dihedral angles of the –CO2H and –CO2 groups to the quinoline system are 8.47 (3 and 88.16 (6°, respectively.

  7. Ion exchange properties of carboxylate bagasse

    International Nuclear Information System (INIS)

    Nada, A.M.A.; Hassan, M.L.

    2005-01-01

    Bagasse fibers were chemically modified using three different reactions: esterification using monochloro acetic acid, esterification using succinic anhydride, and oxidation using sodium periodate and sodium chlorite to prepare cation exchanger bearing carboxylic groups. Bagasse was crosslinked using epichlorohydrin before chemical modification to avoid loss of its constituents during the chemical modification. The structure of the prepared derivatives was proved using Fourier transform infrared (FTIR) and chemical methods. The ability of the prepared bagasse cation exchangers to adsorb heavy metal ions (Cu +2 , Ni +2 , Cr +3 , Fe +3 ), on a separate basis or in a mixture of them, at different metal ion concentration was tested. Thermal stability of the different bagasse derivative was studied using thermogravimetric analysis (TGA)

  8. ATLAS barrel hadron calorimeter. JINR - group activity (July - September 1995)

    International Nuclear Information System (INIS)

    Budagov, Yu.; Lebedev, A.; Kul'chitskij, Yu.

    1995-01-01

    Here we present a short report on the main results of the preparatory work for 0-module, to be manufactured at JINR. The reported period covers July - September 1995 JINR-group activity and includes the main topics considered by TILE-CAL community at September 1995 meeting at CERN. Many of JINR developed propositions have been included in 0-module production final technology. 2 refs., 1 tab

  9. Niacin activates the PI3K/Akt cascade via PKC- and EGFR-transactivation-dependent pathways through hydroxyl-carboxylic acid receptor 2.

    Directory of Open Access Journals (Sweden)

    Huawang Sun

    Full Text Available Niacin has been demonstrated to activate a PI3K/Akt signaling cascade to prevent brain damage after stroke and UV-induced skin damage; however, the underlying molecular mechanisms for HCA2-induced Akt activation remain to be elucidated. Using CHO-K1 cells stably expressing HCA2 and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA2 receptors, we first demonstrated that niacin induced a robust Akt phosphorylation at both Thr308 and Ser473 in a time-dependent fashion, with a maximal activation at 5 min and a subsequent reduction to baseline by 30 min through HCA2, and that the activation was significantly blocked by pertussis toxin. The HCA2-mediated activation of Akt was also significantly inhibited by the PKC inhibitors GF109203x and Go6983 in both cell lines, by the PDGFR-selective inhibitor tyrphostin A9 in CHO-HCA2 cells and by the MMP inhibitor GM6001 and EGFR-specific inhibitor AG1478 in A431 cells. These results suggest that the PKC pathway and PDGFR/EGFR transactivation pathway play important roles in HCA2-mediated Akt activation. Further investigation indicated that PI3K and the Gβγ subunit were likely to play an essential role in HCA2-induced Akt activation. Moreover, Immunobloting analyses using an antibody that recognizes p70S6K1 phosphorylated at Thr389 showed that niacin evoked p70S6K1 activation via the PI3K/Akt pathway. The results of our study provide new insight into the signaling pathways involved in HCA2 activation.

  10. R and D activities of the ESARDA NDA working group

    International Nuclear Information System (INIS)

    Guardini, S.; Bignan, G.

    1999-01-01

    The aim of this paper is to report the R and D activities of the ESARDA Working Group on Techniques and Standards for Non-Destructive Analysis (NDA), as well as to discuss the role and possibilities of the group in the modern R and D scenario in safeguards and non-proliferation. The main tasks of the ESARDA NDA Working have been identified as being to: Define needs for procedural standards and reference materials; Design and manage the production and characterisation of reference materials; Assess and contribute to improving the performances of NDA techniques; Set up and maintain a list of NDA instruments and methods currently used for Safeguards purposes; and, through the above activities, assist Operators and Safeguards Authorities in their duty of Safeguards implementation. Members and observers appointed to the working group represent plant operators, the nuclear industry, R and D laboratories, NDA instrument developers and both safeguards control authorities. The participation of major European plant operators and of the EURATOM Safeguards Directorate and IAEA has always been assured and contributes to the good outcome of the WG activities. The ongoing R and D activities of the NDA Working Group are: Monte Carlo performance intercomparisons; 242 Pu accuracy assessment and improvement; NDA Sampling errors; General NDA performance evaluations. Some milestones have recently been reached: The 242 Pu uncertainty improvement project is coming to an end with the issuing of a new isotopic correlation; The NCC 'reals' evaluation and the Monte Carlo round robin is producing its first results; The Uranium Enrichment Round Robin Exercise has been completed; The waste drum standards are being characterised and constructed: they will be available by spring 1998. The round robin amongst laboratories will then start: summer 1998. Future activities comprise, beside the above issues, technical problems linked with the new challenges posed by new regimes of safeguards and non

  11. Medical Student Perspectives of Active Learning: A Focus Group Study.

    Science.gov (United States)

    Walling, Anne; Istas, Kathryn; Bonaminio, Giulia A; Paolo, Anthony M; Fontes, Joseph D; Davis, Nancy; Berardo, Benito A

    2017-01-01

    Phenomenon: Medical student perspectives were sought about active learning, including concerns, challenges, perceived advantages and disadvantages, and appropriate role in the educational process. Focus groups were conducted with students from all years and campuses of a large U.S. state medical school. Students had considerable experience with active learning prior to medical school and conveyed accurate understanding of the concept and its major strategies. They appreciated the potential of active learning to deepen and broaden learning and its value for long-term professional development but had significant concerns about the efficiency of the process, the clarity of expectations provided, and the importance of receiving preparatory materials. Most significantly, active learning experiences were perceived as disconnected from grading and even as impeding preparation for school and national examinations. Insights: Medical students understand the concepts of active learning and have considerable experience in several formats prior to medical school. They are generally supportive of active learning concepts but frustrated by perceived inefficiencies and lack of contribution to the urgencies of achieving optimal grades and passing United States Medical Licensing Examinations, especially Step 1.

  12. Mining activities of the Cogema group; Activite miniere du groupe Cogema

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1996-12-31

    This brochure is a general presentation of the mining activities of the COGEMA group. COGEMA is specialized in the whole operations of the nuclear fuel cycle and is responsible for about 20% of the worldwide uranium production with the exploitation of French mines and its participation in the exploitation of mines abroad, mainly in Canada, USA, Niger and Gabon. This document is divided in seven chapters: the search for uranium ores and the mining prospecting, the uranium deposits and the worldwide market, the exploitation of uranium ores (techniques and mines exploited by the COGEMA group), the processing of ores, the radioactivity and the mining installations, the environmental protection and the rehabilitation of sites (environmental survey and management of mining sites), application of COGEMA`s know-how to other domains such as: gold ore processing, research and development studies, instrumentation and radioprotection, soils cleansing and sites rehabilitation. This brochure is illustrated with several photos and pictures. (J.S.).

  13. 2-Oxo-1,2-dihydroquinoline-4-carboxylic acid monohydrate

    Directory of Open Access Journals (Sweden)

    Yassir Filali Baba

    2016-06-01

    Full Text Available In the title compound, C10H7NO3·H2O, O—H...O hydrogen bonds involving the carboxyl groups, the keto groups and the lattice water molecules form stepped sheets approximately parallel to {010} which are tied together by pairwise N—H...O interactions. The asymmetric unit contains two independent quinolone derivatives and two water molecules, one of which is disordered over two positions, of equal occupancy.

  14. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 10, Revision 2 (FGE.10Rev2): Aliphatic primary and secondary saturated and unsaturated alcohols, aldehydes, acetals, carboxylic acids and esters containing

    DEFF Research Database (Denmark)

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

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 61 flavouring substances in the Flavouring Group Evaluation 10, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. None of the sub......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 61 flavouring substances in the Flavouring Group Evaluation 10, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. None...... of the substances were considered to have genotoxic potential. The substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity....... The Panel concluded that the 61 substances do not give rise to safety concerns at their levels of dietary intake, estimated on the basis of the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. For four...

  15. Recent activities of the ESARDA working group on NDA

    International Nuclear Information System (INIS)

    Harry, R.J.S.

    1983-01-01

    The European Safeguards Research and Development Association, ESARDA, has one of the largest coordinated safeguards and development programs in the world. There are several working groups for specific R and D activities. One of these is the ''ESARDA Working Group on Techniques and Standards for non-Destructive Analysis''. The NDA working group has initiated the international project of the preparation of uranium oxide certified reference materials for the gamma spectrometric determination of the enrichment, which are made in a collaboration with the US NBS and the European Communities' Central Bureau for Nuclear Measurements, CBNM, at Geel. The possibility of a similar type of reference material for Pu isotopic abundance measurements is investigated at CBNM, and the pilot samples may become available for intercomparisons. Safeguards acceptability and users manual have been considered carefully. The working group has undertaken an intercomparison on the determination of plutonium isotopic ratios by gamma spectrometry, using NBS-SRM's-946, -947 and 948. A new exercise on 0,5 gram samples of seven different isotopic compositions samples will be executed under the name PIDIE (Plutonium Isotopic Determination Intercomparison Exercise)

  16. Influence of muscle groups' activation on proximal femoral growth tendency.

    Science.gov (United States)

    Yadav, Priti; Shefelbine, Sandra J; Pontén, Eva; Gutierrez-Farewik, Elena M

    2017-12-01

    Muscle and joint contact force influence stresses at the proximal growth plate of the femur and thus bone growth, affecting the neck shaft angle (NSA) and femoral anteversion (FA). This study aims to illustrate how different muscle groups' activation during gait affects NSA and FA development in able-bodied children. Subject-specific femur models were developed for three able-bodied children (ages 6, 7, and 11 years) using magnetic resonance images. Contributions of different muscle groups-hip flexors, hip extensors, hip adductors, hip abductors, and knee extensors-to overall hip contact force were computed. Specific growth rate for the growth plate was computed, and the growth was simulated in the principal stress direction at each element in the growth front. The predicted growth indicated decreased NSA and FA (of about [Formula: see text] over a four-month period) for able-bodied children. Hip abductors contributed the most, and hip adductors, the least, to growth rate. All muscles groups contributed to a decrease in predicted NSA ([Formula: see text]0.01[Formula: see text]-0.04[Formula: see text] and FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]), except hip extensors and hip adductors, which showed a tendency to increase the FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]). Understanding influences of different muscle groups on long bone growth tendency can help in treatment planning for growing children with affected gait.

  17. Activities of the PNC Nuclear Safety Working Group

    International Nuclear Information System (INIS)

    Kato, W.Y.

    1991-01-01

    The Nuclear Safety Working Group of the Pacific Nuclear Council promotes nuclear safety cooperation among its members. Status of safety research, emergency planning, development of lists of technical experts, severe accident prevention and mitigation have been the topics of discussion in the NSWG. This paper reviews and compares the severe accident prevention and mitigation program activities in some of the areas of the Pacific Basin region based on papers presented at a special session organized by the NSWG at an ANS Topical Meeting as well as papers from other sources

  18. The Conversion of Carboxylic Acids to Ketones: A Repeated Discovery

    Science.gov (United States)

    Nicholson, John W.; Wilson, Alan

    2004-09-01

    This article describes the history of the reaction converting carboxylic acids to ketones. The reaction has been rediscovered several times, yet has actually been known for centuries. The best known version of the process is the Dakin West reaction (1928), which applies to α-amino acids and also involves the simultaneous conversion of the amine group to amido functionality. Unlike other examples, this particular reaction has attracted a reasonable amount of attention and it appears to be better known than the conversion of simple carboxylic acids to ketones. However, this reaction was described as long ago as 1612, when Beguin published an account of it in his book, Tyrocinium Chymicum . Since then, many chemists have rediscovered the reaction, apparently independently. One of the earliest modern accounts was by W. H. Perkin, Sr., in 1886, who made various simple ketones by refluxing the appropriate carboxylic acids with base. However, this work has been largely ignored, including by his son, W. H. Perkin, Jr., who used a more complicated base-catalyzed ketonization to prepare small ring compounds in the early years of the 20th century. Other articles detailing the application of ketonization to organic acids are discussed, including our own work, which employed the process to crosslink carboxylated polymers for possible technical application in coatings. Despite its relative obscurity, the reaction was used by Woodward et al. in the total synthesis of strychnine, reported in 1963, and this is discussed in detail at the end of the article. See Featured Molecules .

  19. Novel leads from Heliotropium ovalifolium, 4,7,8-trimethoxy-naphthalene-2-carboxylic acid and 6-hydroxy-5,7-dimethoxy-naphthalene-2-carbaldehyde show specific IL-6 inhibitory activity in THP-1 cells and primary human monocytes.

    Science.gov (United States)

    Kulkarni-Almeida, Asha; Suthar, Ashish; Goswami, Hitesh; Vishwakarma, Ram; Chauhan, Vijay Singh; Balakrishnan, Arun; Sharma, Somesh

    2008-12-01

    From our screening program, we identified the anti-inflammatory effects of the extracts of Heliotropium ovalifolium in its ability to inhibit specific cytokines. The H. ovalifolium extract was found to be moderately active with an IC(50) equaling 10 microg/ml for inhibition of interleukin-6 (IL-6) in a human monocytic cell line. Interleukin-6 is a pleiotropic cytokine with implications in the regulation of the immune response, inflammation and hematopoiesis. This prompted us to examine and identify the active molecules that are responsible for the bioactivity in THP-1 cells. Bioassay guided fractionation identified two compounds 4,7,8-trimethoxy-naphthalene-2-carboxylic acid and 6-hydroxy-5,7-dimethoxy-naphthalene-2-carbaldehyde with an IC(50) of 2.4 and 2.0 microM for IL-6 inhibition and an IC(50) of 15.6 and 7.0 microM for tumor necrosis factor-alpha (TNF-alpha) inhibition in THP-1 cells. The protein expression data were supported by the inhibitory effect on mRNA gene expression. The compounds isolated from H. ovalifolium were also non-toxic in human peripheral blood monocytes from normal donors and the activity profile was similar to that obtained on THP-1 cells. Thus, we believe that these scaffolds may be of interest to develop leads for treating rheumatoid arthritis, psoriasis, ulcerative colitis, Crohn's disease and other inflammatory disorders. However, more detailed investigations need to be carried out to explain the efficacy of these compounds as drugs.

  20. Comparative study of the neuroprotective and nootropic activities of the carboxylate and amide forms of the HLDF-6 peptide in animal models of Alzheimer's disease.

    Science.gov (United States)

    Bogachouk, Anna P; Storozheva, Zinaida I; Solovjeva, Olga A; Sherstnev, Vyacheslav V; Zolotarev, Yury A; Azev, Vyacheslav N; Rodionov, Igor L; Surina, Elena A; Lipkin, Valery M

    2016-01-01

    A comparative study of the neuroprotective and nootropic activities of two pharmaceutical substances, the HLDF-6 peptide (HLDF-6-OH) and its amide form (HLDF-6-NH2), was conducted. The study was performed in male rats using two models of a neurodegenerative disorder. Cognitive deficit in rats was induced by injection of the beta-amyloid fragment 25-35 (βA 25-35) into the giant-cell nucleus basalis of Meynert or by coinjection of βA 25-35 and ibotenic acid into the hippocampus. To evaluate cognitive functions in animals, three tests were used: the novel object recognition test, the conditioned passive avoidance task and the Morris maze. Comparative analysis of the data demonstrated that the neuroprotective activity of HLDF-6-NH2, evaluated by improvement of cognitive functions in animals, surpassed that of the native HLDF-6-OH peptide. The greater cognitive/ behavioral effects can be attributed to improved kinetic properties of the amide form of the peptide, such as the character of biodegradation and the half-life time. The effects of HLDF-6-NH2 are comparable to, or exceed, those of the reference compounds. Importantly, HLDF-6-NH2 exerts its effects at much lower doses than the reference compounds. © The Author(s) 2015.

  1. Hydrated electron: a destroyer of perfluorinated carboxylates?

    International Nuclear Information System (INIS)

    Huang Li; Dong Wenbo; Hou Huiqi

    2006-01-01

    As a class, perfluorinated carboxylate (PFCA) was ranked among the most prominent organohalogen contaminants in environment with respect to thermal, chemical and biological inertness. Hydrated electron (e aq - ), a highly reactive and strongly reductive species, has been reported to readily decompose perfluoroaromatic compounds via intermolecular electron transfer process in aqueous solution. Question then arose: what would happen if perfluorinated carboxylates encountered with hydrated electron? Original laboratory trial on the interaction between F(CF 2 ) n COO - (n=1, 3, 7) and hydrated electron was attempted by using laser flash photolysis technique in this research work. Abundant hydrated electron (e aq - ) could be produced by photolysis of 1.25 x 10 -4 M K 4 Fe(CN) 6 in nitrogen saturated water. In the presence of F(CF 2 ) n COO - (n=1, 3, 7), the decay of e aq - was observed to enhance dramatically, indicating e aq - was able to attack PFCAs. On addition of perfluorinated carboxylates, the loss of e aq - was mainly due to the following channels. By mixing the solution of K 4 Fe(CN) 6 with excess K 3 Fe(CN) 6 and PFCAs, e aq - turned to decayed corresponding to mixed first- and second-order kinetics. Rate constants for the reactions of e aq - with PFCAs could be then easily determined by monitoring the decay of e aq - absorption at 690 nm. Since perfluorinated carboxylates were salts, the influence of ionic strength on k 3 was examined systematically by carrying out experiments of varying ionic strength ranging from 0.009 up to 0.102 M by adding NaClO 4 . In this manner, the second order rate constants for e-aq with CF 3 COO - , C 3 F 7 COO - , C 7 F 15 COO - were derived to be (1.9±0.2) x 10 6 M -1 S -1 (μ=0), (7.1±0.2) x 10 6 M -1 S -1 (μ=0) and (1.7±0.5) x10 7 M -1 S -1 (μ=0.009 M) respectively. Apparently, the length of F(CF 2 ) n group exerted substantial influence on the rate constant. Further study on byproducts analysis by ion chromatography

  2. Immobilization of dendrimers on Si-C linked carboxylic acid-terminated monolayers on silicon(111)

    International Nuclear Information System (INIS)

    Boecking, Till; Wong, Elicia L.S.; James, Michael; Watson, Jolanta A.; Brown, Christopher L.; Chilcott, Terry C.; Barrow, Kevin D.; Coster, Hans G.L.

    2006-01-01

    Poly(amidoamine) dendrimers were attached to activated undecanoic acid monolayers, covalently linked to smooth silicon surfaces via Si-C bonds. The resulting ultra-thin dendrimer films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray reflectometry (XR) and atomic force microscopy (AFM). XPS results suggested amide bond formation between the dendrimer and the surface carboxylic acid groups. XR yielded thicknesses of 10 A for the alkyl region of the undecanoic acid monolayer and 12 A for the dendrimer layer, considerably smaller than the diameter of these spherical macromolecules in solution. This was consistent with AFM images showing collapsed dendrimers on the surface. It was concluded that the deformation arose from a large number of amine groups on the surface of each dendrimer reacting efficiently with the activated surface, whereby the dendrimers can deform to fill voids while spreading over the activated surface to form a homogeneous macromolecular layer

  3. Identification of Key Residues for Enzymatic Carboxylate Reduction

    Directory of Open Access Journals (Sweden)

    Holly Stolterfoht

    2018-02-01

    Full Text Available Carboxylate reductases (CARs, E.C. 1.2.1.30 generate aldehydes from their corresponding carboxylic acid with high selectivity. Little is known about the structure of CARs and their catalytically important amino acid residues. The identification of key residues for carboxylate reduction provides a starting point to gain deeper understanding of enzymatic carboxylate reduction. A multiple sequence alignment of CARs with confirmed activity recently identified in our lab and from the literature revealed a fingerprint of conserved amino acids. We studied the function of conserved residues by multiple sequence alignments and mutational replacements of these residues. In this study, single-site alanine variants of Neurospora crassa CAR were investigated to determine the contribution of conserved residues to the function, expressability or stability of the enzyme. The effect of amino acid replacements was investigated by analyzing enzymatic activity of the variants in vivo and in vitro. Supported by molecular modeling, we interpreted that five of these residues are essential for catalytic activity, or substrate and co-substrate binding. We identified amino acid residues having significant impact on CAR activity. Replacement of His 237, Glu 433, Ser 595, Tyr 844, and Lys 848 by Ala abolish CAR activity, indicating their key role in acid reduction. These results may assist in the functional annotation of CAR coding genes in genomic databases. While some other conserved residues decreased activity or had no significant impact, four residues increased the specific activity of NcCAR variants when replaced by alanine. Finally, we showed that NcCAR wild-type and mutants efficiently reduce aliphatic acids.

  4. Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2′-Bipyridine

    Directory of Open Access Journals (Sweden)

    Gina Vasile Scăețeanu

    2018-01-01

    Full Text Available The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2′-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn3(2,2′-bipy2(C3H3O26] (1, meanwhile complexes with general formula [M(2,2′-bipy(C3H3O22(H2Ox]∙yH2O ((2 M: Ni, x = 1, y = 0; (3 M: Cu, x = 1, y = 0; (4 M: Zn, x = 0, y = 1; 2,2′-bipy: 2,2′-bipyridine; C3H3O2: acrylate anion were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC of 128 μg mL−1 was recorded for all four tested complexes against Candida albicans, for complex (3 against Escherichia coli, and for complex (4 against Staphylocococcus aureus. Compounds (3 and (4 were also potent efflux pumps activity inhibitors (EPI, proving their potential for use in synergistic combinations with antibiotics. Complexes (1–(4 revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

  5. Polycomb-group genes sustaining the stem cell activity

    International Nuclear Information System (INIS)

    Takihara, Yoshihiro

    2006-01-01

    Polycomb-group genes (PcG) have a role in constituting the cellular memory mechanisms through which the once expressed phenotypes during development are transmitted thereafter and this review describes, together with authors' findings of sustaining hematopoietic stem cell activity by the PcG products, what molecular bases, involving the control of histone code, are concerned in the memory. Recent investigations have gradually elucidated the outline of epigenetic control mechanisms of the memory: messages are set up as a histone code in the chromatin and the PcG complex recruited by recognition of the code regulates the chromatin structure leading to DNA transcription and maintenance of the phenotype. Proliferation of hematopoietic stem cells ex vivo will be possible if exact and detailed mechanisms for PcG are made clear in future. Such ex vivo techniques are especially awaited for marrow remodeling treatment of hematopoietic failure induced by radiation exposure. (T.I.)

  6. Neural activity reveals perceptual grouping in working memory.

    Science.gov (United States)

    Rabbitt, Laura R; Roberts, Daniel M; McDonald, Craig G; Peterson, Matthew S

    2017-03-01

    There is extensive evidence that the contralateral delay activity (CDA), a scalp recorded event-related brain potential, provides a reliable index of the number of objects held in visual working memory. Here we present evidence that the CDA not only indexes visual object working memory, but also the number of locations held in spatial working memory. In addition, we demonstrate that the CDA can be predictably modulated by the type of encoding strategy employed. When individual locations were held in working memory, the pattern of CDA modulation mimicked previous findings for visual object working memory. Specifically, CDA amplitude increased monotonically until working memory capacity was reached. However, when participants were instructed to group individual locations to form a constellation, the CDA was prolonged and reached an asymptote at two locations. This result provides neural evidence for the formation of a unitary representation of multiple spatial locations. Published by Elsevier B.V.

  7. Photovoltaic Reliability Group activities in USA and Brazil (Presentation Recording)

    Science.gov (United States)

    Dhere, Neelkanth G.; Cruz, Leila R. O.

    2015-09-01

    Recently prices of photovoltaic (PV) systems have been reduced considerably and may continue to be reduced making them attractive. If these systems provide electricity over the stipulated warranty period, it would be possible attain socket parity within the next few years. Current photovoltaic module qualifications tests help in minimizing infant mortality but do not guarantee useful lifetime over the warranty period. The PV Module Quality Assurance Task Force (PVQAT) is trying to formulate accelerated tests that will be useful towards achieving the ultimate goal of assuring useful lifetime over the warranty period as well as to assure manufacturing quality. Unfortunately, assuring the manufacturing quality may require 24/7 presence. Alternatively, collecting data on the performance of fielded systems would assist in assuring manufacturing quality. Here PV systems installed by home-owners and small businesses can constitute as an important untapped source of data. The volunteer group, PV - Reliable, Safe and Sustainable Quality! (PVRessQ!) is providing valuable service to small PV system owners. Photovoltaic Reliability Group (PVRG) is initiating activities in USA and Brazil to assist home owners and small businesses in monitoring photovoltaic (PV) module performance and enforcing warranty. It will work in collaboration with small PV system owners, consumer protection agencies. Brazil is endowed with excellent solar irradiance making it attractive for installation of PV systems. Participating owners of small PV systems would instruct inverter manufacturers to copy the daily e-mails to PVRG and as necessary, will authorize the PVRG to carry out review of PV systems. The presentation will consist of overall activities of PVRG in USA and Brazil.

  8. Adolescents' Views on Active and Non-Active Videogames: A Focus Group Study.

    Science.gov (United States)

    Simons, Monique; de Vet, Emely; Hoornstra, Sjoukje; Brug, Johannes; Seidell, Jaap; Chinapaw, Mai

    2012-06-01

    Active games require whole-body movement and may be an innovative tool to substitute sedentary pastime with more active time and may therefore contribute to adolescents' health. To inform strategies aimed at reducing sedentary behavior by replacing non-active with active gaming, perceptions and context of active and non-active gaming are explored. Six focus groups were conducted with adolescents 12-16 years old representing a range of education levels. A semistructured question route was used containing questions about perceptions and the context of gaming. The adolescents had positive attitudes toward active gaming, especially the social interactive aspect, which was greatly appreciated. A substantial number of adolescents enjoyed non-active games more than active ones, mainly because of better game controls and more diversity in non-active games. Active games were primarily played when there was a social gathering. Few game-related rules and restrictions at home were reported. Given the positive attitudes of adolescents and the limited restrictions for gaming at home, active videogames may potentially be used in a home setting as a tool to reduce sedentary behavior. However, to make active games as appealing as non-active games, attention should be paid to the quality, diversity, and sustainability of active games, as these aspects are currently inferior to those of traditional non-active games.

  9. Ideologically motivated activism: How activist groups influence corporate social change activities

    NARCIS (Netherlands)

    den Hond, F.; de Bakker, F.G.A.; Hickman, G. R.

    2010-01-01

    Using insights from the social movement literature and institutional change theory, we explore how activism influences corporate social change activities. As the responsibility for addressing a variety of social issues is transferred from the state to the private sector, activist groups increasingly

  10. Crystal structure of ethyl 2,4-dichloroquinoline-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Alberto Cabrera

    2015-12-01

    Full Text Available In the crystal structure of the title compound, C12H9Cl2NO2, the mean planes through the quinoline and carboxylate groups have r.m.s. deviations of 0.006 and 0.021 Å, respectively, and form a dihedral angle of 87.06 (19°. In the crystal, molecules are linked via very weak C—H...O hydrogen bonds, forming chains, which propagate along the c-axis direction.

  11. Chiral metal-organic frameworks bearing free carboxylic acids for organocatalyst encapsulation.

    Science.gov (United States)

    Liu, Yan; Xi, Xiaobing; Ye, Chengcheng; Gong, Tengfei; Yang, Zhiwei; Cui, Yong

    2014-12-08

    Two chiral carboxylic acid functionalized micro- and mesoporous metal-organic frameworks (MOFs) are constructed by the stepwise assembly of triple-stranded heptametallic helicates with six carboxylic acid groups. The mesoporous MOF with permanent porosity functions as a host for encapsulation of an enantiopure organic amine catalyst by combining carboxylic acids and chiral amines in situ through acid-base interactions. The organocatalyst-loaded framework is shown to be an efficient and recyclable heterogeneous catalyst for the asymmetric direct aldol reactions with significantly enhanced stereoselectivity in relative to the homogeneous organocatalyst. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Plastic scintillators with high loading of one or more metal carboxylates

    Science.gov (United States)

    Cherepy, Nerine; Sanner, Robert Dean

    2016-01-12

    In one embodiment, a material includes at least one metal compound incorporated into a polymeric matrix, where the metal compound includes a metal and one or more carboxylate ligands, where at least one of the one or more carboxylate ligands includes a tertiary butyl group, and where the material is optically transparent. In another embodiment, a method includes: processing pulse traces corresponding to light pulses from a scintillator material; and outputting a result of the processing, where the scintillator material comprises at least one metal compound incorporated into a polymeric matrix, the at least one metal compound including a metal and one or more carboxylate ligands, where at least one of the one or more carboxylate ligands has a tertiary butyl group, and where the scintillator material is optically transparent and has an energy resolution at 662 keV of less than about 20%.

  13. Physical activity assessment and counseling in Quebec family medicine groups.

    Science.gov (United States)

    Baillot, Aurélie; Baillargeon, Jean-Patrice; Paré, Alex; Poder, Thomas G; Brown, Christine; Langlois, Marie-France

    2018-05-01

    To determine how often primary health care providers (PHCPs) in family medicine groups (FMGs) assess physical activity (PA) levels, provide PA counseling (PAC), and refer patients to exercise professionals; to describe patients' PA levels, physical fitness, and satisfaction regarding their PA management in FMGs; to describe available PA materials in FMGs and PHCPs' PAC self-efficacy and PA knowledge; and to identify characteristics of patients and PHCPs that determine the assessment of PA and PAC provided by PHCPs. Cross-sectional study using questionnaires and a medical chart audit. Ten FMGs within the Integrated University Health Network of the Centre hospitalier universitaire de Sherbrooke in Quebec. Forty FPs, 24 nurses, and 439 patients. Assessment of PA level and PAC provided by PHCPs. Overall, 51.9% of the patients had had their PA level assessed during the past 18 months, but only 21.6% received PAC from at least 1 of the PHCPs. Similar percentages were found among the inactive (n = 244) and more active (n = 195) patients. The median PAC self-efficacy score of PHCPs was 70.2% (interquartile range 52.0% to 84.7%) and the median PA knowledge score was 45.8% (interquartile range 41.7% to 54.2%), with no significant differences between nurses and FPs. In multivariate analysis, 34% of the variance in PAC provided was explained by assessment of PA level, overweight or obese status, type 2 diabetes or prediabetes, less FP experience, lower patient annual family income, more nurse encounters, and a higher patient physical component summary of quality of life. The rates of assessment of PA and provision of PAC in Quebec FMGs were low, even though most of the patients were inactive. Initiatives to support PHCPs and more resources to assess PA levels and provide PAC should be implemented. Copyright© the College of Family Physicians of Canada.

  14. Direct enantioselective conjugate addition of carboxylic acids with chiral lithium amides as traceless auxiliaries.

    Science.gov (United States)

    Lu, Ping; Jackson, Jeffrey J; Eickhoff, John A; Zakarian, Armen

    2015-01-21

    Michael addition is a premier synthetic method for carbon-carbon and carbon-heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B.

  15. Direct Enantioselective Conjugate Addition of Carboxylic Acids with Chiral Lithium Amides as Traceless Auxiliaries

    Science.gov (United States)

    2016-01-01

    Michael addition is a premier synthetic method for carbon–carbon and carbon–heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B. PMID:25562717

  16. Activities of the EMRAS Tritium/C14 Working Group

    International Nuclear Information System (INIS)

    Davis, P.A.; Balonov, M.; Venter, A.

    2005-01-01

    A new model evaluation program, Environmental Modeling for Radiation Safety (EMRAS), was initiated by the International Atomic Energy Agency in September 2003. EMRAS includes a working group (WG) on modeling tritium and C-14 transfer through the environment to biota and man. The main objective of this WG is to develop and test models of the uptake, formation and translocation of organically bound tritium (OBT) in food crops, animals and aquatic systems. To the extent possible, the WG is carrying out its work by comparing model predictions with experimental data to identify the modeling approaches and assumptions that lead to the best agreement between predictions and observations. Results for scenarios involving a chronically contaminated aquatic ecosystem and short-term exposure of soybeans are presently being analyzed. In addition, calculations for scenarios involving chronically contaminated terrestrial food chains and hypothetical short-term releases are currently underway, and a pinetree scenario is being developed. The preparation of datasets on tritium dynamics in large animals and fish is being encouraged, since these are the areas of greatest uncertainty in OBT modeling. These activities will be discussed in this paper

  17. Substrate specificity within a family of outer membrane carboxylate channels.

    Directory of Open Access Journals (Sweden)

    Elif Eren

    2012-01-01

    Full Text Available Many Gram-negative bacteria, including human pathogens such as Pseudomonas aeruginosa, do not have large-channel porins. This results in an outer membrane (OM that is highly impermeable to small polar molecules, making the bacteria intrinsically resistant towards many antibiotics. In such microorganisms, the majority of small molecules are taken up by members of the OprD outer membrane protein family. Here we show that OprD channels require a carboxyl group in the substrate for efficient transport, and based on this we have renamed the family Occ, for outer membrane carboxylate channels. We further show that Occ channels can be divided into two subfamilies, based on their very different substrate specificities. Our results rationalize how certain bacteria can efficiently take up a variety of substrates under nutrient-poor conditions without compromising membrane permeability. In addition, they explain how channel inactivation in response to antibiotics can cause resistance but does not lead to decreased fitness.

  18. Update on Activities of CEOS Disaster Management Support Group

    Science.gov (United States)

    Wood, H. M.; Lauritson, L.

    The Committee on Earth Observation Satellites (CEOS) Disaster Management Support Group (DMSG) has supported natural and technological disaster management on a worldwide basis by fostering improved utilization of existing and planned Earth Observation (EO) satellite data. The DMSG has focused on developing and refining recommendations for the application of satellite data to selected hazard areas--drought, earthquake, fire, flood, ice, landslide, oil spill, and volcanic hazards. Particular emphasis was placed on working closely with space agencies, international and regional organizations, and commercial organizations on the implementation of these recommendations. The DMSG is in its last year with its primary focus on documenting its work and migrating on going activities to other fora. With over 300 participants from more than 140 organizations, the DMSG has found strong support among CEOS space agencies and the Integrated Global Observing Strategy (IGOS), as well as an enthusiastic reception from numerous international, regional, and national emergency managers, and distinct interest from the commercial sector. In addition, the group has worked to give full support to the work of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) in pursuit of decisions taken at UNISPACE III and the United Nations International Strategy on Disaster Reduction (ISDR). In conjunction with the IGOS, several of the DMSG hazards teams (earthquake, landslide, and solid Earth dimensions of volcanoes) are joining in the effort to develop an IGOS Geohazards theme team. Cooperation efforts with organizations such as IGOS, COPUOS, and ISDR will hopefully lead to the pick up of much of the on going DMSG activities. Since the inception of this ad hoc working group and its predecessor project, the DMSG has developed and refined recommendations for the application of satellite data by bringing together experts from eight hazard areas to identify user needs, as well as

  19. Experimental and theoretical elucidation of structural and antioxidant properties of vanillylmandelic acid and its carboxylate anion

    Science.gov (United States)

    Dimić, Dušan; Milenković, Dejan; Ilić, Jelica; Šmit, Biljana; Amić, Ana; Marković, Zoran; Dimitrić Marković, Jasmina

    2018-06-01

    Vanillylmandelic acid (VMA), an important metabolite of catecholamines that is routinely screened as tumor marker, was investigated by the various spectroscopic techniques (IR, Raman, UV-Vis, antioxidant decolorization assay and NMR). Structures optimized by the employment of five common functionals (M05-2X, M06-2X, B3LYP, CAM-B3LYP, B3LYP-D3) were compared with the crystallographic data. The M05-2X functional reproduced the most reliable experimental bond lengths and angles (correlation coefficient >0.999). The importance of intramolecular hydrogen bonds for structural stability was discussed and quantified by the NBO analysis. The most prominent bands in vibrational spectrum were analyzed and compared to the experimental data. The positions of the carbon and hydrogen atoms in NMR spectra were well reproduced. The differences in UV-Vis spectrum were investigated by adding the explicit solvent and by performing NBO and QTAIM analyses. The discrepancy in the two spectra of about 50 nm could be explained by the solvent effect on carboxyl group. The most probable antioxidant activity mechanism was discussed for VMA and its carboxylate anion. The Molecular Docking study with the C - reactive protein additionally proved that variety of functional groups present in VMA and its anion allowed strong hydrogen and hydrophobic interactions.

  20. Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

    Energy Technology Data Exchange (ETDEWEB)

    Uznanski, Pawel, E-mail: puznansk@cbmm.lodz.pl; Zakrzewska, Joanna [Centre of Molecular and Macromolecular Studies, PAS (Poland); Favier, Frederic, E-mail: fredf@univ-montp2.fr [Université Montpellier II, ICGM - UMR5253- Equipe AIME (France); Kazmierski, Slawomir; Bryszewska, Ewa [Centre of Molecular and Macromolecular Studies, PAS (Poland)

    2017-03-15

    A comparative study of amine and silver carboxylate adducts [R{sub 1}COOAg-2(R{sub 2}NH{sub 2})] (R{sub 1} = 1, 7, 11; R{sub 2} = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, {sup 13}C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies ({sup 1}H and {sup 13}C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.

  1. Highly visible-light luminescence properties of the carboxyl-functionalized short and ultrashort MWNTs

    International Nuclear Information System (INIS)

    Luo Yongsong; Xia Xiaohong; Liang Ying; Zhang Yonggang; Ren Qinfeng; Li Jialin; Jia Zhijie; Tang Yiwen

    2007-01-01

    Luminescence of the short multiwalled carbon nanotubes (MWNTs) conjugated with carboxylic acid groups has been studied. The results show that the carboxyl-functionalized short MWNTs could emit luminescence and the emission peak appears at 500 nm with a corresponding optimal excitation wavelength centering at 310 nm. When the short MWNTs are filtered through 0.15 μm polytetrafluoroethylene (PTFE) membrane, the ultrashort MWNTs are obtained from the filtrate. An interesting feature for the ultrashort MWNTs is that the emission intensity is strengthened and the peak is slightly blue shifted to 460 nm. This result indicates that the luminescence properties of MWNTs are strongly affected by the tube length. After chemical oxidization cutting, defects and carboxylic acid groups at the tube end and/or sidewall can be produced; the more shorten of MWNTs, the better dispersion and carboxylic passivation of the nanotubes, and the more intense luminescence emissions. The broad emissions are logically attributed to the trapping of excitation energy by defect sites in the carboxyl-functionalized nanotube structure. - Graphical abstract: Luminescence of the short and ultrashort multiwalled carbon nanotubes (MWNTs) conjugated with carboxylic acid groups, which is logically attributed to the trapping of excitation energy by defect sites, has been studied

  2. Nordic working group on CCF studies. Parameter estimation within the activities of the Nordic CCF Group

    International Nuclear Information System (INIS)

    Johansson, G.

    2002-01-01

    depending on component type. Plant And Regulator Survey: The survey shall provide a background to this project based on the needs and experience form the plant owners and the regulators. The survey shall try to reach a wide spectrum of personnel from regulation, operation, design engineering, safety committees and risk assessment groups. Important elements of the survey are to carry out a dialog with the organisations to engage them in the issues related to this programme and to marked the outcome and use of the analysis. The quantitative work area cover activities related to the quantitative assessment of the data. The procedure for common cause failure data analysis is intended to provide guidance on event analysis, the derivation of event statistics, and the estimation of model parameters. CCF events do often contribute significantly to the PSA results and it is necessary to have the best estimates possible. Qualitative work areas: Provide insights into the plant design and operation; allow credit for existing plant defenses in PSA work; support inspection and operation in assessing plant status with regard to CCF defenses. Qualitative classification. (author)

  3. Group sex offending by juveniles: coercive sex as a group activity

    NARCIS (Netherlands)

    Bijleveld, C.C.J.H.; Weerman, F.; Looije, D.; Hendriks, J.

    2007-01-01

    We study sex offences carried out by groups of juveniles, focusing on offender characteristics and the interaction patterns within offender groups and between offenders and victims. Using reconstructions of offences from court files as well as information retrieved from personality screenings, we

  4. Volatility of atmospherically relevant alkylaminium carboxylate salts.

    Science.gov (United States)

    Lavi, Avi; Segre, Enrico; Gomez-Hernandez, Mario; Zhang, Renyi; Rudich, Yinon

    2015-05-14

    Heterogeneous neutralization reactions of ammonia and alkylamines with sulfuric acid play an important role in aerosol formation and particle growth. However, little is known about the physical and chemical properties of alkylaminium salts of organic acids. In this work we studied the thermal stability and volatility of alkylaminium carboxylate salts of short aliphatic alkylamines with monocarboxylic and dicarboxylic acids. The enthalpy of vaporization and saturation vapor pressure at 298 K were derived using the kinetic model of evaporation and the Clausius-Clapeyron relation. The vapor pressure of alkylaminium dicarboxylate salts is ∼10(-6) Pa, and the vaporization enthalpy ranges from 73 to 134 kJ mol(-1). Alkylaminium monocarboxylate salts show high thermal stability, and their thermograms do not follow our evaporation model. Hence, we inferred their vapor pressure from their thermograms as comparable to that of ammonium sulfate (∼10(-9) Pa). Further characterization showed that alkylaminium monocarboxylates are room temperature protic ionic liquids (RTPILs) that are more hygroscopic than ammonium sulfate (AS). We suggest that the irregular thermograms result from an incomplete neutralization reaction leading to a mixture of ionic and nonionic compounds. We conclude that these salts are expected to contribute to new particle formation and particle growth under ambient conditions and can significantly enhance the CCN activity of mixed particles in areas where SO2 emissions are regulated.

  5. Solvent-Free Esterification of Carboxylic Acids Using Supported Iron Oxide Nanoparticles as an Efficient and Recoverable Catalyst

    Directory of Open Access Journals (Sweden)

    Fatemeh Rajabi

    2016-07-01

    Full Text Available Supported iron oxide nanoparticles on mesoporous materials (FeNP@SBA-15 have been successfully utilized in the esterification of a variety carboxylic acids including aromatic, aliphatic, and long-chain carboxylic acids under convenient reaction conditions. The supported catalyst could be easily recovered after reaction completion and reused several times without any loss in activity after up to 10 runs.

  6. Space Weather Activities of IONOLAB Group: IONOLAB-TEC

    Science.gov (United States)

    Arikan, F.; Sezen, U.; Arikan, O.; Ugurlu, O.; Nayir, H.

    2009-04-01

    Space Weather (SW) is the concept of changing environmental conditions in outer space and affect Earth and its technological systems. SW is a consequence of the solar activities and the coupling of solar energy on Earth's atmosphere due to the Earth's magnetic field. The monitoring and prediction of SW has utmost importance for HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere. Ionosphere is the plasma layer of the atmosphere that is ionized by solar radiation and it is a key player of SW. Ionosphere is a temporally and spatially varying, dispersive, anisotropic and inhomogeneous medium that is characterized primarily by its electron density distribution. IONOLAB is a group of researchers of various disciplines, getting together to handle challenges of the Earth's ionosphere. The team has researchers from Hacettepe University and Bilkent University, Department of Electrical and Electronics Engineering and General Command of Mapping of Turkish Army. One of the most important contributions of IONOLAB group is the automated web-based computation service for Total Electron Content (TEC). TEC corresponds to the line integral of electron density distribution on a given path. TEC can also be expressed as the amount of free electrons within 1 m2 cross-sectional area of the cylinder on the ray path. Global Position System (GPS) provides a cost-effective medium for monitoring of ionosphere using the signals recorded by stationary GPS receivers in estimating TEC. IONOLAB group has developed IONOLAB-TEC for reliable and robust estimates for all latitudes and both calm and disturbed days by using RINEX, IONEX and satellite ephemeris data provided from the IGS centers. IONOLAB-TEC consists of a regularized signal estimation algorithm which combines signals from all GPS satellites for a given instant and a given receiver, for a desired time period or for 24 hours

  7. CARBOXYLIC ACIDS ELECTROOXIDATION ON SHUNGITE ELECTRODE

    Directory of Open Access Journals (Sweden)

    Oleksandr Davydenko

    2017-03-01

    Full Text Available Purpose: This article discusses the electrochemical method of directional conversion of carboxylic acids, which are the most aggressive hydrocarbons oxidation products back into the corresponding hydrocarbons. Existing methods for the regeneration of waste petroleum oils have significant drawbacks, which include the formation of new hard-reclaimed waste and loss of a significant part of the oil during regeneration. Methods: Electrooxidation processes of carboxylic acid on various electrode materials: platinum, graphite and shungite anodes were studied. Results: Potentiostatic polarization curves with simultaneous measurement of near-electrode solution pH showed differences in the process on these anode materials: dimer yield for Kolbe is decreased under the transition from platinum to shungite. At potentials higher than 2.0 v, carboxylic acid has a higher adsorbability compared to water. Therefore Faraday’s side-process of water oxidation doesn’t almost occur, which contributes to high yield of expected product according to current. Electrolysis of carboxylic acids solutions under controlled potential (2.0 and 2.4 V and chromatographic analysis of the formed products showed that along with the dimeric structures formation for Kolbe reaction, the occurrence of a hydrocarbons mixture takes place, which may be the result of disproportionation of hydrocarbon radicals (alkane and alkene and hydrocarbons of isomeric structure, by further oxidation of the hydrocarbon radical to carbocation and its subsequent transformation into the corresponding saturated and unsaturated isomers. Such statement is not supported by conception of the process of one- and two-electron carboxylic acid oxidation. Discussion: General carboxylic acid oxidation scheme according to one-electron mechanism (dimerization and disproportionation of the radical and two-electron mechanism (formation and carbocation rearrangement is proposed. The formation of hydrocarbons under

  8. Thermodynamic properties of alkyl 1H-indole carboxylate derivatives: A combined experimental and computational study

    International Nuclear Information System (INIS)

    Carvalho, Tânia M.T.; Amaral, Luísa M.P.F.; Morais, Victor M.F.; Ribeiro da Silva, Maria D.M.C.

    2016-01-01

    Highlights: • Combustion of methyl 1H-indole-3-carboxylate and ethyl 1H-indole-2-carboxylate by static bomb calorimetry. • The Knudsen mass-loss effusion technique was used to measure the vapour pressures of compounds at different temperatures. • Enthalpies of sublimation of methyl 1H-indole-3-carboxylate and ethyl 1H-indole-2-carboxylate. • Gas-phase enthalpies of formation of methyl 1H-indole-3-carboxylate and ethyl 1H-indole-2-carboxylate have been derived. • Gas-phase enthalpies of formation estimated from G3(MP2) calculations. - Abstract: The standard (p"o = 0.1 MPa) molar enthalpies of formation, in the crystalline phase, of methyl 1H-indole-3-carboxylate and ethyl 1H-indole-2-carboxylate, at T = 298.15 K, were derived from measurements of the standard massic energies of combustion using a static bomb combustion calorimeter. The Knudsen effusion technique was used to measure the vapour pressures as a function of the temperature, which allowed determining the standard molar enthalpies of sublimation of these compounds. The standard (p"o = 0.1 MPa) molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, were calculated by combining, for each compound, the standard molar enthalpy of formation, in the crystalline phase, and the standard molar enthalpy of sublimation, yielding −(207.6 ± 3.6) kJ·mol"−"1 and −(234.4 ± 2.4) kJ·mol"−"1, for methyl 1H-indole-3-carboxylate and ethyl 1H-indole-2-carboxylate, respectively. Quantum chemical studies were also conducted, in order to complement the experimental study. The gas-phase enthalpies of formation were estimated from high level ab initio molecular orbital calculations, at the G3(MP2) level, for the compounds studied experimentally, extending the study to the methyl 1H-indole-2-carboxylate and ethyl 1H-indole-3-carboxylate. The results obtained were compared with the experimental data and were also analysed in terms of structural enthalpic group contributions.

  9. Carboxylic acid-functionalized SBA-15 nanorods for gemcitabine delivery

    International Nuclear Information System (INIS)

    Bahrami, Zohreh; Badiei, Alireza; Ziarani, Ghodsi Mohammadi

    2015-01-01

    The present study deals with the functionalization of mesoporous silica nanoparticles as drug delivery systems. Mono, di, and tri amino-functionalized SBA-15 nanorods were synthesized by post-grafting method using (3-aminopropyl) triethoxysilane, N-(2-aminoethyl-)3- aminopropyltrimethoxysilane, and 3-[2-(2-aminoethylamino) ethylamino] propyl trimethoxysilane, respectively. The carboxylic acid derivatives of the amino-functionalized samples were obtained using succinic anhydride. Tminopropyltrimethoxysilanehe obtained modified materials were investigated as matrixes for the anticancer drug (gemcitabine) delivery. The prepared samples were characterized by SAXS, N 2 adsorption/desorption, SEM, transmission electron microscopy, thermogravimetric analysis, and FTIR and UV spectroscopies. The adsorption and release properties of all samples were studied. It was revealed that the adsorption capacity and release behavior of gemcitabine were highly dependent on the type of the introduced functional groups. The carboxylic acid-modified samples have higher loading content, due to the strong interaction with gemcitabine. The maximum content of deposited drug in the modified SBA-15 nanorods is close to 40 wt%. It was found that the surface functionalization leads toward significant decrease of the drug release rate. The carboxylic acid-functionalized samples have slower release rate in contrast with the amino-functionalized samples

  10. First principles study of edge carboxylated graphene quantum dots

    Science.gov (United States)

    Abdelsalam, Hazem; Elhaes, Hanan; Ibrahim, Medhat A.

    2018-05-01

    The structure stability and electronic properties of edge carboxylated hexagonal and triangular graphene quantum dots are investigated using density functional theory. The calculated binding energies show that the hexagonal clusters with armchair edges have the highest stability among all the quantum dots. The binding energy of carboxylated graphene quantum dots increases by increasing the number of carboxyl groups. Our study shows that the total dipole moment significantly increases by adding COOH with the highest value observed in triangular clusters. The edge states in triangular graphene quantum dots with zigzag edges produce completely different energy spectrum from other dots: (a) the energy gap in triangular zigzag is very small as compared to other clusters and (b) the highest occupied molecular orbital is localized at the edges which is in contrast to other clusters where it is distributed over the cluster surface. The enhanced reactivity and the controllable energy gap by shape and edge termination make graphene quantum dots ideal for various nanodevice applications such as sensors. The infrared spectra are presented to confirm the stability of the quantum dots.

  11. Synthesis and fluorescence study of phenylcoumarin/cyanophenylbenzocoumarin-3-carboxylates

    Directory of Open Access Journals (Sweden)

    Hosanagara N. Harishkumar

    2012-01-01

    Full Text Available The absorption and fluorescence spectra of phenylcoumarin and cyanophenylbenzocoumarin-3-carboxylates 6a-f and 9a-e have been investigated in chloroform, acetonitrile and ethanol. The substituting groups with varying electron donating ability such as N,N-diethyl amine and morpholine at 7-position, in phenylcoumarin-3-carboxylate 6a-f exhibits fluorescence at a longer wavelength i.e. 420-460 nm in chloroform and 460-504 nm in acetonitrile. However the morpholine derivatives 6f-j did not show fluorescence in chloroform. In another series of cyanophenylbenzocoumarin-3-carboxylates 9a-e, the compound 9c exhibits fluorescence at 546 nm in ethanol and 256 nm in acetonitrile, and lower emission wavelength i.e. 356 nm in chloroform. Further the compounds 6e , 9b, 9d and 9e exhibited high quantum yield in ethanol i.e., Φ F = 0.79, 0.70, 0.80 and 0.74 respectively compare to Rhodamine B ( Φ F = 0.24 in ethanol.

  12. Group Problem Solving as a Zone of Proximal Development activity

    Science.gov (United States)

    Brewe, Eric

    2006-12-01

    Vygotsky described learning as a process, intertwined with development, which is strongly influenced by social interactions with others that are at differing developmental stages.i These interactions create a Zone of Proximal Development for each member of the interaction. Vygotsky’s notion of social constructivism is not only a theory of learning, but also of development. While teaching introductory physics in an interactive format, I have found manifestations of Vygotsky’s theory in my classroom. The source of evidence is a paired problem solution. A standard mechanics problem was solved by students in two classes as a homework assignment. Students handed in the homework and then solved the same problem in small groups. The solutions to both the group and individual problem were assessed by multiple reviewers. In many cases the group score was the same as the highest individual score in the group, but in some cases, the group score was higher than any individual score. For this poster, I will analyze the individual and group scores and focus on three groups solutions and video that provide evidence of learning through membership in a Zone of Proximal Development. Endnotes i L. Vygotsky -Mind and society: The development of higher mental processes. Cambridge, MA: Harvard University Press. (1978).

  13. Non-routine activities in RP Group in 1995

    International Nuclear Information System (INIS)

    Hoefert, M.; Stevenson, G.R.

    1996-01-01

    The activities not directly concerned with the daily routine, but nevertheless essential to ensure a steady progress in radiation protection at CERN, concern mostly tests and intercomparisons of existing methods (quality control), development of new ideas, methods, and instruments. New projects, another non-routine activity, require in most cases profound studies to prove their feasibility with respect to radiation protection requirements. All these activities are documented in Divisional Reports, Internal Reports and Technical Memoranda, and are listed

  14. Engineering and service activities in the Cogema group

    International Nuclear Information System (INIS)

    1998-03-01

    This short document presents the engineering and service daughter companies of the Cogema group: SGN (nuclear engineering, fuel cycle, wastes and spent fuels management, decontamination and dismantling); Euriware group (advice, expertise and information systems in nuclear, pharmacy, petroleum, automotive and steel making industries); Game group (industrial maintenance in nuclear, chemistry, petroleum, automotive and steel making industries); Eurisys Mesures (nuclear measurements, instrumentation, radiation protection and nuclear imaging); SICN (mechanics); STMI and Socodei (nuclear cleansing and management of low level radioactive wastes); Krebs/Speichim (chemical engineering, divisions of SGN and Technip). (J.S.)

  15. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 10, Revision 3 (FGE.10Rev3): Aliphatic primary and secondary saturated and unsaturated alcohols, aldehydes, acetals, carboxylic acids and esters containing

    DEFF Research Database (Denmark)

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

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 63 flavouring substances in the Flavouring Group Evaluation 10, including additional two substances in this Revision 3, using the Procedure in Commission...... threshold of concern, and available data on metabolism and toxicity. The Panel concluded that the 62 substances do not give rise to safety concerns at their levels of dietary intake, estimated on the basis of the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications...... for the materials of commerce have also been considered. For four substances evaluated through the Procedure, the stereoisomeric composition has not been specified sufficiently....

  16. Scaffolding of Small Groups' Metacognitive Activities with an Avatar

    Science.gov (United States)

    Molenaar, Inge; Chiu, Ming Ming; Sleegers, Peter; van Boxtel, Carla

    2011-01-01

    Metacognitive scaffolding in a computer-supported learning environment can influence students' metacognitive activities, metacognitive knowledge and domain knowledge. In this study we analyze how metacognitive activities mediate the relationships between different avatar scaffolds on students' learning. Multivariate, multilevel analysis of the…

  17. Properties of the Carboxylate ion exchange resins

    International Nuclear Information System (INIS)

    Allard, Bert; Dario, Maarten; Boren, Hans; Torstenfelt, Boerje; Puigdomenech, Ignasi; Johansson, Claes

    2002-09-01

    Weakly acidic, carboxylic resin has been selected, together with strong base anion resins, for water purification at the Forsmark 1 and 2 reactors. For the strong (but not the weak) ion exchange resin the Nuclear Power Inspectorate has given permission to dispose the spent resins in the SFR 1 (the Final Repository for Radioactive Operational Waste). This report gives a review of the carboxylic resins and comes to the conclusion that the resins are very stable and that there should not exist any risks for increased leaching of radionuclides from SFR 1 if these resins are disposed (compared to the strong resins)

  18. Neutronic activation analysis of antique ceramics. Groups and differenciation

    International Nuclear Information System (INIS)

    Widemann, F.

    1975-01-01

    Different techniques for clay analysis in view of studying the origin of ceramics are exposed. The element abundance is measured by X-ray fluorescence analysis or by neutron activation analysis. Comparative tables of the results are established [fr

  19. Antimalarial activity of abietane ferruginol analogues possessing a phthalimide group.

    Science.gov (United States)

    González, Miguel A; Clark, Julie; Connelly, Michele; Rivas, Fatima

    2014-11-15

    The abietane-type diterpenoid (+)-ferruginol, a bioactive compound isolated from New Zealand's Miro tree (Podocarpus ferruginea), displays relevant pharmacological properties, including antimicrobial, cardioprotective, anti-oxidative, anti-plasmodial, leishmanicidal, anti-ulcerogenic, anti-inflammatory and anticancer. Herein, we demonstrate that ferruginol (1) and some phthalimide containing analogues 2-12 have potential antimalarial activity. The compounds were evaluated against malaria strains 3D7 and K1, and cytotoxicity was measured against a mammalian cell line panel. A promising lead, compound 3, showed potent activity with an EC50 = 86 nM (3D7 strain), 201 nM (K1 strain) and low cytotoxicity in mammalian cells (SI>290). Some structure-activity relationships have been identified for the antimalarial activity in these abietane analogues. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Active facilitation of focus groups: exploring the implementation of ...

    African Journals Online (AJOL)

    The focus group research reported in this article forms part of a broader inter- ..... “scientific research in education” should “refrain from writing [and acting] as if our ..... http://www.qualitative-research.net/index.php/fqs/article/view/338/737.

  1. Active facilitation of focus groups: exploring the implementation of ...

    African Journals Online (AJOL)

    In this article, we explain how we took an “active” approach to focus group discussions with teachers in three South African schools. The topic of discussion was their views on the implementation of inclusive education. We shall also show how we sought feedback from the participants on their experiences of these ...

  2. MobiGroup: Enabling Lifecycle Support to Social Activity Organization and Suggestion with Mobile Crowd Sensing

    OpenAIRE

    Guo, Bin; Yu, Zhiwen; Chen, Liming; Zhou, Xingshe; Ma, Xiaojuan

    2015-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. This paper presents a group-aware mobile crowd sensing system called MobiGroup, which supports group activity organization in real-world settings. Acknowledging the complexity and diversity of group activities, this paper introduces a formal concept model to characterize group activities and classifies them into four organizational stages. We t...

  3. Novel, high-activity hydroprocessing catalysts: Iron group phosphides

    Science.gov (United States)

    Wang, Xianqin

    A series of iron, cobalt and nickel transition metal phosphides was synthesized by means of temperature-programmed reduction (TPR) of the corresponding phosphates. The same materials, Fe2P, CoP and NO, were also prepared on a silica (SiO2) support. The phase purity of these catalysts was established by x-ray diffraction (XRD), and the surface properties were determined by N2 BET specific surface area (Sg) measurements and CO chemisorption. The activities of the silica-supported catalysts were tested in a three-phase trickle bed reactor for the simultaneous hydrodenitrogenation (HDN) of quinoline and hydrodesulfurization (HDS) of dibenzothiophene using a model liquid feed at realistic conditions (30 atm, 370°C). The reactivity studies showed that the nickel phosphide (Ni2P/SiO2) was the most active of the catalysts. Compared with a commercial Ni-Mo-S/gamma-Al 2O3 catalyst at the same conditions, Ni2P/silica had a substantially higher HDS activity (100% vs. 76%) and HDN activity (82% vs. 38%). Because of their good hydrotreating activity, an extensive study of the preparation of silica supported nickel phosphides, Ni2P/SiO 2, was carried out. The parameters investigated were the phosphorus content and the weight loading of the active phase. The most active composition was found to have a starting synthesis Ni/P ratio close to 1/2, and the best loading of this sample on silica was observed to be 18 wt.%. Extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES) measurements were employed to determine the structures of the supported samples. The main phase before and after reaction was found to be Ni2P, but some sulfur was found to be retained after reaction. A comprehensive scrutiny of the HDN reaction mechanism was also made over the Ni2P/SiO2 sample (Ni/P = 1/2) by comparing the HDN activity of a series of piperidine derivatives of different structure. It was found that piperidine adsorption involved an alpha-H activation

  4. Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Richard L. [Colorado School of Mines, Golden, CO (United States)

    2004-09-01

    Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate

  5. Parents' Networking Strategies: Participation of Formal and Informal Parent Groups in School Activities and Decisions

    Science.gov (United States)

    Wanat, Carolyn L.

    2010-01-01

    This case study examined parent groups' involvement in school activities and their participation in decision making. Research questions included the following: (1) What is the nature of parent groups in schools? (2) What activities and issues gain parent groups' attention and participation? (3) How do parent groups communicate concerns about…

  6. On the intermediacy of carboxyphosphate in biotin-dependent carboxylations

    International Nuclear Information System (INIS)

    Ogita, Takeshi; Knowles, J.R.

    1988-01-01

    In the ATP-dependent carboxylation of biotin that is catalyzed by most biotin-dependent carboxylases, a fundamental mechanistic question is whether the ATP activates bicarbonate (via the formation of carboxyphosphate as an intermediate) or whether the ATP activates biotin (via the formation of O-phosphobiotin). The authors have resorted to three mechanistic tests using the biotin carboxylase subunit of acetyl-CoA carboxylase from Escherichia coli: positional isotope exchange, intermediate trapping, and 18 O tracer experiments on the ATPase activity. First, no catalysis of positional isotope exchange in adenosine 5'-([α,β- 18 O,β,β- 18 O 2 ]triphosphate) was observed when either biotin or bicarbonate was absent, nor was any exchange seen in the presence of both N-1-methylbiotin and bicarbonate. Second, the putative carboxyphosphate intermediate could not be trapped as its trimethyl ester, under conditions of incubation and analysis where the authentic triester was shown to be adequately stable. In the third test, however, they showed that the ATPase activity of biotin carboxylase that is seen in the absence of biotin, an activity that is known to parallel the normal carboxylase reaction when biotin is present, occurs with the transfer of an 18 O label directly from [ 18 O]bicarbonate into the product P i . This result suggests that the bicarbonate-dependent biotin-independent ATPase reaction catalyzed by biotin carboxylase goes via carboxyphosphate and that the carboxylation of biotin itself may proceed analogously

  7. (2S,4R-4-Fluoropyrrolidinium-2-carboxylate

    Directory of Open Access Journals (Sweden)

    David B. Hobart Jr

    2012-08-01

    Full Text Available The crystal structure of the title compound, C5H8FNO2, at 100 K, displays intermolecular N—H...O hydrogen bonding between the ammonium and carboxylate groups as a result of its zwitterionic nature in the solid state. The five-membered ring adopts an envelope conformation with the C atom at the 3-position as the flap. The compound is of interest with respect to the synthesis and structural properties of synthetic collagens. The absolute structure was determined by comparison with the commercially available material.

  8. Methyl 3-(Quinolin-2-ylindolizine-1-carboxylate

    Directory of Open Access Journals (Sweden)

    Roumaissa Belguedj

    2015-12-01

    Full Text Available A novel compound, methyl 3-(quinolin-2-ylindolizine-1-carboxylate (2 has been synthesized by cycloaddition reaction of 1-(quinolin-2-ylmethylpyridinium ylide (1 with methyl propiolate in presence of sodium hydride in THF. The structure of this compound was established by IR, 1H-NMR, 13C-NMR and MS data

  9. Carboxylate ligands drastically enhance the rates of oxo exchange and hydrogen peroxide disproportionation by oxo manganese compounds of potential biological significance.

    Science.gov (United States)

    Dubois, Lionel; Pécaut, Jacques; Charlot, Marie-France; Baffert, Carole; Collomb, Marie-Noëlle; Deronzier, Alain; Latour, Jean-Marc

    2008-01-01

    To mimic the carboxylate-rich active site of the manganese catalases more closely we introduced carboxylate groups into dimanganese complexes in place of nitrogen ligands. The series of dimanganese(III,IV) complexes of tripodal ligands [Mn(2)(L)(2)(O)(2)](3+/+/-/3-) was extended from those of tpa (1) and H(bpg) (2) to those of H(2)(pda) (3) and H(3)(nta) (4) (tpa=tris-picolylamine, H(bpg)=bis-picolylglycylamine, H(2)(pda)=picolyldiglycylamine, H(3)(nta)=nitrilotriacetic acid). While 3 [Mn(2)(pda)(2)(O)(2)][Na(H(2)O)(3)] could be synthesized at -20 degrees C and characterized in the solid state, 4 [Mn(2)(nta)(2)(O)(2)](3-) could be obtained and studied only in solution at -60 degrees C. A new synthetic procedure for the dimanganese(III,III) complexes was devised, using stoichiometric reduction of the dimanganese(III,IV) precursor by the benzil radical with EPR monitoring. This enabled the preparation of the parent dimanganese(III,III) complex 5 [Mn(2)(tpa)(2)(O)(2)](ClO(4))(2), which was structurally characterized. The UV/visible, IR, EPR, magnetic, and electrochemical properties of complexes 1-3 and 5 were analyzed to assess the electronic changes brought about by the carboxylate replacement of pyridine ligands. The kinetics of the oxo ligand exchanges with labeled water was examined in acetonitrile solution. A dramatic effect of the number of carboxylates was evidenced. Interestingly, the influence of the second carboxylate substitution differs from that of the first one probably because this substitution occurs on an out-of-plane coordination while the former occurs in the plane of the [Mn(2)O(2)] core. Indeed, on going from 1 to 3 the exchange rate was increased by a factor of 50. Addition of triethylamine caused a rate increase for 1, but not for 3. The abilities of 1-3 to disproportionate H(2)O(2) were assessed volumetrically. The disproportionation exhibited a sensitivity corresponding to the carboxylate substitution. These observations strongly suggest that

  10. Activities of the ICRP task group on dose calculations (DOCAL)

    International Nuclear Information System (INIS)

    Bertelli, Luiz

    1997-01-01

    Full text. The International Commission of Radiological Protection has been doing many efforts to improve dose calculations due to intake of radionuclides by workers and members of the public. More specifically, the biokinetic models have become more and more physiologically based and developed for age-groups ranging from the embryo to the adult. The dosimetric aspects have also been very carefully revised and a new series of phantoms encompassing all developing stages of embryo and fetus were also envisaged. In order to assure the quality of the calculations, dose coefficients have been derived by two different laboratories and the results and methods have been frequently compared and discussed. A CD-ROM has been prepared allowing the user to obtain dose coefficients for the several age-groups for ingestion and inhalation of all important radionuclides. Inhalation dose coefficients will be available for several AMADs. For the particular case of embryo and fetus, doses will be calculated when the intake occurred before and during gestation for single and chronic patterns of intake

  11. Activation Analysis. Proceedings of an Informal Study Group Meeting

    International Nuclear Information System (INIS)

    1971-01-01

    As part of its programme to promote the exchange of information relating to nuclear science and technology, the International Atomic Energy Agency convened in Bangkok, Thailand, from 6-8 July 1970, an informal meeting to discuss the topic of Activation Analysis. The meeting was attended by participants drawn from the following countries: Australia, Burma, Ceylon, Republic of China, India, Indonesia, Prance, Japan, Republic of Korea, New Zealand, Philippines, Singapore, Thailand, United States of America and Vietnam. The proceedings consist of the contributions presented at the meeting with minor editorial changes

  12. Activation Analysis. Proceedings of an Informal Study Group Meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1971-07-01

    As part of its programme to promote the exchange of information relating to nuclear science and technology, the International Atomic Energy Agency convened in Bangkok, Thailand, from 6-8 July 1970, an informal meeting to discuss the topic of Activation Analysis. The meeting was attended by participants drawn from the following countries: Australia, Burma, Ceylon, Republic of China, India, Indonesia, Prance, Japan, Republic of Korea, New Zealand, Philippines, Singapore, Thailand, United States of America and Vietnam. The proceedings consist of the contributions presented at the meeting with minor editorial changes.

  13. l-2-Nitrimino-1,3-diazepane-4-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Harutyun A. Karapetyan

    2008-05-01

    Full Text Available The cyclic form of l-nitroarginine, C6H10N4O4, crystallizes with two independent molecules in the asymmetric unit. According to the geometrical parameters, similar in both molecules, the structure corresponds to that of l-2-nitrimino-1,3-diazepane-4-carboxylic acid; there are, however, conformational differences between the independent molecules, one of them being close to a twisted chair while the other might be described as a rather flattened boat. All six active H atoms in the two molecules are involved in hydrogen bonds, two of which are intramolecular and four intermolecular, forming an infinite chain of molecules along the b axis.

  14. Copper(II) and zinc(II) as metal-carboxylate coordination complexes based on (1-methyl-1H-benzo[d]imidazol-2-yl) methanol derivative: Synthesis, crystal structure, spectroscopy, DFT calculations and antioxidant activity

    Science.gov (United States)

    Benhassine, Anfel; Boulebd, Houssem; Anak, Barkahem; Bouraiou, Abdelmalek; Bouacida, Sofiane; Bencharif, Mustapha; Belfaitah, Ali

    2018-05-01

    This work presents a combined experimental and theoretical study of two new metal-carboxylate coordination compounds. These complexes were prepared from (1-methyl-1H-benzimidazol-2-yl)methanol under mild conditions. The structures of the prepared compounds were characterized by single-crystal X-ray analysis, FTIR and UV-Vis spectroscopy. In the Cupper complex, the Cu(II) ion is coordinated by two ligands, which act as bidentate chelator through the non-substituted N and O atoms, and two carboxylicg oxygen atoms, displaying a hexa-coordinated compound in a distorted octahedral geometry, while in the Zinc complex the ligand is ligated to the Zn(II) ion in monodentate fashion through the N atom, and the metal ion is also bonded to carboxylic oxygen atoms. The tetra-coordinated compound displays a distorted tetrahedral shape. The density functional theory calculations are carried out for the determination of the optimized structures. The electronic transitions and fundamental vibrational wave numbers are calculated and are in good agreement with experimental. In addition, the ligand and its Cu(II) and Zn(II) complexes were screened and evaluated for their potential as DPPH radical scavenger.

  15. Contralateral delay activity tracks the influence of Gestalt grouping principles on active visual working memory representations.

    Science.gov (United States)

    Peterson, Dwight J; Gözenman, Filiz; Arciniega, Hector; Berryhill, Marian E

    2015-10-01

    Recent studies have demonstrated that factors influencing perception, such as Gestalt grouping cues, can influence the storage of information in visual working memory (VWM). In some cases, stationary cues, such as stimulus similarity, lead to superior VWM performance. However, the neural correlates underlying these benefits to VWM performance remain unclear. One neural index, the contralateral delay activity (CDA), is an event-related potential that shows increased amplitude according to the number of items held in VWM and asymptotes at an individual's VWM capacity limit. Here, we applied the CDA to determine whether previously reported behavioral benefits supplied by similarity, proximity, and uniform connectedness were reflected as a neural savings such that the CDA amplitude was reduced when these cues were present. We implemented VWM change-detection tasks with arrays including similarity and proximity (Experiment 1); uniform connectedness (Experiments 2a and 2b); and similarity/proximity and uniform connectedness (Experiment 3). The results indicated that when there was a behavioral benefit to VWM, this was echoed by a reduction in CDA amplitude, which suggests more efficient processing. However, not all perceptual grouping cues provided a VWM benefit in the same measure (e.g., accuracy) or of the same magnitude. We also found unexpected interactions between cues. We observed a mixed bag of effects, suggesting that these powerful perceptual grouping benefits are not as predictable in VWM. The current findings indicate that when grouping cues produce behavioral benefits, there is a parallel reduction in the neural resources required to maintain grouped items within VWM.

  16. Development Research of new boron-compounds for boron neutron capture therapy. Biological activity evaluation of amino group in p-boronophenylalanine and p-boronophenylalaninol

    International Nuclear Information System (INIS)

    Kumanisi, A.; Uehara, K.; Takikawa, S.; Kirihata, M.; Takagaki, M.; Ono, K.; Sakurai, Y.; Kobayashi, T.

    2001-01-01

    Para-boronophenylalanine (BPA) is used as a leading compound for development and research of some of new boron carriers for boron neutron capture therapy. Para-boronophenylalaninol (BPA-ol) is designed molecularly by converting carboxyl group of the BPA to hydroxyl group. The BPA-ol gets a good result in biological test in-vitro and in-vivo. N-methyl-BPA and N-methyl-BPA-ol are synthesized for biological activity evaluation of amino group in the BPA. Two pathways for methylation of amino group in the BPA are investigated. These synthesized compounds of N-methyl-BPA, N-methyl-BPA-ol, and the BPA-ol are tested by colony formation method using gliosarcoma C6 cultured cells of rats. Absorbed doses (thermal neutron fluences) corresponding to the 10% surviving fraction are 1.69 x 10 13 for N-methyl-BPA, 1.13 x 10 13 for N-methyl-BPA-ol, and 6.87 x 10 12 for BPA-ol, respectively. Toxicity of N-methyl-BPA or N-Methyl-BPA-ol to the cultured cells is below that of the BPA. The toxicity of N-methyl-BPA-ol, particularly, is less than 1/100 of that of the BPA. (M. Suetake)

  17. Structure of ganglioside with CAD blood group antigen activity

    International Nuclear Information System (INIS)

    Gillard, B.K.; Blanchard, D.; Cartron, J.P.; van Kuik, G.A.; Vliegenthart, J.F.G.; Marcus, D.M.

    1986-01-01

    The novel erythrocyte ganglioside which carries the blood group Cad determinant has been isolated, and its structure has been determined. The ganglioside contained Glu:Gal:GalNAc:GlcNAc in a molar ratio of 1.00:1.94:0.93:0.95. The ganglioside binds Helix pomatia lectin and its chromatographic mobility is similar to G/sub D3/. After treatment with β-hexosaminidase (human placenta HexA) the product migrated with sialosylparagloboside (SPG), no longer binds Helix lectin, and binds a human anti-SPG antibody. Treatment of this material with neuraminidase (V. cholera) yielded a product with the mobility of paragloboside that bound monoclonal antibody 1B2. NMR analysis revealed that the terminal GalNAc is linked β1-4 to Gal, and confirms the structure proposed previously: GalNAcβ1-4(NeuAcα2-3)Galβ1-4GlcNAcβ1-3Galβ1-4Glc-Cer. This structure is consistent with the previous demonstration that a compound with the same chromatographic mobility as the Cad ganglioside could be synthesized by enzymatic transfer of GalNAc to sialosylparagloboside

  18. Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates

    Science.gov (United States)

    Uddin, Noor; Sirajuddin, Muhammad; Uddin, Nizam; Tariq, Muhammad; Ullah, Hameed; Ali, Saqib; Tirmizi, Syed Ahmed; Khan, Abdur Rehman

    2015-04-01

    This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.

  19. Recovery and esterification of aqueous carboxylates by using CO

    NARCIS (Netherlands)

    Cabrera-Rodríguez, Carlos I.; Paltrinieri, Laura; Smet, De Louis C.P.M.; Wielen, Van Der Luuk A.M.; Straathof, Adrie J.J.

    2017-01-01

    The recovery of carboxylic acids from fermentation broth is one of the main bottlenecks for the industrial production of bio-based esters. This paper proposes an alternative for the recovery of carboxylates produced by fermentations at pH values above the pKa of the carboxylic acid. In this

  20. Production of carboxylic acid and salt co-products

    Science.gov (United States)

    Hanchar, Robert J.; Kleff, Susanne; Guettler, Michael V.

    2014-09-09

    This invention provide processes for producing carboxylic acid product, along with useful salts. The carboxylic acid product that is produced according to this invention is preferably a C.sub.2-C.sub.12 carboxylic acid. Among the salts produced in the process of the invention are ammonium salts.

  1. Atmospheric chemistry of carboxylic acids: microbial implication versus photochemistry

    Science.gov (United States)

    Vaïtilingom, M.; Charbouillot, T.; Deguillaume, L.; Maisonobe, R.; Parazols, M.; Amato, P.; Sancelme, M.; Delort, A.-M.

    2011-08-01

    The objective of this work was to compare experimentally the contribution of photochemistry vs. microbial activity to the degradation of carboxylic acids present in cloud water. For this, we selected 17 strains representative of the microflora existing in real clouds and worked on two distinct artificial cloud media that reproduce marine and continental cloud chemical composition. Photodegradation experiments with hydrogen peroxide (H2O2) as a source of hydroxyl radicals were performed under the same microcosm conditions using two irradiation systems. Biodegradation and photodegradation rates of acetate, formate, oxalate and succinate were measured on both media at 5 °C and 17 °C and were shown to be on the same order of magnitude (around 10-10-10-11 M s-1). The chemical composition (marine or continental origin) had little influence on photodegradation and biodegradation rates while the temperature shift from 17 °C to 5 °C decreased biodegradation rates of a factor 2 to 5. In order to test other photochemical scenarios, theoretical photodegradation rates were calculated considering hydroxyl (OH) radical concentration values in cloud water estimated by cloud chemistry modelling studies and available reaction rate constants of carboxylic compounds with both hydroxyl and nitrate radicals. Considering high OH concentration ([OH] = 1 × 10-12 M) led to no significant contribution of microbial activity in the destruction of carboxylic acids. On the contrary, for lower OH concentration (at noon, [OH] = 1 × 10-14 M), microorganisms could efficiently compete with photochemistry and in similar contributions than the ones estimated by our experimental approach. Combining these two approaches (experimental and theoretical), our results led to the following conclusions: oxalate was only photodegraded; the photodegradation of formate was usually more efficient than its biodegradation; the biodegradation of acetate and succinate seemed to exceed their photodegradation.

  2. Correction: Synthesis of pyrrolidine-3-carboxylic acid derivatives via asymmetric Michael addition reactions of carboxylate-substituted enones.

    Science.gov (United States)

    Yin, Feng; Garifullina, Ainash; Tanaka, Fujie

    2018-04-25

    Correction for 'Synthesis of pyrrolidine-3-carboxylic acid derivatives via asymmetric Michael addition reactions of carboxylate-substituted enones' by Feng Yin et al., Org. Biomol. Chem., 2017, 15, 6089-6092.

  3. Analysis of carboxylate coordination function of the isomeric lanthanide pyridinedicarboxylates by means of vibration spectroscopy

    International Nuclear Information System (INIS)

    Puntus, L.; Zolin, V.; Kudryashova, V.

    2004-01-01

    The investigation of IR spectra of salts of six isomers of pyridinedicarboxylic acid (PDA): 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-pyridinedicarboxylic acids, have demonstrated that properties of these salts are dependent on the bonding manner of carboxylate groups and on coordination of heterocyclic nitrogen atom. The most prominent differences in properties and spectra of 2,6- and 3,4-PDA salts are conditioned correspondingly by monodentate and bidentate coordination functions of the carboxylate groups in these compounds. The correlation of the breathing vibration frequency, reflecting the rigidity of the heterocyclic ring, with position of the carboxylate substituents, conditioning intramolecular charge transfer (CT), was postulated and proved by shifts of the breathing vibration frequency dependent on the structure of isomeric ligand

  4. Active versus receptive group music therapy for major depressive disorder-A pilot study.

    Science.gov (United States)

    Atiwannapat, Penchaya; Thaipisuttikul, Papan; Poopityastaporn, Patchawan; Katekaew, Wanwisa

    2016-06-01

    To compare the effects of 1) active group music therapy and 2) receptive group music therapy to group counseling in treatment of major depressive disorder (MDD). On top of standard care, 14 MDD outpatients were randomly assigned to receive 1) active group music therapy (n=5), 2) receptive group music therapy (n=5), or 3) group counseling (n=4). There were 12 one-hour weekly group sessions in each arm. Participants were assessed at baseline, 1 month (after 4 sessions), 3 months (end of interventions), and 6 months. Primary outcomes were depressive scores measured by Montgomery-Åsberg Depression Rating Scale (MADRS) Thai version. Secondary outcomes were self-rated depression score and quality of life. At 1 month, 3 months, and 6 months, both therapy groups showed statistically non-significant reduction in MADRS Thai scores when compared with the control group (group counseling). The reduction was slightly greater in the active group than the receptive group. Although there were trend toward better outcomes on self-report depression and quality of life, the differences were not statistically significant. Group music therapy, either active or receptive, is an interesting adjunctive treatment option for outpatients with MDD. The receptive group may reach peak therapeutic effect faster, but the active group may have higher peak effect. Group music therapy deserves further comprehensive studies. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. When Two Heads Aren't Better than One: Conformity in a Group Activity

    Science.gov (United States)

    Fender, C. Melissa; Stickney, Lisa T.

    2017-01-01

    Group and team class decision-making activities often focus on demonstrating that "two heads are better than one." Typically, students solve a problem or complete an assessment individually, then in a group. Generally, the group does better and that is what the students learn. However, if that is all such an activity conveys, then a…

  6. Simple approach to carboxyl-rich materials through low-temperature heat treatment of hydrothermal carbon in air

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhen; Ma Lijian; Li Shuqiong; Geng Junxia; Song Qiang; Liu Jun; Wang Chunli; Wang Hang; Li Juan [College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Chengdu 610064 (China); Qin Zhi [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Li Shoujian, E-mail: sjli000616@scu.edu.cn [College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education, Chengdu 610064 (China)

    2011-08-01

    It was found that a large number of oxygen-containing functional groups (OFGs) could be created on the surface of hydrothermal carbon (HTC) by simply heating at lower temperature in air during the course of our preliminary experiments which focused on oxidation pre-treatment of pristine HTC for the purpose of grafting functionalization. Especially carboxyl groups on HTC would increase significantly, from 0.53 to 3.70 mmol/g after heat treatment at 300 deg. C. So, effects of heat-treatment on the OFGs on the carbon microsphere were deeply studied to confirm and explain the findings. Experiments involving different materials (HTC, activated carbon and glucose) were performed under varying conditions (heating temperature and time, in air or in Ar atmosphere). A reaction mechanism for newly generating carboxyl groups on HTC surface during heat-treatment process was supposed based on the results from the sample characterization using Boehm titrations, infrared spectra, X-ray photoelectron spectroscopy, energy dispersive spectrometry and elemental analysis. In addition, the as heat-treated product has excellent sorption capability for Pb{sup 2+} and Cd{sup 2+} ions.

  7. Carboxylated nitrile butadiene rubber/hybrid filler composites

    Directory of Open Access Journals (Sweden)

    Ahmad Mousa

    2012-08-01

    Full Text Available The surface properties of the OSW and NLS are measured with the dynamic contact-angle technique. The x-ray photoelectron spectroscopy (XPS of the OSW reveals that the OSW possesses various reactive functional groups namely hydroxyl groups (OH. Hybrid filler from NLS and OSW were incorporated into carboxylated nitrile rubber (XNBR to produce XNBR hybrid composites. The reaction of OH groups from the OSW with COOH of the XNBR is checked by attenuated total reflectance spectra (ATR-IR of the composites. The degree of curing ΔM (maximum torque-minimum torque as a function of hybrid filler as derived from moving die rheometer (MDR is reported. The stress-strain behavior of the hybrid composites as well as the dynamic mechanical thermal analysis (DMTA is studied. Bonding quality and dispersion of the hybrid filler with and in XNBR are examined using scanning-transmission electron microscopy (STEM in SEM.

  8. Understanding Mathematic Concept in Relation and Function Method through Active Learning Type Group to Group Distributed LKS

    Science.gov (United States)

    Kudri, F.; Rahmi, R.; Haryono, Y.

    2018-04-01

    This research is motivated by the lack of understanding of mathematical concepts students and teachers have not familiarize students discussed in groups. This researchaims to determine whether an understanding of mathematical concepts junior class VIII SMPN 2 in Ranah Batahan Kabupaten Pasaman Barat by applying active learning strategy group to group types with LKS better than conventional learning. The type of research is experimental the design of randomized trials on the subject. The population in the study were all students VIII SMPN 2 Ranah Batahan Kabupaten Pasaman Barat in year 2012/2013 which consists of our class room experiment to determine the grade and control class with do nerandomly, so that classes VIII1 elected as a experiment class and class VIII4 as a control class. The instruments used in the test empirically understanding mathematical concepts are shaped by the essay with rt=0,82 greater than rt=0,468 means reliable tests used. The data analysis technique used is the test with the help of MINITAB. Based on the results of the data analisis known that both of the sample are normal and homogenity in real rate α = 0,05, so the hypothesis of this research is received. So, it can be concluded students’ understanding mathematical concept applied the active Group to Group learning strategy with LKS is better than the students’ understanding mathematical concept with Conventional Learning.

  9. The Ameliorative Effects of L-2-Oxothiazolidine-4-Carboxylate on Acetaminophen-Induced Hepatotoxicity in Mice

    Directory of Open Access Journals (Sweden)

    Jun Ho Shin

    2013-03-01

    Full Text Available The aim of the study was to investigate the ameliorative effects and the mechanism of action of L-2-oxothiazolidine-4-carboxylate (OTC on acetaminophen (APAP-induced hepatotoxicity in mice. Mice were randomly divided into six groups: normal control group, APAP only treated group, APAP + 25 mg/kg OTC, APAP + 50 mg/kg OTC, APAP + 100 mg/kg OTC, and APAP + 100 mg/kg N-acetylcysteine (NAC as a reference control group. OTC treatment significantly reduced serum alanine aminotransferase and aspartate aminotransferase levels in a dose dependent manner. OTC treatment was markedly increased glutathione (GSH production and glutathione peroxidase (GSH-px activity in a dose dependent manner. The contents of malondialdehyde and 4-hydroxynonenal in liver tissues were significantly decreased by administration of OTC and the inhibitory effect of OTC was similar to that of NAC. Moreover, OTC treatment on APAP-induced hepatotoxicity significantly reduced the formation of nitrotyrosin and terminal deoxynucleotidyl transferase dUTP nick end labeling positive areas of liver tissues in a dose dependent manner. Furthermore, the activity of caspase-3 in liver tissues was reduced by administration of OTC in a dose dependent manner. The ameliorative effects of OTC on APAP-induced liver damage in mice was similar to that of NAC. These results suggest that OTC has ameliorative effects on APAP-induced hepatotoxicity in mice through anti-oxidative stress and anti-apoptotic processes.

  10. Influence of surface oxygenated groups on the formation of active Cu species and the catalytic activity of Cu/AC catalyst for the synthesis of dimethyl carbonate

    Science.gov (United States)

    Zhang, Guoqiang; Li, Zhong; Zheng, Huayan; Hao, Zhiqiang; Wang, Xia; Wang, Jiajun

    2016-12-01

    Activated carbon (AC) supported Cu catalysts are employed to study the influence of surface oxygenated groups on the formation of active Cu species and the catalytic activity of Cu/AC catalyst for oxidative carbonylation of methanol to dimethyl carbonate (DMC). The AC supports are thermal treated under different temperatures in order to adjust the levels of surface oxygenated groups. The AC supports are characterized by BET, TPD-MS and XRD, and the Cu/AC catalysts are characterized by BET, XRD, TEM, XPS, AAS, CH3OH-TPD and N2O chemisorption. The results show that as the treatment temperature is below 800 °C, the BET surface area of the corresponding AC supports are nearly unchanged and close to that of the original AC (1529.6 m2/g). But as the thermal treatment temperature is elevated from 1000 to 1600 °C, the BET surface area of AC supports gradually decreases from 1407.6 to 972.2 m2/g. After loading of Cu, the BET surface area of copper catalysts is in the range of 834.4 to 1545.3 m2/g, which is slightly less than that of the respective supports. When AC is thermal treated at 400 and 600 °C, the unstable carboxylic acid and anhydrides groups are selectively removed, which has weakened the mobility and agglomeration of Cu species during the calcination process, and thus improve the Cu species dispersion over AC support. But as the treatment temperature is elevated from 600 °C to 1200 °C, the Cu species dispersion begins to decline suggesting further removal of stable surface oxygenated groups is unfavorable for Cu species dispersion. Moreover, higher thermal treatment temperature (above 1200 °C) promotes the graphitization degree of AC and leds to the decrease of Cu loading on AC support. Meanwhile, the removal of surface oxygenated groups by thermal treatment is conducive to the formation of more π-sites, and thus promote the reduction of Cu2+ to Cu+ and Cu0 as active centers. The specific surface area of (Cu+ + Cu0) is improved by thermal treatment of AC

  11. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 06, Revision 3 (FGE.06Rev3): Straight- and branched-chain aliphatic unsaturated primary alcohols, aldehydes, carboxylic acids, and esters from chemical groups 1

    DEFF Research Database (Denmark)

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

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 50 flavouring substances in the Flavouring Group Evaluation 6, Revision 3, using the Procedure in Commission Regulation (EC) No 1565/2000. None of the subs......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 50 flavouring substances in the Flavouring Group Evaluation 6, Revision 3, using the Procedure in Commission Regulation (EC) No 1565/2000. None...... of the substances were considered to have genotoxic potential. The substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity...... of these flavouring substances, the specifications for the materials of commerce have also been considered. For one substance [FL-no: 09.938] an identity test is missing and for two substances [FL-no: 05.226 and 09.950] the range of the specific gravity is too wide. Additional, the stereoisomeric mixture has not been...

  12. Carboxylic acid exchangers in analytical chemistry

    International Nuclear Information System (INIS)

    Venkateswarlu, Ch.

    1976-01-01

    The literature on the use of carboxylic acid exchangers in inorganic analytical chemistry is reviewed. It is classified under two heads, based on the ionic form in which the exchanger is employed, viz., the salt form and the acid form. In the salt form, the separations reported in the beginning are mostly carried out in alkaline medium, employing ammonia and its derivatives as complexing agents to hold cations in solution. This was followed by the use of ammonium ion as an eluent from heavy weakly or neutral solutions. There are a few separations reported making use of EDTA as eluent. It appears that separation of some anions from cations can be achieved with greater ease with these exchangers than with sulphonic acid type. Contary to the general belief, carboxylic acid exchangers are used in H + form to achieve some analytical separations of cations of interest. These exchangers exhibit better sorption of some cations in presence of complexing agents containing basic nitrogen as a donor. In fact, a careful study of these exchangers with different matrices might yield really selective exchangers, than the chelating ones known commercially. From the separation cited, carboxylic acid exchangers appear to have greater potentialities in their applications, than what is normally expected. (author)

  13. The potential impact of carboxylic-functionalized multi-walled carbon nanotubes on trypsin: A Comprehensive spectroscopic and molecular dynamics simulation study.

    Directory of Open Access Journals (Sweden)

    Maryam Noordadi

    Full Text Available In this study, we report a detailed experimental, binding free energy calculation and molecular dynamics (MD simulation investigation of the interactions of carboxylic-functionalized multi-walled carbon nanotubes (COOH-f-MWCNTs with porcine trypsin (pTry. The enzyme exhibits decreased thermostability at 330K in the presence of COOH-f-MWCNTs. Furthermore, the activity of pTry also decreases in the presence of COOH-f-MWCNTs. The restricted diffusion of the substrate to the active site of the enzyme was observed in the experiment. The MD simulation analysis suggested that this could be because of the blocking of the S1 pocket of pTry, which plays a vital role in the substrate selectivity. The intrinsic fluorescence of pTry is quenched with increase in the COOH-f-MWCNTs concentration. Circular dichroism (CD and UV-visible absorption spectroscopies indicate the ability of COOH-f-MWCNTs to experience conformational change in the native structure of the enzyme. The binding free energy calculations also show that electrostatics, π-cation, and π-π stacking interactions play important roles in the binding of the carboxylated CNTs with pTry. The MD simulation results demonstrated that the carboxylated CNTs adsorb to the enzyme stronger than the CNT without the-COOH groups. Our observations can provide an example of the nanoscale toxicity of COOH-f-MWCNTs for proteins, which is a critical issue for in vivo application of COOH-f-MWCNTs.

  14. One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres with enhanced photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Lingling [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Luo, Zhijun, E-mail: lzj@ujs.edu.cn [School of the Environment, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Tang, Chao [Maple Leaf International High School, Zhenjiang 212013 (China)

    2013-11-15

    Graphical abstract: Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core–shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs). Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation. - Highlights: • One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres. • Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@CRCSs. • Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits enhanced photocatalytic activity under visible light irradiation. - Abstract: Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core-shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs) have been synthesized via a one-step method. The core–shell nanosturctures of the as-prepared samples were confirmed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and Raman spectroscopy. The formation of Bi@Bi{sub 2}O{sub 3}@CRCSs core–shell nanosturctures should attribute to the synergetic roles of different functional groups of sodium gluconate. Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation (λ > 420 nm) and shows an O{sub 2}-dependent feature. According to trapping experiments of radicals and holes, hydroxyl radicals were not the main active oxidative species in the photocatalytic degradation of MB, but O{sub 2}·{sup −} are the main active oxidative species.

  15. Carboxylic acids in crystallization of macromolecules: learning from successful crystallization experiments.

    Science.gov (United States)

    Offermann, Lesa R; He, John Z; Mank, Nicholas J; Booth, William T; Chruszcz, Maksymilian

    2014-03-01

    The production of macromolecular crystals suitable for structural analysis is one of the most important and limiting steps in the structure determination process. Often, preliminary crystallization trials are performed using hundreds of empirically selected conditions. Carboxylic acids and/or their salts are one of the most popular components of these empirically derived crystallization conditions. Our findings indicate that almost 40 % of entries deposited to the Protein Data Bank (PDB) reporting crystallization conditions contain at least one carboxylic acid. In order to analyze the role of carboxylic acids in macromolecular crystallization, a large-scale analysis of the successful crystallization experiments reported to the PDB was performed. The PDB is currently the largest source of crystallization data, however it is not easily searchable. These complications are due to a combination of a free text format, which is used to capture information on the crystallization experiments, and the inconsistent naming of chemicals used in crystallization experiments. Despite these difficulties, our approach allows for the extraction of over 47,000 crystallization conditions from the PDB. Initially, the selected conditions were investigated to determine which carboxylic acids or their salts are most often present in crystallization solutions. From this group, selected sets of crystallization conditions were analyzed in detail, assessing parameters such as concentration, pH, and precipitant used. Our findings will lead to the design of new crystallization screens focused around carboxylic acids.

  16. Selective Reductive Removal of Ester and Amide Groups from Arenes and Heteroarenes through Nickel-Catalyzed C−O and C−N Bond Activation

    KAUST Repository

    Yue, Huifeng

    2017-03-21

    An inexpensive nickel(II) catalyst and a hydrosilane were used for the efficient reductive defunctionalization of aryl and heteroaryl esters through a decarbonylative pathway. This versatile method could be used for the removal of ester and amide functional groups from various organic molecules. Moreover, a scale-up experiment and a synthetic application based on the use of a removable carboxylic acid directing group highlight the usefulness of this reaction.

  17. Selective Reductive Removal of Ester and Amide Groups from Arenes and Heteroarenes through Nickel-Catalyzed C−O and C−N Bond Activation

    KAUST Repository

    Yue, Huifeng; Guo, Lin; Lee, Shao-Chi; Liu, Xiangqian; Rueping, Magnus

    2017-01-01

    An inexpensive nickel(II) catalyst and a hydrosilane were used for the efficient reductive defunctionalization of aryl and heteroaryl esters through a decarbonylative pathway. This versatile method could be used for the removal of ester and amide functional groups from various organic molecules. Moreover, a scale-up experiment and a synthetic application based on the use of a removable carboxylic acid directing group highlight the usefulness of this reaction.

  18. Derivatization of carboxylic acids with 4-APEBA for detection by positive-ion LC-ESI-MS(/MS) applied for the analysis of prostanoids and NSAID in urine

    NARCIS (Netherlands)

    Kretschmer, A.; Giera, M.A.; Wijtmans, M.; de Vries, L.; Lingeman, H.; Irth, H.; Niessen, W.M.A.

    2011-01-01

    In order to develop a generic positive ionization ESI LC-MS method for a variety of interesting substance classes, a new derivatization strategy for carboxylic acids was developed. The carboxylic acid group is labeled with the bromine containing 4-APEBA reagent based on carbodiimide chemistry. The

  19. [14C]-radiolabeling of {[trans-(8β)]-6-methyl-1-(1-methylethyl) ergoline-8-carboxylic acid, 4-methoxycyclohexyl ester (Z)-2-buteneidioate (1:1)}

    International Nuclear Information System (INIS)

    Marzoni, G.; Wheeler, W.J.; Garbrecht, W.L.

    1988-01-01

    The 5HT 2 -receptor antagonist, [ 14 C]-labeled brace[trans-(8β)]-6-methyl-1-(1-methylethyl)ergoline-8-carboxylic acid, 4-methoxycyclohexyl ester (Z)-2-butenedioate (1:1)brace (LY281067) was synthesized from unlabeled 6-methyl-1-(1-methylethyl)ergoline-8-carboxylic acid. The [ 14 C] label was introduced into the carboxyl group attached to the 8 position of the ergoline nucleus. This site is stable to metabolism. The synthesis involves removal of an unlabeled carboxyl group and subsequent reinsertion of a [ 14 C]-labeled carboxyl group into the same position. The radiolabel is not introduced until near the end of the synthesis which allows for ease of handling and scale-up of intermediates. (author)

  20. Carboxylated SiO2-coated α-Fe nanoparticles: towards a versatile platform for biomedical applications.

    Science.gov (United States)

    Kohara, Kaori; Yamamoto, Shinpei; Seinberg, Liis; Murakami, Tatsuya; Tsujimoto, Masahiko; Ogawa, Tetsuya; Kurata, Hiroki; Kageyama, Hiroshi; Takano, Mikio

    2013-03-28

    Carboxylated SiO2-coated α-Fe nanoparticles have been successfully prepared via CaH2-mediated reduction of SiO2-coated Fe3O4 nanoparticles followed by surface carboxylation. These α-Fe-based nanoparticles, which are characterized by ease of coating with additional functional groups, a large magnetization of 154 emu per g-Fe, enhanced corrosion resistivity, excellent aqueous dispersibility, and low cytotoxicity, have potential to be a versatile platform in biomedical applications.

  1. New Synthesis, Structure and Analgesic Properties of Methyl 1-R-4-Methyl-2,2-Dioxo-1H-2λ6,1-Benzothiazine-3-Carboxylates

    Directory of Open Access Journals (Sweden)

    Liliana Azotla-Cruz

    2017-01-01

    Full Text Available According to the principles of the methodology of bioisosteric replacements a series of methyl 1-R-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylates has been obtained as potential analgesics. In addition, a fundamentally new strategy for the synthesis of compounds of this chemical class involving the introduction of N-alkyl substituent at the final stage in 2,1-benzothiazine nucleus already formed has been proposed. Using nuclear magnetic resonance (NMR spectroscopy, mass spectrometry and X-ray diffraction analysis it has been proven that in the DMSO/K2CO3 system the reaction of methyl 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate and alkyl halides leads to formation of N-substituted derivatives with good yields regardless of the structure of the alkylating agent. The peculiarities of NMR (1Н and 13С spectra of the compounds synthesized, their mass spectrometric behavior and the spatial structure are discussed. In N-benzyl derivative the ability to form a monosolvate with methanol has been found. According to the results of the pharmacological testing conducted on the model of the thermal tail-flick it has been determined that replacement of 4-ОН-group in methyl 1-R-4-hydroxy-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylates for the methyl group is actually bioisosteric since all methyl 1-R-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylates synthesized demonstrated a statistically significant analgesic effect. The majority of the substances can inhibit the thermal pain response much more effective than piroxicam in the same dose. Under the same conditions as an analgesic the N-methyl-substituted analog exceeds not only piroxicam, but more active meloxicam as well. Therefore, it deserves in-depth biological studies on other experimental models.

  2. Catalytic transformation of functionalized carboxylic acids using multifunctional rhenium complexes.

    Science.gov (United States)

    Naruto, Masayuki; Agrawal, Santosh; Toda, Katsuaki; Saito, Susumu

    2017-06-13

    Carboxylic acids (CAs) are one of the most ubiquitous and important chemical feedstocks available from biorenewable resources, CO 2 , and the petrochemical industry. Unfortunately, chemoselective catalytic transformations of CH n CO 2 H (n = 1-3) groups into other functionalities remain a significant challenge. Herein, we report rhenium V complexes as extremely effective precatalysts for this purpose. Compared to previously reported heterogeneous and homogeneous catalysts derived from high- or low-valent metals, the present method involves a α-C-H bond functionalization, a hydrogenation, and a hydrogenolysis, which affords functionalized alcohols with a wide substrate scope and high chemoselectivity under relatively mild reaction conditions. The results represent an important step toward a paradigm shift from 'low-valent' to 'high-valent' metal complexes by exploring a new portfolio of selective functional group transformations of highly oxygenated organic substrates, as well as toward the exploitation of CAs as a valuable biorenewable feedstock.

  3. Biocompatibility studies of polyacrylonitrile membranes modified with carboxylated polyetherimide

    Energy Technology Data Exchange (ETDEWEB)

    Senthilkumar, S.; Rajesh, S.; Jayalakshmi, A.; Mohan, D., E-mail: mohantarun@gmail.com

    2013-10-15

    Poly (ether-imide) (PEI) was carboxylated and used as the hydrophilic modification agent for the preparation of polyacrylonitrile (PAN) membranes. Membranes were prepared with different blend compositions of PAN and CPEI by diffusion induced precipitation. The modified membranes were characterized by thermo gravimetric analysis (TGA), mechanical analysis, scanning electron microscopy (SEM) and contact angle measurement to understand the influence of CPEI on the properties of the membranes. The biocompatibility studies exhibited reduced plasma protein adsorption, platelet adhesion and thrombus formation on the modified membrane surface. The complete blood count (CBC) results of CPEI incorporated membranes showed stable CBC values and significant decrease in the complement activation were also observed. In addition to good cytocompatibility, monocytes cultured on these modified membranes exhibited improved functional profiles in 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Thus it could be concluded that PAN/CPEI membranes with excellent biocompatibility can be useful for hemodialysis. Highlights: • Carboxylated PEI was prepared and utilized as hydrophilic modification agent. • CPEI incorporated into PAN to improved biocompatibility and cyto compatibility • Biocompatibility of membranes was correlated with morphology and hydrophilicity. • Antifouling studies of the PAN/CPEI membranes was studied by BSA as model foulant.

  4. Cooperation of phosphates and carboxylates controls calcium oxalate crystallization in ultrafiltered urine.

    Science.gov (United States)

    Grohe, Bernd; Chan, Brian P H; Sørensen, Esben S; Lajoie, Gilles; Goldberg, Harvey A; Hunter, Graeme K

    2011-10-01

    Osteopontin (OPN) is one of a group of proteins found in urine that are believed to limit the formation of kidney stones. In the present study, we investigate the roles of phosphate and carboxylate groups in the OPN-mediated modulation of calcium oxalate (CaOx), the principal mineral phase found in kidney stones. To this end, crystallization was induced by addition of CaOx solution to ultrafiltered human urine containing either human kidney OPN (kOPN; 7 consecutive carboxylates, 8 phosphates) or synthesized peptides corresponding to residues 65-80 (pSHDHMDDDDDDDDDGD; pOPAR) or 220-235 (pSHEpSTEQSDAIDpSAEK; P3) of rat bone OPN. Sequence 65-80 was also synthesized without the phosphate group (OPAR). Effects on calcium oxalate monohydrate (COM) and dihydrate (COD) formation were studied by scanning electron microscopy. We found that controls form large, partly intergrown COM platelets; COD was never observed. Adding any of the polyelectrolytes was sufficient to prevent intergrowth of COM platelets entirely, inhibiting formation of these platelets strongly, and inducing formation of the COD phase. Strongest effects on COM formation were found for pOPAR and OPAR followed by kOPN and then P3, showing that acidity and hydrophilicity are crucial in polyelectrolyte-affected COM crystallization. At higher concentrations, OPAR also inhibited COD formation, while P3, kOPN and, in particular, pOPAR promoted COD, a difference explainable by the variations of carboxylate and phosphate groups present in the molecules. Thus, we conclude that carboxylate groups play a primary role in inhibiting COM formation, but phosphate and carboxylate groups are both important in initiating and promoting COD formation.

  5. Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

    Directory of Open Access Journals (Sweden)

    Yunfei Wang

    2015-06-01

    Full Text Available A class of carboxyl and carboxylate ester-substituted dithiafulvene (DTF derivatives and tetrathiafulvalene vinylogues (TTFVs has been synthesized and their electronic and electrochemical redox properties were characterized by UV–vis spectroscopic and cyclic voltammetric analyses. The carboxyl-TTFV was applied as a redox-active ligand to complex with Zn(II ions, forming a stable Zn-TTFV coordination polymer. The structural, electrochemical, and thermal properties of the coordination polymer were investigated by infrared spectroscopy, cyclic voltammetry, powder X-ray diffraction, and differential scanning calorimetric analyses. Furthermore, the microscopic porosity and surface area of the Zn-TTFV coordination polymer were measured by nitrogen gas adsorption analysis, showing a BET surface of 148.2 m2 g−1 and an average pore diameter of 10.2 nm.

  6. The importance of group activities for quality of life of women in postmenopause

    Directory of Open Access Journals (Sweden)

    Renata Calazans Negrão

    2011-12-01

    Full Text Available Objective: To assess the quality of life of postmenopausal women who participate in different activities groups for elderly. Methods: We selected 59 women, divided as follows: hydrotherapy group (n = 15, physical activity and bingo group (n = 15, and a control group(n = 29. Data collection was done through a questionnaire evaluating the Quality of Life(WHOQOL-Bref, the Blatt and Kupperman Menopausal Index and Geriatric Depression Scale (GDS. The assessments were conducted in two stages with an interval of two monthsbetween each one. Results: There was an improvement in quality of life of women participants in activities groups with respect to the control group, and in all domains of quality of life questionnaire, the control group had lower values. Significant differences occurred in the environment domain, in comparing the hydrotherapy group and physical activity/bingo groups, of which the latter showed better responses. Conclusion: The activities groups were positive for improving quality of life of postmenopausal women, emphasizing the importance of encouraging the practice of not only physical activities, but also those that stimulate the social and psychological profile of these women.

  7. 75 FR 4904 - Railroad Safety Advisory Committee (RSAC); Working Group Activity Update

    Science.gov (United States)

    2010-01-29

    ... amend regulations protecting persons who work on, under, or between rolling equipment; and persons...-7257] Railroad Safety Advisory Committee (RSAC); Working Group Activity Update AGENCY: Federal Railroad... Committee (RSAC) Working Group Activities. SUMMARY: The FRA is updating its announcement of RSAC's Working...

  8. LIQUID-CHROMATOGRAPHIC ANALYSIS OF CARBOXYLIC-ACIDS USING N-(4-AMINOBUTYL)-N-ETHYLISOLUMINOL AS CHEMILUMINESCENT LABEL - DETERMINATION OF IBUPROFEN IN SALIVA

    NARCIS (Netherlands)

    STEIJGER, OM; LINGEMAN, H; BRINKMAN, UAT; HOLTHUIS, JJM; SMILDE, AK; DOORNBOS, DA

    1993-01-01

    N-(4-Aminobutyl)-N-ethylisoluminol was used for labelling of carboxylic acids. The derivatization reaction was carried out with 1-hydroxybenzotriazole as pre-activator of the carboxylic acid function and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide as the coupling reagent. Optimum conditions for

  9. Liquid chromatographic analysis of carboxylic acids using N-(4-aminobutyl)-N-ethylisoluminol as chemiluminescent label: determination of ibuprofen in saliva

    NARCIS (Netherlands)

    Steijger, O. M.; Lingeman, H.; Brinkman, U. A.; Holthuis, J. J.; Smilde, A. K.; Doornbos, D. A.

    1993-01-01

    N-(4-Aminobutyl)-N-ethylisoluminol was used for labelling of carboxylic acids. The derivatization reaction was carried out with 1-hydroxybenzotriazole as pre-activator of the carboxylic acid function and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide as the coupling reagent. Optimum conditions for

  10. Active placebo control groups of pharmacological interventions were rarely used but merited serious consideration

    DEFF Research Database (Denmark)

    Jensen, Jakob Solgaard; Bielefeldt, Andreas Ørsted; Hróbjartsson, Asbjørn

    2017-01-01

    groups based on a random sample of 200 PubMed indexed placebo-controlled randomized drug trials published in October 2013. In a systematic review, we identified and characterized trials with active placebo control groups irrespective of publication time. In a third substudy, we reviewed publications...... with substantial methodological comments on active placebo groups (searches in PubMed, The Cochrane Library, Google Scholar, and HighWirePress). Results The prevalence of trials with active placebo groups published in 2013 was 1 out of 200 (95% confidence interval: 0–2), 0.5% (0–1%). We identified...

  11. Immunological evaluation of lipopeptide group A streptococcus (GAS vaccine: structure-activity relationship.

    Directory of Open Access Journals (Sweden)

    Mehfuz Zaman

    Full Text Available Streptococcus pyogenes (group A streptococcus, GAS is a Gram-positive bacterial pathogen responsible for a wide variety of diseases. To date, GAS vaccine development has focused primarily on the M-protein. The M-protein is highly variable at the amino (N-terminus (determining serotype but is conserved at the carboxyl (C-terminus. Previously a 29 amino acid peptide (named J14 from the conserved region of the M-protein was identified as a potential vaccine candidate. J14 was capable of eliciting protective antibodies that recognized many GAS serotypes when co-administered with immuno-stimulants. This minimal epitope however showed no immunogenicity when administered alone. In an attempt overcome this immunological non-responsiveness, we developed a self-adjuvanting vaccine candidate composed of three components: the B-cell epitope (J14, a universal helper T-cell epitope (P25 and a lipid moiety consisting of lipoamino acids (Laas which target Toll-like receptor 2 (TLR2. Immunological evaluation in B10.BR (H-2k mice demonstrated that the epitope attachment to the point of lipid moiety, and the length of the Laa alkyl chain have a profound effect on vaccine immunogenicity after intranasal administration. It was demonstrated that a vaccine featuring C-terminal lipid moiety containing alkyl chains of 16 carbons, with P25 located at the N-terminus, and J14 attached to the side chain of a central lysine residue was capable of inducing optimal antibody response. These findings have considerable relevance to the development of a broad spectrum J14-based GAS vaccine and in particular provided a rational basis for peptide vaccine design based on this self-adjuvanting lipopeptide technology.

  12. The Exploration of the Relationship between Participation in Organized Activity and Cross-Group Friendships

    Directory of Open Access Journals (Sweden)

    Wonseok Suh

    2011-12-01

    Full Text Available Cross-group friendship is an important element in regard to reducing prejudice and increasing positive interracial interactions among young adults. In order to facilitate the formation of cross-group friendships, organized activity participation (e.g., community service and school-based extracurricular activities may provide an environment that supports positive cross-cultural interactions and contacts. The sample used for this study consisted of 601 college students. We tested whether participation in an organized activity contributes to the formation of cross-group friendships. The results of this study indicate that community service and school-based extracurricular activities significantly contribute to the formation of cross-group friendships among young adults. The findings also suggest that a variety of organized activities should be developed and implemented to facilitate cross-group friendships. We also discuss the practical implications of these findings.

  13. Using Electronic Communication Tools in Online Group Activities to Develop Collaborative Learning Skills

    Science.gov (United States)

    Khalil, Hanan; Ebner, Martin

    2017-01-01

    The purpose of this study was to investigate the effect of using synchronous and asynchronous communication tools in online group activities to develop collaborative learning skills. An experimental study was implemented on a sample of faculty of education students in Mansoura University. The sample was divided into two groups, a group studied…

  14. Activity Plans of Group Games for Social and Emotional Development of Kindergarten Children in Korea.

    Science.gov (United States)

    Choi, Kee Young

    Although classroom group games have been used to effectively teach mathematics in Korean kindergarten, ethnographic research has revealed some unexpected negative effects of such games on young children due to children's over-competitiveness and the teacher's unskilled group management. This paper proposes some activity plans for group games to…

  15. Photosynthetic carboxylating enzymes in Phaeodactylum tricornutum: assay methods and properties

    Energy Technology Data Exchange (ETDEWEB)

    Mukerji, D [Bigelow Lab. for Ocean Sciences, West Boothbay Harbor, ME; Morris, I

    1976-01-01

    Rapid freezing (in liquid nitrogen) of the marine diatom Phaeodactylum tricornutum Bohlin followed by thawing permits a convenient and sensitive measurement of the activities of carboxylating enzymes without the need to prepare a cell-free extract. Using this method, the properties of RuDP and PEP carboxylases have been compared with those assayed in cell-free extracts. The most significant difference was in the Michaelis' constants (K/sub m/'s), the values being lower in the freeze/thaw assay. The absolute rate of carbon-dioxide fixation by the enzymes was less than the rate of photosynthesis by the intact alga. Significantly, the activity of PEP carboxylase was comparable (in some experiments, greater) to that of RuDP carboxylase. The significance of this and the possibility of an enzymatic approach to measurements of marine primary productivity are discussed.

  16. Metal extraction by amides of carboxylic acids

    International Nuclear Information System (INIS)

    Skorovarov, D.I.; Chumakova, G.M.; Rusin, L.I.; Ul'anov, V.S.; Sviridova, R.A.; Sviridov, A.L.

    1988-01-01

    Extraction ability of various amides was studied. Data on extraction of rare earths, vanadium, molybdenum, rhenium, uranium, niobium, tantalum by N,N-dibutyl-amides of acetic, nonanic acids and fatly synthetic acids of C 7 -C 9 fractions are presented. Effect of salting-out agents, inorganic acid concentrations on extraction process was studied. Potential ability of using amides of carboxylic acids for extractional concentration of rare earths as well as for recovery and separation of iron, rhenium, vanadium, molybdenum, uranium, niobium, and tantalum was shown

  17. THEORETICAL PRINCIPLES OF PSYCHOLOGICAL ANALYSIS OF STUDENTS’ GROUP PROJECT ACTIVITY WHILE LEARNING FOREIGN LANGUAGE

    Directory of Open Access Journals (Sweden)

    Viktoriia Kalamazh

    2016-06-01

    Full Text Available In this research the theoretical principles of psychological analysis of group project activity of students in the process of learning foreign language are defined on the basis of subject-activity, socio-psychological and cognitive paradigms. The approaches of different authors to the understanding of the concept of project and in particular group project activity are considered. The difficulties of the theoretical analysis of this specific notion are indicated due to the considerable variety of subjects, types and forms of the pedagogical activity, academic disciplines regarding which the researches are being carried out. Not disclosed aspects of organizing the group project activity of students are being determined, among them is a project group as an autonomous subject of joint activity for the realization students’ project activity while learning a foreign language; forming psychological readiness of teacher and student to use project method; the role of metacognitive aspect in the surrounding, where the project activity is being carried out; group functioning through the project work as a subject of group examination. It has been indicated that the analysis of project activity as an innovative technology must include its assessment as a condition of student’s developing as a subject of learning activity, his personal, socio-psychological, intellectual and professional self-perfection. Three levels of subjectivity in group project activity are being distinguished: teacher; each particular student; and student project group. Interaction between teacher and student is based on subject-subject relations. An organization of a project activity while learning a foreign language is considered as the one in which the student is moving in order to get the manager position and to master the basis of expert knowledge. Hereby, the main stress is on the group role as a subject of group examination, and also on metacognitive character of the

  18. Theoretical study on the interactions between chlordecone hydrate and acidic surface groups of activated carbon under basic pH conditions.

    Science.gov (United States)

    Melchor-Rodríguez, Kenia; Gamboa-Carballo, Juan José; Ferino-Pérez, Anthuan; Passé-Coutrin, Nady; Gaspard, Sarra; Jáuregui-Haza, Ulises Javier

    2018-05-01

    A theoretical study of the influence of acidic surface groups (SG) of activated carbon (AC) on chlordecone hydrate (CLDh) adsorption is presented, in order to help understanding the adsorption process under basic pH conditions. A seven rings aromatic system (coronene) with a functional group in the edge was used as a simplified model of AC to evaluate the influence of SG in the course of adsorption from aqueous solution at basic pH conditions. Two SG were modeled in their deprotonated form: carboxyl and hydroxyl (COO - and O - ), interacting with CLDh. In order to model the solvation process, all systems under study were calculated with up to three water molecules. Multiple Minima Hypersurface (MMH) methodology was employed to study the interactions of CLDh with SG on AC using PM7 semiempirical Hamiltonian, to explore the potential energy surfaces of the systems and evaluate their thermodynamic association energies. The re-optimization of representative structures obtained from MMH was done using M06-2X Density Functional Theory. The Quantum Theory of Atoms in Molecules (QTAIM) was used to characterize the interaction types. As result, the association of CLDh with acidic SG at basic pH conditions preferentially occurs between the two alcohol groups of CLDh with COO - and O - groups and by dispersive interactions of chlorine atoms of CLDh with the graphitic surface. On the other hand, the presence of covalent interactions between the negatively charged oxygen of SG and one hydrogen atom of CLDh alcohol groups (O - ⋯HO interactions) without water molecules, was confirmed by QTAIM study. It can be concluded that the interactions of CLDh with acidic SG of AC under basic pH conditions confirms the physical mechanisms of adsorption process. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Technip. Group dynamics and activities. Competitive environment and strategic perspectives. Release - February 2017

    International Nuclear Information System (INIS)

    2017-02-01

    After a synthesis which notably proposes a SWOT analysis of the Technip group, this report proposes a presentation of the Technip Group (general overview, presentation of activities per department, human resources, stock market data, and competitive environment). It gives an overview of the Technip group dynamics and of its activities through a presentation of an environment analysis (world oil demand and production, hydrocarbon prices), a presentation of the group activity (turnover, order takings, performance per activity pole, turnover per geographical area, operational income). It addresses important events and development axes: strategic axes, group restructuring, widening of service provision, R and D investments. Financial data are presented along with the main economic and financial indicators. Important statistical data are provided

  20. Development of active learning modules in pharmacology for small group teaching.

    Science.gov (United States)

    Tripathi, Raakhi K; Sarkate, Pankaj V; Jalgaonkar, Sharmila V; Rege, Nirmala N

    2015-01-01

    Current teaching in pharmacology in undergraduate medical curriculum in India is primarily drug centered and stresses imparting factual knowledge rather than on pharmacotherapeutic skills. These skills would be better developed through active learning by the students. Hence modules that will encourage active learning were developed and compared with traditional methods within the Seth GS Medical College, Mumbai. After Institutional Review Board approval, 90 second year undergraduate medical students who consented were randomized into six sub-groups, each with 15 students. Pre-test was administered. The three sub-groups were taught a topic using active learning modules (active learning groups), which included problems on case scenarios, critical appraisal of prescriptions and drug identification. The remaining three sub-groups were taught the same topic in a conventional tutorial mode (tutorial learning groups). There was crossover for the second topic. Performance was assessed using post-test. Questionnaires with Likert-scaled items were used to assess feedback on teaching technique, student interaction and group dynamics. The active and tutorial learning groups differed significantly in their post-test scores (11.3 ± 1.9 and 15.9 ± 2.7, respectively, P active learning session as interactive (vs. 37/90 students in tutorial group) and enhanced their understanding vs. 56/90 in tutorial group), aroused intellectual curiosity (47/90 students of active learning group vs. 30/90 in tutorial group) and provoked self-learning (41/90 active learning group vs. 14/90 in tutorial group). Sixty-four students in the active learning group felt that questioning each other helped in understanding the topic, which was the experience of 25/90 students in tutorial group. Nevertheless, students (55/90) preferred tutorial mode of learning to help them score better in their examinations. In this study, students preferred an active learning environment, though to pass examinations, they

  1. Complexation of carboxylate on smectite surfaces.

    Science.gov (United States)

    Liu, Xiandong; Lu, Xiancai; Zhang, Yingchun; Zhang, Chi; Wang, Rucheng

    2017-07-19

    We report a first principles molecular dynamics (FPMD) study of carboxylate complexation on clay surfaces. By taking acetate as a model carboxylate, we investigate its inner-sphere complexes adsorbed on clay edges (including (010) and (110) surfaces) and in interlayer space. Simulations show that acetate forms stable monodentate complexes on edge surfaces and a bidentate complex with Ca 2+ in the interlayer region. The free energy calculations indicate that the complexation on edge surfaces is slightly more stable than in interlayer space. By integrating pK a s and desorption free energies of Al coordinated water calculated previously (X. Liu, X. Lu, E. J. Meijer, R. Wang and H. Zhou, Geochim. Cosmochim. Acta, 2012, 81, 56-68; X. Liu, J. Cheng, M. Sprik, X. Lu and R. Wang, Geochim. Cosmochim. Acta, 2014, 140, 410-417), the pH dependence of acetate complexation has been revealed. It shows that acetate forms inner-sphere complexes on (110) in a very limited mildly acidic pH range while it can complex on (010) in the whole common pH range. The results presented in this study form a physical basis for understanding the geochemical processes involving clay-organics interactions.

  2. Short Carboxylic Acid–Carboxylate Hydrogen Bonds Can Have Fully Localized Protons

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jiusheng; Pozharski, Edwin; Wilson, Mark A.

    2017-01-17

    Short hydrogen bonds (H-bonds) have been proposed to play key functional roles in several proteins. The location of the proton in short H-bonds is of central importance, as proton delocalization is a defining feature of low-barrier hydrogen bonds (LBHBs). Experimentally determining proton location in H-bonds is challenging. Here, bond length analysis of atomic (1.15–0.98 Å) resolution X-ray crystal structures of the human protein DJ-1 and its bacterial homologue, YajL, was used to determine the protonation states of H-bonded carboxylic acids. DJ-1 contains a buried, dimer-spanning 2.49 Å H-bond between Glu15 and Asp24 that satisfies standard donor–acceptor distance criteria for a LBHB. Bond length analysis indicates that the proton is localized on Asp24, excluding a LBHB at this location. However, similar analysis of the Escherichia coli homologue YajL shows both residues may be protonated at the H-bonded oxygen atoms, potentially consistent with a LBHB. A Protein Data Bank-wide screen identifies candidate carboxylic acid H-bonds in approximately 14% of proteins, which are typically short [O–O> = 2.542(2) Å]. Chemically similar H-bonds between hydroxylated residues (Ser/Thr/Tyr) and carboxylates show a trend of lengthening O–O distance with increasing H-bond donor pKa. This trend suggests that conventional electronic effects provide an adequate explanation for short, charge-assisted carboxylic acid–carboxylate H-bonds in proteins, without the need to invoke LBHBs in general. This study demonstrates that bond length analysis of atomic resolution X-ray crystal structures provides a useful experimental test of certain candidate LBHBs.

  3. Total. Group dynamics and activities. Competitive environment and strategic perspectives. Release - July 2017

    International Nuclear Information System (INIS)

    2017-07-01

    After a synthesis which notably proposes a SWOT analysis of the Total group, this report proposes a presentation of the Total Group (general overview, presentation of activities, human resources, shareholder structure and stock market data, competitive environment). It gives an overview of the Total group dynamics and of its activities through a presentation of an environment analysis (world oil demand, refining-chemistry activity, hydrocarbon prices), a presentation of the group activity (turnover, turnover per segment, operational income and financial results of competitors). It comments important events and development axes: four strategic orientations, strengthening of the upstream pole, restructuring of refining and chemical activities, widening of the energy provision, consolidation of positions in the marketing and services sector. Financial data are presented along with the main economic and financial indicators. Important statistical data are provided

  4. New trends and applications in carboxylation for isotope chemistry.

    Science.gov (United States)

    Bragg, Ryan A; Sardana, Malvika; Artelsmair, Markus; Elmore, Charles S

    2018-05-08

    Carboxylations are an important method for the incorporation of isotopically labeled 14 CO 2 into molecules. This manuscript will review labeled carboxylations since 2010 and will present a perspective on the potential of recent unlabeled methodology for labeled carboxylations. The perspective portion of the manuscript is broken into 3 major sections based on product type, arylcarboxylic acids, benzylcarboxylic acids, and alkyl carboxylic acids, and each of those sections is further subdivided by substrate. © 2018 AstraZeneca. Journal of Labelled Compounds and Radiopharmaceuticals Published by John Wiley & Sons, Ltd.

  5. A hydrazone Schiff base single crystal (E)-Methyl N"′-(3,4,5-trimethoxybenzylidene) hydrazine carboxylate: Physicochemical, in vitro investigation of antimicrobial activities and molecular docking with DNA gyrase protein

    International Nuclear Information System (INIS)

    Gomathi, G.; Gopalakrishnan, R.

    2016-01-01

    Hydrazone Schiff bases have been widely explored for their antimicrobial, anticancer, anticonvulsant properties. The aim of the present work is to investigate the spectroscopic, electrochemical, thermal properties, in vitro study of antimicrobial activity and molecular docking studies of the MBHC compound. Slow evaporation solution growth technique was used to grow the single crystal of the MBHC compound. Single crystal X-ray diffraction, FTIR and FT-Raman spectroscopic studies are performed and confirmed the grown MBHC compound. UV–Vis spectroscopy and electrochemical studies deduced the absorption region and HOMO-LUMO band gap value of the compound. Resazurin reduction assay method was utilized to perform antibacterial and antifungal studies which resulted in lesser effectiveness of the MBHC compound compared to the erythromycin and fluconazole tablets. Molecular docking of the MBHC compound with the DNA gyrase protein exhibited the good binding affinity with energy of − 43.196 kcal/mol and docking score of − 6.266 and having good interaction with aminoacids – ASP81 and ARG84. - Highlights: • MBHC single crystal was grown by employing slow evaporation solution growth technique. • The compound crystallizes in monoclinic crystal system with space group P2_1/c. • The HOMO-LUMO band gap value was found to be 1.96 eV. • The compound has lesser antimicrobial activity when compared to erythromycin and fluconazole. • MBHC shows better binding affinity towards DNA gyrase protein.

  6. A hydrazone Schiff base single crystal (E)-Methyl N{sup ′}-(3,4,5-trimethoxybenzylidene) hydrazine carboxylate: Physicochemical, in vitro investigation of antimicrobial activities and molecular docking with DNA gyrase protein

    Energy Technology Data Exchange (ETDEWEB)

    Gomathi, G.; Gopalakrishnan, R., E-mail: krgkrishnan@annauniv.edu

    2016-07-01

    Hydrazone Schiff bases have been widely explored for their antimicrobial, anticancer, anticonvulsant properties. The aim of the present work is to investigate the spectroscopic, electrochemical, thermal properties, in vitro study of antimicrobial activity and molecular docking studies of the MBHC compound. Slow evaporation solution growth technique was used to grow the single crystal of the MBHC compound. Single crystal X-ray diffraction, FTIR and FT-Raman spectroscopic studies are performed and confirmed the grown MBHC compound. UV–Vis spectroscopy and electrochemical studies deduced the absorption region and HOMO-LUMO band gap value of the compound. Resazurin reduction assay method was utilized to perform antibacterial and antifungal studies which resulted in lesser effectiveness of the MBHC compound compared to the erythromycin and fluconazole tablets. Molecular docking of the MBHC compound with the DNA gyrase protein exhibited the good binding affinity with energy of − 43.196 kcal/mol and docking score of − 6.266 and having good interaction with aminoacids – ASP81 and ARG84. - Highlights: • MBHC single crystal was grown by employing slow evaporation solution growth technique. • The compound crystallizes in monoclinic crystal system with space group P2{sub 1}/c. • The HOMO-LUMO band gap value was found to be 1.96 eV. • The compound has lesser antimicrobial activity when compared to erythromycin and fluconazole. • MBHC shows better binding affinity towards DNA gyrase protein.

  7. Enhancing Cooperativity in Bifunctional Acid–Pd Catalysts with Carboxylic Acid-Functionalized Organic Monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Coan, Patrick D. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Ellis, Lucas D. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Griffin, Michael B. [National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Schwartz, Daniel K. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Medlin, J. Will [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States

    2018-03-01

    Cooperative catalysts containing a combination of noble metal hydrogenation sites and Bronsted acid sites are critical for many reactions, including the deoxygenation (DO) of biomass-derived oxygenates in the upgrading of pyrolysis oil. One route toward the design of cooperative catalysts is to tether two different catalytically active functions so that they are in close proximity while avoiding undesirable interactions that can block active sites. Here, we deposited carboxylic acid (CA)-functionalized organophosphonate monolayers onto Al2O3-supported Pd nanoparticle catalysts to prepare bifunctional catalysts containing both Bronsted acid and metal sites. Modification with phosphonic acids (PAs) improved activity and selectivity for gas-phase DO reactions, but the degree of improvement was highly sensitive to both the presence and positioning of the CA group, suggesting a significant contribution from both the PA and CA sites. Short spacer lengths of 1-2 methylene groups between the phosphonate head and CA tail were found to yield the best DO rates and selectivities, whereas longer chains performed similarly to self-assembled monolayers having alkyl tails. Results from a combination of density functional theory and Fourier transform infrared spectroscopy suggested that the enhanced catalyst performance on the optimally positioned CAs was due to the generation of strong acid sites on the Al2O3 support adjacent to the metal. Furthermore, the high activity of these sites was found to result from a hydrogen-bonded cyclic structure involving cooperativity between the phosphonate head group and CA tail function. More broadly, these results indicate that functional groups tethered to supports via organic ligands can influence catalytic chemistry on metal nanoparticles.

  8. Microbial synthesis of a branched-chain ester platform from organic waste carboxylates

    Directory of Open Access Journals (Sweden)

    Donovan S. Layton

    2016-12-01

    Full Text Available Processing of lignocellulosic biomass or organic wastes produces a plethora of chemicals such as short, linear carboxylic acids, known as carboxylates, derived from anaerobic digestion. While these carboxylates have low values and are inhibitory to microbes during fermentation, they can be biologically upgraded to high-value products. In this study, we expanded our general framework for biological upgrading of carboxylates to branched-chain esters by using three highly active alcohol acyltransferases (AATs for alcohol and acyl CoA condensation and modulating the alcohol moiety from ethanol to isobutanol in the modular chassis cell. With this framework, we demonstrated the production of an ester library comprised of 16 out of all 18 potential esters, including acetate, propionate, butanoate, pentanoate, and hexanoate esters, from the 5 linear, saturated C2-C6 carboxylic acids. Among these esters, 5 new branched-chain esters, including isobutyl acetate, isobutyl propionate, isobutyl butyrate, isobutyl pentanoate, and isobutyl hexanoate were synthesized in vivo. During 24 h in situ fermentation and extraction, one of the engineered strains, EcDL208 harnessing the SAAT of Fragaria ananassa produced ~63 mg/L of a mixture of butyl and isobutyl butyrates from glucose and butyrate co-fermentation and ~127 mg/L of a mixture of isobutyl and pentyl pentanoates from glucose and pentanoate co-fermentation, with high specificity. These butyrate and pentanoate esters are potential drop-in liquid fuels. This study provides better understanding of functional roles of AATs for microbial biosynthesis of branched-chain esters and expands the potential use of these esters as drop-in biofuels beyond their conventional flavor, fragrance, and solvent applications. Keywords: Carboxylate platform, Ester platform, Branched-chain ester, Modular cell, Biological upgrading, Organic waste, Lignocellulosic biomass, Isobutyl esters

  9. Atmospheric chemistry of carboxylic acids: microbial implication versus photochemistry

    Directory of Open Access Journals (Sweden)

    M. Vaïtilingom

    2011-08-01

    Full Text Available The objective of this work was to compare experimentally the contribution of photochemistry vs. microbial activity to the degradation of carboxylic acids present in cloud water. For this, we selected 17 strains representative of the microflora existing in real clouds and worked on two distinct artificial cloud media that reproduce marine and continental cloud chemical composition. Photodegradation experiments with hydrogen peroxide (H2O2 as a source of hydroxyl radicals were performed under the same microcosm conditions using two irradiation systems. Biodegradation and photodegradation rates of acetate, formate, oxalate and succinate were measured on both media at 5 °C and 17 °C and were shown to be on the same order of magnitude (around 10−10–10−11 M s−1. The chemical composition (marine or continental origin had little influence on photodegradation and biodegradation rates while the temperature shift from 17 °C to 5 °C decreased biodegradation rates of a factor 2 to 5.

    In order to test other photochemical scenarios, theoretical photodegradation rates were calculated considering hydroxyl (OH radical concentration values in cloud water estimated by cloud chemistry modelling studies and available reaction rate constants of carboxylic compounds with both hydroxyl and nitrate radicals. Considering high OH concentration ([OH] = 1 × 10−12 M led to no significant contribution of microbial activity in the destruction of carboxylic acids. On the contrary, for lower OH concentration (at noon, [OH] = 1 × 10−14 M, microorganisms could efficiently compete with photochemistry and in similar contributions than the ones estimated by our experimental approach.

    Combining these two approaches (experimental and theoretical, our results led to the following conclusions: oxalate was only photodegraded; the photodegradation of formate was usually more

  10. Synthesis and characterization of carboxylic cation exchange bio-resin for heavy metal remediation.

    Science.gov (United States)

    Kulkarni, Vihangraj V; Golder, Animes Kumar; Ghosh, Pranab Kumar

    2018-01-05

    A new carboxylic bio-resin was synthesized from raw arecanut husk through mercerization and ethylenediaminetetraacetic dianhydride (EDTAD) carboxylation. The synthesized bio-resin was characterized using thermogravimetric analysis, field emission scanning electron microscopy, proximate & ultimate analyses, mass percent gain/loss, potentiometric titrations, and Fourier transform infrared spectroscopy. Mercerization extracted lignin from the vesicles on the husk and EDTAD was ridged in to, through an acylation reaction in dimethylformamide media. The reaction induced carboxylic groups as high as 0.735mM/g and a cation exchange capacity of 2.01meq/g functionalized mercerized husk (FMH). Potentiometric titration data were fitted to a newly developed single-site proton adsorption model (PAM) that gave pKa of 3.29 and carboxylic groups concentration of 0.741mM/g. FMH showed 99% efficiency in Pb(II) removal from synthetic wastewater (initial concentration 0.157mM), for which the Pb(II) binding constant was 1.73×10 3 L/mol as estimated from modified PAM. The exhaustion capacity was estimated to be 18.7mg/g of FMH. Desorption efficiency of Pb(II) from exhausted FMH was found to be about 97% with 0.1N HCl. The FMH simultaneously removed lead and cadmium below detection limit from a real lead acid battery wastewater along with the removal of Fe, Mg, Ni, and Co. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Impact of physical activity in group versus individual physical activity on fatigue in patients with breast cancer: A pilot study.

    Science.gov (United States)

    Desbiens, Christine; Filion, Myriam; Brien, Marie-Chantale; Hogue, Jean-Charles; Laflamme, Christian; Lemieux, Julie

    2017-10-01

    Physical activity improves the quality of life of cancer survivors, but whether there is a difference between individual vs. group physical activity is unknown. To compare fatigue at 12 weeks in breast cancer survivors after participation in a program of group vs. individual video-assisted physical activity. This was a randomized phase II pilot study carried out in breast cancer survivors at a tertiary breast cancer center. Eligible patients were randomized to individual or group 12-week physical activity program. The primary outcome was fatigue (FACT-F). Aerobic capacity (6-min walk test), muscular strength, and quality-of-life (FACT-G and FACT-B) were assessed. Because of poor accrual, 200 consecutive breast cancer patients were surveyed about their physical activity habits to assess reasons for low recruitment. For all participants (n = 26; n = 12 for group vs. n = 14 for individual), there were some improvement in FACT-F, FACT-G, FACT-B, physical activity level, aerobic capacity, and shoulder strength. Among the 200 patients surveyed, 58% were interested to increase their physical activity level, 15% declared that they were already exercising enough, 9% declared being unable to, 3% declared having no time, and 2% declared having no interest, and other reasons (13%). Among the 200 patients surveyed, 25% preferred in group, 57% preferred alone, and 18% had no preference. Low recruitment precluded conclusions about the efficacy of physical activity practiced in group vs. individually, but both groups derived a benefit. Low willingness to change exercising habits could be the biggest barrier to physical activity in breast cancer survivors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 4-Methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic Acid. Peculiarities of Preparation, Structure, and Biological Properties

    Directory of Open Access Journals (Sweden)

    Igor V. Ukrainets

    2018-03-01

    Full Text Available In order to determine the regularities of the structure–analgesic activity relationship, the peculiarities of obtaining, the spatial structure, and biological properties of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and some of its derivatives have been studied. Using nuclear magnetic resonance (NMR spectroscopy and X-ray diffraction analysis, it has been proven that varying the reaction conditions using alkaline hydrolysis of methyl 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate makes it possible to successfully synthesize a monohydrate of the target acid, its sodium salt, or 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine. The derivatographic study of the thermal stability of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid monohydrate has been carried out; based on this study, the optimal conditions completely eliminating the possibility of unwanted decomposition have been proposed for obtaining its anhydrous form. It has been shown that 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine is easily formed during the decarboxylation of not only 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid, but also its sodium salt, which is capable of losing СО2 both in rather soft conditions of boiling in an aqueous solution, and in more rigid conditions of dry heating. The NMR spectra of the compounds synthesized are given; their spatial structure is discussed. To study the biological properties of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid and its sodium salt, the experimental model of inflammation caused by subplantar introduction of the carrageenan solution in one of the hind limbs of white rats was used. The anti-inflammatory activity and analgesic effect were assessed by the degree of edema reduction and the ability to affect the pain response compared to the animals of control groups. According to the results of the tests performed, it has been found that after intraperitoneal injection

  13. Individual and Group-Based Engagement in an Online Physical Activity Monitoring Program in Georgia.

    Science.gov (United States)

    Smith, Matthew Lee; Durrett, Nicholas K; Bowie, Maria; Berg, Alison; McCullick, Bryan A; LoPilato, Alexander C; Murray, Deborah

    2018-06-07

    Given the rising prevalence of obesity in the United States, innovative methods are needed to increase physical activity (PA) in community settings. Evidence suggests that individuals are more likely to engage in PA if they are given a choice of activities and have support from others (for encouragement, motivation, and accountability). The objective of this study was to describe the use of the online Walk Georgia PA tracking platform according to whether the user was an individual user or group user. Walk Georgia is a free, interactive online tracking platform that enables users to log PA by duration, activity, and perceived difficulty, and then converts these data into points based on metabolic equivalents. Users join individually or in groups and are encouraged to set weekly PA goals. Data were examined for 6,639 users (65.8% were group users) over 28 months. We used independent sample t tests and Mann-Whitney U tests to compare means between individual and group users. Two linear regression models were fitted to identify factors associated with activity logging. Users logged 218,766 activities (15,119,249 minutes of PA spanning 592,714 miles [41,858,446 points]). On average, group users had created accounts more recently than individual users (P < .001); however, group users logged more activities (P < .001). On average, group users logged more minutes of PA (P < .001) and earned more points (P < .001). Being in a group was associated with a larger proportion of weeks in which 150 minutes or more of weekly PA was logged (B = 20.47, P < .001). Use of Walk Georgia was significantly higher among group users than among individual users. To expand use and dissemination of online tracking of PA, programs should target naturally occurring groups (eg, workplaces, schools, faith-based groups).

  14. Nano-graphene oxide carboxylation for efficient bioconjugation applications: a quantitative optimization approach

    Science.gov (United States)

    Imani, Rana; Emami, Shahriar Hojjati; Faghihi, Shahab

    2015-02-01

    A method for carboxylation of graphene oxide (GO) with chloroacetic acid that precisely optimizes and controls the efficacy of the process for bioconjugation applications is proposed. Quantification of COOH groups on nano-graphene oxide sheets (NGOS) is performed by novel colorimetric methylene blue (MB) assay. The GO is synthesized and carboxylated by chloroacetic acid treatment under strong basic condition. The size and morphology of the as-prepared NGOS are characterized by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy (AFM). The effect of acid to base molar ratio on the physical, chemical, and morphological properties of NGOS is analyzed by Fourier-transformed infrared spectrometry (FTIR), UV-Vis spectroscopy, X-ray diffraction (XRD), AFM, and zeta potential. For evaluation of bioconjugation efficacy, the synthesized nano-carriers with different carboxylation ratios are functionalized by octaarginine peptide sequence (R8) as a biomolecule model containing amine groups. The quantification of attached R8 peptides to graphene nano-sheets' surface is performed with a colorimetric-based assay which includes the application of 2,4,6-Trinitrobenzene sulfonic acid (TNBS). The results show that the thickness and lateral size of nano-sheets are dramatically decreased to 0.8 nm and 50-100 nm after carboxylation process, respectively. X-ray analysis shows the nano-sheets interlaying space is affected by the alteration of chloroacetic acid to base ratio. The MB assay reveals that the COOH groups on the surface of NGOS are maximized at the acid to base ratio of 2 which is confirmed by FTIR, XRD, and zeta potential. The TNBS assay also shows that bioconjugation of the optimized carboxylated NGOS sample with octaarginine peptide is 2.5 times more efficient compared to bare NGOS. The present work provides evidence that treatment of GO by chloroacetic acid under an optimized condition would create a functionalized high surface

  15. Conclusive report on the activities of the Containment Expert Group 1975-87

    International Nuclear Information System (INIS)

    Balz, W.; Dufresne, J.

    1988-01-01

    The report summarizes the results of the activities of the CONT Expert Group, a subgroup of the CEC Fast Reactor Safety Working Group (SWG). The CONT group's work has over the last 12 years (1975-87) covered a wide spectrum of problems related to the behaviour of the primary containment of a sodium-cooled fast reactor following an accident releasing a large amount of mechanical energy. In particular the CONT group followed closely the code development and validation (COVA) programme carried out at the JRC Ispra. This activity also included an assessment of related material programmes. From a comparison of containment codes and a sensitivity analysis, it was concluded that the codes developed in the EC Member States and at the JRC Ispra allow to treat the consequences of a hypothetical core-disruptive accident on primary containment with adequate accuracy. Consequently the the group considered its mandate fulfilled and terminated its activities

  16. Air Force Supply Management Analysis of Activity Groups Financial Reports, Prices, and Cash Management

    National Research Council Canada - National Science Library

    1998-01-01

    The Air Force supply management activity group provides about two million types of inventory items, including weapon system spare parts, fuels, and medical-dental supplies, to customers which consist...

  17. Barriers for recess physical activity: a gender specific qualitative focus group exploration

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Tjørnhøj-Thomsen, Tine; Schipperijn, Jasper

    Background: Many children, in particular girls, do not reach the recommended amount of daily physical activity. School recess provides an opportunity for both boys and girls to be physically active, but barriers to recess physical activity are not well understood. This study explores gender...... (53 boys) from fourth grade, with a mean age of 10.4 years. The focus groups included an open group discussion, go-along group interviews, and a gender segregated post-it note activity. A content analysis of the post-it notes was used to prioritize the children´s perceived barriers. This was verified...... barriers, there were both inter- and intra-gender differences in the children´s perceptions of these barriers. Weather was a barrier for all children, apart from the most active boys. Conflicts were perceived as a barrier particularly for those boys who played ballgames. Girls said they would like to have...

  18. 75 FR 51525 - Railroad Safety Advisory Committee (RSAC); Working Group Activity Update

    Science.gov (United States)

    2010-08-20

    .... The Working Group continues to work on after arrival orders, and at the September 25-26, 2008, meeting... protecting persons who work on, under, or between rolling equipment and persons applying, removing or.... 63] Railroad Safety Advisory Committee (RSAC); Working Group Activity Update AGENCY: Federal Railroad...

  19. Need for Cognition and Active Information Search in Small Student Groups

    Science.gov (United States)

    Curseu, Petru Lucian

    2011-01-01

    In a sample of 213 students organized in 44 groups this study tests the impact of need for cognition on active information search by using a multilevel analysis. The results show that group members with high need for cognition seek more advice in task related issues than those with low need for cognition and this pattern of information exchange is…

  20. Brazilian pediatric research groups, lines of research, and main areas of activity

    Directory of Open Access Journals (Sweden)

    Priscila H.A. Oliveira

    2015-05-01

    Conclusions: The pediatric research groups in Brazil have relevant scientific production, including works published in international publications, and are concentrated in regions with higher socioeconomic index. Most groups registered in CNPq started their activity in the last five years (46%, reflecting the recent growth of scientific production in this area.

  1. Similarity-based grouping to support teachers on collaborative activities in exploratory learning environments

    OpenAIRE

    Gutierrez-Santos, Sergio; Mavrikis, M.; Geraniou, E.; Poulovassilis, Alexandra

    2016-01-01

    This paper describes a computer-based tool that helps teachers group their students for collaborative activities in the classroom, the challenge being to organise groups of students based on their recent work so that their collaboration results in meaningful interactions. Students first work on an exploratory task individually, and then the computer suggests possible groupings of students to the teacher. The complexity of the tasks is such that teachers would require too long a time to create...

  2. Does the group leader matter? The impact of monitoring activities and social ties of group leaders on the repayment performance of groupbased lending Eritrea

    NARCIS (Netherlands)

    Hermes, Niels; Lensink, Robert; Mehrteab, Habteab T.

    2005-01-01

    This paper analyzes whether the effects of monitoring and social ties of the group leader and other group members on repayment performance of groups differ, using data from an extensive questionnaire held in Eritrea among participants of 102 groups. We hypothesize that the monitoring activities and

  3. Using Group Drawings Activities to Facilitate the Understanding of the Systemic Aspects of Projects

    Directory of Open Access Journals (Sweden)

    João Alberto Arantes do Amaral

    2017-04-01

    Full Text Available In this article, we present our findings regarding promoting group drawing activities in order to facilitate the learning of systemic aspects of projects. We discuss the approach we used to engage the students and foster learning in our classes. We used group drawing activities in two project management undergraduate courses. The courses, which involved 41 students, took place during the second semester of 2016 in a public university in Brazil. We conducted qualitative research, using qualitative observation and focus group interviews. In order to gauge the effects of the use of this educational technique, we followed the five-phased qualitative analysis method, combined with a systems analysis of the data obtained from observation. Five recurrent themes emerged: 1 Making drawings in groups helps content retention and facilitates connections between the concepts explained by the professor; 2 Making drawings in groups promotes knowledge sharing among team members; 3 Making drawings in group fosters creativity and communication between students; 4 Drawing in groups reduces the students’ boredom, makes the lecture more dynamic and interesting; 5 Drawing in groups reinforces bonds between students. Our systems analysis suggests that group drawing improves student participation in classroom activities, strengthens bonds between students, and enhances learning.

  4. Taking It to the Classroom: Number Board Games as a Small Group Learning Activity

    Science.gov (United States)

    Ramani, Geetha B.; Siegler, Robert S.; Hitti, Aline

    2012-01-01

    We examined whether a theoretically based number board game could be translated into a practical classroom activity that improves Head Start children's numerical knowledge. Playing the number board game as a small group learning activity promoted low-income children's number line estimation, magnitude comparison, numeral identification, and…

  5. What Do We Want Small Group Activities For? Voices from EFL Teachers in Japan

    Science.gov (United States)

    Kato, Yoshitaka

    2016-01-01

    This paper discusses the fundamental issue of why small group activities are utilized in the language learning classroom. Although these activities have gained popularity in the field of Teaching English as a Second Language (TESL), supported by a sound theoretical base, few studies have so far examined the reasons why language teachers are…

  6. Resident-Assisted Montessori Programming (RAMP): training persons with dementia to serve as group activity leaders.

    Science.gov (United States)

    Camp, Cameron J; Skrajner, Michael J

    2004-06-01

    The purpose of this study was to determine the effects of an activity implemented by means of Resident-Assisted Montessori Programming (RAMP). Four persons with early-stage dementia were trained to serve as leaders for a small-group activity played by nine persons with more advanced dementia. Assessments of leaders' ability to learn the procedures of leading a group, as well as their satisfaction with this role, were taken, as were measures of players' engagement and affect during standard activities programming and RAMP activities. Leaders demonstrated the potential to fill the role of group activity leader effectively, and they expressed a high level of satisfaction with this role. Players' levels of positive engagement and pleasure during the RAMP activity were higher than during standard group activities. This study suggests that to the extent that procedural learning is available to persons with early-stage dementia, especially when they are assisted with external cueing, these individuals can successfully fill the role of volunteers when working with persons with more advanced dementia. This can provide a meaningful social role for leaders and increase access to high quality activities programming for large numbers of persons with dementia. Copyright 2004 The Gerontological Society of America

  7. REECo activities and sample logistics in support of the Nevada Applied Ecology Group

    International Nuclear Information System (INIS)

    Wireman, D.L.; Rosenberry, C.E. Jr.

    1975-01-01

    Activities and sample logistics of Reynolds Electrical and Engineering Co., Inc. (REECo), in support of the Nevada Applied Ecology Group (NAEG), are discussed in this summary report. Activities include the collection, preparation, and shipment of samples of soils, vegetation, and small animals collected at Pu-contaminated areas of the Nevada Test Site and Tonopah Test Range. (CH)

  8. Supporting intra-group social metacognitive activities with technology: A grammar learning game

    NARCIS (Netherlands)

    Molenaar, I.; Horvers, A.; Desain, P.W.M.

    2017-01-01

    This study investigates the effects of a technology enhanced collaborative grammar learning activity on students sentence parsing and formulation. These types of collaborative learning activities for grammar education are expected to support more effective learning. Yet, effective intra-group social

  9. Using Group Drawings Activities to Facilitate the Understanding of Systemic Aspects of Projects

    DEFF Research Database (Denmark)

    Arantes do Amaral, João Alberto; Hess, Aurélio; Gonçalves, Paulo

    2017-01-01

    In this article, we present our findings regarding promoting group drawing activities in order to facilitate the learning of systemic aspects of projects. We discuss the approach we used to engage the students and foster learning in our classes. We used group drawing activities in two project...... technique, we followed the five-phased qualitative analysis method, combined with a systems analysis of the data obtained from observation. Five recurrent themes emerged: 1) Making drawings in groups helps content retention and facilitates connections between the concepts explained by the professor; 2...

  10. Brazilian pediatric research groups, lines of research, and main areas of activity

    Directory of Open Access Journals (Sweden)

    Priscila H.A. Oliveira

    2015-06-01

    Full Text Available OBJECTIVES: The Brazilian scientific production in the pediatrics field has been increasing significantly. It is important to identify the distribution and activity of these groups in the country and the main study areas, contributing with data for better resource allocation by institutions. METHODS: An active research was conducted in the National Council of Technological and Scientific Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPq] website, using as filters the macro area of the research group (Health Sciences, the area (Medicine, and descriptors related to pediatrics. Research lines and main area of pediatric research groups were classified according to the subject predominantly studied by each group. The scientific production of the leader of the pediatric research group between 2011 and 2014 was also analyzed. RESULTS: Most pediatric research groups in Brazil have more than five years of activity and are concentrated in the Southeast and South regions of the country; São Paulo, Rio Grande do Sul, and Minas Gerais are the states with most groups. Of the 132 specific pediatric research groups analyzed, 14.4% have lines of research in multiple areas and 11.4% in child and adolescent health. Among the 585 lines of research of these groups, the most prevalent areas were: oncology, infectious diseases, epidemiology, and gastroenterology. CONCLUSIONS: The pediatric research groups in Brazil have relevant scientific production, including works published in international publications, and are concentrated in regions with higher socioeconomic index. Most groups registered in CNPq started their activity in the last five years (46%, reflecting the recent growth of scientific production in this area.

  11. Electronic and magnetic properties of infinite 1D chains of paddlewheel carboxylates M2(COOR)4 (M = Mo, W, Ru, Rh, Ir, Cu)

    KAUST Repository

    Peskov, Maxim; Miao, Xiaohe; Heryadi, Dodi; Eppinger, Jö rg; Schwingenschlö gl, Udo

    2013-01-01

    Dinuclear complexes of transition metals bridged by four carboxylate-groups are examples of stable atomic configurations serving as fundamental building blocks of catalysts and prototypical molecular electronic devices. The electronic structure

  12. A facile and novel approach towards carboxylic acid functionalization of multiwalled carbon nanotubes and efficient water dispersion

    KAUST Repository

    Rehman, Ata Ur

    2013-10-01

    A convenient, cheap and mild covalent functionalization route for multiwalled carbon nanotubes (MWCNTs) have been developed for the first time. The MWCNTs were treated with wet chemical oxidants (NaNO2/HCl, HNO3/H2O2) in order to modify MWCNTs with carboxyl groups. Surface functionality groups and morphology of MWCNTs were analyzed by FTIR, TGA, SEM and TEM. The results consistently confirmed the formation of carboxyl functionalities on MWCNTs, while the structure of MWCNTs has remained relatively intact. Functionalized MWCNTs showed good dispersion in aqueous media than untreated MWCNTs. Results show that NaNO2/HCl treatment is best suited for the chemical functionalization, giving optimum surface carboxyl groups and minimum length shortening of MWCNTs. © 2013 Elsevier B.V.

  13. A facile and novel approach towards carboxylic acid functionalization of multiwalled carbon nanotubes and efficient water dispersion

    KAUST Repository

    Rehman, Ata Ur; Abbas, Syed Mustansar; Ammad, Hafiz Muhammad; Badshah, Amin; Ali, Zulfiqar; Anjum, Dalaver H.

    2013-01-01

    A convenient, cheap and mild covalent functionalization route for multiwalled carbon nanotubes (MWCNTs) have been developed for the first time. The MWCNTs were treated with wet chemical oxidants (NaNO2/HCl, HNO3/H2O2) in order to modify MWCNTs with carboxyl groups. Surface functionality groups and morphology of MWCNTs were analyzed by FTIR, TGA, SEM and TEM. The results consistently confirmed the formation of carboxyl functionalities on MWCNTs, while the structure of MWCNTs has remained relatively intact. Functionalized MWCNTs showed good dispersion in aqueous media than untreated MWCNTs. Results show that NaNO2/HCl treatment is best suited for the chemical functionalization, giving optimum surface carboxyl groups and minimum length shortening of MWCNTs. © 2013 Elsevier B.V.

  14. Human Cells as Platform to Produce Gamma-Carboxylated Proteins.

    Science.gov (United States)

    de Sousa Bomfim, Aline; de Freitas, Marcela Cristina Corrêa; Covas, Dimas Tadeu; de Sousa Russo, Elisa Maria

    2018-01-01

    The gamma-carboxylated proteins belong to a family of proteins that depend on vitamin K for normal biosynthesis. The major representative gamma-carboxylated proteins are the coagulation system proteins, for example, factor VII, factor IX, factor X, prothrombin, and proteins C, S, and Z. These molecules have harbored posttranslational modifications, such as glycosylation and gamma-carboxylation, and for this reason they need to be produced in mammalian cell lines. Human cells lines have emerged as the most promising alternative to the production of gamma-carboxylated proteins. In this chapter, the methods to generate human cells as a platform to produce gamma-carboxylated proteins, for example the coagulation factors VII and IX, are presented. From the cell line modification up to the vitamin K adaptation of the produced cells is described in the protocols presented in this chapter.

  15. Listening to young people with special needs: the influence of group activities.

    Science.gov (United States)

    Burke, Peter

    2005-12-01

    The article reports on the experiences of group activities within an area of Yorkshire that helped young people with special needs to express their views and opinions. Significant issues were raised by the ethics of undertaking work with young people and these are reviewed. The young people involved in the research reported that their participation in the groups developed their self-confidence and advocacy skills. This led them to be more confident in expressing their needs at school and in the community. To establish wider generalizability for the study findings, the Yorkshire group activities were compared with another similar group in London where further data were collected from the young people involved. In facilitating group activities, willing staff were an important addition to the group because their presence provided and encouraged positive reactions to the distinctive achievements of the young people themselves. In both groups, members were committed to participation in project-based activities that raised their self-esteem and helped establish a sense of their own identity and purpose.

  16. The acidic functional groups of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shanxiang, Li; Shuhe, Sun; Zhai Zongxi, Wu Qihu

    1983-09-01

    The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)

  17. Synthesis and Insecticidal Activities of Novel Analogues of Chlorantraniliprole Containing Nitro Group

    Institute of Scientific and Technical Information of China (English)

    FENG Qi; WANG Ming-zhong; XIONG Li-xia; LIU Zhi-li; LI Zheng-ming

    2011-01-01

    Twelve novel analogues of chlorantraniliprole containing nitro group were synthesized,and their structures were characterized by 1H NMR and high-resolution mass spectrometry(HRMS).Their evaluated insecticidal activities against oriental armyworm(Mythimna separata) indicate that the nitro-containing analogues showed favorable insecticidal activities,while the activity of compounds 5g at 0.25 mg/L was 40%,but still lower than chlorantraniliprole.

  18. Activity groups for persons with dementia: Personal predictors of participation, engagement and mood.

    Science.gov (United States)

    Cohen-Mansfield, Jiska

    2017-11-01

    This study examined the relationship between personal characteristics and attendance, engagement, sleep, and mood outcomes of persons with dementia participating in group activities. The purpose of this study is to examine which persons with dementia benefit most from group interventions. Sixty-nine persons with dementia were observed by research and therapeutic recreation staff during 10 types of group activities (reading aloud with discussion, choral-singing, baking, creative storytelling, brain games, active games, exercise, reminiscence poetry, holiday newsletter, and holiday discussions) on multiple outcomes (attendance duration, sleep, engagement, active participation, attitude, and positive mood). Correlations between these outcomes and personal characteristics (demographics, functional and medical characteristics, personal preferences for group activities) were conducted. Variables with significant correlations were then entered into regression analyses. Many of the personal characteristics were significantly correlated with the outcomes. Cognitive function was the most consistent predictor of all outcomes. Personal characteristics, particularly cognitive function, can predict the responses of persons with dementia during group activities. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 06, Revision 2 (FGE.06Rev2): Straight- and branched-chain aliphatic unsaturated primary alcohols, aldehydes, carboxylic acids, and esters from chemical groups 1

    DEFF Research Database (Denmark)

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

    The European Food Safety Authority (EFSA) asked the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (the Panel) to provide scientific advice to the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs...... in the commercial flavouring material. Forty-six candidate substances are classified into structural class I. The remaining two substances [FL-no: 05.143 and 09.884] are classified into structural class II. Thirty-eight of the flavouring substances in the present group have been reported to occur naturally...... in a wide range of food items. According to the default MSDI approach, the 48 flavouring substances in this group have intakes in Europe from 0.001 to 120 microgram/capita/day, which are below the thresholds of concern value for both structural class I (1800 microgram/person/day) and structural class II...

  20. Li-Carboxylate Anode Structure-Property Relationships from Molecular Modeling

    KAUST Repository

    Burkhardt, Stephen E.

    2013-01-22

    The full realization of a renewable energy strategy hinges upon electrical energy storage (EES). EES devices play a key role in storing energy from renewable sources (which are inherently intermittent), to efficient transmission (e.g., grid load-leveling), and finally into the electrification of transportation. Organic materials represent a promising class of electrode active materials for Li-ion and post-Li-ion batteries. Organics consist of low-cost, lightweight, widely available materials, and their properties can be rationally tuned using the well-established principles of organic chemistry. Within the class of organic EES materials, carboxylates distinguish themselves for Li-ion anode materials based on their observed thermal stability, rate capability, and high cyclability. Further, many of the carboxylates studied to date can be synthesized from renewable or waste feedstocks. This report begins with a preliminary molecular density-functional theory (DFT) study, in which the calculated molecular properties of a set of 12 known Li-ion electrode materials based on carboxylate and carbonyl redox couples are compared to literature data. Based on the agreement between theoretical and experimental data, an expanded study was undertaken to identify promising materials and establish design principles for anodes based on Li-carboxylate salts. Predictive computational studies represent an important step forward for the identification of organic anode materials. © 2012 American Chemical Society.

  1. Effects of group exercise on functional abilities: Differences between physically active and physically inactive women.

    Science.gov (United States)

    Cokorilo, Nebojsa; Mikalacki, Milena; Satara, Goran; Cvetkovic, Milan; Marinkovic, Dragan; Zvekic-Svorcan, Jelena; Obradovic, Borislav

    2018-03-30

    Aerobic exercises to music can have a positive effect on functional and motor skills of an exerciser, their health, as well as an aesthetic and socio-psychological component. The objective of this study was to determine the effects of reactive exercising in a group on functional capabilities in physically active and physically inactive women. A prospective study included 64 healthy women aged 40-60 years. The sample was divided into the experimental group (n= 36), i.e. physically active women who have been engaged in recreational group exercises at the Faculty of Sport and Physical Education, University of Novi Sad, Serbia, and the control group (n= 28), which consisted of physically inactive women. All the participants were monitored using the same protocol before and after the implementation of the research. All women had their height, weight, body mass index measured as well as spiroergometric parameters determined according to the Bruce protocol. A univariate analysis of variance has shown that there is a statistically significant difference between the experimental group and the control group in maximum speed, the total duration of the test, relative oxygen consumption, absolute oxygen consumption and ventilation during the final measurement. After the training intervention, the experimental group showed improvements in all the parameters analyzed compared with pretest values. The recreational group exercise model significantly improves aerobic capacity and functioning of the cardiovascular system. Therefore, it is essential for women to be involved more in any form of recreational group exercising in order to improve functional capacity and health.

  2. Basis of integrated approach to sports and recreational activities of students of special medical groups

    Directory of Open Access Journals (Sweden)

    L.V. Zaharova

    2014-02-01

    Full Text Available Purpose : to prove the superiority of techniques integrated approach to sports and recreational activities of students of special medical groups in the educational institution. Material / methods : the annual pedagogical experiment conducted on three groups that have been formed based on the results of preliminary studies based on diagnosis. Learning process based on the principle of improving training. Results : the advantages of an integrated approach to sports and recreational activities of students with disorders of the musculoskeletal system. Recommended approaches to increase physical and functional training. Also - the formation of a stable demand of motor activity, leading healthy lifestyles, in the acquisition of social status in the educational activity. Conclusions : the integrated approach will meet the educational needs of students to form a cultural competence of the individual in the preservation and conservation of health, ability to adapt and successfully implement their professional activities.

  3. Promoting Physical Activity With Group Pictures. Affiliation-Based Visual Communication for High-Risk Populations.

    Science.gov (United States)

    Reifegerste, Doreen; Rossmann, Constanze

    2017-02-01

    Past research in social and health psychology has shown that affiliation motivation is associated with health behavior, especially for high-risk populations, suggesting that targeting this motivation could be a promising strategy to promote physical activity. However, the effects that affiliation appeals (e.g., pictures depicting companionship during physical activities) and accompanying slogans have on motivating physical activity have been largely unexplored. Hence, our two studies experimentally tested the effects of exposure to affiliation-based pictures for overweight or less active people, as well as the moderating effect of affiliation motivation. The results of these two studies give some indication that group pictures (with or without an accompanying slogan) can be an effective strategy to improve high-risk populations' attitudes, self-efficacy, and intentions to engage in physical activity. Affiliation motivation as a personality trait did not interact with these effects, but was positively associated with attitudes, independent of the group picture effect.

  4. Specificity of a prodrug-activating enzyme hVACVase: the leaving group effect.

    Science.gov (United States)

    Sun, Jing; Dahan, Arik; Walls, Zachary F; Lai, Longsheng; Lee, Kyung-Dall; Amidon, Gordon L

    2010-12-06

    Human valacyclovirase (hVACVase) is a prodrug-activating enzyme for amino acid prodrugs including the antiviral drugs valacyclovir and valganciclovir. In hVACVase-catalyzed reactions, the leaving group of the substrate corresponds to the drug moiety of the prodrug, making the leaving group effect essential for the rational design of new prodrugs targeting hVACVase activation. In this study, a series of valine esters, phenylalanine esters, and a valine amide were characterized for the effect of the leaving group on the efficiency of hVACVase-mediated prodrug activation. Except for phenylalanine methyl and ethyl esters, all of the ester substrates exhibited a relatively high specificity constant (k(cat)/K(m)), ranging from 850 to 9490 mM(-1)·s(-1). The valine amide Val-3-APG exhibited significantly higher K(m) and lower k(cat) values compared to the corresponding ester Val-3-HPG, indicating poor specificity for hVACVase. In conclusion, the substrate leaving group has been shown to affect both binding and specific activity of hVACVase-catalyzed activation. It is proposed that hVACVase is an ideal target for α-amino acid ester prodrugs with relatively labile leaving groups while it is relatively inactivate toward amide prodrugs.

  5. Structural and thermal properties of carboxylic acid functionalized polythiophenes

    Directory of Open Access Journals (Sweden)

    Ariane de França Mescoloto

    2014-01-01

    Full Text Available Polythiophenes functionalized with polar groups at the end of side-chain have emerged as an alternative method to obtain good compatibility between this class of conjugated polymers and electron acceptor compounds. The aim is to prevent phase segregation and to improve the efficiency of the polythiophene technological devices. However, homopolymers synthesized from thiophene rings with high polar groups at the end of the side-chain, such as hydroxyl and carboxylic acid groups, are poorly soluble in common volatile organic solvents. We report on a systematic preparation of copolymers of 3-hexylthiophene (HT and thiophene-3-acetic acid (TAA, using different feed ratios. The chemical structures of the copolymers were confirmed by FTIR and ¹H-NMR. The TAA content in these copolymers were 33, 38 and 54 mol %. HPSEC results did not show any remarkable correlation with TAA contents in the copolymers. In contrast, the thermal analyses showed a decrease in the thermal stability and an increase in rigidity of their backbones, for the copolymers with high amounts of TAA. The solubility and optical property of copolymers were also related to the TAA contents. Thus, the properties of these copolymers can be modulated by a simple control of feed ratio of TAA in the copolymerization.

  6. Leisure-time Physical Activity Among Different Social Groups of Estonia: Results of the National Physical Activity Survey

    Directory of Open Access Journals (Sweden)

    Lusmägi Peeter

    2016-03-01

    Full Text Available According to the Eurobarometer (European Commission, 2010, 39% of the Estonian adult population is not physically active at all. This percentage is relatively high compared to other countries that are culturally close to Estonia; the corresponding figure of close neighbors Finland and Sweden is below 10%. The article aims to present the results of a survey of physical activity (n=1,009 conducted in Estonia in 2013 and analyzes physical activity levels across various social groups. The results of the article show that employment, age, education, and ethnicity are important factors for engaging in leisure-time physical activity in Estonia. Non-ethnic Estonians, the less educated, the elderly, the unemployed, and those on maternity leave are less engaged in regular leisure exercise than people in other social groups. The results of the article were used to develop Estonia’s Sports 2030 strategy.

  7. Organocatalyzed, Visible-Light Photoredox-Mediated, One-Pot Minisci Reaction Using Carboxylic Acids via N-(Acyloxy)phthalimides.

    Science.gov (United States)

    Sherwood, Trevor C; Li, Ning; Yazdani, Aliza N; Dhar, T G Murali

    2018-03-02

    An improved, one-pot Minisci reaction has been developed using visible light, an organic photocatalyst, and carboxylic acids as radical precursors via the intermediacy of in situ-generated N-(acyloxy)phthalimides. The conditions employed are mild, demonstrate a high degree of functional group tolerance, and do not require a large excess of the carboxylic acid reactant. As a result, this reaction can be applied to drug-like scaffolds and molecules with sensitive functional groups, enabling late-stage functionalization, which is of high interest to medicinal chemistry.

  8. Chemical rescue of the post-translationally carboxylated lysine mutant of allantoinase and dihydroorotase by metal ions and short-chain carboxylic acids.

    Science.gov (United States)

    Ho, Ya-Yeh; Huang, Yen-Hua; Huang, Cheng-Yang

    2013-04-01

    Bacterial allantoinase (ALLase) and dihydroorotase (DHOase) are members of the cyclic amidohydrolase family. ALLase and DHOase possess similar binuclear metal centers in the active site in which two metals are bridged by a post-translationally carboxylated lysine. In this study, we determined the effects of carboxylated lysine and metal binding on the activities of ALLase and DHOase. Although DHOase is a metalloenzyme, purified DHOase showed high activity without additional metal supplementation in a reaction mixture or bacterial culture. However, unlike DHOase, ALLase had no activity unless some specific metal ions were added to the reaction mixture or culture. Substituting the metal binding sites H59, H61, K146, H186, H242, or D315 with alanine completely abolished the activity of ALLase. However, the K146C, K146D and K146E mutants of ALLase were still active with about 1-6% activity of the wild-type enzyme. These ALLase K146 mutants were found to have 1.4-1.7 mol metal per mole enzyme subunit, which may indicate that they still contained the binuclear metal center in the active site. The activity of the K146A mutant of the ALLase and the K103A mutant of DHOase can be chemically rescued by short-chain carboxylic acids, such as acetic, propionic, and butyric acids, but not by ethanol, propan-1-ol, and imidazole, in the presence of Co2+ or Mn2+ ions. However, the activity was still ~10-fold less than that of wild-type ALLase. Overall, these results indicated that the 20 natural basic amino acid residues were not sufficiently able to play the role of lysine. Accordingly, we proposed that during evolution, the post-translational modification of carboxylated lysine in the cyclic amidohydrolase family was selected for promoting binuclear metal center self-assembly and increasing the nucleophilicity of the hydroxide at the active site for enzyme catalysis. This kind of chemical rescue combined with site-directed mutagenesis may also be used to identify a binuclear metal

  9. DFT Study of Binding and Electron Transfer from a Metal-Free Dye with Carboxyl, Hydroxyl, and Sulfonic Anchors to a Titanium Dioxide Nanocluster

    Directory of Open Access Journals (Sweden)

    Corneliu I. Oprea

    2013-01-01

    Full Text Available We report results of density functional theory (DFT calculations of a metal-free dye, 5-(4-sulfophenylazosalicylic acid disodium salt, known as Mordant Yellow 10 (MY-10, used as sensitizer for TiO2 dye-sensitized solar cells (DSSCs. Given the need to better understand the behavior of the dyes adsorbed on the TiO2 nanoparticle, we studied various single and double deprotonated forms of the dye bound to a TiO2 cluster, taking advantage of the presence of the carboxyl, hydroxyl, and sulfonic groups as possible anchors. We discuss various binding configurations to the TiO2 substrate and the charge transfer from the pigment to the oxide by means of DFT calculations. In agreement with other reports, we find that the carboxyl group tends to bind in bidentate bridging configurations. The salicylate uses both the carboxyl and hydroxyl substituent groups for either a tridentate binding to adjacent Ti(IV ions or a bidentate Ti-O binding together with an O-H-O binding, due to the rotation of the carboxyl group out of the plane of the dye. The sulfonic group prefers a tridentate binding. We analyze the propensity for electron transfer of the various dyes and find that for MY-10, as a function of the anchor group, the DSSC performance decreases in the order hydroxyl + carboxyl > carboxyl > sulfonate.

  10. Microwave assisted one-pot catalyst free green synthesis of new methyl-7-amino-4-oxo-5-phenyl-2-thioxo-2,3,4,5-tetrahydro-1H-pyrano[2,3-d]pyrimidine-6-carboxylates as potent in vitro antibacterial and antifungal activity

    Directory of Open Access Journals (Sweden)

    Ajmal R. Bhat

    2015-11-01

    Full Text Available An efficiently simple protocol for the synthesis of methyl 7 amino-4-oxo-5-phenyl-2-thioxo-2, 3, 4,5-tetrahydro-1H-pyrano[2,3-d]pyrimidine-6-carboxylates via one-pot three component condensation pathway is established via microwave irradiation using varied benzaldehyde derivatives, methylcyanoacetate and thio-barbituric acid in water as a green solvent. A variety of functionalized substrates were found to react under this methodology due to its easy operability and offers several advantages like, high yields (78–94%, short reaction time (3–6 min, safety and environment friendly without used any catalyst. The synthesized compounds (4a–4k showed comparatively good in vitro antimicrobial and antifungal activities against different strains. The Compounds 4a, 4b, 4c, 4d 4e and 4f showed maximum antimicrobial activity against Staphylococcus aureus, Bacillus cereus (gram-positive bacteria, Escherichia coli, Klebshiella pneumonia, Pseudomonas aeruginosa (gram-negative bacteria. The synthesized compound 4f showed maximum antifungal activity against Aspergillus Niger and Penicillium chrysogenum strains. Streptomycin is used as standard for bacterial studies and Mycostatin as standards for fungal studies. Structure of all newly synthesized products was characterized on the basis of IR, 1H NMR, 13C NMR and mass spectral analysis.

  11. Work group I: Measures of the food and physical activity environment: instruments.

    Science.gov (United States)

    Saelens, Brian E; Glanz, Karen

    2009-04-01

    A work group was convened to identify the core challenges, content gaps, and corresponding possible solutions for improving food- and physical activity-environment instrumentation. Identified challenges included instrument proliferation, the scaling or grain of instruments and appropriate aggregation to the neighborhood or community level, and unknown sensitivity to change of most instruments. Solutions for addressing these challenges included establishing an interactive and real-time instrument repository, developing and enforcing high standards for instrument reporting, increasing community-researcher collaborations, and implementing surveillance of food and physical activity environment. Solid instrumentation will accelerate a better understanding of food- and physical activity-environment effects on eating and physical activity behaviors.

  12. Modeling Perceptual Grouping and Figure-Ground Segregation by Means of Active Reentrant Connections

    Science.gov (United States)

    Sporns, Olaf; Tononi, Giulio; Edelman, Gerald M.

    1991-01-01

    The segmentation of visual scenes is a fundamental process of early vision, but the underlying neural mechanisms are still largely unknown. Theoretical considerations as well as neurophysiological findings point to the importance in such processes of temporal correlations in neuronal activity. In a previous model, we showed that reentrant signaling among rhythmically active neuronal groups can correlate responses along spatially extended contours. We now have modified and extended this model to address the problems of perceptual grouping and figure-ground segregation in vision. A novel feature is that the efficacy of the connections is allowed to change on a fast time scale. This results in active reentrant connections that amplify the correlations among neuronal groups. The responses of the model are able to link the elements corresponding to a coherent figure and to segregate them from the background or from another figure in a way that is consistent with the so-called Gestalt laws.

  13. Modeling perceptual grouping and figure-ground segregation by means of active reentrant connections.

    Science.gov (United States)

    Sporns, O; Tononi, G; Edelman, G M

    1991-01-01

    The segmentation of visual scenes is a fundamental process of early vision, but the underlying neural mechanisms are still largely unknown. Theoretical considerations as well as neurophysiological findings point to the importance in such processes of temporal correlations in neuronal activity. In a previous model, we showed that reentrant signaling among rhythmically active neuronal groups can correlate responses along spatially extended contours. We now have modified and extended this model to address the problems of perceptual grouping and figure-ground segregation in vision. A novel feature is that the efficacy of the connections is allowed to change on a fast time scale. This results in active reentrant connections that amplify the correlations among neuronal groups. The responses of the model are able to link the elements corresponding to a coherent figure and to segregate them from the background or from another figure in a way that is consistent with the so-called Gestalt laws.

  14. Areva. Group dynamics and activities. Competitive environment and strategic perspectives. Release - October 2016

    International Nuclear Information System (INIS)

    2016-10-01

    After a synthesis which notably proposes a SWOT analysis of the Areva group, this report proposes a presentation of the Areva Group (general overview, mining, upstream and downstream poles, shareholder structure and stock market data, competitive environment). It gives an overview of the Areva group dynamics and of its activities through a presentation of an environment analysis (world electric power production, uranium production and consumption, operated nuclear plants in the world), a presentation of the group activity (turnover and order backlog, turnover per segment and per geographical area, operational and net income). It indicates important events and comments development axes: strategic orientations, new partnership with EDF, stronger presence in China, asset disposal, and organisation optimisation. Financial data are presented along with the main economic and financial indicators. Important statistical data are provided

  15. Preparation and reactivity of carboxylic acid-terminated boron-doped diamond electrodes

    International Nuclear Information System (INIS)

    Niedziolka-Joensson, Joanna; Boland, Susan; Leech, Donal; Boukherroub, Rabah; Szunerits, Sabine

    2010-01-01

    The paper reports on the formation of carboxy-terminated boron-doped diamond (BDD) electrodes. The carboxylic acid termination was prepared in a controlled way by reacting photochemically oxidized BDD with succinic anhydride. The resulting interface was readily employed for the linking of an amine-terminated ligand such as an osmium complex bearing an amine terminal group. The interfaces were characterized using X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). Contact angle measurements were used to follow the changes in surface wetting properties due to surface functionalization. The chemical reactivity of the carboxyl-terminated BDD was investigated by covalent coupling of the acid groups to an amine-terminated osmium complex.

  16. Redshift or adduct stabilization -- a computational study of hydrogen bonding in adducts of protonated carboxylic acids

    DEFF Research Database (Denmark)

    Olesen, Solveig Gaarn; Hammerum, Steen

    2009-01-01

    It is generally expected that the hydrogen bond strength in a D-H-A adduct is predicted by the difference between the proton affinities of D and A, measured by the adduct stabilization, and demonstrated by the IR redshift of the D-H bond stretching vibrational frequency. These criteria do...... not always yield consistent predictions, as illustrated by the hydrogen bonds formed by the E and Z OH groups of protonated carboxylic acids. The delta-PA and the stabilization of a series of hydrogen bonded adducts indicate that the E OH group forms the stronger hydrogen bonds, whereas the bond length...... carboxylic acids are different. The OH bond length and IR redshift afford the better measure of hydrogen bond strength....

  17. Salivary alpha amylase activity in human beings of different age groups subjected to psychological stress.

    Science.gov (United States)

    Sahu, Gopal K; Upadhyay, Seema; Panna, Shradha M

    2014-10-01

    Salivary alpha-amylase (sAA) has been proposed as a sensitive non-invasive biomarker for stress-induced changes in the body that reflect the activity of the sympathetic nervous system. Though several experiments have been conducted to determine the validity of this salivary component as a reliable stress marker in human subjects, the effect of stress induced changes on sAA level in different age groups is least studied. This article reports the activity of sAA in human subjects of different age groups subjected to psychological stress induced through stressful video clip. Differences in sAA level based on sex of different age groups under stress have also been studied. A total of 112 subjects consisting of both the male and female subjects, divided into two groups on basis of age were viewed a video clip of corneal transplant surgery as stressor. Activity of sAA from saliva samples of the stressed subjects were measured and compared with the activity of the samples collected from the subjects before viewing the clip. The age ranges of subjects were 18-25 and 40-60 years. The sAA level increased significantly in both the groups after viewing the stressful video. The increase was more pronounced in the younger subjects. The level of sAA was comparatively more in males than females in the respective groups. No significant change in sAA activity was observed after viewing the soothed video clip. Significant increase of sAA level in response to psychological stress suggests that it might act as a reliable sympathetic activity biochemical marker in different stages of human beings.

  18. Sensitive method for dosing carboxylic functions of carbons and its application to the study of thermally processed carbon blacks

    International Nuclear Information System (INIS)

    Bernardin, Jacques

    1968-01-01

    This research thesis reports the development of a sensitive method for the dosing of carboxylic functions present at the surface of carbon blacks, and the use of this method to study the evolution of a carbon black during heat treatments. After a brief description of modes of fabrication of carbon blacks and of their structure, the author proposes an overview of knowledge on their oxidation and functional analysis. After having outlined that existing methods do not allow the measurement of function quantities less than ten micro-equivalent per gram of carbon, the author reports the development of a method which allows such measurements. By using this method, the author shows that carboxylic groups of a carbon black, oxidized by air or not, decompose during degassing by forming carbon dioxide, and that, reciprocally, the released carbon dioxide is exclusively produced by the decomposition of carboxylic groups [fr

  19. A Dynamic Active Multicast Group Access Control Framework Based on Trust Management System

    Institute of Scientific and Technical Information of China (English)

    YANG Chang; CHEN Xiaolin; ZHANG Huanguo

    2006-01-01

    The current multicast model provides no access control mechanism. Any host can send data directly to a multicast address or join a multicast group to become a member, which brings safety problems to multicast. In this paper, we present a new active multicast group access control mechanism that is founded on trust management. This structure can solve the problem that exists in multicast members' access control and distributing authorization of traditional IP multicast.

  20. Interaction Between the Biotin Carboxyl Carrier Domain and the Biotin Carboxylase Domain in Pyruvate Carboxylase from Rhizobium etli†

    Science.gov (United States)

    Lietzan, Adam D.; Menefee, Ann L.; Zeczycki, Tonya N.; Kumar, Sudhanshu; Attwood, Paul V.; Wallace, John C.; Cleland, W. Wallace; Maurice, Martin St.

    2011-01-01

    Pyruvate carboxylase (PC) catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To effect catalysis, the tethered biotin of PC must gain access to active sites in both the biotin carboxylase domain and the carboxyl transferase domain. Previous studies have demonstrated that a mutation of threonine 882 to alanine in PC from Rhizobium etli renders the carboxyl transferase domain inactive and favors the positioning of biotin in the biotin carboxylase domain. We report the 2.4 Å resolution X-ray crystal structure of the Rhizobium etli PC T882A mutant which reveals the first high-resolution description of the domain interaction between the biotin carboxyl carrier protein domain and the biotin carboxylase domain. The overall quaternary arrangement of Rhizobium etli PC remains highly asymmetrical and is independent of the presence of allosteric activator. While biotin is observed in the biotin carboxylase domain, its access to the active site is precluded by the interaction between Arg353 and Glu248, revealing a mechanism for regulating carboxybiotin access to the BC domain active site. The binding location for the biotin carboxyl carrier protein domain demonstrates that tethered biotin cannot bind in the biotin carboxylase domain active site in the same orientation as free biotin, helping to explain the difference in catalysis observed between tethered biotin and free biotin substrates in biotin carboxylase enzymes. Electron density located in the biotin carboxylase domain active site is assigned to phosphonoacetate, offering a probable location for the putative carboxyphosphate intermediate formed during biotin carboxylation. The insights gained from the T882A Rhizobium etli PC crystal structure provide a new series of catalytic snapshots in PC and offer a revised perspective on catalysis in the biotin-dependent enzyme family. PMID:21958016

  1. Interventions to improve physical activity among socioeconomically disadvantaged groups: an umbrella review.

    Science.gov (United States)

    Craike, Melinda; Wiesner, Glen; Hilland, Toni A; Bengoechea, Enrique Garcia

    2018-05-15

    People from socioeconomically disadvantaged population groups are less likely to be physically active and more likely to experience adverse health outcomes than those who are less disadvantaged. In this umbrella review we examined across all age groups, (1) the effectiveness of interventions to improve physical activity among socioeconomically disadvantaged groups, (2) the characteristics of effective interventions, and (3) directions for future research. PubMed/MEDLINE and Scopus were searched up to May 2017 to identify systematic reviews reporting physical activity interventions in socioeconomically disadvantaged populations or sub-groups. Two authors independently conducted study screening and selection, data extraction (one author, with data checked by two others) and assessment of methodological quality using the 'Assessment of Multiple Systematic Reviews' scale. Results were synthesized narratively. Seventeen reviews met our inclusion criteria, with only 5 (30%) reviews being assessed as high quality. Seven (41%) reviews focused on obesity prevention and an additional four focused on multiple behavioural outcomes. For pre school children, parent-focused, group-based interventions were effective in improving physical activity. For children, school-based interventions and policies were effective; few studies focused on adolescents and those that did were generally not effective; for adults, there was mixed evidence of effectiveness but characteristics such as group-based interventions and those that focused on physical activity only were associated with effectiveness. Few studies focused on older adults. Across all ages, interventions that were more intensive tended to be more effective. Most studies reported short-term, rather than longer-term, outcomes and common methodological limitations included high probability of selection bias, low response rates, and high attrition. Interventions can be successful at improving physical activity among children from

  2. Ultradian activity rhythms in large groups of newly hatched chicks (Gallus gallus domesticus).

    Science.gov (United States)

    Nielsen, B L; Erhard, H W; Friggens, N C; McLeod, J E

    2008-07-01

    A clutch of young chicks housed with a mother hen exhibit ultradian (within day) rhythms of activity corresponding to the brooding cycle of the hen. In the present study clear evidence was found of ultradian activity rhythms in newly hatched domestic chicks housed in groups larger than natural clutch size without a mother hen or any other obvious external time-keeper. No consistent synchrony was found between groups housed in different pens within the same room. The ultradian rhythms disappeared with time and little evidence of group rhythmicity remained by the third night. This disappearance over time suggests that the presence of a mother hen may be pivotal for the long-term maintenance of these rhythms. The ultradian rhythm of the chicks may also play an important role in the initiation of brooding cycles during the behavioural transition of the mother hen from incubation to brooding. Computer simulations of individual activity rhythms were found to reproduce the observations made on a group basis. This was achievable even when individual chick rhythms were modelled as independent of each other, thus no assumptions of social facilitation are necessary to obtain ultradian activity rhythms on a group level.

  3. Summary of the activities of the ISAM Confidence Building Working Group

    International Nuclear Information System (INIS)

    Dolinar, G.M.; Batandjieva, B.

    2002-01-01

    During the early stages of the ISAM project confidence building was a relatively new topic in the radioactive waste disposal literature, but it was beginning to receive some attention. Although almost all safety assessment activities are intended to provide a level of confidence in the results of the assessment, considering the activities from the viewpoint of how they contributed to the decision making of various 'audiences' was relatively new. The ISAM project included the Confidence Building Working Group (CBWG) to examine the topic of Confidence Building and this paper provides a summary of the working group findings. (author)

  4. ACT-1000. Group activation cross-section library for WWER-1000 type reactors

    Energy Technology Data Exchange (ETDEWEB)

    Zolotarev, K I; Pashchenko, A B [National Research Centre - A.I. Leipunsky Institute for Physics and Power Engineering, Obninsk (Russian Federation)

    2001-10-01

    The ACT-1000, a problem-oriented library of group-averaged activation cross-sections for WWER-1000 type reactors, is based on evaluated microscopic cross-section data files. The ACT-1000 data library was designed for calculating induced activity for the main dose-generated nuclides contained in WWER-1000 structural materials. In preparing the ACT-1000 library, 47 group-averaged cross-section data for the 10{sup -9}-17.33 MeV energy range were used to calculate the spatial-energy neutron flux distribution. (author)

  5. Vitamin K-Dependent Carboxylation of Matrix Gla Protein Influences the Risk of Calciphylaxis.

    Science.gov (United States)

    Nigwekar, Sagar U; Bloch, Donald B; Nazarian, Rosalynn M; Vermeer, Cees; Booth, Sarah L; Xu, Dihua; Thadhani, Ravi I; Malhotra, Rajeev

    2017-06-01

    Matrix Gla protein (MGP) is a potent inhibitor of vascular calcification. The ability of MGP to inhibit calcification requires the activity of a vitamin K-dependent enzyme, which mediates MGP carboxylation. We investigated how MGP carboxylation influences the risk of calciphylaxis in adult patients receiving dialysis and examined the effects of vitamin K deficiency on MGP carboxylation. Our study included 20 patients receiving hemodialysis with calciphylaxis (cases) and 20 patients receiving hemodialysis without calciphylaxis (controls) matched for age, sex, race, and warfarin use. Cases had higher plasma levels of uncarboxylated MGP (ucMGP) and carboxylated MGP (cMGP) than controls. However, the fraction of total MGP that was carboxylated (relative cMGP concentration = cMGP/[cMGP + uncarboxylated MGP]) was lower in cases than in controls (0.58±0.02 versus 0.69±0.03, respectively; P =0.003). In patients not taking warfarin, cases had a similarly lower relative cMGP concentration. Each 0.1 unit reduction in relative cMGP concentration associated with a more than two-fold increase in calciphylaxis risk. Vitamin K deficiency associated with lower relative cMGP concentration in multivariable adjusted analyses ( β =-8.99; P =0.04). In conclusion, vitamin K deficiency-mediated reduction in relative cMGP concentration may have a role in the pathogenesis of calciphylaxis. Whether vitamin K supplementation can prevent and/or treat calciphylaxis requires further study. Copyright © 2017 by the American Society of Nephrology.

  6. Floral Benzenoid Carboxyl Methyltransferases: From in Vitro to in Planta Function

    Energy Technology Data Exchange (ETDEWEB)

    Effmert,U.; Saschenbrecker, S.; Ross, J.; Negre, F.; Fraser, C.; Noel, J.; Dudareva, N.; Piechulla, B.

    2005-01-01

    Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT's three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in plants depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses

  7. Leadership in physical activity groups for older adults: a qualitative analysis.

    Science.gov (United States)

    Estabrooks, Paul A; Munroe, Krista J; Fox, Elizabeth H; Gyurcsik, Nancy C; Hill, Jennie L; Lyon, Robert; Rosenkranz, Sara; Shannon, Vanessa R

    2004-07-01

    The purpose of this study was to determine whether a theory-based framework could be used to deductively identify and understand the characteristics of motivational leaders of physical activity groups for older adults. Participants were 23 older adults (mean age = 78.5 +/- 8.0 years, 65% women). An interview-guide approach was employed to elicit older adults' thoughts on important characteristics of physical activity group leaders. The data suggested that effective leaders are those whom the participants feel are properly qualified, are able to develop a personal bond with participants, and can use their knowledge and the group to demonstrate collective accomplishments. It was concluded that the findings could be used to extend the leadership activities beyond the traditional technical performance and individual feedback to include activities of social integration. Furthermore, the conceptual framework identified can serve as a valuable tool in guiding future researchers in their examination of leadership in physical activity groups for older adults. Copyright 2004 Human Kinetics Publishers, Inc.

  8. N-Alkylation Using Sodium Triacetoxyborohydride with Carboxylic Acids as Alkyl Sources.

    Science.gov (United States)

    Tamura, Satoru; Sato, Keigo; Kawano, Tomikazu

    2018-01-01

    A versatile N-alkylation was performed using sodium triacetoxyborohydride and carboxylic acid as an alkyl source. The combination of these reagents furnished products different from those given previously by a similar reaction. Moreover, the mild conditions of our method allowed some functional groups to remain through the reaction, whereas they would react and be converted into other moieties in the similar reductive N-alkylation reported previously. Herein, we provide a new procedure for the preparation of various compounds containing nitrogen atoms.

  9. Edge-carboxylated graphene nanoflakes from nitric acid oxidised arc-discharge material

    OpenAIRE

    NICOLOSI, VALERIA

    2010-01-01

    PUBLISHED Graphene nanoflakes (GNFs) with average diameters of 30 nm have been prepared by a single-step oxidation procedure using single-wall carbon nanotube arc-discharge material and nitric acid. The GNFs are predominately single sheets containing a small number of internal defects. The edges are decorated with primarily carboxylic acid groups which allow facile chemical functionalisation and cross-linking of the fragments using multivalent cations

  10. Research Activities of Geotechnical Research Group of NIIS from the Past to Present

    Science.gov (United States)

    Horii, N.; Toyosawa, Y.; Tamate, S.; Itoh, K.

    In this paper, firstly the memories of Prof. Tatsuoka's laboratory and research works carried out when the first author visited Prof. Tatsuoka's laboratory as a visiting researcher from May 1986 for about 1 year are described. Secondly, the research activities of Geotechnical Research Group of NIIS are introduced. Main emphasis is given on the research activities conducted using old geotechnical centrifuge (NIIS Mark-I centrifuge) and newly developed geotechnical centrifuge (NIIS Mark-II centrifuge).

  11. Barriers for recess physical activity: a gender specific qualitative focus group exploration.

    Science.gov (United States)

    Pawlowski, Charlotte Skau; Tjørnhøj-Thomsen, Tine; Schipperijn, Jasper; Troelsen, Jens

    2014-06-23

    Many children, in particular girls, do not reach the recommended amount of daily physical activity. School recess provides an opportunity for both boys and girls to be physically active, but barriers to recess physical activity are not well understood. This study explores gender differences in children's perceptions of barriers to recess physical activity. Based on the socio-ecological model four types of environmental barriers were distinguished: natural, social, physical and organizational environment. Data were collected through 17 focus groups (at 17 different schools) with in total 111 children (53 boys) from fourth grade, with a mean age of 10.4 years. The focus groups included an open group discussion, go-along group interviews, and a gender segregated post-it note activity. A content analysis of the post-it notes was used to rank the children's perceived barriers. This was verified by a thematic analysis of transcripts from the open discussions and go-along interviews. The most frequently identified barriers for both boys and girls were weather, conflicts, lack of space, lack of play facilities and a newly-found barrier, use of electronic devices. While boys and girls identified the same barriers, there were both inter- and intra-gender differences in the perception of these barriers. Weather was a barrier for all children, apart from the most active boys. Conflicts were perceived as a barrier particularly by those boys who played ballgames. Girls said they would like to have more secluded areas added to the school playground, even in large schoolyards where lack of space was not a barrier. This aligned with girls' requests for more "hanging-out" facilities, whereas boys primarily wanted activity promoting facilities. Based on the results from this study, we recommend promoting recess physical activity through a combination of actions, addressing barriers within the natural, social, physical and organizational environment.

  12. Modeling perceptual grouping and figure-ground segregation by means of active reentrant connections.

    OpenAIRE

    Sporns, O; Tononi, G; Edelman, G M

    1991-01-01

    The segmentation of visual scenes is a fundamental process of early vision, but the underlying neural mechanisms are still largely unknown. Theoretical considerations as well as neurophysiological findings point to the importance in such processes of temporal correlations in neuronal activity. In a previous model, we showed that reentrant signaling among rhythmically active neuronal groups can correlate responses along spatially extended contours. We now have modified and extended this model ...

  13. College students’ perceptions of a caring climate in group physical activity classes

    Directory of Open Access Journals (Sweden)

    Newland Aubrey

    2017-02-01

    Full Text Available Study aim: Research suggests that physical activity rates decline sharply after high school. The pattern of activity or inactivity during college tends to persist into adulthood. A critical need exists for examination of strategies to engage college-age students in physical activity habits. One way to do this is through physical activity courses offered in colleges. This study examines the relationship between perceptions of a caring psychological climate and group connectedness, enjoyment, and attitudes toward classmates and the instructor in group physical activity courses. Material and methods: Participants were 174 students (107 males and 67 females; Mage = 21.71 enrolled in exercise, martial arts, and sports courses at a large university in the Mountain West. Results: Perceptions of a caring climate were significantly related to enhanced feelings of group connectedness, heightened enjoyment, and more positive attitudes toward classmates and instructor. Discussion: These findings suggest that a strategy to foster engagement in physical activity courses on campus is to train instructors to value, support, and welcome students.

  14. Involving postgraduate's students in undergraduate small group teaching promotes active learning in both

    Science.gov (United States)

    Kalra, Ruchi; Modi, Jyoti Nath; Vyas, Rashmi

    2015-01-01

    Background: Lecture is a common traditional method for teaching, but it may not stimulate higher order thinking and students may also be hesitant to express and interact. The postgraduate (PG) students are less involved with undergraduate (UG) teaching. Team based small group active learning method can contribute to better learning experience. Aim: To-promote active learning skills among the UG students using small group teaching methods involving PG students as facilitators to impart hands-on supervised training in teaching and managerial skills. Methodology: After Institutional approval under faculty supervision 92 UGs and 8 PGs participated in 6 small group sessions utilizing the jigsaw technique. Feedback was collected from both. Observations: Undergraduate Feedback (Percentage of Students Agreed): Learning in small groups was a good experience as it helped in better understanding of the subject (72%), students explored multiple reading resources (79%), they were actively involved in self-learning (88%), students reported initial apprehension of performance (71%), identified their learning gaps (86%), team enhanced their learning process (71%), informal learning in place of lecture was a welcome change (86%), it improved their communication skills (82%), small group learning can be useful for future self-learning (75%). Postgraduate Feedback: Majority performed facilitation for first time, perceived their performance as good (75%), it was helpful in self-learning (100%), felt confident of managing students in small groups (100%), as facilitator they improved their teaching skills, found it more useful and better identified own learning gaps (87.5%). Conclusions: Learning in small groups adopting team based approach involving both UGs and PGs promoted active learning in both and enhanced the teaching skills of the PGs. PMID:26380201

  15. A method to quantify movement activity of groups of animals using automated image analysis

    Science.gov (United States)

    Xu, Jianyu; Yu, Haizhen; Liu, Ying

    2009-07-01

    Most physiological and environmental changes are capable of inducing variations in animal behavior. The behavioral parameters have the possibility to be measured continuously in-situ by a non-invasive and non-contact approach, and have the potential to be used in the actual productions to predict stress conditions. Most vertebrates tend to live in groups, herds, flocks, shoals, bands, packs of conspecific individuals. Under culture conditions, the livestock or fish are in groups and interact on each other, so the aggregate behavior of the group should be studied rather than that of individuals. This paper presents a method to calculate the movement speed of a group of animal in a enclosure or a tank denoted by body length speed that correspond to group activity using computer vision technique. Frame sequences captured at special time interval were subtracted in pairs after image segmentation and identification. By labeling components caused by object movement in difference frame, the projected area caused by the movement of every object in the capture interval was calculated; this projected area was divided by the projected area of every object in the later frame to get body length moving distance of each object, and further could obtain the relative body length speed. The average speed of all object can well respond to the activity of the group. The group activity of a tilapia (Oreochromis niloticus) school to high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were quantified based on these methods. High UIA level condition elicited a marked increase in school activity at the first hour (P<0.05) exhibiting an avoidance reaction (trying to flee from high UIA condition), and then decreased gradually.

  16. Chemo-spectroscopic sensor for carboxyl terminus overexpressed in carcinoma cell membrane.

    Science.gov (United States)

    Stanca, Sarmiza E; Matthäus, Christian; Neugebauer, Ute; Nietzsche, Sandor; Fritzsche, Wolfgang; Dellith, Jan; Heintzmann, Rainer; Weber, Karina; Deckert, Volker; Krafft, Christoph; Popp, Jürgen

    2015-10-01

    Certain carboxyl groups of the plasma membrane are involved in tumorgenesis processes. A gold core-hydroxyapatite shell (AuHA) nanocomposite is introduced as chemo-spectroscopic sensor to monitor these carboxyl groups of the cell membrane. Hydroxyapatite (HA) plays the role both of a chemical detector and of a biocompatible Raman marker. The principle of detection is based on chemical interaction between the hydroxyl groups of the HA and the carboxyl terminus of the proteins. The AuHA exhibits a surface enhanced Raman scattering (SERS) signal at 954 cm(-1) which can be used for its localization. The bio-sensing capacity of AuHA towards human skin epidermoid carcinoma (A431) and Chinese hamster ovary (CHO) cell lines is investigated using Raman microspectroscopic imaging. The localization of AuHA on cells is correlated with scanning electron microscopy, transmission electron microscopy and structured illumination fluorescence microscopy. This qualitative approach is a step towards a quantitative study of the proteins terminus. This method would enable further studies on the molecular profiling of the plasma membrane, in an attempt to provide accurate cell identification. Using a gold core-hydroxyapatite shell (AuHA) nanocomposite, the authors in this paper showed the feasibility of detecting and differentiating cell surface molecules by surface enhanced Raman scattering. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Feeding activity in Groups of Newly Hatched Broiler Chicks: Effects of strain and hatching time

    DEFF Research Database (Denmark)

    Nielsen, Birte Lindstrøm; Juul-Madsen, Helle Risdahl; Steenfeldt, Sanna

    2010-01-01

    The feeding activity of 2 strains of broiler chickens was investigated during their first week of life in relation to their hatching time. Fast (Ross 308) and slow-growing (LB) strains were allocated to 1 of 3 (early, middle, or late hatch) single-strain groups of 80 to 100 as-hatched birds in 4...

  18. Singing as Language Learning Activity in Multilingual Toddler Groups in Preschool

    Science.gov (United States)

    Kultti, Anne

    2013-01-01

    This research focused on learning conditions in preschool that support multilingual children's linguistic development. The aim of this paper was to study singing activities through the experiences of ten multilingual children in toddler groups (one to three years of age) in eight Swedish preschools. A sociocultural theoretical approach is used to…

  19. Information Activities and Appropriation in Teacher Trainees' Digital, Group-Based Learning

    Science.gov (United States)

    Hanell, Fredrik

    2016-01-01

    Introduction: This paper reports results from an ethnographic study of teacher trainees' information activities in digital, group-based learning and their relation to the interplay between use and appropriation of digital tools and the learning environment. Method: The participants in the present study are 249 pre-school teacher trainees in…

  20. 76 FR 16478 - Proposed Information Collection (Disability Benefits Questionnaires-Group 2) Activity: Comment...

    Science.gov (United States)

    2011-03-23

    ... Collection (Disability Benefits Questionnaires--Group 2) Activity: Comment Request AGENCY: Veterans Benefits... Conditions (Vascular Diseases including Varicose Veins) Disability Benefits Questionnaire, VA Form 21-0960A-2. b. Hypertension Disability Benefits Questionnaire, VA Form 21- 0960A-3. c. Non-ischemic Heart...

  1. 76 FR 61149 - Agency Information Collection (Disability Benefits Questionnaires-Group 4) Activity Under OMB Review

    Science.gov (United States)

    2011-10-03

    ... Collection (Disability Benefits Questionnaires--Group 4) Activity Under OMB Review AGENCY: Veterans Benefits... INFORMATION: Titles: Cranial Nerve Conditions Disability Benefits Questionnaire, VA Form 21- 0960C3. Narcolepsy Disability Benefits Questionnaire, VA Form 21-0960C6. Fibromyalgia Disability Benefits...

  2. 76 FR 45008 - Proposed Information Collection (Disability Benefits Questionnaires-Group 4) Activity: Comment...

    Science.gov (United States)

    2011-07-27

    ... Collection (Disability Benefits Questionnaires--Group 4) Activity: Comment Request AGENCY: . Department of... Benefits Questionnaire, VA Form 21-0960C3. b. Narcolepsy Disability Benefits Questionnaire, VA Form 21-0960C6. c. Fibromyalgia Disability Benefits Questionnaire, VA Form 21- 0960C7. d. Seizure Disorders...

  3. 76 FR 35950 - Agency Information Collection (Disability Benefits Questionnaires-Group 3) Activity Under OMB Review

    Science.gov (United States)

    2011-06-20

    ... Collection (Disability Benefits Questionnaires--Group 3) Activity Under OMB Review AGENCY: Veterans Benefits... Questionnaire, VA Form 21-0960C-5. b. Headaches (Including Migraine Headaches), Disability Benefits Questionnaire, VA Form 21-0960C-8. c. Multiple Sclerosis (MS), Disability Benefits Questionnaire, VA Form 21...

  4. 76 FR 8846 - Proposed Information Collection (Disability Benefits Questionnaires-Group 1) Activity: Comment...

    Science.gov (United States)

    2011-02-15

    ... Collection (Disability Benefits Questionnaires--Group 1) Activity: Comment Request AGENCY: Veterans Benefits... Lymphatic Conditions, Including Leukemia Disability Benefits Questionnaire, VA Form 21-0960B-2. b. Amyotrophic Lateral Sclerosis (Lou Gehrig's Disease) Disability Benefits Questionnaire, VA Form 21-0960C-2. c...

  5. 76 FR 33417 - Agency Information Collection (Disability Benefits Questionnaires-Group 2) Activity Under OMB Review

    Science.gov (United States)

    2011-06-08

    ... Collection (Disability Benefits Questionnaires--Group 2) Activity Under OMB Review AGENCY: Veterans Benefits... Questionnaire, VA Form 21-0960A-2. b. Hypertension Disability Benefits Questionnaire, VA Form 21- 0960A-3. c. Non-ischemic Heart Disease (including Arrhythmias and Surgery, Disability Benefits Questionnaire, VA...

  6. Bill Gates' Great-Great-Granddaughter's Honeymoon: An Astronomy Activity for Several Different Age Groups

    Science.gov (United States)

    Fraknoi, Andrew

    2009-01-01

    When students finish a unit or course on the planets these days, they are often overwhelmed with facts, comparisons, and images. A good culminating activity, to help them organize their thinking (and review), is to have them divide into small groups (travel agencies) and come up with their top ten solar system "tourist sights" for future space…

  7. SOCIAL SERVICE USE GOOGLE-GROUPS INTO THE CURRICULUM AND EDUCATIONAL ACTIVITIES

    Directory of Open Access Journals (Sweden)

    T. Nosenko

    2010-06-01

    Full Text Available The article considers the use of Web2.0 services for organizing training activities high school teachers, formulated and analyzed the benefits of using social services issues in educational purposes. Determined that united in groups, students of pedagogical universities, thus preparing for the profession, enhancing professional knowledge.

  8. Coaching Paraprofessionals to Promote Engagement and Social Interactions during Small Group Activities

    Science.gov (United States)

    Ledford, Jennifer R.; Zimmerman, Kathleen N.; Chazin, Kate T.; Patel, Natasha M.; Morales, Vivian A.; Bennett, Brittany P.

    2017-01-01

    Paraprofessionals need adequate training and supports to assist young children with autism spectrum disorders to engage in appropriate social interactions during small group activities with their peers. In this study, we used in situ coaching and brief post-session feedback to improve the use of environmental arrangement, prompting, and praise by…

  9. Collaborative learning in higher education : design, implementation and evaluation of group learning activities

    NARCIS (Netherlands)

    Hei, de M.S.A.

    2016-01-01

    In higher education, group learning activities (GLAs) are frequently implemented in online, blended or face-to-face educational contexts. A major problem for the design and implementation of good quality GLAs that lead to the desired learning outcomes is that many approaches to GLAs have been

  10. Healthful Eating and Physical Activity in the Home Environment: Results from Multifamily Focus Groups

    Science.gov (United States)

    Berge, Jerica M.; Arikian, Aimee; Doherty, William J.; Neumark-Sztainer, Dianne

    2012-01-01

    Objective: To explore multiple family members' perceptions of risk and protective factors for healthful eating and physical activity in the home. Design: Ten multifamily focus groups were conducted with 26 families. Setting and Participants: Community setting with primarily black and white families. Family members (n = 103) were aged 8 to 61…

  11. Activation analysis for platinum in gold and metals of the platinum group through 199Au

    International Nuclear Information System (INIS)

    Foerster, H.

    1976-01-01

    Platinum was determined in gold and in metals of the platinum group through 199 Au by activation analysis. The matrix was separated at the end of irradiation before the daughter nuclide was formed. Gold was separated by extraction with MIBK from 1

  12. Annual activity report of Ignalina NPP Safety Analysis Group for 1995 year

    International Nuclear Information System (INIS)

    Ushpuras, E.; Augutis, J.; Bubelis, E.

    1995-01-01

    The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for 1995 are presented. ISAG is concentrating its research activities into four areas: the neutrons dynamics modelling, simulation of transient processes during loss of coolant accident, the reactor cooling systems modelling and the probabilistic safety assessment of accident confinement system. 18 refs., 9 tabs., 110 figs

  13. Annual activity report of Ignalina NPP Safety Analysis Group for 1994 year

    International Nuclear Information System (INIS)

    Ushpuras, E.; Kaliatka, A.; Chesna, B.; Dundulis, G.

    1995-01-01

    The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for 1994 are presented. ISAG is concentrated its research activities into 3 areas: the neutrons dynamics modeling, simulation of transient processes during loss of coolant accident and calculation of reactor building structure's streses and other mechanical properties in the case of accident. 6 refs., 13 tabs., 69 figs

  14. Annual activity report of Ignalina NPP Safety Analysis Group for the year 1997

    International Nuclear Information System (INIS)

    Ushpuras, E.; Augutis, J.; Bubelis, E.; Kaliatka, A

    1998-01-01

    The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for the year 1997 are presented. ISAG is concentrating its research activities into four areas: the neutrons dynamics modelling, simulation of transient processes during loss of coolant accident, the reactor cooling systems modelling and the probabilistic safety assessment of accident confinement system

  15. [Correlation Between Functional Groups and Radical Scavenging Activities of Acidic Polysaccharides from Dendrobium].

    Science.gov (United States)

    Liao, Ying; Yuan, Wen-yu; Zheng, Wen-ke; Luo, Ao-xue; Fan, Yi-jun

    2015-11-01

    To compare the radical scavenging activity of five different acidic polysaccharides, and to find the correlation with the functional groups. Alkali extraction method and Stepwise ethanol precipitation method were used to extract and concentrate the five Dendrobium polysaccharides, and to determine the contents of sulfuric acid and uronic acid of each kind of acidic polysaccharides, and the scavenging activity to ABTS+ radical and hydroxyl radical. Functional group structures were examined by FTIR Spectrometer. Five kinds of Dendrobium polysaccharides had different ability of scavenging ABTS+ free radical and hydroxyl free radical. Moreover, the study had shown that five kinds of antioxidant activity of acidic polysaccharides had obvious correlation withuronic acid and sulfuric acid. The antioxidant activity of each sample was positively correlated with the content of uronic acid, and negatively correlated with the content of sulfuric acid. Sulfuric acid can inhibit the antioxidant activity of acidic polysaccharide but uronic acid can enhance the free radical scavenging activity. By analyzing the structure characteristics of five acidic polysaccharides, all samples have similar structures, however, Dendrobium denneanum, Dendrobium devonianum and Dendrobium officinale which had β configuration have higher antioxidant activity than Dendrobium nobile and Dendrobium fimbriatum which had a configuration.

  16. A Small-Group Activity Introducing the Use and Interpretation of BLAST

    Directory of Open Access Journals (Sweden)

    Peter D. Newell

    2013-08-01

    Full Text Available As biological sequence data are generated at an ever increasing rate, the role of bioinformatics in biological research also grows. Students must be trained to complete and interpret bioinformatic searches to enable them to effectively utilize the trove of sequence data available. A key bioinformatic tool for sequence comparison and genome database searching is BLAST (Basic Local Alignment Search Tool. BLAST identifies sequences in a database that are similar to the entered query sequence, and ranks them based on the length and quality of the alignment. Our goal was to introduce sophomore and junior level undergraduate students to the basic functions and uses of BLAST with a small group activity lasting a single class period. The activity provides students an opportunity to perform a BLAST search, interpret the data output, and use the data to make inferences about bacterial cell envelope structure. The activity consists of two parts. Part 1 is a handout to be completed prior to class, complete with video tutorial, that reviews cell envelope structure, introduces key terms, and allows students to familiarize themselves with the mechanics of a BLAST search. Part 2 consists of a hands-on, web-based small group activity to be completed during the class period. Evaluation of the activity through student performance assessments suggests that students who complete the activity can better interpret the BLAST output parameters % query coverage and % max identity. While the topic of the activity is bacterial cell wall structure, it could be adapted to address other biological concepts.

  17. The Influence of Some Romanian Interest Groups Upon the Activity of Government and Parliament

    Directory of Open Access Journals (Sweden)

    Bianca COBÂRZAN

    2005-10-01

    Full Text Available The paper focuses on two specific interest groups, NGOs and trade unions, and on their influence upon the government and parliament. Our paper is based on an analyze of the activity of several interest groups during the period 2002-2004 and on the results of several researches and reports published on the last years. The analyze identifies petitioning for rule making, public meetings and debates, monitoring the activity of the public institutions and participating in advisory or regulatory committees as being the most common used mechanisms to influence the government and the parliament in Romania. Also, the analyze shows that administrative procedures affect the degree of bureaucratic autonomy. Overall, the results of this brief research show some pluralist forms of the interaction between the interest groups and the public institutions.

  18. Aminolysis of resin-bound N-nosylaziridine-2-carboxylic acids

    DEFF Research Database (Denmark)

    Olsen, Christian A; Christensen, Caspar; Nielsen, Birgitte

    2006-01-01

    [Structure: see text] Solid-phase synthesis is a rapidly developing area of organic chemistry, of particular importance for medicinal chemistry and chemical biology. Aziridines have previously only rarely been applied in solid-phase synthesis. In the present work, aminolysis of resin-bound, sprin......-loaded N-nitrobenzenesulfonyl-activated aziridine-2-carboxylic acids has been optimized and employed in the synthesis of a number of open-chain and heterocyclic scaffolds, including enantiopure products....

  19. Energy Cost Expression for a Youth Compendium of Physical Activities: Rationale for Using Age Groups.

    Science.gov (United States)

    Pfeiffer, Karin A; Watson, Kathleen B; McMurray, Robert G; Bassett, David R; Butte, Nancy F; Crouter, Scott E; Herrmann, Stephen D; Trost, Stewart G; Ainsworth, Barbara E; Fulton, Janet E; Berrigan, David

    2018-02-01

    This study compared the accuracy of physical activity energy expenditure (PAEE) prediction using 2 methods of accounting for age dependency versus 1 standard (single) value across all ages. PAEE estimates were derived by pooling data from 5 studies. Participants, 6-18 years (n = 929), engaged in 14 activities while in a room calorimeter or wearing a portable metabolic analyzer. Linear regression was used to estimate the measurement error in PAEE (expressed as youth metabolic equivalent) associated with using age groups (6-9, 10-12, 13-15, and 16-18 y) and age-in-years [each year of chronological age (eg, 12 = 12.0-12.99 y)] versus the standard (a single value across all ages). Age groups and age-in-years showed similar error, and both showed less error than the standard method for cycling, skilled, and moderate- to vigorous-intensity activities. For sedentary and light activities, the standard had similar error to the other 2 methods. Mean values for root mean square error ranged from 0.2 to 1.7 youth metabolic equivalent across all activities. Error reduction ranged from -0.2% to 21.7% for age groups and -0.23% to 18.2% for age-in-years compared with the standard. Accounting for age showed lower errors than a standard (single) value; using an age-dependent model in the Youth Compendium is recommended.

  20. Pre-Session Satiation as a Treatment for Stereotypy During Group Activities.

    Science.gov (United States)

    Rispoli, Mandy; Camargo, Síglia Hoher; Neely, Leslie; Gerow, Stephanie; Lang, Russell; Goodwyn, Fara; Ninci, Jennifer

    2014-05-01

    Individuals with developmental disabilities may engage in automatically reinforced behaviors that may interfere with learning opportunities. Manipulation of motivating operations has been shown to reduce automatically maintained behavior in some individuals. Considering behavioral indicators of satiation may assist in identifying the point at which an abolishing operation has begun to effect behavior. The purpose of this study was to evaluate the effects of pre-session satiation of automatic reinforcement on subsequent levels of stereotypy and activity engagement during group activities for three males ages 5 to 13 years with developmental disabilities. Following functional analyses with analogue conditions, an alternating treatment design compared a pre-session access to stereotypy condition with a no-pre-session access condition prior to group activity sessions. Results indicated that pre-session satiation of the putative reinforcer produced by stereotypy was effective in decreasing stereotypy and increasing activity engagement during subsequent group activities for all participants. These findings add to the literature supporting the effectiveness of abolishing operations to decrease automatically maintained stereotypy. © The Author(s) 2013.

  1. Determination of Carboxylic Acids and Water-soluble Inorganic Ions ...

    African Journals Online (AJOL)

    NICO

    radiation balance.4,5 Major water-soluble inorganic ions are associated with atmospheric ... molecular weight carboxylic acids in aerosol samples collected from a rural ... include biomass burning, agriculture, livestock and soil dust. Tropical ...

  2. EDF. Group dynamics and activities. Competitive environment and strategic perspectives. Release - October 2017

    International Nuclear Information System (INIS)

    2017-10-01

    After a synthesis, this report proposes a presentation of the EDF Group (general overview, activities, human resources, share-holding structure, stock market data). It gives an overview of the EDF Group dynamics and of its activities: environment analysis (world electric power production, power consumption in France, regulated and spot prices, turnover in France and per area and market segment), performance analysis, and competitive analysis (comparison with the main European energy companies). It analyses the different development axes and discusses main events regarding the consolidation of nuclear activities, investments in renewable energies, withdrawal from coal and fuel, diversification in energy services, and financial consolidation. Financial data are presented along with the main economic and financial indicators. Important statistical data are provided

  3. Rational design of a carboxylic esterase RhEst1 based on computational analysis of substrate binding.

    Science.gov (United States)

    Chen, Qi; Luan, Zheng-Jiao; Yu, Hui-Lei; Cheng, Xiaolin; Xu, Jian-He

    2015-11-01

    A new carboxylic esterase RhEst1 which catalyzes the hydrolysis of (S)-(+)-2,2-dimethylcyclopropanecarboxylate (S-DmCpCe), the key chiral building block of cilastatin, was identified and subsequently crystallized in our previous work. Mutant RhEst1A147I/V148F/G254A was found to show a 5-fold increase in the catalytic activity. In this work, molecular dynamic simulations were performed to elucidate the molecular determinant of the enzyme activity. Our simulations show that the substrate binds much more strongly in the A147I/V148F/G254A mutant than in wild type, with more hydrogen bonds formed between the substrate and the catalytic triad and the oxyanion hole. The OH group of the catalytic residue Ser101 in the mutant is better positioned to initiate the nucleophilic attack on S-DmCpCe. Interestingly, the "170-179" loop which is involved in shaping the catalytic sites and facilitating the product release shows remarkable dynamic differences in the two systems. Based on the simulation results, six residues were identified as potential "hot-spots" for further experimental testing. Consequently, the G126S and R133L mutants show higher catalytic efficiency as compared with the wild type. This work provides molecular-level insights into the substrate binding mechanism of carboxylic esterase RhEst1, facilitating future experimental efforts toward developing more efficient RhEst1 variants for industrial applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. “Conviv\\^{e}ncia” Groups: Building Active and Healthy Communities of Older Adults in Brazil

    Directory of Open Access Journals (Sweden)

    Tânia R. Bertoldo Benedetti

    2012-01-01

    Full Text Available In old age, social groups can be a crucial component for health and well-being. In 2009-2010, a follow-up survey was carried out in Florianópolis, Brazil to understand the impact of a variety of programs established since 2002 that were designed to enhance social activities among the older adult population. This study employed two surveys within the population of older adults in Florianópolis. The first survey interviewed a total of 875 older adults in 2002, and the second survey involved 1,705 older adults between 2009 and 2010. By 2010, many new programs were offered in the community and the enrollment of older adults in social programs followed similar trends. “Convivência” groups stood out as extremely popular social groups among this population. This paper discusses some of the potential outcomes associated with participation in “convivência” groups.

  5. Townes Group Activities from 1983-2000: Personal Recollections of William Danchi

    Science.gov (United States)

    Danchi, William C.

    2015-01-01

    I arrived in Berkeley in October 1983 as a post-doc, and my appointment was at the Space Sciences Laboratory (SSL). During that time the group was very large, with multiple activities led by Charlie himself and also by Senior Fellows such as John Lacy, Dan Jaffe, and Al Betz at the top of the hill at Space Sciences. Another significant contingent of the Townes group was housed in Birge Hall on campus, led by Reinhard Genzel when he was an Assistant Professor in the Physics Department. Although the group encompassed two separate locations, it functioned as one large group. Either we rode with Charlie up and down the hill, or (if we were concerned about our safety!) we took the bus.

  6. Crystal and Molecular Structure Studies of Ethyl 4-(4-Hydroxyphenyl-6-(6-methoxy-2-naphthyl-2-oxocyclohex-3-ene-1-carboxylate and Ethyl 4-(3-Bromophenyl-6-(6-methoxy-2-naphthyl-2-oxocyclohex-3-ene-1-carboxylate

    Directory of Open Access Journals (Sweden)

    Badiadka Narayana

    2012-08-01

    Full Text Available The crystal and molecular structures of the title compounds, ethyl 4-(4-hydroxyphenyl-6-(6-methoxy-2-naphthyl-2-oxocyclohex-3-ene-1-carboxylate (I and ethyl 4-(3-bromophenyl-6-(6-methoxy-2-naphthyl-2-oxocyclohex-3-ene-1-carboxylate (II, are reported and confirmed by single crystal X-ray diffraction data. Compound (I, C26H24O5, crystallizes from a methanol solution in the monoclinic C2/c space group with eight molecules in the unit cell. The unit cell parameters are: a = 25.4114(5 Å, b = 8.47440(10 Å, c = 20.6921(4 Å, β = 108.328(2° and V = 4229.92(13 Å3. Disorder is observed throughout the entire molecule with an occupancy ratio 0.690(2:0.310(2. Compound (II, C26H23O4Br, crystallizes from an ethyl acetate solution in the monoclinic P21/c spacegroup with four molecules in the unit cell. The unit cell parameters are a = 17.8991(9 Å, b = 11.4369(6 Å, c = 10.8507(5 Å, β = 92.428(4° and V = 2219.25(19 Å3. Disorder is observed in the cyclohexenone ring and the carboxylate group with an occupancy ratio 0.830(6:0.170(6. Weak O–H...O (I or C–H...O (II intermolecular interactions are observed which influence crystal packing stability. These chalcone derivative types of molecules are important in their ability to act as activated unsaturated systems in conjugated addition reactions of carbanions in the presence of basic catalysts which exhibit a multitude of biological activities.

  7. FRESH ACTIVITY IN OLD SYSTEMS: RADIO AGNs IN FOSSIL GROUPS OF GALAXIES

    International Nuclear Information System (INIS)

    Hess, Kelley M.; Wilcots, Eric M.; Hartwick, Victoria L.

    2012-01-01

    We present the first systematic 1.4 GHz Very Large Array radio continuum survey of fossil galaxy group candidates. These are virialized systems believed to have assembled over a gigayear in the past through the merging of galaxy group members into a single, isolated, massive elliptical galaxy and featuring an extended hot X-ray halo. We use new photometric and spectroscopic data from Sloan Digital Sky Survey Data Release 7 to determine that three of the candidates are clearly not fossil groups. Of the remaining 30 candidates, 67% contain a radio-loud (L 1.4GHz > 10 23 W Hz –1 ) active galactic nucleus (AGN) at the center of their dominant elliptical galaxy. We find a weak correlation between the radio luminosity of the AGN and the X-ray luminosity of the halo suggesting that the AGN contributes to energy deposition into the intragroup medium. We only find a correlation between the radio and optical luminosity of the central elliptical galaxy when we include X-ray-selected, elliptically dominated non-fossil groups, indicating a weak relationship between AGN strength and the mass assembly history of the groups. The dominant elliptical galaxy of fossil groups is on average roughly an order of magnitude more luminous than normal group elliptical galaxies in optical, X-ray, and radio luminosities and our findings are consistent with previous results that the radio-loud fraction in elliptical galaxies is linked to the stellar mass of a population. The current level of activity in fossil groups suggests that AGN fueling continues long after the last major merger. We discuss several possibilities for fueling the AGN at the present epoch.

  8. The value of psychosocial group activity in nursing education: A qualitative analysis.

    Science.gov (United States)

    Choi, Yun-Jung

    2018-05-01

    Nursing faculty often struggle to find effective teaching strategies for nursing students that integrate group work into nursing students' learning activities. This study was conducted to evaluate students' experiences in a psychiatric and mental health nursing course using psychosocial group activities to develop therapeutic communication and interpersonal relationship skills, as well as to introduce psychosocial nursing interventions. A qualitative research design was used. The study explored nursing students' experiences of the course in accordance with the inductive, interpretative, and constructive approaches via focus group interviews. Participants were 17 undergraduate nursing students who registered for a psychiatric and mental health nursing course. The collected data were analyzed by qualitative content analysis. The analysis resulted in 28 codes, 14 interpretive codes, 4 themes (developing interpersonal relationships, learning problem-solving skills, practicing cooperation and altruism, and getting insight and healing), and a core theme (interdependent growth in self-confidence). The psychosocial group activity provided constructive opportunities for the students to work independently and interdependently as healthcare team members through reflective learning experiences. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Thermodynamics of formation of cadmium dicarboxylate and carboxylate mixed complexes with benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, G V; Bolotov, V M; Kharitonova, R I [Voronezhskij Tekhnologicheskij Inst. (USSR)

    1980-01-01

    Thermodynamic parameters of the mixed complexing of cadmium propionate, butyrate, valerate, succinate, maleinate and malate with benzimidazole in 20 % aqUeous-ethanol solution of 0.1 M KNO/sub 3/ are studied using polarographic method. It is shown that stability of mixed complexes of cadmium carboxylates with benzimidazole is connected with the process enthalpy and is determined by covalency of the metal-carboxylate bond. Increasing length of hydrocarbon chain of acyl group of monobasic acids hampers amine coordination with central complexing agent (..delta..S<0). The presence of dicarboxylate-ion in the inner coordination sphere decreases the enthalpy and increases the entropy of the process (..delta..S>0).

  10. Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

    Science.gov (United States)

    Liu, Huiyu; Chen, Dong; Tang, Fangqiong; Du, Gangjun; Li, Linlin; Meng, Xianwei; Liang, Wei; Zhang, Yangde; Teng, Xu; Li, Yi

    2008-11-01

    A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm-2) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

  11. Carboxylic acid functionalization of halloysite nanotubes for sustained release of diphenhydramine hydrochloride

    Energy Technology Data Exchange (ETDEWEB)

    Zargarian, S. Sh.; Haddadi-Asl, V., E-mail: haddadi@aut.ac.ir; Hematpour, H. [Amirkabir University of Technology, Department of Polymer Engineering and Color Technology (Iran, Islamic Republic of)

    2015-05-15

    Halloysite nanotubes (HNT) (cylindrical shape with external diameter and length in the range of 30–80 nm and 0.2–1 µm, respectively) were functionalized with 3-aminopropyltriethoxysilane (APTES) from hydroxyl groups by a coupling reaction. Subsequently, maleic anhydride was attached to the APTES moieties to yield carboxylic acid-functionalized HNT. Loading and subsequent release of a model drug molecule diphenhydramine hydrochloride (DPH) on modified and unmodified nanotubes were investigated. Morphology of HNT was studied by electron microscopy. Successful attachment of APTES and carboxylic acid groups to halloysite and drug loading were evaluated by Fourier transform infrared spectroscopy. The amount of surface modification and drug adsorption capacity were calculated via thermogravimetric analysis. The ordered crystal structure of loaded drug was evaluated by X-ray diffraction. UV–Visible spectrophotometer was used to study drug release from modified and unmodified samples. Carboxylated halloysite exhibits higher loading capacity and prolonged release of DPH as compared to that of the natural halloysite.

  12. Carboxylic Terminated Thermo-Responsive Copolymer Hydrogel and Improvement in Peptide Release Profile

    Directory of Open Access Journals (Sweden)

    Zi-Kun Rao

    2018-02-01

    Full Text Available To improve the release profile of peptide drugs, thermos-responsive triblock copolymer poly (ε-caprolactone-co-p-dioxanone-b-poly (ethylene glycol-b-poly (ε-caprolactone-co-p-dioxanone (PECP was prepared and end capped by succinic anhydride to give its carboxylic terminated derivative. Both PCEP block copolymer and its end group modified derivative showed temperature-dependent reversible sol-gel transition in water. The carboxylic end group could significantly decrease the sol-gel transition temperature by nearly 10 °C and strengthen the gel due to enhanced intermolecular force among triblock copolymer chains. Furthermore, compared with the original PECP triblock copolymer, HOOC–PECP–COOH copolymer displayed a retarded and sustained release profile for leuprorelin acetate over one month while effectively avoiding the initial burst. The controlled release was believed to be related to the formation of conjugated copolymer-peptide pair by ionic interaction and enhanced solubility of drug molecules into the hydrophobic domains of the hydrogel. Therefore, carboxyl terminated HOOC–PECP–COOH hydrogel was a promising and well-exhibited sustained release carrier for peptide drugs with the advantage of being able to develop injectable formulation by simple mixing.

  13. Carboxylic acid functionalization of halloysite nanotubes for sustained release of diphenhydramine hydrochloride

    International Nuclear Information System (INIS)

    Zargarian, S. Sh.; Haddadi-Asl, V.; Hematpour, H.

    2015-01-01

    Halloysite nanotubes (HNT) (cylindrical shape with external diameter and length in the range of 30–80 nm and 0.2–1 µm, respectively) were functionalized with 3-aminopropyltriethoxysilane (APTES) from hydroxyl groups by a coupling reaction. Subsequently, maleic anhydride was attached to the APTES moieties to yield carboxylic acid-functionalized HNT. Loading and subsequent release of a model drug molecule diphenhydramine hydrochloride (DPH) on modified and unmodified nanotubes were investigated. Morphology of HNT was studied by electron microscopy. Successful attachment of APTES and carboxylic acid groups to halloysite and drug loading were evaluated by Fourier transform infrared spectroscopy. The amount of surface modification and drug adsorption capacity were calculated via thermogravimetric analysis. The ordered crystal structure of loaded drug was evaluated by X-ray diffraction. UV–Visible spectrophotometer was used to study drug release from modified and unmodified samples. Carboxylated halloysite exhibits higher loading capacity and prolonged release of DPH as compared to that of the natural halloysite

  14. Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

    International Nuclear Information System (INIS)

    Liu Huiyu; Chen Dong; Tang Fangqiong; Li Linlin; Meng Xianwei; Li Yi; Du Gangjun; Liang Wei; Zhang Yangde; Teng Xu

    2008-01-01

    A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm -2 ) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

  15. Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond

    International Nuclear Information System (INIS)

    Liu, K-K; Chen, P-Y; Lee, Tony J F; Chao, J-I; Chen, M-F; Cheng, C-L; Chang, C-C; Ho, Y-P

    2008-01-01

    Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin (α-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor (α7-nAChR). The electrostatic binding of cND-α-BTX was mediated by the negative charge of the cND and the positive charge of the α-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that α-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled α-BTX presented a yellow color at the same location, which indicated that α-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human α7-nAChR proteins by microinjection with α7-nAChR mRNA. The cND-α-BTX complexes were bound to α7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked α7-nAChR-mediated inward currents of the oocytes were blocked by cND-α-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-α-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated α-BTX still preserves its biological activity in blocking the function of α7-nAChR, and provide a visual system showing the binding of α-BTX to α7-nAChR

  16. Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond

    Energy Technology Data Exchange (ETDEWEB)

    Liu, K-K; Chen, P-Y; Lee, Tony J F; Chao, J-I [Institute of Pharmacology and Toxicology, Tzu Chi University, Hualien 970, Taiwan (China); Chen, M-F [Neuro-Medical Scientific Center, Tzu Chi General Hospital, Hualien 970, Taiwan (China); Cheng, C-L [Department of Physics, National Dong Hwa University, Hualien 974, Taiwan (China); Chang, C-C [Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu 300, Taiwan (China); Ho, Y-P [Department of Chemistry, National Dong Hwa University, Hualien 974, Taiwan (China)], E-mail: chaoji@mail.tcu.edu.tw

    2008-05-21

    Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin ({alpha}-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor ({alpha}7-nAChR). The electrostatic binding of cND-{alpha}-BTX was mediated by the negative charge of the cND and the positive charge of the {alpha}-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that {alpha}-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled {alpha}-BTX presented a yellow color at the same location, which indicated that {alpha}-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human {alpha}7-nAChR proteins by microinjection with {alpha}7-nAChR mRNA. The cND-{alpha}-BTX complexes were bound to {alpha}7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked {alpha}7-nAChR-mediated inward currents of the oocytes were blocked by cND-{alpha}-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-{alpha}-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated {alpha}-BTX still preserves its biological activity in blocking the function of {alpha}7-nAChR, and provide a visual

  17. Somali women's view of physical activity--a focus group study.

    Science.gov (United States)

    Persson, Gerthi; Mahmud, Amina Jama; Hansson, Eva Ekvall; Strandberg, Eva Lena

    2014-10-23

    Physical inactivity presents a major public health challenge and is estimated to cause six to ten percent of the major non-communicable diseases. Studies show that immigrants, especially women, have an increased risk of non-communicable diseases compared to ethnic Swedes. Somali immigrant women have increased rates of overweight and obesity, low fitness levels and low levels of cardiorespiratory fitness compared to non-immigrant women. These findings suggest that Somali women are at increased risk of developing lifestyle-related diseases. Few studies explore determinants of physical activity among Somali women. The aim of this study was to explore Somali women's views and experiences of physical activity after migration to Sweden. A qualitative focused ethnographic approach was used in this study. Four focus groups were conducted with twenty-six Somali women ranging from 17 to 67 years of age. Focus group discussions were recorded, transcribed verbatim and analysed using qualitative content analysis. The analysis resulted in four main themes and ten categories: Life in Somalia and Life in Sweden, Understanding and enhancing health and Facilitators and barriers to physical activity. Great differences were seen between living in Somalia and in Sweden but also similarities such as finding time to manage housework, the family and the health of the woman. The extended family is non-existent in Sweden, making life more difficult. Health was considered a gift from God but living a healthy life was perceived as the responsibility of the individual. Misconceptions about enhancing health occurred depending on the woman's previous life experience and traditions. There was an awareness of the importance of physical activity among the participants but lack of knowledge of how to enhance activity on an individual basis. Enhancing factors to an active lifestyle were identified as being a safe and comfortable environment. Some barriers, such as climate, lack of motivation and time

  18. Sulfhydryl group content of chicken progesterone receptor: effect of oxidation on DNA binding activity

    International Nuclear Information System (INIS)

    Peleg, S.; Schrader, W.T.; O'Malley, B.W.

    1988-01-01

    DNA binding activity of chicken progesterone receptor B form (PRB) and A form (PRA) has been examined. This activity is strongly dependent upon the presence of thiols in the buffer. Stability studies showed that PRB was more sensitive to oxidation that was PRA. Receptor preparations were fractionated by DNA-cellulose chromatography to DNA-positive and DNA-negative subpopulations, and sulfhydryl groups were quantified on immunopurified receptor by labeling with [ 3 H]-N-ethylmaleimide. Labeling of DNA-negative receptors with [ 3 H]-N-ethylmaleimide showed 21-23 sulfhydryl groups on either PRA or PRB form when the proteins were reduced and denatured. A similar number was seen without reduction if denatured DNA-positive receptor species were tested. In contrast, the DNA-negative PRB had only 10-12 sulfhydryl groups detectable without reduction. A similar number (12-13 sulfhydryl groups) was found for PRA species that lost DNA binding activity after exposure to a nonreducing environment in vitro. The authors conclude that the naturally occurring receptor forms unable to bind to DNA, as well as receptor forms that have lost DNA binding activity due to exposure to nonreducing environment in vitro, contain 10-12 oxidized cysteine residues, likely present as disulfide bonds. Since they were unable to reduce the disulfide bonds when the native DNA-negative receptor proteins were treated with dithiothreitol (DTT), they speculate that irreversible loss of DNA binding activity of receptor in vitro is due to oxidation of cysteine residues that are not accessible to DTT in the native state

  19. Design, syntheses, and anti-tuberculosis activities of conjugates of piperazino-1,3-benzothiazin-4-ones (pBTZs) with 2,7-dimethylimidazo [1,2-a]pyridine-3-carboxylic acids and 7-phenylacetyl cephalosporins.

    Science.gov (United States)

    Majewski, Mark W; Tiwari, Rohit; Miller, Patricia A; Cho, Sanghyun; Franzblau, Scott G; Miller, Marvin J

    2016-04-15

    Tuberculosis (TB) remains one of the most threatening diseases in the world and the need for development of new therapies is dire. Herein we describe the rationale for the design and subsequent syntheses and studies of conjugates between pBTZ and both the imidazopyridine and cephalosporin scaffolds. Overall some compounds exhibited notable anti-TB activity in the range of 2-0.2 μM in the Microplate Alamar Blue (MABA) Assay. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Evaluation of the leishmanicidal activity of plants used by Peruvian Chayahuita ethnic group.

    Science.gov (United States)

    Estevez, Y; Castillo, D; Pisango, M Tangoa; Arevalo, J; Rojas, R; Alban, J; Deharo, E; Bourdy, G; Sauvain, M

    2007-11-01

    A total of 27 ethanolic plant extracts from 27 species were screened for leishmanicidal activity in vitro against Leishmania amazonensis. Most of the selected species (19) are traditionally used by the Chayahuitas, an Amazonian Peruvian ethnic group, to treat skin affections and/or leishmaniasis. A colorimetric method based on the reduction of tetrazolium salt (MTT) was used to measure the viability of Leishmania amazonensis promastigote and amastigote stages. Only the leaves of two species of the Piperaceae family (Piper hispidum Sw., and Piper strigosum Trel.) showed good leishmanicidal activities (IC(50)Cycadaceae) showed low activity against amastigote stage (IC(50) around 50 microg/ml). Of those only Tabernaemontana sananho displayed also good activity on promastigotes (IC(50)<10 microg/ml). Results are discussed herein, in relation with the traditional use of the plants and compared with other data from the relevant literature.

  1. Characterisation and application of new carboxylic acid-functionalised ruthenium complexes as dye-sensitisers for solar cells

    DEFF Research Database (Denmark)

    Duprez, Virginie; Biancardo, Matteo; Krebs, Frederik C

    2007-01-01

    A series of ruthenium complexes with and without TiO2, anchoring carboxylic acid groups have been synthesised and characterised using nuclear magnetic resonance (NMR), UV-vis and luminescence. These complexes were adsorbed on thin films of the wide band-gap semiconductor anatase and were tested a...

  2. Microscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodes

    KAUST Repository

    Li, Yang; Tu, Xingchen; Wang, Minglang; Wang, Hao; Sanvito, Stefano; Hou, Shimin

    2014-01-01

    © 2014 AIP Publishing LLC. The atomic structure and the electron transfer properties of hydrogen bonds formed between two carboxylated alkanethiol molecules connected to gold electrodes are investigated by employing the non-equilibrium Green's function formalism combined with density functional theory. Three types of molecular junctions are constructed, in which one carboxyl alkanethiol molecule contains two methylene, -CH2, groups and the other one is composed of one, two, or three -CH2 groups. Our calculations show that, similarly to the cases of isolated carboxylic acid dimers, in these molecular junctions the two carboxyl, -COOH, groups form two H-bonds resulting in a cyclic structure. When self-interaction corrections are explicitly considered, the calculated transmission coefficients of these three H-bonded molecular junctions at the Fermi level are in good agreement with the experimental values. The analysis of the projected density of states confirms that the covalent Au-S bonds localized at the molecule-electrode interfaces and the electronic coupling between -COOH and S dominate the low-bias junction conductance. Following the increase of the number of the -CH2 groups, the coupling between -COOH and S decreases deeply. As a result, the junction conductance decays rapidly as the length of the H-bonded molecules increases. These findings not only provide an explanation to the observed distance dependence of the electron transfer properties of H-bonds, but also help the design of molecular devices constructed through H-bonds.

  3. Crystal structure of 7,7-dimethyl-6-methylidenetricyclo[6.2.1.01,5]undecane-2-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Noureddine Beghidja

    2015-02-01

    Full Text Available In the title compound, C15H22O2, both five-membered rings display an envelope conformation whereas the six-membered ring displays a chair conformation. In the crystal, pairs of O—H...O hydrogen bonds between carboxylic groups link molecules, related by a twofold rotation axis, into supramolecular dimers.

  4. Microscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodes

    KAUST Repository

    Li, Yang

    2014-11-07

    © 2014 AIP Publishing LLC. The atomic structure and the electron transfer properties of hydrogen bonds formed between two carboxylated alkanethiol molecules connected to gold electrodes are investigated by employing the non-equilibrium Green\\'s function formalism combined with density functional theory. Three types of molecular junctions are constructed, in which one carboxyl alkanethiol molecule contains two methylene, -CH2, groups and the other one is composed of one, two, or three -CH2 groups. Our calculations show that, similarly to the cases of isolated carboxylic acid dimers, in these molecular junctions the two carboxyl, -COOH, groups form two H-bonds resulting in a cyclic structure. When self-interaction corrections are explicitly considered, the calculated transmission coefficients of these three H-bonded molecular junctions at the Fermi level are in good agreement with the experimental values. The analysis of the projected density of states confirms that the covalent Au-S bonds localized at the molecule-electrode interfaces and the electronic coupling between -COOH and S dominate the low-bias junction conductance. Following the increase of the number of the -CH2 groups, the coupling between -COOH and S decreases deeply. As a result, the junction conductance decays rapidly as the length of the H-bonded molecules increases. These findings not only provide an explanation to the observed distance dependence of the electron transfer properties of H-bonds, but also help the design of molecular devices constructed through H-bonds.

  5. Rational Design and Synthesis of Carboxylate Gemini Surfactants with an Excellent Aggregate Behavior for Nano-La2O3 Morphology-Controllable Preparation.

    Science.gov (United States)

    Liao, Xueming; Gao, Zhinong; Xia, Yan; Niu, Fei; Zhai, Wenzhong

    2017-04-04

    A series of carboxylate gemini surfactants (CGS, C n -Φ-C n , n = 12, 14, 16, 18) with diphenyl ketone as a spacer group were prepared using a simple and feasible synthetic method. These CGS exhibited an excellent surface activity with extremely low critical micelle concentration (CMC) value (approximately 10 -5 mol/L), good performance in reducing surface tension (nearly 30 mN/m), and the ability of molecular self-assembly into different aggregate morphologies via adjusting the concentrations, which is attributed to the introduction of diphenyl ketone and carboxylic acid ammonium salt in the molecular structure. Moreover, the surface activity and self-assembly ability of CGS were further optimized by tuning the length of the tail chain. These excellent properties imply that CGS can be a soft template to prepare nanomaterials, especially in morphology-controllable synthesis. By adjusting the concentration of one of CGS (C 12 -Φ-C 12 ), nano-La 2 O 3 particles with diverse morphologies were obtained, including spherical shape, bead-chain shape, rod shape, velvet-antler shape, cedar shape, and bowknot shape. This work offers a vital insight into the rational design of template agents for the development of morphology-controllable nanomaterials.

  6. The Method of Optimization of Hydropower Plant Performance for Use in Group Active Power Controller

    Directory of Open Access Journals (Sweden)

    Glazyrin G.V.

    2017-04-01

    Full Text Available The problem of optimization of hydropower plant performance is considered in this paper. A new method of calculation of optimal load-sharing is proposed. The method is based on application of incremental water flow curves representing relationship between the per unit increase of water flow and active power. The optimal load-sharing is obtained by solving the nonlinear equation governing the balance of total active power and the station power set point with the same specific increase of water flow for all turbines. Unlike traditional optimization techniques, the solution of the equation is obtained without taking into account unit safe operating zones. Instead, if calculated active power of a unit violates the permissible power range, load-sharing is recalculated for the remaining generating units. Thus, optimal load-sharing algorithm suitable for digital control systems is developed. The proposed algorithm is implemented in group active power controller in Novosibirsk hydropower plant. An analysis of operation of group active power controller proves that the application of the proposed method allows obtaining optimal load-sharing at each control step with sufficient precision.

  7. Antibacterial activity of berberine-NorA pump inhibitor hybrids with a methylene ether linking group.

    Science.gov (United States)

    Samosorn, Siritron; Tanwirat, Bongkot; Muhamad, Nussara; Casadei, Gabriele; Tomkiewicz, Danuta; Lewis, Kim; Suksamrarn, Apichart; Prammananan, Therdsak; Gornall, Karina C; Beck, Jennifer L; Bremner, John B

    2009-06-01

    Conjugation of the NorA substrate berberine and the NorA inhibitor 5-nitro-2-phenyl-1H-indole via a methylene ether linking group gave the 13-substituted berberine-NorA inhibitor hybrid, 3. A series of simpler arylmethyl ether hybrid structures were also synthesized. The hybrid 3 showed excellent antibacterial activity (MIC Staphylococcus aureus, 1.7 microM), which was over 382-fold more active than the parent antibacterial berberine, against this bacterium. This compound was also shown to block the NorA efflux pump in S. aureus.

  8. Synthesis of carboxyl superparamagnetic ultrasmall iron oxide (USPIO) nanoparticles by a novel flocculation-redispersion process

    International Nuclear Information System (INIS)

    Cheng Changming; Kou Geng; Wang Xiaoliang; Wang Shuhui; Gu Hongchen; Guo Yajun

    2009-01-01

    We report a novel flocculation-redispersion method to synthesize and purify the biocompatible superparamagnetic ultrasmall iron oxide (USPIO) nanoparticles coated with carboxyl dextran derivative. First, USPIO nanoparticles were synthesized and flocculated to form the large clusters through bridging effect of polyvinyl alcohol (PVA) during coprecipitation process. Then the flocculated USPIO was separated and purified from the solution conveniently through magnetic sedimentation. Finally, USPIO in the clusters were released again and well dispersed through electrostatic repelling effect of citric acid with the aid of ultrasonic. The dispersed carboxyl-functionalized USPIO was conjugated with the monoclonal antibodies. And it has been proved that the antibodies anchored on USPIO still retained their bioactivity after the conjugation. These results implied that the USPIO synthesized have good potential as active targeting molecular probe in biomedical application.

  9. Group Cognitive Behavioural Therapy and Group Recreational Activity for Adults with Autism Spectrum Disorders: A Preliminary Randomized Controlled Trial

    Science.gov (United States)

    Hesselmark, Eva; Plenty, Stephanie; Bejerot, Susanne

    2014-01-01

    Although adults with autism spectrum disorder are an increasingly identified patient population, few treatment options are available. This "preliminary" randomized controlled open trial with a parallel design developed two group interventions for adults with autism spectrum disorders and intelligence within the normal range: cognitive…

  10. Physical Activity and Sedentary Behavior in an Ethnically Diverse Group of South African School Children

    Directory of Open Access Journals (Sweden)

    Joanne McVeigh, Rebecca Meiring

    2014-06-01

    Full Text Available Few studies have examined physical activity and inactivity levels in an urban South African setting across 12 years of formal schooling. This information is important for implementing strategies to curb increasing trends of physical inactivity and related negative consequences, especially in low to middle income countries facing multiple challenges on overburdened health care systems. We examined levels of physical activity and sedentary behaviour cross-sectionally over 12 school years from childhood to adolescence in Black, White and Indian boys and girls. The aim of our study was to describe gender and race related patterns of physical and sedentary activity levels in a sample of South African children and to determine whether there were associations between these variables and body mass status. Physical activity questionnaires, previously validated in a South African setting, were used to gather information about activity and sedentary behaviours among 767 Black, White and Indian children (5-18 years of age across the 12 grades of formal schooling. Body mass and height were also measured. Time spent in moderate-vigorous physical activity declined over the school years for all race groups and was consistently lower for girls than boys (p = 0.03, while time spent in sedentary activity increased with increasing grade (p 0.05 whereas time spent in sedentary activities was significantly and positively correlated with body mass across all race groups: Indian (r = 0.25, p < 0.001, White (r = 0.22, p < 0.001 and Black (r = 0.37, p = 0.001. The strength of the associations was similar for boys and girls. Black and Indian children were less physically active than their white peers (p < 0.05, and Black children also spent more time in sedentary activity (p < 0.05. Additionally, Black children had the highest proportion of overweight participants (30%, and Indian children the most number of underweight children (13%. Regardless of ethnicity, children who

  11. Inactivation of 1-aminocyclopropane-1-carboxylate oxidase involves oxidative modifications.

    Science.gov (United States)

    Barlow, J N; Zhang, Z; John, P; Baldwin, J E; Schofield, C J

    1997-03-25

    1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the final step in the biosynthesis of the plant signaling molecule ethylene. It is a member of the ferrous iron dependent family of oxidases and dioxygenases and is unusual in that it displays a very short half-life under catalytic conditions, typically less than 20 min, and a requirement for CO2 as an activator. The rates of inactivation of purified, recombinant ACC oxidase from tomato under various combinations of substrates and cofactors were measured. Inactivation was relatively slow in the presence of buffer alone (t1/2 > 1 h), but fast in the presence of ferrous iron and ascorbate (t1/2 approximately 10 min). The rate of iron/ascorbate-mediated inactivation was increased by the addition of ACC, unaffected by the addition of CO2 at saturation (supplied as bicarbonate) but decreased by the addition of catalase or ACC + CO2 at saturation (supplied as bicarbonate). Iron/ascorbate-mediated inactivation was accompanied by partial proteolysis as observed by SDS-PAGE analysis. The fragmentation pattern was altered when ACC was also included, suggesting that ACC can bind to ACC oxidase in the absence of bicarbonate. N-terminal sequencing of fragments resulted in identification of an internal cleavage site which we propose is proximate to active-site bound iron. Thus, ACC oxidase inactivates via relatively slow partial unfolding of the catalytically active conformation, oxidative damage mediated via hydrogen peroxide which is catalase protectable and oxidative damage to the active site which results in partial proteolysis and is not catalase protectable.

  12. Antimony Complexes for Electrocatalysis: Activity of a Main-Group Element in Proton Reduction.

    Science.gov (United States)

    Jiang, Jianbing; Materna, Kelly L; Hedström, Svante; Yang, Ke R; Crabtree, Robert H; Batista, Victor S; Brudvig, Gary W

    2017-07-24

    Main-group complexes are shown to be viable electrocatalysts for the H 2 -evolution reaction (HER) from acid. A series of antimony porphyrins with varying axial ligands were synthesized for electrocatalysis applications. The proton-reduction catalytic properties of TPSb(OH) 2 (TP=5,10,15,20-tetra(p-tolyl)porphyrin) with two axial hydroxy ligands were studied in detail, demonstrating catalytic H 2 production. Experiments, in conjunction with quantum chemistry calculations, show that the catalytic cycle is driven via the redox activity of both the porphyrin ligand and the Sb center. This study brings insight into main group catalysis and the role of redox-active ligands during catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Group behavioral activation for patients with severe obesity and binge eating disorder: a randomized controlled trial.

    Science.gov (United States)

    Alfonsson, Sven; Parling, Thomas; Ghaderi, Ata

    2015-03-01

    The aim of the present study was to assess whether behavioral activation (BA) is an efficacious treatment for decreasing eating disorder symptoms in patients with obesity and binge eating disorder (BED). Ninety-six patients with severe obesity and BED were randomized to either 10 sessions of group BA or wait-list control. The study was conducted at an obesity clinic in a regular hospital setting. The treatment improved some aspects of disordered eating and had a positive effect on depressive symptoms but there was no significant difference between the groups regarding binge eating and most other symptoms. Improved mood but lack of effect on binge eating suggests that dysfunctional eating (including BED) is maintained by other mechanisms than low activation and negative mood. However, future studies need to investigate whether effects of BA on binge eating might emerge later than at post-assessment, as in interpersonal psychotherapy for bulimia nervosa. © The Author(s) 2014.

  14. Barriers related to physical activity practice in adolescents. A focus-group study

    Directory of Open Access Journals (Sweden)

    Ciro Romélio Rodriguez Añez

    2010-04-01

    Full Text Available The aim of study was to identify barriers to physical activity in adolescents. Focus group interviews were conducted with subjects aged 15 to 18 years (n=59, 50.8% girls and divided according to gender. Content analysis was used to classify the reports into specific dimensions. Descriptive statistics employing relative and absolute frequencies of similar reports was performed using the SPSS 11.0 software. The most frequent barriers among adolescents were those associated with “psychological, cognitive and emotional” and “cultural and social” dimensions. For boys, the most frequently reported barriers were “feeling lazy”, “lack of company” and “lack of time”. For girls, “feeling lazy”, “lack of com-pany” and “occupation” were the most common barriers. In conclusion, the perception of barriers by adolescents varies according to gender, a fact requiring specific actions for the promotion of physical activity in this group.

  15. New Horizons in C-F Activation by Main Group Electrophiles

    Energy Technology Data Exchange (ETDEWEB)

    Ozerov, Oleg V. [Texas A & M Univ., College Station, TX (United States). Dept. of Chemistry

    2016-02-13

    This technical report describes progress on the DOE sponsored project "New Horizons in C-F Activation by Main Group Electrophiles" during the period of 09/15/2010 – 08/31/2015. The main goal of this project was to develop improved catalysts for conversion of carbon-fluorine bonds in potentially harmful compounds. The approach involved combining of a highly reactive positively charged main-group compound with a highly unreactive negatively charged species (anions) as a way to access potent catalysts for carbon-fluorine bond activation. This report details progress made in improving synthetic pathways to a variety of new anions with improved properties and analysis of their potential in catalysis.

  16. Solid state structure of thorium(IV) complexes with common aminopoly-carboxylate ligands

    International Nuclear Information System (INIS)

    Thuery, Pierre

    2011-01-01

    The crystal structures of the complexes formed by reaction of thorium(IV) nitrate with iminodiacetic acid (H 2 IDA), nitrilotriacetic acid (H 3 NTA), and ethylenediaminetetraacetic acid (H 4 EDTA) under hydrothermal conditions are reported. In [Th(HIDA) 2 (C 2 O 4 )].H 2 O (1), the metal atom is chelated by two carboxylate groups from two HIDA - anions and by two oxalate ligands formed in situ; two additional oxygen atoms from two more HIDA - anions complete the ten-coordinate environment of bi-capped square anti-prismatic geometry. The uncoordinated nitrogen atom is protonated and involved in hydrogen bonding. Two different ligands are present in [Th(NTA)(H 2 NTA)(H 2 O)].H 2 O (2), one of them being a O 3 ,N-chelating tri-anion which acts also as a bridge toward two neighboring metal ions, and the other being a bis-monodentate bridging species with an uncoordinated carboxylic arm and a central ammonium group. An aqua ligand completes the nine-coordinated, capped square anti-prismatic metal environment. The EDTA 4- anion in [Th(EDTA)(H 2 O)].2H 2 O (3) is chelating through one oxygen atom from each carboxylate group and the two nitrogen atoms, as in a previously reported molecular complex. Two carboxylate groups are bridging, which, with the addition of an aqua ligand, gives a capped square anti-prismatic coordination polyhedron. Aminopoly-carboxylate ligands have been much investigated in relation with actinide decorporation and nuclear wastes management studies, and the present results add to the structural information available on their complexes with thorium(IV), which has mainly been obtained up to now by extended X-ray absorption fine structure (EXAFS) spectroscopy. In particular, the bridging (non-chelating) coordination mode of H 2 NTA - is a novel feature in this context. All three complexes crystallize as two-dimensional assemblies and are thus novel examples of thorium-organic coordination polymers. (author)

  17. Vitamin K-dependent carboxylation of pulmonary surfactant-associated proteins

    International Nuclear Information System (INIS)

    Rannels, S.R.; Gallaher, K.J.; Wallin, R.; Rannels, D.E.

    1987-01-01

    Rat type II pneumocytes expressed vitamin K-dependent carboxylase activity that incorporated 14 CO 2 into microsomal protein precursors of molecular weights similar to those of surfactant-associated proteins (SAP). Compared to carboxylated precursor proteins present in the liver, these molecules appeared to be unique to the lung. Antibodies raised against purified rat surfactant reacted with SAP resolved by NaDodSO 4 /PAGE and with surfactant-containing lamellar bodies in type II pneumocyte cytoplasm. NaDodSO 4 /PAGE of microsomal proteins, after carboxylase-catalyzed incorporation of 14 CO 2 , demonstrated radiolabeled, immunoreactive products identical to SAP. The presence of γ-carboxyglutamic acid in these proteins was confirmed by HPLC analysis of SAP hydrolysates. Furthermore, lung carboxylase activity and SAP matured over similar time courses during fetal lung development. These results show that SAP are carboxylated by type II cells via a vitamin K-dependent pathway analogous to that for hepatic carboxylation of clotting factors. Further analogy to the clotting system suggest that γ-carboxyglutamic acid residues in SAP polypeptides play a role in Ca 2+ binding and thus in the known requirements for both cation and SAP in the physiological function of pulmonary surfactant

  18. Modelling the exposure of wildlife to radiation: key findings and activities of IAEA working groups

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, Nicholas A. [NERC Centre for Ecology and Hydrology, Lancaster Environment Center, Library Av., Bailrigg, Lancaster, LA1 4AP (United Kingdom); School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Vives i Batlle, Jordi; Vandenhove, Hildegarde [Belgian Nuclear Research Centre, Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Beaugelin-Seiller, Karine [Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, LM2E, Cadarache (France); Johansen, Mathew P. [ANSTO Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Menai, NSW (Australia); Goulet, Richard [Canadian Nuclear Safety Commission, Environmental Risk Assessment Division, 280 Slater, Ottawa, K1A0H3 (Canada); Wood, Michael D. [School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Ruedig, Elizabeth [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins (United States); Stark, Karolina; Bradshaw, Clare [Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691 (Sweden); Andersson, Pal [Swedish Radiation Safety Authority, SE-171 16, Stockholm (Sweden); Copplestone, David [Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom); Yankovich, Tamara L.; Fesenko, Sergey [International Atomic Energy Agency, Vienna International Centre, 1400, Vienna (Austria)

    2014-07-01

    In total, participants from 14 countries, representing 19 organisations, actively participated in the model application/inter-comparison activities of the IAEA's EMRAS II programme Biota Modelling Group. A range of models/approaches were used by participants (e.g. the ERICA Tool, RESRAD-BIOTA, the ICRP Framework). The agreed objectives of the group were: 'To improve Member State's capabilities for protection of the environment by comparing and validating models being used, or developed, for biota dose assessment (that may be used) as part of the regulatory process of licensing and compliance monitoring of authorised releases of radionuclides.' The activities of the group, the findings of which will be described, included: - An assessment of the predicted unweighted absorbed dose rates for 74 radionuclides estimated by 10 approaches for five of the ICRPs Reference Animal and Plant geometries assuming 1 Bq per unit organism or media. - Modelling the effect of heterogeneous distributions of radionuclides in sediment profiles on the estimated exposure of organisms. - Model prediction - field data comparisons for freshwater ecosystems in a uranium mining area and a number of wetland environments. - An evaluation of the application of available models to a scenario considering radioactive waste buried in shallow trenches. - Estimating the contribution of {sup 235}U to dose rates in freshwater environments. - Evaluation of the factors contributing to variation in modelling results. The work of the group continues within the framework of the IAEA's MODARIA programme, which was initiated in 2012. The work plan of the MODARIA working group has largely been defined by the findings of the previous EMRAS programme. On-going activities of the working group, which will be described, include the development of a database of dynamic parameters for wildlife dose assessment and exercises involving modelling the exposure of organisms in the marine coastal

  19. Moms in motion: a group-mediated cognitive-behavioral physical activity intervention

    Directory of Open Access Journals (Sweden)

    Brawley Lawrence R

    2006-08-01

    Full Text Available Abstract Background When examining the prevalence of physical inactivity by gender and age, women over the age of 25 are at an increased risk for sedentary behavior. Childbearing and motherhood have been explored as one possible explanation for this increased risk. Post natal exercise studies to date demonstrate promising physical and psychological outcomes, however few physical activity interventions have been theory-driven and tailored to post natal exercise initiates. The purpose of this study was to compare the effects of a group-mediated cognitive behavioral intervention based upon social-cognitive theory and group dynamics (GMCB to a standard care postnatal exercise program (SE. Method A randomized, two-arm intervention design was used. Fifty-seven post natal women were randomized to one of two conditions: (1 a standard exercise treatment (SE and (2 a standard exercise treatment plus group-mediated cognitive behavioral intervention (GMCB. Participants in both conditions participated in a four-week intensive phase where participants received standard exercise training. In addition, GMCB participants received self-regulatory behavioral skills training via six group-mediated counseling sessions. Following the intensive phase, participants engaged in a four-week home-based phase of self-structured exercise. Measures of physical activity, barrier efficacy, and proximal outcome expectations were administered and data were analyzed using ANCOVA procedures. Results and discussion ANCOVA of change scores for frequency, minutes, and volume of physical activity revealed significant treatment effects over the intensive and home-based phases (p's Conclusion While both exercise programs resulted in improvements to exercise participation, the GMCB intervention produced greater improvement in overall physical activity, barrier efficacy and proximal outcome expectations.

  20. The 1986-1989 activity report of the Radiochemistry Group of the Orsay IPN

    International Nuclear Information System (INIS)

    Guillaumont, R.

    1989-01-01

    The 1986-1989 activity report of the Radiochemistry Group of the Nuclear Physics Institute (at Orsay), is presented. The research fields purposes and evolution are summarized. The following topics are presented: synthesis and study of pure or doped thorium compounds, high resolution spectroscopy, thermodynamics/kinetics in aqueous solutions, 6d elements, investigations on Ta, Kd, U, UO2 and cold fusion. The presentation of the research team, administrative aspects, publications, conferences and future research programs are also included [fr

  1. Annual activity report of Ignalina NPP Safety Analysis Group for 1996 year

    International Nuclear Information System (INIS)

    Ushpuras, E.; Augutis, J.; Bubelis, E.

    1997-03-01

    The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for 1996 are presented. ISAG is concentrating its research activities into four areas: the neutrons dynamics modelling, simulation of transient processes during loss of coolant accident, the reactor cooling systems modelling and the probabilistic safety assessment of accident confinement system. Ignalina Safety Analysis Report was prepared on the basis of these results. 37 refs., 9 tabs., 96 figs

  2. Adsorption of volatile sulphur compounds onto modified activated carbons: Effect of oxygen functional groups

    International Nuclear Information System (INIS)

    Vega, Esther; Lemus, Jesús; Anfruns, Alba; Gonzalez-Olmos, Rafael; Palomar, José; Martin, María J.

    2013-01-01

    Highlights: • HNO 3 oxidation incorporates a higher amount of functionalities than O 3 oxidation. • The loss of porosity is compensated by the massive incorporation of oxygen groups. • HNO 3 oxidation increases OH groups in AC and the ETM and DMS adsorption capacities. • The oxygen functional groups in the AC surface did not affect the DMDS adsorption. • COSMO-RS predicts the important role of OH groups for VSC adsorption. -- Abstract: The effect of physical and chemical properties of activated carbon (AC) on the adsorption of ethyl mercaptan, dimethyl sulphide and dimethyl disulphide was investigated by treating a commercial AC with nitric acid and ozone. The chemical properties of ACs were characterised by temperature programme desorption and X-ray photoelectron spectroscopy. AC treated with nitric acid presented a larger amount of oxygen functional groups than materials oxidised with ozone. This enrichment allowed a significant improvement on adsorption capacities for ethyl mercaptan and dimethyl sulphide but not for dimethyl disulphide. In order to gain a deeper knowledge on the effect of the surface chemistry of AC on the adsorption of volatile sulphur compounds, the quantum-chemical COSMO-RS method was used to simulate the interactions between AC surface groups and the studied volatile sulphur compounds. In agreement with experimental data, this model predicted a greater affinity of dimethyl disulphide towards AC, unaffected by the incorporation of oxygen functional groups in the surface. Moreover, the model pointed out to an increase of the adsorption capacity of AC by the incorporation of hydroxyl functional groups in the case of ethyl mercaptan and dimethyl sulphide due to the hydrogen bond interactions

  3. Adsorption of volatile sulphur compounds onto modified activated carbons: Effect of oxygen functional groups

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Esther, E-mail: esther@lequia.udg.cat [LEQUIA, Institute of the Environment, University of Girona, Campus Montilivi, Girona, Catalonia E-17071 (Spain); Lemus, Jesús [Universidad de Madrid, Sección de Ingeniería Química, Cantoblanco, Madrid E-28049 (Spain); Anfruns, Alba; Gonzalez-Olmos, Rafael [LEQUIA, Institute of the Environment, University of Girona, Campus Montilivi, Girona, Catalonia E-17071 (Spain); Palomar, José [Universidad de Madrid, Sección de Ingeniería Química, Cantoblanco, Madrid E-28049 (Spain); Martin, María J. [LEQUIA, Institute of the Environment, University of Girona, Campus Montilivi, Girona, Catalonia E-17071 (Spain)

    2013-08-15

    Highlights: • HNO{sub 3} oxidation incorporates a higher amount of functionalities than O{sub 3} oxidation. • The loss of porosity is compensated by the massive incorporation of oxygen groups. • HNO{sub 3} oxidation increases OH groups in AC and the ETM and DMS adsorption capacities. • The oxygen functional groups in the AC surface did not affect the DMDS adsorption. • COSMO-RS predicts the important role of OH groups for VSC adsorption. -- Abstract: The effect of physical and chemical properties of activated carbon (AC) on the adsorption of ethyl mercaptan, dimethyl sulphide and dimethyl disulphide was investigated by treating a commercial AC with nitric acid and ozone. The chemical properties of ACs were characterised by temperature programme desorption and X-ray photoelectron spectroscopy. AC treated with nitric acid presented a larger amount of oxygen functional groups than materials oxidised with ozone. This enrichment allowed a significant improvement on adsorption capacities for ethyl mercaptan and dimethyl sulphide but not for dimethyl disulphide. In order to gain a deeper knowledge on the effect of the surface chemistry of AC on the adsorption of volatile sulphur compounds, the quantum-chemical COSMO-RS method was used to simulate the interactions between AC surface groups and the studied volatile sulphur compounds. In agreement with experimental data, this model predicted a greater affinity of dimethyl disulphide towards AC, unaffected by the incorporation of oxygen functional groups in the surface. Moreover, the model pointed out to an increase of the adsorption capacity of AC by the incorporation of hydroxyl functional groups in the case of ethyl mercaptan and dimethyl sulphide due to the hydrogen bond interactions.

  4. Engie. Group dynamics and activities. Competitive environment and strategic perspectives. Release - October 2017

    International Nuclear Information System (INIS)

    2017-09-01

    After a synthesis, this report proposes a presentation of the Engie Group (general overview, activities in the different parts of the world, evolution of human resources, share-holding structure, stock market data, high management, competitive environment). It gives an overview of the Engie group dynamics and of its activities through a presentation of an environment analysis (world energy market, European gas and electricity market, gas consumption in France, regulated tariffs and spot prices, temperatures in France, regulatory evolutions), a presentation of the group activity (turnover in France, gas and electricity sales, turnover per area and market segment), a performance analysis (operating income), and a competitive analysis (comparison with the main European energy companies). It analyses the different development axes and discusses main events regarding Engie's strategy, the implementation of a large asset disposal, how Engie gets on the path of renewable energies, and the development of energy services. Financial data are presented along with the main economic and financial indicators. Important statistical data are provided

  5. Assessing Activity and Location of Individual Laying Hens in Large Groups Using Modern Technology

    Directory of Open Access Journals (Sweden)

    Janice M. Siegford

    2016-02-01

    Full Text Available Tracking individual animals within large groups is increasingly possible, offering an exciting opportunity to researchers. Whereas previously only relatively indistinguishable groups of individual animals could be observed and combined into pen level data, we can now focus on individual actors within these large groups and track their activities across time and space with minimal intervention and disturbance. The development is particularly relevant to the poultry industry as, due to a shift away from battery cages, flock sizes are increasingly becoming larger and environments more complex. Many efforts have been made to track individual bird behavior and activity in large groups using a variety of methodologies with variable success. Of the technologies in use, each has associated benefits and detriments, which can make the approach more or less suitable for certain environments and experiments. Within this article, we have divided several tracking systems that are currently available into two major categories (radio frequency identification and radio signal strength and review the strengths and weaknesses of each, as well as environments or conditions for which they may be most suitable. We also describe related topics including types of analysis for the data and concerns with selecting focal birds.

  6. Assessing Activity and Location of Individual Laying Hens in Large Groups Using Modern Technology.

    Science.gov (United States)

    Siegford, Janice M; Berezowski, John; Biswas, Subir K; Daigle, Courtney L; Gebhardt-Henrich, Sabine G; Hernandez, Carlos E; Thurner, Stefan; Toscano, Michael J

    2016-02-02

    Tracking individual animals within large groups is increasingly possible, offering an exciting opportunity to researchers. Whereas previously only relatively indistinguishable groups of individual animals could be observed and combined into pen level data, we can now focus on individual actors within these large groups and track their activities across time and space with minimal intervention and disturbance. The development is particularly relevant to the poultry industry as, due to a shift away from battery cages, flock sizes are increasingly becoming larger and environments more complex. Many efforts have been made to track individual bird behavior and activity in large groups using a variety of methodologies with variable success. Of the technologies in use, each has associated benefits and detriments, which can make the approach more or less suitable for certain environments and experiments. Within this article, we have divided several tracking systems that are currently available into two major categories (radio frequency identification and radio signal strength) and review the strengths and weaknesses of each, as well as environments or conditions for which they may be most suitable. We also describe related topics including types of analysis for the data and concerns with selecting focal birds.

  7. Pd(II)-Catalyzed C–H Functionalizations Directed by Distal Weakly Coordinating Functional Groups

    Science.gov (United States)

    Li, Gang; Wan, Li; Zhang, Guofu; Leow, Dasheng; Spangler, Jillian

    2015-01-01

    Ortho-C(sp2)–H olefination and acetoxylation of broadly useful synthetic building blocks phenylacetyl Weinreb amides, esters, and ketones are developed without installing an additional directing group. The interplay between the distal weak coordination and the ligand-acceleration is crucial for these reactions to proceed under mild conditions. The tolerance of longer distance between the target C–H bonds and the directing functional groups also allows for the functionalizations of more distal C–H bonds in hydrocinnamoyl ketones, Weinreb amides and biphenyl Weinreb amides. Mechanistically, the coordination of these carbonyl groups and the bisdentate amino acid ligand with Pd(II) centers provides further evidence for our early hypothesis that the carbonyl groups of the potassium carboxylate is responsible for the directed C–H activation of carboxylic acids. PMID:25768039

  8. Tyrosine and carboxyl protonation changes in the bacteriorhodopsin photocycle. 1. M412 and L550 intermediates

    International Nuclear Information System (INIS)

    Roepe, P.; Ahl, P.L.; Gupta, S.K.D.; Herzfeld, J.; Rothschild, K.J.

    1987-01-01

    The role of tyrosines in the bacteriorhodopsin (bR) photocycle has been investigated by using Fourier transform infrared (FTIR) and UV difference spectroscopies. Tyrosine contributions to the BR 570 → M 412 FTIR difference spectra recorded at several temperatures and pH's were identified by isotopically labeling tyrosine residues in bacteriorhodopsin. The frequencies and deuterium/hydrogen exchange sensitivities of these peaks and of peaks in spectra of model compounds in several environments suggest that at least two different tyrosine groups participate in the bR photocycle during the formation of M 412 . One group undergoes a tyrosinate → tyrosine conversion during the BR 570 → K 630 transition. A second tyrosine group deprotonates between L 550 and M 412 . Low-temperature UV difference spectra in the 220-350-nm region of both purple membrane suspensions and rehydrated films support these conclusions. The UV spectra also indicate perturbations(s) of one or more tryptophan group(s). Several carboxyl groups appear to undergo a series of protonation changes between BR 570 and M 412 , as indicated by infrared absorption changes in the 1770-1720-cm -1 region. These results are consistent with the existence of a proton wire in bacteriorhodopsin that involves both tyrosine and carboxyl groups

  9. Decellularized Bovine Articular Cartilage Matrix Reinforced by Carboxylated-SWCNT for Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Zari Majidi Mohammadie

    2018-01-01

    Full Text Available ABSTRACT Nanotubes with their unique properties have diversified mechanical and biological applications. Due to similarity of dimensions with extracellular matrix (ECM elements, these materials are used in designing scaffolds. In this research, Carboxylated Single-Wall Carbon Nanotubes in optimization of decellularized scaffold of bovine articular cartilage was used. At first, the articular cartilage was decellularized. Then the scaffolds were analyzed in: (i decellularized scaffolds, and (ii scaffolds plunged into homogenous suspension of nanotubes in distilled water, were smeared with Carboxylated-SWCNT. The tissue rings derived from the rabbit's ear were assembled with reinforced scaffolds and they were placed in a culture media for 15 days. The scaffolds in two groups and the assembled scaffolds underwent histologic and electron microscopy. Scanning electron microscopy showed that the structure of ECM of articular cartilage has been maintained well after decellularization. Fourier transform infrared analysis showed that the contents of ECM have not been changed under treatment process. Atomic force microscopy analysis showed the difference in surface topography and roughness of group (ii scaffolds in comparison with group (i. Transmission electron microscopy studies showed the Carboxylated-SWCNT bond with the surface of decellularized scaffold and no penetration of these compounds into the scaffold. The porosity percentage with median rate of 91.04 in group (i scaffolds did not have significant difference with group (ii scaffolds. The electron microscopy observations confirmed migration and penetration of the blastema cells into the group (ii assembled scaffolds. This research presents a technique for provision of nanocomposite scaffolds for cartilage engineering applications.

  10. Phenazine-1-carboxylic acid influences biofilm development and turnover of rhizobacterial biomass in a soil moisture-dependent manner

    Science.gov (United States)

    Rhizobacterial biofilm development influences terrestrial carbon and nitrogen cycles with ramifications for crop and soil health. Phenazine-1-carboxylic acid (PCA) is a redox-active metabolite produced by rhizobacteria in dryland wheat fields of Washington and Oregon, USA. PCA promotes biofilm dev...

  11. Correlation of group C meningococcal conjugate vaccine response with B- and T-lymphocyte activity.

    Directory of Open Access Journals (Sweden)

    James B Wing

    Full Text Available Despite the success of conjugate vaccination against meningococcal group C (MenC disease, post-vaccination, some individuals still exhibit rapid waning of initially protective bactericidal antibody levels. The mechanism of this relative loss of humoral protection remains undetermined. In this report we have investigated the relationship between T- and B-cell activation and co-stimulation and the loss of protective antibody titers. We have found that healthy volunteers who lose protective MenC antibody levels one year after receipt of glycoconjugate vaccine exhibit no detectable cellular defect in polyclonal B- or T-cell activation, proliferation or the B-memory pool. This suggests that the processes underlying the more rapid loss of antibody levels are independent of defects in either initial T- or B-cell activation.

  12. Design, synthesis, and antifungal activities of novel triazole derivatives containing the benzyl group

    Directory of Open Access Journals (Sweden)

    Xu K

    2015-03-01

    Full Text Available Kehan Xu,1,* Lei Huang,1,* Zheng Xu,2 Yanwei Wang,1,3 Guojing Bai,1 Qiuye Wu,1 Xiaoyan Wang,1 Shichong Yu,1 Yuanying Jiang1 1School of Pharmacy, Second Military Medical University, Shanghai, 2Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 3Number 422 Hospital of PLA, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Abstract: In previous studies undertaken by our group, a series of 1-(1H-1,2,4-triazole-1-yl-2-(2,4-difluorophenyl-3-substituted-2-propanols (1a–r, which were analogs of fluconazole, was designed and synthesized by click chemistry. In the study reported here, the in vitro antifungal activities of all the target compounds were evaluated against eight human pathogenic fungi. Compounds 1a, 1q, and 1r showed the more antifungal activity than the others. Keywords: triazole, synthesis, antifungal activity, CYP51

  13. Low back pain in female elite football and handball players compared with an active control group.

    Science.gov (United States)

    Tunås, Paula; Nilstad, Agnethe; Myklebust, Grethe

    2015-09-01

    The purpose of this cross-sectional study was to compare the prevalence of low back pain (LBP) among female elite football and handball players to a matched non-professional active control group. The participants were requested to answer a questionnaire based on standardized Nordic questionnaires for musculoskeletal symptoms to assess the prevalence of LBP. Included participants were elite female football (n = 277) and handball players (n = 190), and a randomly selected control group from the Norwegian population (n = 167). Fifty-seven percentage of the football players, 59 % of the handball players and 60 % of the control group had experienced LBP the previous year. There were no significant group differences in the prevalence of LBP ever (p = 0.62), the previous year (p = 0.85) or the previous 7 days (p = 0.63). For both sports, there was a significant increase in prevalence of LBP from the resting period to the competitive periods of the season (p ≤ 0.001). Seventy percent of the goalkeepers in both football and handball had experienced LBP the previous year. There were no difference in LBP among female elite football and handball players compared with the control group. However, female elite athletes in football and handball reported a high prevalence of LBP compared to previous studies. The variations in LBP and playing positions indicate that specific field positions, in football and handball, is a risk factor for developing LBP.

  14. Lysis of typhus-group rickettsia-infected targets by lymphokine activated killers

    International Nuclear Information System (INIS)

    Carl, M.; Dasch, G.A.

    1986-01-01

    The authors recently described a subset of OKT8, OKT3-positive lymphocytes from typhus-group rickettsia immune individuals which were capable of lysing autologous PHA-blasts or Epstein-Barr virus transformed B cells (LCL) infected with typhus-group rickettsiae. In order to determine if killing by these effectors was HLA-restricted, they stimulated peripheral blood mononuclear cells (PBMC) from typhus-group rickettsia immune individuals in vitro with typhus-group rickettsia-derived antigen for one week and then measured lysis of autologous LCL or HLA-mismatched LCL in a 4-6 hour Cr 51 -release assay. There was significant lysis of both the autologous and the HLA-mismatched infected targets as compared to the corresponding uninfected targets. Since this suggested that the effectors were lymphokine activated killers (LAK) rather than cytotoxic T lymphocytes, they then tested this hypothesis by stimulating PBMC from both immune and non-immune individuals in vitro for one week with purified interleukin 2 and measuring lysis of infected, autologous LCL. PBMC thus treated, from both immune and non-immune individuals, were capable of significantly lysing autologous, infected LCL as compared to the non-infected control. They therefore conclude that targets infected with typhus-group rickettsiae are susceptible to lysis to LAK

  15. Nano-graphene oxide carboxylation for efficient bioconjugation applications: a quantitative optimization approach

    Energy Technology Data Exchange (ETDEWEB)

    Imani, Rana; Emami, Shahriar Hojjati, E-mail: semami@aut.ac.ir [Amirkabir University of Technology, Department of Biomedical Engineering (Iran, Islamic Republic of); Faghihi, Shahab, E-mail: shahabeddin.faghihi@mail.mcgill.ca, E-mail: sfaghihi@nigeb.ac.ir [National Institute of Genetic Engineering and Biotechnology, Tissue Engineering and Biomaterials Division (Iran, Islamic Republic of)

    2015-02-15

    A method for carboxylation of graphene oxide (GO) with chloroacetic acid that precisely optimizes and controls the efficacy of the process for bioconjugation applications is proposed. Quantification of COOH groups on nano-graphene oxide sheets (NGOS) is performed by novel colorimetric methylene blue (MB) assay. The GO is synthesized and carboxylated by chloroacetic acid treatment under strong basic condition. The size and morphology of the as-prepared NGOS are characterized by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy (AFM). The effect of acid to base molar ratio on the physical, chemical, and morphological properties of NGOS is analyzed by Fourier-transformed infrared spectrometry (FTIR), UV–Vis spectroscopy, X-ray diffraction (XRD), AFM, and zeta potential. For evaluation of bioconjugation efficacy, the synthesized nano-carriers with different carboxylation ratios are functionalized by octaarginine peptide sequence (R8) as a biomolecule model containing amine groups. The quantification of attached R8 peptides to graphene nano-sheets’ surface is performed with a colorimetric-based assay which includes the application of 2,4,6-Trinitrobenzene sulfonic acid (TNBS). The results show that the thickness and lateral size of nano-sheets are dramatically decreased to 0.8 nm and 50–100 nm after carboxylation process, respectively. X-ray analysis shows the nano-sheets interlaying space is affected by the alteration of chloroacetic acid to base ratio. The MB assay reveals that the COOH groups on the surface of NGOS are maximized at the acid to base ratio of 2 which is confirmed by FTIR, XRD, and zeta potential. The TNBS assay also shows that bioconjugation of the optimized carboxylated NGOS sample with octaarginine peptide is 2.5 times more efficient compared to bare NGOS. The present work provides evidence that treatment of GO by chloroacetic acid under an optimized condition would create a functionalized high

  16. Nano-graphene oxide carboxylation for efficient bioconjugation applications: a quantitative optimization approach

    International Nuclear Information System (INIS)

    Imani, Rana; Emami, Shahriar Hojjati; Faghihi, Shahab

    2015-01-01

    A method for carboxylation of graphene oxide (GO) with chloroacetic acid that precisely optimizes and controls the efficacy of the process for bioconjugation applications is proposed. Quantification of COOH groups on nano-graphene oxide sheets (NGOS) is performed by novel colorimetric methylene blue (MB) assay. The GO is synthesized and carboxylated by chloroacetic acid treatment under strong basic condition. The size and morphology of the as-prepared NGOS are characterized by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy (AFM). The effect of acid to base molar ratio on the physical, chemical, and morphological properties of NGOS is analyzed by Fourier-transformed infrared spectrometry (FTIR), UV–Vis spectroscopy, X-ray diffraction (XRD), AFM, and zeta potential. For evaluation of bioconjugation efficacy, the synthesized nano-carriers with different carboxylation ratios are functionalized by octaarginine peptide sequence (R8) as a biomolecule model containing amine groups. The quantification of attached R8 peptides to graphene nano-sheets’ surface is performed with a colorimetric-based assay which includes the application of 2,4,6-Trinitrobenzene sulfonic acid (TNBS). The results show that the thickness and lateral size of nano-sheets are dramatically decreased to 0.8 nm and 50–100 nm after carboxylation process, respectively. X-ray analysis shows the nano-sheets interlaying space is affected by the alteration of chloroacetic acid to base ratio. The MB assay reveals that the COOH groups on the surface of NGOS are maximized at the acid to base ratio of 2 which is confirmed by FTIR, XRD, and zeta potential. The TNBS assay also shows that bioconjugation of the optimized carboxylated NGOS sample with octaarginine peptide is 2.5 times more efficient compared to bare NGOS. The present work provides evidence that treatment of GO by chloroacetic acid under an optimized condition would create a functionalized high

  17. Biotransformation of fluorophenyl pyridine carboxylic acids by the model fungus Cunninghamella elegans.

    Science.gov (United States)

    Palmer-Brown, William; Dunne, Brian; Ortin, Yannick; Fox, Mark A; Sandford, Graham; Murphy, Cormac D

    2017-09-01

    1. Fluorine plays a key role in the design of new drugs and recent FDA approvals included two fluorinated drugs, tedizolid phosphate and vorapaxar, both of which contain the fluorophenyl pyridyl moiety. 2. To investigate the likely phase-I (oxidative) metabolic fate of this group, various fluorinated phenyl pyridine carboxylic acids were incubated with the fungus Cunninghamella elegans, which is an established model of mammalian drug metabolism. 3.  19 F NMR spectroscopy established the degree of biotransformation, which varied depending on the position of fluorine substitution, and gas chromatography-mass spectrometry (GC-MS) identified alcohols and hydroxylated carboxylic acids as metabolites. The hydroxylated metabolites were further structurally characterised by nuclear magnetic resonance spectroscopy (NMR), which demonstrated that hydroxylation occurred on the 4' position; fluorine in that position blocked the hydroxylation. 4. The fluorophenyl pyridine carboxylic acids were not biotransformed by rat liver microsomes and this was a consequence of inhibitory action, and thus, the fungal model was crucial in obtaining metabolites to establish the mechanism of catabolism.

  18. Multifunctional PEG-carboxylate copolymer coated superparamagnetic iron oxide nanoparticles for biomedical application

    Science.gov (United States)

    Illés, Erzsébet; Szekeres, Márta; Tóth, Ildikó Y.; Szabó, Ákos; Iván, Béla; Turcu, Rodica; Vékás, Ladislau; Zupkó, István; Jaics, György; Tombácz, Etelka

    2018-04-01

    Biocompatible magnetite nanoparticles (MNPs) were prepared by post-coating the magnetic nanocores with a synthetic polymer designed specifically to shield the particles from non-specific interaction with cells. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers and acrylic acid (AA) small molecular monomers were chemically coupled by quasi-living atom transfer radical polymerization (ATRP) to a comb-like copolymer, P(PEGMA-co-AA) designated here as P(PEGMA-AA). The polymer contains pendant carboxylate moieties near the backbone and PEG side chains. It is able to bind spontaneously to MNPs; stabilize the particles electrostatically via the carboxylate moieties and sterically via the PEG moieties; provide high protein repellency via the structured PEG layer; and anchor bioactive proteins via peptide bond formation with the free carboxylate groups. The presence of the P(PEGMA-AA) coating was verified in XPS experiments. The electrosteric (i.e., combined electrostatic and steric) stabilization is efficient down to pH 4 (at 10 mM ionic strength). Static magnetization and AC susceptibility measurements showed that the P(PEGMA-AA)@MNPs are superparamagnetic with a saturation magnetization value of 55 emu/g and that both single core nanoparticles and multicore structures are present in the samples. The multicore components make our product well suited for magnetic hyperthermia applications (SAR values up to 17.44 W/g). In vitro biocompatibility, cell internalization, and magnetic hyperthermia studies demonstrate the excellent theranostic potential of our product.

  19. Gold nanostar-enhanced surface plasmon resonance biosensor based on carboxyl-functionalized graphene oxide

    International Nuclear Information System (INIS)

    Wu, Qiong; Sun, Ying; Ma, Pinyi; Zhang, Di; Li, Shuo; Wang, Xinghua; Song, Daqian

    2016-01-01

    A new high-sensitivity surface plasmon resonance (SPR) biosensor based on biofunctional gold nanostars (AuNSs) and carboxyl-functionalized graphene oxide (cGO) sheets was described. Compared with spherical gold nanoparticles (AuNPs), the anisotropic structure of AuNSs, which concentrates the electric charge density on its sharp tips, could enhance the local electromagnetic field and the electronic coupling effect significantly. cGO was obtained by a diazonium reaction of graphene oxide (GO) with 4-aminobenzoic acid. Compared with GO, cGO could immobilize more antibodies due to the abundant carboxylic groups on its surface. Testing results show that there are fairly large improvements in the analytical performance of the SPR biosensor using cGO/AuNSs-antigen conjugate, and the detection limit of the proposed biosensor is 0.0375 μg mL"−"1, which is 32 times lower than that of graphene oxide-based biosensor. - Highlights: • A sensitive and versatile SPR biosensor was constructed for detection of pig IgG. • Biofunctional gold nanostars were used to amplify the response signals. • The strategy employed carboxyl-functionalized graphene oxide as biosensing substrate. • The detection limit of the proposed biosensor is 32 times lower than that of graphene oxide-based biosensor.

  20. Gold nanostar-enhanced surface plasmon resonance biosensor based on carboxyl-functionalized graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiong; Sun, Ying; Ma, Pinyi; Zhang, Di; Li, Shuo; Wang, Xinghua; Song, Daqian, E-mail: songdq@jlu.edu.cn

    2016-03-24

    A new high-sensitivity surface plasmon resonance (SPR) biosensor based on biofunctional gold nanostars (AuNSs) and carboxyl-functionalized graphene oxide (cGO) sheets was described. Compared with spherical gold nanoparticles (AuNPs), the anisotropic structure of AuNSs, which concentrates the electric charge density on its sharp tips, could enhance the local electromagnetic field and the electronic coupling effect significantly. cGO was obtained by a diazonium reaction of graphene oxide (GO) with 4-aminobenzoic acid. Compared with GO, cGO could immobilize more antibodies due to the abundant carboxylic groups on its surface. Testing results show that there are fairly large improvements in the analytical performance of the SPR biosensor using cGO/AuNSs-antigen conjugate, and the detection limit of the proposed biosensor is 0.0375 μg mL{sup −1}, which is 32 times lower than that of graphene oxide-based biosensor. - Highlights: • A sensitive and versatile SPR biosensor was constructed for detection of pig IgG. • Biofunctional gold nanostars were used to amplify the response signals. • The strategy employed carboxyl-functionalized graphene oxide as biosensing substrate. • The detection limit of the proposed biosensor is 32 times lower than that of graphene oxide-based biosensor.

  1. Activities in a social networking-based discussion group by endoscopic retrograde cholangiopancreatography doctors.

    Science.gov (United States)

    Kang, Xiaoyu; Zhao, Lina; Liu, Na; Wang, Xiangping; Zhang, Rongchun; Liu, Zhiguo; Liang, Shuhui; Yao, Shaowei; Tao, Qin; Jia, Hui; Pan, Yanglin; Guo, Xuegang

    2017-10-01

    Online social networking is increasingly being used among medical practitioners. However, few studies have evaluated its use in therapeutic endoscopy. Here, we aimed to analyze the shared topics and activities of a group of endoscopic retrograde cholangiopancreatography (ERCP) doctors in a social networking-based endoscopic retrograde cholangiopancreatography discussion group (EDG). Six ERCP trainers working in Xijing Hospital and 48 graduated endoscopists who had finished ERCP training in the same hospital were invited to join in EDG. All group members were informed not to divulge any private information of patients when using EDG. The activities of group members on EDG were retrospectively extracted. The individual data of the graduated endoscopists were collected by a questionnaire. From June 2014 to May 2015, 6924 messages were posted on EDG, half of which were ERCP related. In total, 214 ERCP-related topics were shared, which could be categorized into three types: sharing experience/cases (52.3%), asking questions (38.3%), and sharing literatures/advances (9.3%). Among the 48 graduated endoscopists, 21 had a low case volume of less than 50 per year and 27 had a high volume case volume of 50 or more. High-volume graduated endoscopists posted more ERCP-related messages (P=0.008) and shared more discussion topics (P=0.003) compared with low-volume graduated endoscopists. A survey showed that EDG was useful for graduated endoscopists in ERCP performance and management of post-ERCP complications, etc. A wide range of ERCP-related topics were shared on the social networking-based EDG. The ERCP-related behaviors on EDG were more active in graduated endoscopists with an ERCP case volume of more than 50 per year.

  2. Generation of 3D templates of active sites of proteins with rigid prosthetic groups.

    Science.gov (United States)

    Nebel, Jean-Christophe

    2006-05-15

    With the increasing availability of protein structures, the generation of biologically meaningful 3D patterns from the simultaneous alignment of several protein structures is an exciting prospect: active sites could be better understood, protein functions and protein 3D structures could be predicted more accurately. Although patterns can already be generated at the fold and topological levels, no system produces high-resolution 3D patterns including atom and cavity positions. To address this challenge, our research focuses on generating patterns from proteins with rigid prosthetic groups. Since these groups are key elements of protein active sites, the generated 3D patterns are expected to be biologically meaningful. In this paper, we present a new approach which allows the generation of 3D patterns from proteins with rigid prosthetic groups. Using 237 protein chains representing proteins containing porphyrin rings, our method was validated by comparing 3D templates generated from homologues with the 3D structure of the proteins they model. Atom positions were predicted reliably: 93% of them had an accuracy of 1.00 A or less. Moreover, similar results were obtained regarding chemical group and cavity positions. Results also suggested our system could contribute to the validation of 3D protein models. Finally, a 3D template was generated for the active site of human cytochrome P450 CYP17, the 3D structure of which is unknown. Its analysis showed that it is biologically meaningful: our method detected the main patterns of the cytochrome P450 superfamily and the motifs linked to catalytic reactions. The 3D template also suggested the position of a residue, which could be involved in a hydrogen bond with CYP17 substrates and the shape and location of a cavity. Comparisons with independently generated 3D models comforted these hypotheses. Alignment software (Nestor3D) is available at http://www.kingston.ac.uk/~ku33185/Nestor3D.html

  3. Multi-group transport methods for high-resolution neutron activation analysis

    International Nuclear Information System (INIS)

    Burns, K. A.; Smith, L. E.; Gesh, C. J.; Shaver, M. W.

    2009-01-01

    The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples. In these applications, high-resolution gamma-ray spectrometers are used to preserve as much information as possible about the emitted photon flux, which consists of both continuum and characteristic gamma rays with discrete energies. Monte Carlo transport is the most commonly used modeling tool for this type of problem, but computational times for many problems can be prohibitive. This work explores the use of multi-group deterministic methods for the simulation of neutron activation problems. Central to this work is the development of a method for generating multi-group neutron-photon cross-sections in a way that separates the discrete and continuum photon emissions so that the key signatures in neutron activation analysis (i.e., the characteristic line energies) are preserved. The mechanics of the cross-section preparation method are described and contrasted with standard neutron-gamma cross-section sets. These custom cross-sections are then applied to several benchmark problems. Multi-group results for neutron and photon flux are compared to MCNP results. Finally, calculated responses of high-resolution spectrometers are compared. Preliminary findings show promising results when compared to MCNP. A detailed discussion of the potential benefits and shortcomings of the multi-group-based approach, in terms of accuracy, and computational efficiency, is provided. (authors)

  4. Factors affecting walking activity of older people from culturally diverse groups: an Australian experience.

    Science.gov (United States)

    Bird, Stephen R; Radermacher, Harriet; Sims, Jane; Feldman, Susan; Browning, Colette; Thomas, Shane

    2010-07-01

    This study sought to investigate the walking habits of older people from diverse cultural backgrounds, and to identify the factors associated with their walking. Three hundred and thirty three people over the age of 60 years were recruited from seven culturally diverse groups from the Western suburbs of Melbourne, Australia. A survey questionnaire recording physical activity, and various factors related to activity, was interviewer-administered in the participants' preferred language. Data were analysed using Kruskal-Wallis, chi(2) and Mann-Whitney tests. Forty-seven percent of the participants walked at least 150 min per week, with no significant difference in prevalence between genders or cultural groups. Some cultural differences were found in relation to reasons and locations for walking, and women were more likely than men to report walking in the shopping mall, whilst men were more likely than women to report walking in the park and along walking trails. Those who attained >150 min of walking were more likely to report health and fitness as reasons for walking, to perceive their walking environment as more pleasurable, to use walking trails, and to consider their environment safe and to facilitate social interaction. This study indicates that the continued advocating of walking as a health promoting activity should be central to future campaigns to increase physical activity in this age group. The provision of locations that are accessible, safe, aesthetically pleasing, and encourage social engagement are likely to facilitate older people's participation in walking. For maximum effectiveness, however, strategies may benefit from being tailored to meet specific gender and cultural preferences. Copyright 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. Qualitative Evaluation of a Physical Activity Health Promotion Programme for People with Intellectual Disabilities in a Group Home Setting

    Science.gov (United States)

    Dixon-Ibarra, A.; Driver, S.; Nery-Hurwit, M.; VanVolkenburg, H.

    2018-01-01

    Background: There is a lack of health promotion programming designed to change the physical activity environment of the group home setting. The Menu-Choice programme assists staff in creating physical activity goals alongside residents with intellectual disabilities and provides strategies to incorporate activity into the group home schedule. The…

  6. Increasing Physical Activity in Mothers Using Video Exercise Groups and Exercise Mobile Apps: Randomized Controlled Trial.

    Science.gov (United States)

    Mascarenhas, Maya Nina; Chan, June Maylin; Vittinghoff, Eric; Van Blarigan, Erin Lynn; Hecht, Frederick

    2018-05-18

    Women significantly decrease their activity levels in the transition to motherhood. Digital health technologies are low cost, scalable, and can provide an effective delivery mechanism for behavior change. This is the first study that examines the use of videoconferencing and mobile apps to create exercise groups for mothers. The aim of the study was to test the feasibility, acceptability, and effectiveness of an individually adaptive and socially supportive physical activity intervention incorporating videoconferencing and mobile apps for mothers. The Moms Online Video Exercise Study was an 8-week, 2-armed, Web-based randomized trial comparing the effectiveness of a group exercise intervention with a waitlist control. Healthy mothers with at least 1 child under the age of 12 years were recruited through Facebook and email listservs. Intervention participants joined exercise groups using videoconferencing (Google Hangouts) every morning on weekdays and exercised together in real time, guided by exercise mobile apps (eg, Nike+, Sworkit) of their choice. Waitlist control participants had access to recommended mobile apps and an invitation to join an exercise group after the 8-week study period. Main outcomes assessed included changes in self-reported moderate, vigorous, and moderate to vigorous physical activity (MVPA) minutes per week in aggregate and stratified by whether women met Centers for Disease Control and Prevention guidelines for sufficient aerobic activity at baseline. Outcomes were measured through self-assessed Web-based questionnaires at baseline and 8 weeks. The intervention was effective at increasing exercise for inactive women and proved to be feasible and acceptable to all participants. A total of 64 women were randomized, 30 to intervention and 34 to control. Women attended 2.8 sessions per week. There was a strong, but not statistically significant, trend toward increasing moderate, vigorous, and MVPA minutes for all women. As hypothesized, in

  7. Assessing the reliability of predictive activity coefficient models for molecules consisting of several functional groups

    Directory of Open Access Journals (Sweden)

    R. P. Gerber

    2013-03-01

    Full Text Available Currently, the most successful predictive models for activity coefficients are those based on functional groups such as UNIFAC. In contrast, these models require a large amount of experimental data for the determination of their parameter matrix. A more recent alternative is the models based on COSMO, for which only a small set of universal parameters must be calibrated. In this work, a recalibrated COSMO-SAC model was compared with the UNIFAC (Do model employing experimental infinite dilution activity coefficient data for 2236 non-hydrogen-bonding binary mixtures at different temperatures. As expected, UNIFAC (Do presented better overall performance, with a mean absolute error of 0.12 ln-units against 0.22 for our COSMO-SAC implementation. However, in cases involving molecules with several functional groups or when functional groups appear in an unusual way, the deviation for UNIFAC was 0.44 as opposed to 0.20 for COSMO-SAC. These results show that COSMO-SAC provides more reliable predictions for multi-functional or more complex molecules, reaffirming its future prospects.

  8. Galaxy And Mass Assembly (GAMA): the effect of galaxy group environment on active galactic nuclei

    Science.gov (United States)

    Gordon, Yjan A.; Pimbblet, Kevin A.; Owers, Matt S.; Bland-Hawthorn, Joss; Brough, Sarah; Brown, Michael J. I.; Cluver, Michelle E.; Croom, Scott M.; Holwerda, Benne W.; Loveday, Jonathan; Mahajan, Smriti; Wang, Lingyu

    2018-04-01

    In galaxy clusters, efficiently accreting active galactic nuclei (AGNs) are preferentially located in the infall regions of the cluster projected phase-space, and are rarely found in the cluster core. This has been attributed to both an increase in triggering opportunities for infalling galaxies, and a reduction of those mechanisms in the hot, virialized, cluster core. Exploiting the depth and completeness (98 per cent at r 9.9 in 695 groups with 11.53 ≤ log10(M200/M⊙) ≤ 14.56 at z 13.5, AGNs are preferentially found in the infalling galaxy population with 3.6σ confidence. At lower halo masses, we observe no difference in AGN fraction between core and infalling galaxies. These observations support a model where a reduced number of low-speed interactions, ram pressure stripping and intra-group/cluster medium temperature, the dominance of which increase with halo mass, work to inhibit AGN in the cores of groups and clusters with log10(M200/M⊙) > 13.5, but do not significantly affect nuclear activity in cores of less massive structures.

  9. Synthesis, crystal structures, and luminescent properties of two series' of new lanthanide (III) amino-carboxylate-phosphonates.

    Science.gov (United States)

    Zhou, Tian-Hua; Yi, Fei-Yan; Li, Pei-Xin; Mao, Jiang-Gao

    2010-02-01

    Hydrothermal reactions of lanthanide(III) chlorides with 4-HOOC-C(6)H(4)-CH(2)NHCH(2)PO(3)H(2) (H(3)L) at different ligand-to-metal (L/M) ratios afforded nine new lanthanide(III) carboxylate-phosphonates with two types of 3D network structures, namely, LnCl(HL)(H(2)O)(2) (Ln = Sm, 1; Eu, 2; Gd, 3; Tb, 4; Dy, 5; Er, 6) and [Ln(2)(HL)(H(2)L)(L)(H(2)O)(2)].4H(2)O (Ln = Nd, 7; Sm, 8; Eu, 9). Compounds 1-6 are isostructural and feature a 3D network in which the LnO(7)Cl polyhedra are interconnected by bridging CPO(3) tetrahedra into 2D inorganic layers parallel to the bc plane. These layers are further cross-linked by organic groups of the carboxylate-phosphonate ligands via the coordination of the carboxylate groups into a pillared-layered architecture. Compounds 7-9 are also isostructural and feature a 3D open-framework composed of 1D lanthanide(III) phosphonate inorganic slabs which are further bridged by organic groups of the carboxylate-phosphonate liagnds via the coordination of the carboxylate groups, forming large 1D tunnels along the b-axis which are filled by lattice water molecules. Luminescent measurements indicate that compounds 2, 4, and 5 show strong emission bands in red, green, and yellow light region, respectively. Magnetic properties of 2, 3, 5, and 7 have also been studied.

  10. [Nursing activities in family medicine groups for patients with chronic pain].

    Science.gov (United States)

    Bergeron, Dave A; Bourgault, Patricia; Gallagher, Frances

    2015-01-01

    Thousands of people treated in primary care are currently experiencing chronic pain (CP), for which management is often inadequate. In Quebec, nurses in family medicine groups (FMGs) play a key role in the management of chronic health problems. The present study aimed to describe the activities performed by FMG nurses in relation to CP management and to describe barriers to those activities. A descriptive correlational cross-sectional postal survey was used. The accessible population includes FMG nurses on the Ordre des infirmières et infirmiers du Québec list. All nurses on the list who provided consent to be contacted at home for research purposes were contacted. A self-administered postal questionnaire (Pain Management Activities Questionnaire) was completed by 53 FMG nurses. Three activities most often performed by nurses were to establish a therapeutic relationship with the client; discuss the effectiveness of therapeutic measures with the physician; and conduct personalized teaching for the patient. The average number of individuals seen by interviewed nurses that they believe suffer from CP was 2.68 per week. The lack of knowledge of possible interventions in pain management (71.7%) and the nonavailability of information on pain management (52.8%) are the main barriers perceived by FMG nurses. FMG nurses are currently performing few activities in CP management. The nonrecognition of CP may explain this situation.

  11. Quality assurance activities by the companies in the Mitsubishi group for nuclear power plants in Japan

    International Nuclear Information System (INIS)

    Fujiwara, K.; Moriyama, A.; Okabe, K.

    1982-01-01

    The paper summarizes the quality assurance (QA) activities of the Mitsubishi group regarding PWR plant construction. 1. To ensure a uniform approach to QA activities in the group, the Nuclear System Quality Assurance Administration Centre was established at the headquarters of Mitsubishi Heavy Industries. This Centre is engaged in establishing and promoting comprehensive QA plans, in supervising the interface control between the companies concerned, and in auditing each company's QA programme. 2. In parallel with endeavours to complete QA systems, a great effort has been made to instill consciousness of QA in everyone concerned with the work. It is emphasized that quality control (QC) circle activities play an important role in maintaining a high level of quality. An innovative system of design computerization coupled with model engineering is now being developed to improve design reliability and to prevent human error. Reliability improvement and preventive maintenance systems using computers are being introduced with the object of performing systematic corrective actions based on analyses of plant operation. (author)

  12. Relationship between physical activity and physical performance in later life in different birth weight groups.

    Science.gov (United States)

    Jantunen, H; Wasenius, N S; Salonen, M K; Perälä, M-M; Kautiainen, H; Simonen, M; Pohjolainen, P; Kajantie, E; von Bonsdorff, M B; Eriksson, J G

    2018-02-01

    There is strong evidence that physical activity (PA) has an influence on physical performance in later life. Also, a small body size at birth has been associated with lower physical functioning in older age and both small and high birth weight have shown to be associated with lower leisure time physical activity. However, it is unknown whether size at birth modulates the association between PA and physical performance in old age. We examined 695 individuals from the Helsinki Birth Cohort Study born in Helsinki, Finland between 1934 and 1944. At a mean age of 70.7 years PA was objectively assessed with a multisensory activity monitor and physical performance with the Senior Fitness Test (SFT). Information on birth weight and gestational age was retrieved from hospital birth records. The study participants were divided in three birth weight groups, that is birth weight groups. However, the effect size of the association was large and significant only in men with a birth weight confidence interval 0.37-0.81, Pbirth weight. Our results suggest that men with low birth weight might benefit most from engaging in PA in order to maintain a better physical performance.

  13. NEWBORNS OF HIGH RISK GROUPS AND ELECTROPHYSIOLOGICAL CARDIAC ACTIVITY DURING THE PERIOD OF EARLY ADAPTATION

    Directory of Open Access Journals (Sweden)

    T. S. Tumaeva

    2014-01-01

    Full Text Available Aim: to study characteristics of electrophysiological cardiac activity in children of risk groups and to assess possibilities of Holter-electrocardiography (H-ECG in revealing of cardiac dysfunction during the period of early adaptation. Patients and methods: 250 newborns were examined. The main group consisted of 200 children with cerebral ischemia (CI. This group was divided into 2 subgroups: 100 full-term and 100 premature (at various gestation age infants. Control group contained 50 children born at 38–40th weeks of gestation with physiological course of pregnancy and delivery, APGAR score of 8–9 points. Complex examination included H-ECG according the standard technic with evaluation of the hearth rate (HR during sleep and wakefulness; HRmin, HRmax; arrhythmias, conductivity disorders, duration of the intervals; rhythm variability. Results: according to the ECG children with CI, especially premature ones, and children delivered via Cesarean section more often had ST-T disturbances, arrhythmias (sinus tachycardia, less often — sinus bradycardia and conductivity disorders, Q-Tc prolongation. H-EGC revealed decrease of sleep HR, HRmin and HRmax in children with CI especially in delivered via Cesarean section. The most common arrhythmia was supraventricular extrasystole.  Pauses in rhythms and variability were the highest in premature children delivered via Cesarean section. Conclusions: hypoxia/ischemia is a trigger for development of cardiovascular dysfuncion in newborns. Premature and children delivered via Cesarean section form a group of high risk. H-ECG widens possibilities of revealing of symptoms of cardiac dysfunction (disturbances at the basal level of functioning, of adaptation resources of the sinus node, electric instability of the myocardium and heart rate variability in children of risk group for development of cardiovascular disorders. 

  14. ACTIVE GALACTIC NUCLEI IN GROUPS AND CLUSTERS OF GALAXIES: DETECTION AND HOST MORPHOLOGY

    International Nuclear Information System (INIS)

    Arnold, Timothy J.; Martini, Paul; Mulchaey, John S.; Berti, Angela; Jeltema, Tesla E.

    2009-01-01

    The incidence and properties of active galactic nuclei (AGNs) in the field, groups, and clusters can provide new information about how these objects are triggered and fueled, similar to how these environments have been employed to study galaxy evolution. We have obtained new XMM-Newton observations of seven X-ray selected groups and poor clusters with 0.02 -1 ). We find that the X-ray selected AGN fraction increases from f A (L X ≥ 10 41 ; M R ≤ M* R + 1) = 0.047 +0.023 -0.016 in clusters to 0.091 +0.049 -0.034 for the groups (85% significance), or a factor of 2, for AGN above an 0.3-8 keV X-ray luminosity of 10 41 ergs -1 hosted by galaxies more luminous than M* R + 1. The trend is similar, although less significant, for a lower-luminosity host threshold of M R = -20 mag. For many of the groups in the sample, we have also identified AGN via standard emission-line diagnostics and find that these AGNs are nearly disjoint from the X-ray selected AGN. Because there are substantial differences in the morphological mix of galaxies between groups and clusters, we have also measured the AGN fraction for early-type galaxies alone to determine if the differences are directly due to environment, or indirectly due to the change in the morphological mix. We find that the AGN fraction in early-type galaxies is also lower in clusters f A,n≥2.5 (L X ≥ 10 41 ; M R ≤ M* R + 1) = 0.048 +0.028 -0.019 compared to 0.119 +0.064 -0.044 for the groups (92% significance), a result consistent with the hypothesis that the change in AGN fraction is directly connected to environment.

  15. The use of music in group educational activities in Family Health.

    Science.gov (United States)

    Silva, Líliam Barbosa; Soares, Sônia Maria; da Silva, Maria Júlia Paes; Santos, Graziela da Costa; Fernandes, Maria Teresinha de Oliveira

    2013-01-01

    describe how music is used in the development of group educational activity in Family Health. a qualitative, descriptive and exploratory study, developed with 10 group coordinators, distributed in five basic care units in Belo Horizonte, Minas Gerais, Brazil. Data were collected from March to July, 2009, with non participant observation in the group itself, and semi-structured interviews with the coordinators. Information was organized and categorized according to thematic analysis. To interpret the data, the Snyderian concepts in addition to theoretical references about music, communication and health education were used. three thematic nuclei were found: the affective dimension of music; recreative dimension of music and the reflexive dimension of music. an attempt by the coordinators was observed, to overcome the pathological barriers with the use of music, considering the group as a whole. As advancement for the production of knowledge, this study shows the need for qualification of these coordinators, by means of workshops and constant follow-up of their musical practices.

  16. Amination of activated carbon for enhancing phenol adsorption: Effect of nitrogen-containing functional groups

    International Nuclear Information System (INIS)

    Yang, Guo; Chen, Honglin; Qin, Hangdao; Feng, Yujun

    2014-01-01

    To study the contribution of different nitrogen-containing functional groups to enhancement of phenol adsorption, the aminated activated carbons (AC) were characterized by N2 adsorption/desorption, XPS, Boehm titration, and pH drift method and tested for adsorption behaviors of phenol. Adsorption isotherm fitting revealed that the Langmuir model was preferred for the aminated ACs. The adsorption capacity per unit surface area (q m /SSA BET ) was linearly correlated with the amount of pyridinic and pyrrolic N, which suggested that these two functional groups played a critical role in phenol adsorption. The enhancement of adsorption capacity was attributed to the strengthened π–π dispersion between phenol and basal plane of AC by pyridinic, pyrrolic N. The adsorption kinetics was found to follow the pseudo-second-order kinetic model, and intraparticle diffusion was one of the rate-controlling steps in the adsorption process.

  17. Oxidation of an activated carbon commercial and characterization of the content of superficial acid groups

    International Nuclear Information System (INIS)

    Cortes, Juan Carlos; Giraldo Liliana; Garcia, Andres A; Garcia, Cesar; Moreno, Juan C

    2008-01-01

    The changes of the surface acid groups of an activated commercial carbon after placing it under oxidation treatment with nitric acid are studied. The time used was in the range 1.5 and 9 hours, the concentrations range was from 4 to 7 molL -1 . The study included the determination of immersion enthalpy. Boehm's type titrations, FTIR, and pH at the point of zero charge, pH p zc. It was found that total acid groups are in a range from 0.207 mmolg -1 to 1.247 mmolg -1 , and that they are proportional to the immersion enthalpy in NaOH that are between 40 and 54Jg -1 . The pH p zc decreases with the oxidation treatment and have values between 8.3 and 4.3

  18. Organotin(IV) Carboxylates as Promising Potential Drug Candidates in the Field of Cancer Chemotherapy.

    Science.gov (United States)

    Sirajuddin, Muhammad; Ali, Saqib

    2016-01-01

    Medicinal inorganic chemistry plays an important role in exploring the properties of metal ions for the designing of new drugs. The field has been stimulated by the success of cis-platin, the world best selling anticancer drug and platinum complexes with reduced toxicity, oral activity and activity against resistant tumors are currently on clinical trial. The use of cis-platin is, however, severely limited by its toxic side-effects. This has stimulated chemists to employ different strategies in the development of new metal-based anticancer agents with different mechanisms of action. The discovery of new non-covalent interactions with the classical target, DNA, was the first developing step in the treatment of cancer. The use of organometallic compounds as a medicine is very common now a days because it offers potential advantages over the more common organic-based drugs. In this article we have highlighted the anticancer activity of the organotin(IV) carboxylates published in the last few years (from 2008 to 2016). In most cases they present lower IC50 values than those of cisplatin, which indicates their high activity against the cancer cell lines. The summarized data reveal that every year new organotin(IV) carboxylate complexes are synthesized with the aim of new anticancer agent with much better results than the than the corresponding activity of cis-platin or other clinically approved drugs. In addition to the advantages of high activity, compared to the platinum compound, tin complexes are much cheaper. Thus by using organotin carboxylate for clinical medicine, cost reduction, dosage reduction and effect enhancement will be reached. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Nitrile rubber and carboxylated nitrile rubber resistance to soybean biodiesel

    Directory of Open Access Journals (Sweden)

    Felipe Nunes Linhares

    2018-03-01

    Full Text Available Abstract Biodiesel has been considered a suitable substitute for petroleum diesel, but their chemical composition differs greatly. For this reason, biodiesel interacts differently than petroleum diesel with various materials, including rubbers. Therefore, the resistance of some elastomers should be thoroughly evaluated, specifically those which are commonly used in automotive industry. Nitrile rubber (NBR is widely used to produce vehicular parts that are constantly in contact with fuels. This paper aimed to assess the resistance of carboxylated nitrile rubber (XNBR with 28% of acrylonitrile content to soybean biodiesel in comparison with non-carboxylated nitrile rubber samples, with high and medium acrylonitrile content (33 and 45%. NBR with medium acrylonitrile content showed little resistance to biodiesel. However, carboxylated nitrile rubber even with low acrylonitrile content had similar performance to NBR with high acrylonitrile content.

  20. Active case finding and treatment adherence in risk groups in the tuberculosis pre-elimination era.

    Science.gov (United States)

    Gupta, R K; Lipman, M; Story, A; Hayward, A; de Vries, G; van Hest, R; Erkens, C; Rangaka, M X; Abubakar, I

    2018-05-01

    Vulnerable populations, including homeless persons, high-risk drug and alcohol users, prison inmates and other marginalised populations, contribute a disproportionate burden of tuberculosis (TB) cases in low-incidence settings. Drivers of this disease burden include an increased risk of both TB transmission in congregate settings, and progression from infection to active disease. Late diagnosis and poor treatment completion further propagate the epidemic and fuel the acquisition of drug resistance. These groups are therefore a major priority for TB control programmes in low-incidence settings. Targeted strategies include active case finding (ACF) initiatives and interventions to improve treatment completion, both of which should be tailored to local populations. ACF usually deploys mobile X-ray unit screening, which allows sensitive, high-throughput screening with immediate availability of results. Such initiatives have been found to be effective and cost-effective, and associated with reductions in proxy measures of transmission in hard-to-reach groups. The addition of point-of-care molecular diagnostics and automated X-ray readers may further streamline the screening pathway. There is little evidence to support interventions to improve adherence among these risk groups. Such approaches include enhanced case management and directly observed treatment, while video-observed therapy (currently under evaluation) appears to be a promising tool for the future. Integrating outreach services to include both case detection and case-management interventions that share a resource infrastructure may allow cost-effectiveness to be maximised. Integrating screening and treatment for other diseases that are prevalent among targeted risk groups into TB outreach interventions may further improve cost-effectiveness. This article reviews the existing literature, and highlights priorities for further research.