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Sample records for arene di-oxygenases involved

  1. Characterization of arene di-oxygenases involved in polycyclic aromatic hydrocarbons biodegradation in Mycobacterium sp. 6PY1; Caracterisation d'arene dioxygenases impliquees dans la biodegradation des hydrocarbures aromatiques polycycliques chez Mycobacterium sp. 6PY1

    Energy Technology Data Exchange (ETDEWEB)

    Kuony, S.

    2005-06-15

    This thesis deals with the bacterial biodegradation of pollutants called polycyclic aromatic hydrocarbons (PAHs). The bacterium Mycobacterium sp. 6PY1 was isolated from a polluted soil for its ability to use pyrene, a 4-ring PAH, as sole source of carbon and energy. To learn about the pyrene metabolic pathway, the identification of the enzymes involved in this process has been undertaken using a proteomic approach. This approach revealed the occurrence of two ring-hydroxylating di-oxygenases in strain 6PY1, which could catalyze the initial attack of pyrene. The goal of this study was to clone the genes encoding the di-oxygenases identified in Mycobacterium sp. 6PY1, over-express these genes in an heterologous system in order to facilitate the purification of the corresponding enzymes, and determine the biochemical and catalytic properties of these enzymes. The pdoA1B1 genes encoding the terminal component of a di-oxygenase were cloned and over-expressed in Escherichia coli. The catalytic properties of this enzyme, called Pdo1, were determined in vivo by measuring the oxidation products of 2- to 4-ring PAHs by gas chromatography coupled to mass spectrometry (GC-MS). Analysis of the selectivity of the enzyme, as determined using GC-MS, showed that Pdo1 preferentially oxidized 3- or 4-ring PAHs, including phenanthrene and pyrene, but was inactive on di-aromatic compounds such as naphthalene and biphenyl. Pdo1 was unstable and was therefore purified in inactive form. The genes encoding a second di-oxygenase component were found in a locus containing two other catabolic genes. The pdoA2B2 genes encoded an enzyme called Pdo2 showing a narrow specificity towards 2- to 3-ring PAHs, and a high preference for phenanthrene. Pdo2 is an a3{beta}3 hexamer, containing [2Fe-2S] Rieske clusters which confer it a characteristic absorbance spectrum. A third set of genes possibly encoding another di-oxygenase was discovered in the genome of Mycobacterium sp. 6PY1. This set is closely

  2. Arene ruthenium chemistry

    OpenAIRE

    Bates, Richard Simon

    1990-01-01

    This thesis describes the synthesis and reactivity studies of new arene-ruthenium(II) and arene-ruthenium(O) complexes. Ultrasound has been investigated as an alternative energy source, with the overall aim of synthesising arene ruthenium clusters. Chapter 1 gives an introduction and summary of the known arene ruthenium chemistry reported to date. Chapter 2 reports the synthesis of (CGH6)Ru(C2H4)2 and (MeC6H4CHMe2)Ru(C2H4)2. Low temperature protonation studies generated (C6H6)Ru(H)(CZH4...

  3. Arene ruthenium complexes as anticancer agents

    OpenAIRE

    Süss-Fink, Georg

    2012-01-01

    Neutral or cationic arene ruthenium complexes providing both hydrophilic as well as hydrophobic properties due to the robustness of the ruthenium–arene unit hold a high potential for the development of metal-based anticancer drugs. Mononuclear arene ruthenium complexes containing P- or N-donor ligands or N,N-, N,O- or O,O-chelating ligands, dinuclear arene ruthenium systems with adjustable organic linkers, trinuclear arene ruthenium clusters containing an oxo cap, tetranuclear arene ruthenium...

  4. Pyrogallo4arenes: a synthetic investigation

    OpenAIRE

    Griffin, Pauline

    2007-01-01

    The first part of this work involved the study of the acid condensation of pyrogallol with acataldehyde. The product formed, pyrogallol[4]arene, is present as a mixture of two isomers, the rccc cone and the rctt flattened partial cone conformations, which could be separated using an extractiodreprecipitation procedure. A series of studies was undertaken to determine if these two isomers could be interconverted. We found that both the rctt flattened partial cone and rccc cone isomers could not...

  5. Negative ion gas-phase chemistry of arenes.

    Science.gov (United States)

    Danikiewicz, Witold; Zimnicka, Magdalena

    2016-01-01

    Reactions of aromatic and heteroaromatic compounds involving anions are of great importance in organic synthesis. Some of these reactions have been studied in the gas phase and are occasionally mentioned in reviews devoted to gas-phase negative ion chemistry, but no reviews exist that collect all existing information about these reactions. This work is intended to fill this gap. In the first part of this review, methods for generating arene anions in the gas phase and studying their physicochemical properties and fragmentation reactions are presented. The main topics in this part are as follows: processes in which gas-phase arene anions are formed, measurements and calculations of the proton affinities of arene anions, proton exchange reactions, and fragmentation processes of substituted arene anions, especially phenide ions. The second part is devoted to gas-phase reactions of arene anions. The most important of these are reactions with electrophiles such as carbonyl compounds and α,β-unsaturated carbonyl and related compounds (Michael acceptors). Other reactions including oxidation of arene anions and halogenophilic reactions are also presented. In the last part of the review, reactions of electrophilic arenes with nucleophiles are discussed. The best known of these is the aromatic nucleophilic substitution (SN Ar) reaction; however, other processes that lead to the substitution of a hydrogen atom in the aromatic ring are also very important. Aromatic substrates in these reactions are usually but not always nitroarenes bearing other substituents in the ring. The first step in these reactions is the formation of an anionic σ-adduct, which, depending on the substituents in the aromatic ring and the structure of the attacking nucleophile, is either an intermediate or a transition state in the reaction path. In the present review, we attempted to collect the results of both experimental and computational studies of the aforementioned reactions conducted since the

  6. An Efficient Ag+ Ionophore Based on Thiacalix[4]arene

    Institute of Scientific and Technical Information of China (English)

    LI Xiong; GONG Shu-Ling; YANG Wei-Ping; CHEN Yuan-Yin

    2008-01-01

    A novel Ag+ ionophore, p-tert-butyi-tetrakis(hydrazinocarbonylmethoxy)thiacalix[4]arene in 1,3-alternate conformation (thiacalix[4]arene tetrahydrazide, 1) was synthesized. Its binding properties towards alkali and transition metal cations were studied by noncompetitive liquid-liquid extraction of alkali metal (Li+, Na+, K+ and Cs+)and transition metal (Co2+, Ni2+, Cu2+, Zn2+, Ag+) picrates. It was found that the thiacalix[4]arene tetrahydrazide exhibited high extractability towards Ag+, lower percent extraction towards Cu2+, and little or no extraction ability towards the others. The selectivity towards Ag+ was further evaluated by competitive Ag+ extraction experiments in the mixture of the above-mentioned nine cations, the concentration of which was monitored with ICP-OES. 1HNMR titration experiments and ESI-MS proved the stoichiometry of 1 to Ag+ was 1 : 1, and the 'N-Ag+' interaction with the assistance of thiacalixarene skeleton was primarily involved in the complexation.

  7. Spontaneous reduction and C-H borylation of arenes mediated by uranium(III) disproportionation.

    Science.gov (United States)

    Arnold, Polly L; Mansell, Stephen M; Maron, Laurent; McKay, David

    2012-07-15

    Transition-metal-arene complexes such as bis(benzene)chromium Cr(η(6)-C(6)H(6))(2) are historically important to d-orbital bonding theory and have modern importance in organic synthesis, catalysis and organic spintronics. In investigations of f-block chemistry, however, arenes are invariably used as solvents rather than ligands. Here, we show that simple uranium complexes UX(3) (X = aryloxide, amide) spontaneously disproportionate, transferring an electron and X-ligand, allowing the resulting UX(2) to bind and reduce arenes, forming inverse sandwich molecules [X(2)U(µ-η(6):η(6)-arene)UX(2)] and a UX(4) by-product. Calculations and kinetic studies suggest a 'cooperative small-molecule activation' mechanism involving spontaneous arene reduction as an X-ligand is transferred. These mild reaction conditions allow functionalized arenes such as arylsilanes to be incorporated. The bulky UX(3) are also inert to reagents such as boranes that would react with the traditional harsh reaction conditions, allowing the development of a new in situ arene C-H bond functionalization methodology converting C-H to C-B bonds.

  8. Extraction Capability of Calix[4]/arene-R14 Extraction Chromatography

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In order to partition effectively 137Cs from high-level radioactive sample by extraction chromato- graphy, a kind of macroporous silica-based polymeric materials, Calix[4]arene-R14/SiO2-P were used. A

  9. Anion–arene adducts: C–H hydrogen bonding, anion– interaction, and carbon bonding motifs

    OpenAIRE

    Hay, Benjamin P.; Bryantsev, Vyacheslav S.

    2008-01-01

    This article summarizes experimental and theoretical evidence for the existence of four distinct binding modes for complexes of anions with charge-neutral arenes. These include C–H hydrogen bonding and three motifs involving the arene– system—the noncovalent anion– interaction, weakly covalent interaction, and strongly covalent interaction.

  10. A New Efficient Synthesis of p-Nitrocalix[4]arene

    Institute of Scientific and Technical Information of China (English)

    Yong LI; Jia Song WANG; Qi WANG; De Shan LI

    2004-01-01

    A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described. The compound is an useful intermediates for the introduction of other functional groups to obtain N containing substituted calix[4]arene.The reaction mechanism is briefly discussed.

  11. STRATEGI PENGEMBANGAN AGROINDUSTRI GULA SEMUT AREN

    Directory of Open Access Journals (Sweden)

    Nur Afni Evalia

    2015-03-01

    Full Text Available Aren is a type of palm that has a highly potential economic value. Lareh Sago Sub-district is the largest producer in the District of Lima Puluh Kota; however, it is only processed to produce wine and molded sugar. This study aimed to formulate a strategy for the sugar palm sugar agro-industrial development in Lareh Sagohalaban. The research method was a case study in the form of quantitative descriptive, and the data were processed using IFE/EFE, SWOT and AHP. The values obtained from IFE and EFE matrixes were 2.646 and 2.298 respectively. From the SWOT analysis, alternative strategies were obtained, namely, SO Strategy: Strengthening the R & D to develop market-based sugar processing for commercial scale and diversification of palm downstream products; WO Strategy: Improving upstream subsystem to develop nursery based on palm local seed varieties and providing institutional assistance; ST Strategy: Determining agro-technopark for palm industrialization, providing assistance in the form of appropriate packaging technology accordance with the standards, and WT Strategy: increasing commitment and cooperation among stakeholders in strengthening palm agro-industry, increasing marketing and promotion for the expansion and sanction policy for any company selling Aren in the form of wine. From the result of AHP analysis, the determinant factors in developing the business include Technology (0.439, the Government as the actor (0.577, and product diversification as the strategy (0.388.Keyword: Aren (palm, cluster- agro technopark, IFE/EFE matrixes, SWOT analysis, AHPABSTRAKAren (Arenga pinnata Merr adalah jenis palma yang memiliki potensi nilai ekonomi yang tinggi. Kecamatan Lareh sago halaban merupakan penghasil Aren terbesar di Kabupaten Lima Puluh Kota, namun dalam pengolahannya masih mengolah menjadi gula cetak dan lebih banyak dalam bentuk tuak. Penelitian ini bertujuan merumuskan strategi pengembangan agroindustri gula semut aren di Kecamatan

  12. Haptotropic Migration of Metal Templates on Arene Surfaces

    Institute of Scientific and Technical Information of China (English)

    K.H.Dtz; H.C.Jahr; J.Bennewitz; J.Dubarle-offner

    2007-01-01

    1 Results The chromium-templated benzannulation of arylcarbenes by alkynes provides a direct regio- and diastereoselective access to densely functionalized chromium arenes[1]. The chromium fragment undergoes a haptotropic migration along the π-face of the fused arenes which can be controlled by thermodynamics,by the substitution pattern of the arene and by the metal coligand sphere(See Scheme 1).The controlled regioselective labeling of benzene rings can be exploited in diastereoselective C-C bond forma...

  13. Synthesis of (p-Formylphenyl)azo Calix[4]arenes

    Institute of Scientific and Technical Information of China (English)

    BAI,Zhu(柏祝); YU,Lei(俞磊); LU,Guo-Yuan(陆国元); GUO,Xun(郭勋)

    2004-01-01

    Five novel azo calix[4]arenes were reported.The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution.Mono-,bis-,tris- and tetrakis(p-formylphenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arene (1) under pH=7.5-8.5 at 0-5℃.All (p-formylphenyl)azo calix[4]arenes were characterized by 1H NMR,13C NMR,IR,MS (ESIMS) spectroscopies and elemental analysis.

  14. EFEKTIVITAS NIRA AREN SEBAGAI BAHAN PENGEMBANG ADONAN ROTI

    Directory of Open Access Journals (Sweden)

    Mody Lempang

    2013-12-01

    Full Text Available Fermentation is a natural process that happen in fresh-sweet sap of aren trees (Arenga pinnata Merr., because many kinds of microorganism stay and life in this substance e.g. bakteria (Acetobacter acetic and yeast (Saccharomyces tuac. Species of yeast from genus of Saccharomyses, e.g. Saccharomyses serivisae is wellknown as microorganism that can ferment sugar (glucose into alchohol and CO2. This natural process as well happen in aren sap, so that this substance potencially using as a swollen agent of bread or cake dough. This research objective is to recognize the effectiveness of aren sap as a swollen agent of bread dough. Fermentation duration of bread dough was one hour by using swollen agent of fresh, 10 hours old and 20 hours old of aren sap. Daily yield of sap tapped from aren trees in Maros district, South Sulawesi province was 7 litre (4-5 litre collected in the morning and 2-3 litre colected in the afternoon. Aren sap containt some of nutritions e.g. carbohydrate, protein, fat, vitamin C and mineral. Sweet taste of aren sap caused by it’s charbohydrate content of 11.18%. The effectiveness of aren sap as a swollen agent of bread dough is lower than instant (commercial yeast. The older of aren sap the lower of it’s effectiveness as a swollen agent of dough and kuality of bread yield.    Keywords : Sap, Arenga pinnata, swollen agent, bread dough

  15. Arene Ruthenium Cages: Boxes Full of Surprises

    OpenAIRE

    Therrien, Bruno

    2010-01-01

    Self-assembly of polypyridyl ligands with dinuclear arene ruthenium building blocks bridged by chlorido, oxalato or benzoquinonato ligands has allowed the construction of a wide range of cationic metalla complexes possessing different architectures and functionalities: (i) metalla-rectangles showing host-guest possibilities and allowing intramolecular template-controlled photochemical [2 + 2] dimerisation reactions; (ii) metalla-prisms allowing encapsulation of molecules and giving rise to po...

  16. Gas Concentration Mapping of Arenal Volcano Using AVEMS

    Science.gov (United States)

    Diaz, J. Andres; Arkin, C. Richard; Griffin, Timothy P.; Conejo, Elian; Heinrich, Kristel; Soto, Carlomagno

    2005-01-01

    The Airborne Volcanic Emissions Mass Spectrometer (AVEMS) System developed by NASA-Kennedy Space Center and deployed in collaboration with the National Center for Advanced Technology (CENAT) and the University of Costa Rica was used for mapping the volcanic plume of Arenal Volcano, the most active volcano in Costa Rica. The measurements were conducted as part of the second CARTA (Costa Rica Airborne Research and Technology Application) mission conducted in March 2005. The CARTA 2005 mission, involving multiple sensors and agencies, consisted of three different planes collecting data over all of Costa Rica. The WB-57F from NASA collected ground data with a digital camera, an analog photogrametric camera (RC-30), a multispectral scanner (MASTER) and a hyperspectral sensor (HYMAP). The second aircraft, a King Air 200 from DoE, mounted with a LIDAR based instrument, targeted topography mapping and forest density measurements. A smaller third aircraft, a Navajo from Costa Rica, integrated with the AVEMS instrument and designed for real-time measurements of air pollutants from both natural and anthropogenic sources, was flown over the volcanoes. The improved AVEMS system is designed for deployment via aircraft, car or hand-transport. The 85 pound system employs a 200 Da quadrupole mass analyzer, has a volume of 92,000 cubic cm, requires 350 W of power at steady state, can operate up to an altitude of 41,000 feet above sea level (-65 C; 50 torr). The system uses on-board gas bottles on-site calibration and is capable of monitoring and quantifying up to 16 gases simultaneously. The in-situ gas data in this work, consisting of helium, carbon dioxide, sulfur dioxide and acetone, was acquired in conjunction of GPS data which was plotted with the ground imagery, topography and remote sensing data collected by the other instruments, allowing the 3 dimensional visualization of the volcanic plume at Arenal Volcano. The modeling of possible scenarios of Arenal s activity and its

  17. STRATEGI PENGEMBANGAN AGROINDUSTRI GULA SEMUT AREN

    OpenAIRE

    Nur Afni Evalia

    2015-01-01

    Aren is a type of palm that has a highly potential economic value. Lareh Sago Sub-district is the largest producer in the District of Lima Puluh Kota; however, it is only processed to produce wine and molded sugar. This study aimed to formulate a strategy for the sugar palm sugar agro-industrial development in Lareh Sagohalaban. The research method was a case study in the form of quantitative descriptive, and the data were processed using IFE/EFE, SWOT and AHP. The values obtained from IFE an...

  18. Synthesis of Schiff Base Calix[4]arene Crowns

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This letter reports the synthesis of Schiff base calix[4]arene crowns containing m-xylylene phenol subunit, in which calix[4]arene Schiff base crowns 2a, 2b and 2c were formed by 1:1 condensation of calix[4]arene diamine 1 with dialdehydes (2, 6-diformyl-4-chlorophenol 3a, 2, 6-diformyl-4-methylphenol 3b, 2, 6-diformyl-4-tert-butylphenol 3c) under high dilute condition in refluxing anhydrous ethanol in 65-70% yield.

  19. Heteroatom-free arene-cobalt and arene-iron catalysts for hydrogenations.

    Science.gov (United States)

    Gärtner, Dominik; Welther, Alice; Rad, Babak Rezaei; Wolf, Robert; Jacobi von Wangelin, Axel

    2014-04-01

    75 years after the discovery of hydroformylation, cobalt catalysts are now undergoing a renaissance in hydrogenation reactions. We have evaluated arene metalates in which the low-valent metal species is--conceptually different from heteroatom-based ligands--stabilized by π coordination to hydrocarbons. Potassium bis(anthracene)cobaltate 1 and -ferrate 2 can be viewed as synthetic precursors of quasi-"naked" anionic metal species; their aggregation is effectively impeded by (labile) coordination to the various π acceptors present in the hydrogenation reactions of unsaturated molecules (alkenes, arenes, carbonyl compounds). Kinetic studies, NMR spectroscopy, and poisoning studies of alkene hydrogenations support the formation of a homogeneous catalyst derived from 1 which is stabilized by the coordination of alkenes. This catalyst concept complements the use of complexes with heteroatom donor ligands for reductive processes. PMID:24616276

  20. Functioned Calix[4]arenes as Artificial Enzymes Catalyze Aldol Condensation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Aldolase models derived from calix[4]arene were designed and synthesized. The aldol condensation of p-nitrobenzaldehyde with acetone was catalyzed by the synthetic enzymes proceeded under mild conditions to offer chiefly aldol-type product in good yield.

  1. Synthesis of a New Type Tetraamides Bridged Calix[4]arene

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two new tetraamides bridged calix[4]arenes were synthesized by the condensation reaction of 1,3-bis-chlorocarbonylmethyl p-tert-butylcalix[4]arene with 1,2-bis (2,-amino- 2,-methylpropanamido)benzene or 1,2-bis (2,-amino-2,- methylpropanamido) -4,5- dichloro benzene, respectively. The new compounds were characterized by 1H-NMR, MS-FAB, and elemental analysis; macrocyclic polyamine.

  2. Fifty years of oxacalix[3]arenes: A review

    Directory of Open Access Journals (Sweden)

    Kevin Cottet

    2012-02-01

    Full Text Available Hexahomotrioxacalix[3]arenes, commonly called oxacalix[3]arenes, were first reported in 1962. Since then, their chemistry has been expanded to include numerous derivatives and complexes. This review describes the syntheses of the parent compounds, their derivatives, and their complexation behaviour towards cations. Extraction data are presented, as are crystal structures of the macrocycles and their complexes with guest species. Applications in fields as diverse as ion selective electrode modifiers, fluorescence sensors, fullerene separations and biomimetic chemistry are described.

  3. Calix[4]arenes in the 1,3-alternate conformation

    OpenAIRE

    Dordea, Crenguta

    2006-01-01

    Calix[4]arenes fixed in the 1,3-alternate conformation offer an interesting platform for the attachment of further functionalities which has been less frequently used than the cone conformer. Several synthetic strategies were developed to attach four amino functions to the narrow rim, to the wide rim and to both rims of the calix[4]arene fixed in the 1,3-alternate conformation. Using different precursor groups (nitrile/phthalimide or nitro/phthalimide) which can be independently converted int...

  4. Chiral Supramolecular Chemistry of Basket Resorc[4]arenes

    OpenAIRE

    Calcaterra, Andrea

    2013-01-01

    Chiral Basket Resorc[4]arenes are well known chiral solvating agents that can induce enantiodiscrimination towards aminoacids, peptides and nucleosides. We synthesized both enantiomer of some basket resorc[4]arenes capable of forming stable diasteromeric host-guest complexes with some nucleosides like cytidine and cytarabine. The reactivity and the structures of the complexes were investigated in gas-phase (ESI-IRMPD, ESI-FT-ICR) and in solution (DOSY, ROESY). Different "in" and "out" struct...

  5. New arene ruthenium complexes with planar chirality

    OpenAIRE

    Therrien, Bruno; Süss-Fink, Georg

    2009-01-01

    1,2,4-Trimethyl-cyclohexadiene reacts with RuCl3 • nH2O in refluxing ethanol to afford quantitatively [RuCl2(1,2,4-C6H3Me3)]2 (1), the coordination of 1,2,4-trimethylbenzene to the ruthenium atom introducing planar chirality at the η6-arene ligand. The dinuclear complex 1 reacts with two equivalents of triphenylphosphine (PPh3) to give quantitatively, as a racemic mixture of enantiomers, [RuCl2(1,2,4-C6H3Me3)(PPh3)] (2), the structure of which has been determined by a single-crystal X-ray str...

  6. Annelation of furan rings to arenes

    Science.gov (United States)

    Omelchuk, O. A.; Tikhomirov, A. S.; Shchekotikhin, A. E.

    2016-08-01

    Benzo[b]furans have been used in various fields of chemistry and technology due to their unique physical, chemical and biological properties. It is primarily a wide range of biological activities of natural and synthetic benzo[b]furan derivatives and their polyfused analogues (naphthofurans, anthrafurans, etc.) that attracts a significant scientific interest in the context of using these heterocycles as privileged scaffolds in drug design. This survey covers those methods for the annelation of a furan ring to arenes that have been developed mostly during the last decade. We also analyze trends in synthetic methods of benzo[b]furans. Some synthetic schemes are highly efficient in the synthesis of polyfunctionalized furan derivatives. The bibliography includes 110 references.

  7. From Pillar[n]arene Scaffolds for the Preparation of Nanomaterials to Pillar[5]arene-containing Rotaxanes.

    Science.gov (United States)

    Nierengarten, Iwona; Deschenaux, Robert; Nierengarten, Jean-François

    2016-01-01

    Pillar[n]arenes are a new class of macrocycles that are efficiently prepared from readily available building blocks. In this particular field, our research teams became interested in the use of a pillar[5]arene core as a compact scaffold for the synthesis of nanomaterials with a controlled distribution of functional groups on both rims of the macrocyclic framework. Such compounds have found applications in biology as multivalent ligands for specific lectines or as polycationic compounds for gene delivery. Liquid-crystalline derivatives have been prepared by grafting mesogenic subunits on the pillar[5]arene core. On the other hand, we also became interested in the preparation of pillar[5]arene-containing [2]rotaxanes. In particular, we have shown that pillar[5] arene-based [2]rotaxanes can be obtained from the reaction of amine stoppers with pseudo-rotaxanes resulting from the association of a pillar[5]arene derivative with a diacyl chloride reagent. Finally, amphiphilic [2]rotaxanes have been prepared and incorporated in thin ordered films at the air-water interface. PMID:26931219

  8. Study: Ex-NFL Players Aren't At Greater Risk for Suicide

    Science.gov (United States)

    ... NFL Players Aren't at Greater Risk for Suicide Rate was lower than would be expected among ... football players aren't at greater risk of suicide than the general U.S. population, federal health officials ...

  9. Exploring new avenues for Arene-Ruthenium complexes: coordination to [60]fullerene, hydrogen bonding assemblies and liquid-crystalline materials

    OpenAIRE

    Appavoo-Gupta, Divambal; Deschenaux, Robert

    2016-01-01

    The thesis aims at using arene-ruthenium complexes as building blocks for the synthesis of diverse compounds to obtain potential mesomorphic and/or biological properties. The thesis consists of three main projects. The first project deals with supramolecular assemblies. New supramolecular di- and tetranuclear ruthenium arrangements, the latter bearing a cavity, were designed. H-bonding was the key interaction involved in the synthesis of the spacer ligands, which exist as dimers. Different s...

  10. An asymmetric trihydrido-bridged arene ruthenium complex

    OpenAIRE

    Vieille-Petit, Ludovic; Therrien, Bruno; Süss-Fink, Georg

    2009-01-01

    Reaction of [Ru(η6-indane)(H2O)3]2+ and [Ru(η6-C6Me6)(H2O)3]2+ with NaBH4 in water gives a mixture of three triple hydrido-bridged arene ruthenium cations [(η6-arene)Ru(μ-H)3Ru(η6-arene′)]+ (arene=indane and hexamethylbenzene; arene′=indane and hexamethylbenzene). After treatment with NaBF4, the three complexes are separated by column chromatography and the asymmetrical [(η6-indane)Ru(μ-H)3Ru(η6-C6Me6)][BF4] (cation 1a) can be isolated in moderate yield. 1a decomposes in solution to give the ...

  11. Spatially Directional Resorcin[4]arene Cavitand Glycoconjugates for Organic Catalysis.

    Science.gov (United States)

    Husain, Ali A; Maknenko, Arthur M; Bisht, Kirpal S

    2016-04-25

    The synthesis of novel spatially directional multivalent resorcin[4]arene cavitand glycoconjugates (RCGs) and their ability to catalyze organic reactions is reported. The β-d-glucopyranoside moieties on the upper rim of the "bowl"-shaped resorcin[4]arene cavitand core are capable of multiple hydrogen-bond interactions resulting in a pseudo-cavity, which has been investigated for organic transformations in aqueous media. The RCGs have been demonstrated to catalyze thiazole formation, thiocyanation, copper(I)-catalyzed azide alkyne cycloaddition (CuAAC), and Mannich reactions; they impart stereoselectivity in the three-component Mannich reaction. Thermodynamic values obtained from (1) H diffusion-ordered spectroscopy (DOSY) experiments suggest that the upper saccharide cavity of the RCG and not the resorcin[4]arene cavity is the site of the complexation event.

  12. Molecular Recognition of Natural Products by Resorc[4]arene Receptors.

    Science.gov (United States)

    D'Acquarica, Ilaria; Ghirga, Francesca; Quaglio, Deborah; Cerreto, Antonella; Ingallina, Cinzia; Tafi, Andrea; Botta, Bruno

    2016-01-01

    This review is aimed at providing an overview of the up-to-now published literature on resorc[4]arene macrocycles exploited as artificial receptors for the molecular recognition of some classes of natural products. A concise illustration of the main synthetic strategies developed to afford the resorc[4]arene scaffold is followed by a report on the principles of the gas-phase investigation of recognition phenomena by mass spectrometry (MS). Emphasis is placed on gas-phase studies of diastereoisomeric complexes generated inside a Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometer by resorc[4]arene receptors towards a series of natural products, namely amino acids, amphetamine, ethanolamine neurotransmitters, dipeptides, vinca alkaloids and nucleosides. The literature outcomes discussed here, taken largely from our own revisited work, have been completed by references to other studies, in order to draw a broader picture of this rapidly evolving field of research. PMID:26654589

  13. Valge villa / Karen Jagodin ; kommenteerinud Krista Aren, Emil Urbel

    Index Scriptorium Estoniae

    Jagodin, Karen, 1982-

    2009-01-01

    Villa (623 m² + kelder) Merirahu elamurajoonis Tallinnas. Arhitektid: Emil Urbel, Andrus Mark (AB Emil Urbel OÜ). Sisearhitektid: Krista Aren, Mati Veermets. Inseneriosad: AS Meistri Projekt. Haljastaja: Piret Kukk. Projekt: 2005-2008, valmis: 2009. Villa madalamat osa katab murtud pinnaga graniit, kõrgemat valge krohv

  14. Hydrogen-bonded 1D and 2D Assemblies of Tetra- iso-butyl-resorcin[4]arene in the Crystalline State

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang; LIU Yu-Jie; ZHANG Qian-Feng

    2005-01-01

    X-ray crystal structures of co-crystals involving tetra-iso-butyl-resorcin[4]arene 1 with both acetone and acetonitrile solvents were reported. The component 1(2(CH3)2CO 2 assembles such that the resorcin[4]arene adopts a C2v conformation and the acetone serves as hydrogen bond acceptors, forming a 1D hydrogen-bonded polymer. 2 (C50H68O10) crystallizes in the triclinic, space group P with a = 10.0440(7), b = 13.7498(9), c = 17.6374(12) (A), α = 77.726(2), β = 86.733(2), γ = 88.634(2)°, V = 2376.1(3) (A)3, Dc = 1.159 g/cm3, and Z = 2. The assembly process of component 1(2CH3CN(H2O 3 yields a 2D hydrogen-bonded polymer formed by intermolecular hydrogen bonds between resorcin[4]arene and water molecules. In the case of component 3, the acetonitrile molecule serves as guest inside the bowl of resorcin[4]arene host. 3 (C48H64N2O9) crystallizes in the monoclinic, space group P2/n with a = 13.7570(18), b = 9.0961(12), c = 19.453(3) (A), β = 103.017(3)°, V = 2371.7(5) (A)3, Dc = 1.138 g/cm3, and Z = 2.

  15. Synthesis and Crystal Structure of a Novel Calix [8] arene Ester Derivative

    Institute of Scientific and Technical Information of China (English)

    DaQiangYUAN; RuJiWANG; 等

    2002-01-01

    The synthesis and crystal structure of a novel calix[8] arene ester are reported herein. The calix [8] arene ester derivative has been characterized by IR,NMR and X-ray crystal analysis. The X-ray structure analysis revealed that the 8 phenolic hydroxy groups of the calix [8] arene have been substituted by 4 diethyl dibromomalonate molecules with each two adjacent hydroxy oxygen atoms attached to a bridge diethyl malonate.

  16. Molecular recognition study of Carbamazepine, antiseizure drug, by p-t-butyl calix(8)arene

    Science.gov (United States)

    Meenakshi, C.; Jayabal, P.; Ramakrishnan, V.

    2014-03-01

    The formation of inclusion complex of Carbamazepine, a antiseizure drug molecule, with the supra molecule, p-t-butyl calix(8)arene was studied. p-t-Butyl calix(8)arene was the host molecule and Carbamazepine was the guest molecule. Optical absorption spectral studies were carried out to study the molecular recognition properties of p-t-butyl calix(8)arene with Carbamazepine. The stochiometry of the host-guest complex and the binding constant were determined.

  17. Nanoscaled carborane ruthenium(II)-arene complex inducing lung cancer cells apoptosis

    OpenAIRE

    Yan Hong; Ye Hongde; Wu Chunhui; Zhang Gen; Wang Xuemei

    2011-01-01

    Abstract Background The new ruthenium(II)-arene complex, which bearing a carborane unit, ruthenium and ferrocenyl functional groups, has a novel versatile synthetic chemistry and unique properties of the respective material at the nanoscale level. The ruthenium(II)-arene complex shows significant cytotoxicity to cancer cells and tumor-inhibiting properties. However, ruthenium(II)-arene complex of mechanism of anticancer activity are scarcely explored. Therefore, it is necessary to explore rut...

  18. Self-assembled monolayers of calix[4]arene derivatives on gold

    NARCIS (Netherlands)

    Huisman, Bart-Hendrik; Thoden van Velzen, Eggo U.; Veggel, van Frank C.J.M.; Engbersen, Johan F.J.; Reinhoudt, David N.

    1995-01-01

    Dialkylsulfide substituted calix[4]arenes were synthesized and adsorbed onto gold substrates. Infrared spectroscopy, thickness, and wettability studies revealed that well-ordered monolayers were formed.

  19. Enantioselective molecular sensing of aromatic amines using tetra-(S)-di-2-naphthylprolinol calix[4]arene.

    Science.gov (United States)

    Jennings, K; Diamond, D

    2001-07-01

    This paper presents new analytical data, and evidence of the fluorescence quenching mechanism involved in enantioselective signals obtained with the chiral host tetra-(S)-di-2-naphthylprolinol calix[4]arene. Excellent selectivity is obtained with phenylglycinol and norephidrine in methanol, and samples of unknown enantiomeric composition have been determined with an average error of 1.08 and 0.62%, respectively (n = 6), on the basis of a single fluorescence measurement. The absence of any quenching observed with the related amines of phenylalaninol is attributed to a methylene spacer which inhibits efficient interaction between the aryl group of the guest and the naphthyl group of the host. The importance of the phenyl group of the guest in the quenching mechanism is confirmed by the complete absence of any quenching effect with cyclohexylethylamine. PMID:11478636

  20. Calix[4]arene-Based New Neutral Sensors for Fluoride

    Institute of Scientific and Technical Information of China (English)

    LIU,Shun-Ying; MENG,Ling-Zhi; LIU,Xin; HE,Yong-Bing

    2004-01-01

    @@ The development of new receptors which can recognize neutral and charged species has attracted considerable interest in the recent past.[1] Anions such as fluoride, chloride, phosphate and carboxylate play crucial roles in a range of biological phenomena and are implicated in many disease states.[2] Investigations on molecular and/or ionic recognition by calixarenes and their derivatives as synthetic receptors have attracted increasing attention in supramolecular chemistry because of their modifiable structure.[3] However, calix[4]arenes-based neutral receptors containing thiourea and amide groups are still rare. In this paper, we report fluoride selective optical chemosensors 4 and 5, based on calix[4]arene thiourea and amide derivatives, which only show a remarkable absorption change in the presence of fluoride ions, while have no any change upon addition of other anions (Cl- Br-, I-, AcO- and H2PO4-). The association constants are 947 and 2883 mol·L-1, respectively. The synthesis of calix[4]arene derivatives 4 and 5 is outlined in the following Scheme 1.

  1. Theoretical investigation on the molecular inclusion process of prilocaine into p-sulfonic acid calix[6]arene

    Science.gov (United States)

    de Sousa, Sara M. R.; Fernandes, Sergio A.; De Almeida, Wagner B.; Guimarães, Luciana; Abranches, Paula A. S.; Varejão, Eduardo V. V.; Nascimento, Clebio S., Jr.

    2016-02-01

    The present letter reports, for the first time, results from a theoretical analysis of the inclusion process involving the prilocaine into the p-sulfonic acid calix[6]arene. Structure and stabilization energies were calculated, in both gas and aqueous phases, using a sequential methodology based on semiempirical and Density Functional Theory (DFT) calculations. From the results, a qualitative structure property relationship could be established with some main structural features being relevant for inclusion complex stabilization: (i) the hydrogen bonds established between guest and host molecules, (ii) the dispersion effect and (iii) the inclusion mode of guest molecule into the host cavity.

  2. Binding properties of oxacalix[4]arenes derivatives toward metal cations; Interactions entre cations metalliques et derives des oxacalix[4]arenes

    Energy Technology Data Exchange (ETDEWEB)

    Mellah, B

    2006-11-15

    The objective of this work was to establish the binding properties of oxacalix[4]arene derivatives with different numbers of the oxa bridges, functional groups (ketones, pyridine, ester, amide and methoxy) and conformations. Their interactions with alkali and alkaline-earth, heavy and transition metal cations have been evaluated according to different approaches: (i) extraction of corresponding picrates from an aqueous phase into dichloromethane; (ii) determination of the thermodynamic parameters of complexation in methanol and/or acetonitrile by UV-spectrophotometry and micro-calorimetry; (iii) determination of the stoichiometry of the complexes by ESI-MS; (iv) {sup 1}H-NMR titrations allowing to localize the metal ions in the ligand cavity. In a first part dealing on homo-oxacalix[4]arenes, selectivities for Na{sup +}, K{sup +}, Ca{sup 2+}, Pb{sup 2+} and Mn{sup 2+} of ketones derivatives was shown. The presence of oxa bridge in these derivatives increases their efficiency while decreasing their selectivity with respect to related calixarenes. The pyridine derivative prefers transition and heavy metal cations, in agreement with the presence of the soft nitrogen atoms. In the second part, di-oxacalix[4]arene ester and secondary amide derivatives were shown to be less effective than tertiary amide counterparts but to present high selectivities for Li{sup +}, Ba{sup 2+}, Zn{sup 2+} and Hg{sup 2+}. A third part devoted to the octa-homo-tetra-oxacalix[4]arene tetra-methoxy shows that the 1:1 metal complexes formed are generally more stable than those of calixarenes, suggesting the participation of the oxygen atoms of the bridge in the complexation. Selectivity for Cs{sup +}, Ba{sup 2+}, Cu{sup 2+} and Hg{sup 2+} were noted. (author)

  3. Inventarisasi dan Pemanfaatan Aren (Arenga pinnata Merr) oleh Masyarakat Sekitar Hutan (Studi Kasus Desa Sihombu, Kecamatan Tarabintang,

    OpenAIRE

    Damanik, Rionaldo

    2014-01-01

    Aren (A. pinnata) are included in the arecaceae (areca nut) and are included in the inclosed seed plants (angiospermae). Aren is a forest plant that has many benefits but is not yet used by forest communities widely. The purpose of this study is to elevate the potential, distribution and utilization of aren. This research was using compartment sampling with compartment strip technique. The result showed that optimal growth of aren in elevate 550-560 mdpl and the utilization ...

  4. Calix[4]arene Based Single-Molecule Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Karotsis, Georgios; Teat, Simon J.; Wernsdorfer, Wolfgang; Piligkos, Stergios; Dalgarno, Scott J.; Brechin, Euan K.

    2009-06-04

    Single-molecule magnets (SMMs) have been the subject of much interest in recent years because their molecular nature and inherent physical properties allow the crossover between classical and quantum physics to be observed. The macroscopic observation of quantum phenomena - tunneling between different spin states, quantum interference between tunnel paths - not only allows scientists to study quantum mechanical laws in great detail, but also provides model systems with which to investigate the possible implementation of spin-based solid state qubits and molecular spintronics. The isolation of small, simple SMMs is therefore an exciting prospect. To date almost all SMMs have been made via the self-assembly of 3d metal ions in the presence of bridging/chelating organic ligands. However, very recently an exciting new class of SMMs, based on 3d metal clusters (or single lanthanide ions) housed within polyoxometalates, has appeared. These types of molecule, in which the SMM is completely encapsulated within (or shrouded by) a 'protective' organic or inorganic sheath have much potential for design and manipulation: for example, for the removal of unwanted dipolar interactions, the introduction of redox activity, or to simply aid functionalization for surface grafting. Calix[4]arenes are cyclic (typically bowl-shaped) polyphenols that have been used extensively in the formation of versatile self-assembled supramolecular structures. Although many have been reported, p-{sup t}But-calix[4]arene and calix[4]arene (TBC4 and C4 respectively, Figure 1A) are frequently encountered due to (a) synthetic accessibility, and (b) vast potential for alteration at either the upper or lower rim of the macrocyclic framework. Within the field of supramolecular chemistry, TBC4 is well known for interesting polymorphic behavior and phase transformations within anti-parallel bi-layer arrays, while C4 often forms self-included trimers. The polyphenolic nature of calix[n]arenes (where

  5. Influence of the π-coordinated arene on the anticancer activity of ruthenium(II) carbohydrate organometallic complexes

    NARCIS (Netherlands)

    Hanif, Muhammad; Meier, Samuel M; Nazarov, Alexey A; Risse, Julie; Legin, Anton; Casini, Angela; Jakupec, Michael A; Keppler, Bernhard K; Hartinger, Christian G

    2013-01-01

    The synthesis and in vitro cytotoxicity of a series of Ru(II)(arene) complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well

  6. Inter-rater reliability of surgical reviews for AREN03B2: A COG renal tumor committee study✩

    Science.gov (United States)

    Hamilton, Thomas E.; Barnhart, Douglas; Gow, Kenneth; Ferrer, Fernando; Kandel, Jessica; Glick, Richard; Dasgupta, Roshni; Naranjo, Arlene; He, Ying; Gratias, Eric; Geller, James; Mullen, Elizabeth; Ehrlich, Peter

    2014-01-01

    Purpose The Children's Oncology Group (COG) renal tumor study (AREN03B2) requires real-time central review of radiology, pathology, and the surgical procedure to determine appropriate risk-based therapy. The purpose of this study was to determine the inter-rater reliability of the surgical reviews. Methods Of the first 3200 enrolled AREN03B2 patients, a sample of 100 enriched for blood vessel involvement, spill, rupture, and lymph node involvement was selected for analysis. The surgical assessment was then performed independently by two blinded surgical reviewers and compared to the original assessment, which had been completed by another of the committee surgeons. Variables assessed included surgeon-determined local tumor stage, overall disease stage, type of renal procedure performed, presence of tumor rupture, occurrence of intraoperative tumor spill, blood vessel involvement, presence of peritoneal implants, and interpretation of residual disease. Inter-rater reliability was measured using the Fleiss' Kappa statistic two-sided hypothesis tests (Kappa, p-value). Results Local tumor stage correlated in all 3 reviews except in one case (Kappa = 0.9775, p stratagem for multimodal cancer therapy. PMID:24439601

  7. Studies on the Synthesis and Property of A New Podand-armed Calix[4]arene Derivative

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new ligand 25, 26, 27, 28-tetrakis[2-(o-methoxyphenoxy)ethoxy]calix[4]arene 3 was synthesized by direct base-strength-driven O-alkylation of calix[4]arene 1.3 has been used as ionophore for cesium selective PVC membrane electrode.The extraction for cesium and sodium with 3 have been also studied.

  8. Versatile coordination of cyclopentadienyl-arene ligands and its role in titanium-catalyzed ethylene trimerization

    NARCIS (Netherlands)

    Otten, Edwin; Batinas, Aurora A.; Meetsma, Auke; Hessen, Bart

    2009-01-01

    Cationic titanium(IV) complexes with ansa-(eta(5)-cyclopentadienyl,eta(6)-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C, bridge between

  9. Arylative Desulfonation of Diarylmethyl Phenyl Sulfone with Arenes Catalyzed by Scandium Triflate.

    Science.gov (United States)

    Nambo, Masakazu; Ariki, Zachary T; Canseco-Gonzalez, Daniel; Beattie, D Dawson; Crudden, Cathleen M

    2016-05-20

    A scandium-triflate-catalyzed arylative desulfonation of diarylmethyl phenyl sulfones with arenes and heteroarenes was established. A variety of both sulfone and arene substrates were reacted to afford symmetric and nonsymmetric triarylmethanes in good yields. Further transformations of the resulting triarylmethanes and application to the concise synthesis of a bactericidal agent analogue were also demonstrated. PMID:27124389

  10. Synthesis of deep-cavity fluorous calix[4]arenes as molecular recognition scaffolds

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available Several lower-rim perfluoroalkylated (fluorous calix[4]arenes have been synthesized by O-alkylation of the parent calix[4]arene. The compounds are formed in the cone conformation. They are soluble in several fluorous solvents and show promise for use in sensing, selective extractions and other applications.

  11. Buchner and Beyond: Arene Cyclopropanation as Applied to Natural Product Total Synthesis

    OpenAIRE

    Reisman, Sarah E.; Nani, Roger R.; Levin, Sergiy

    2011-01-01

    Buchner and Curtius first reported the cyclopropanation of arenes in 1885. Since the initial discovery, the Buchner reaction has been the subject of significant research by both physical and synthetic organic chemists. Described herein is a brief overview of the Buchner reaction and related arene cyclopropanation processes, with an emphasis on their application to natural product total synthesis.

  12. Cellular delivery of pyrenyl-arene ruthenium complexes by a water-soluble arene ruthenium metalla-cage.

    Science.gov (United States)

    Furrer, Mona Anca; Schmitt, Frédéric; Wiederkehr, Michaël; Juillerat-Jeanneret, Lucienne; Therrien, Bruno

    2012-06-28

    Three pyrenyl-arene ruthenium complexes (M(1)-M(3)) of the general formula [Ru(η(6)-arene-pyrenyl)Cl(2)(pta)] (pta = 1,3,5-triaza-7-phosphaadamantane) have been synthesised and characterised. Prior to the coordination to ruthenium, pyrene was connected to the arene ligand via an alkane chain containing different functional groups: ester (L(1)), ether (L(2)) and amide (L(3)), respectively. Furthermore, the pyrenyl moieties of the M(n) complexes were encapsulated within the hydrophobic cavity of the water soluble metalla-cage, [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) (tpt = 2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; donq = 5,8-dioxydo-1,4-naphthoquinonato), while the arene ruthenium end was pointing out of the cage, thus giving rise to the corresponding host-guest systems [M(n)⊂Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) ([M(n)⊂cage](6+)). The antitumor activity of the pyrenyl-arene ruthenium complexes (M(n)) and the corresponding host-guest systems [M(n)⊂cage][CF(3)SO(3)](6) were evaluated in vitro in different types of human cancer cell lines (A549, A2780, A2780cisR, Me300 and HeLa). Complex M(2), which contains an ether group within the alkane chain, demonstrated at least a 10 times higher cytotoxicity than the reference compound [Ru(η(6)-p-cymene)Cl(2)(pta)] (RAPTA-C). All host-guest systems [M(n)⊂cage](6+) showed good anticancer activity with IC(50) values ranging from 2 to 8 μM after 72 h exposure. The fluorescence of the pyrenyl moiety allowed the monitoring of the cellular uptake and revealed an increase of uptake by a factor two of the M(2) complex when encapsulated in the metalla-cage [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+). PMID:22506276

  13. Synthesis and Structure of Novel Double Flexible Spacer BridgedBiscalix [4] arenes

    Institute of Scientific and Technical Information of China (English)

    ZENG, Xian-Shun; WENG, Lin-Hong; CHEN,Lang-Xing; JU, Hong-Fang; LENG, Xue-Bing; HE, Xi-Wen

    2001-01-01

    25,25′ ,27,27′-Bis ( 1,3-dioxypropane ) -bis (5,11,17,23-tetratert-butylcalix[4]arene-26,28-diol) (4) and 25,25′,27,27′-bis( 1, 4-dioxybutane)-bis (5, 11, 17, 23-tetra-tert-butylcalix[4]arene-26,28-diol) (5) were synthesized by the reaction of p-tert-butylcalix[4]arene (1) with preorganized 25,27-bis(3-bromoproxyl)calix[4]arene-26,27-diol (2) and 25,27-bis(3-bromobutoxyl)calix[4]arene-26,27-diol (3) in the presence of K2CO3 and KI. Compounds 4 and 5 were characterized with X-ray analysis and the selectivity of 4 and 5 to ward K + over other alkali metal ions, alkaline metal ions as well as NH4 + were investigated with an ion-selective electrode.

  14. Rational Design of Cesium-Selective Ionophores and Chemosensors: Dihydrocalix[4]arene Crown-6 Ethers

    Energy Technology Data Exchange (ETDEWEB)

    Sachleben, Richard A.; Bryan, Jeffrey C.; Brown, Gilbert M.; Engle, Nancy L.; Haverlock, Tamara J.; Hay, Benjamin P.; Urvoas, Agathe; Moyer, Bruce A.

    2003-12-15

    Molecular mechanics calculations performed on calix[4]arene crown-6 ethers predict that the 1,3-dihydro derivatives will exhibit greater complementarity for potassium and cesium ions than the parent 1,3-dialkoxy calix crowns. The X-ray crystal structures of 1,3-alt bis-octyloxycalix[4]arene benzocrown-6 ether, dihydrocalix[4]arene benzocrown-6 ether, and the cesium nitrate complex of dihydrocalix[4]arene benzocrown-6 ether were determined. The cesium complex structure corresponds closely to the structure predicted by molecular mechanics. The dihydrocalix[4]arene crown-6 ethers exhibit enhanced cesium selectivity in the extraction of alkali metal salts and provide a platform for a highly sensitive and selective cesium chemosensor.

  15. Characterization of a sensitive and selective copper optode based on β-ketoimine modified calix[4]arene derivative

    Energy Technology Data Exchange (ETDEWEB)

    Rouis, A., E-mail: rouisahlem2@yahoo.fr [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia); Echabaane, M.; Sakly, N. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Institut de Chimie and Biochimie Moléculaires and Supramoléculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Université Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ben Ouada, H. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia)

    2015-01-01

    In this paper, an optical sensor was proposed for sensitive determination of copper (II) ions in aqueous solution. The sensing membrane was prepared by coating β-ketoimine calix[4]arene derivative as ionophore on a glass plate surface. Thin β-ketoimine calix[4]arene layer was characterized by contact angle measurements showing a good surface coverage. Besides, a smooth and homogeneous morphology of the calixarene membrane was examined by atomic force microscopy (AFM). The response of the optode is based on the decrease in the absorbance signal at 309 nm upon exposure to buffer solutions containing Cu{sup 2+} ions. At a pH 6.8, the proposed sensor displays a calibration response for copper over a wide concentration range of 1.0 × 10{sup −7} M to 1.0 × 10{sup −4} M with a detection limit of 2.0 × 10{sup −8} M and response time of 7–10 min. This optode exhibits good selectivity toward copper ions in comparison with common ions including Hg{sup 2+} and Ag{sup +} ions. The copper sensing film can be regenerated using 0.01 M HNO{sub 3} solution. In addition to its high stability, repeatability and reproducibility, the sensor shows operational life time of 4 weeks. - Highlights: • Optical sensor for Cu{sup 2+} ion based on β-ketoimine calix[4]arene was developed. • Sensing mechanism involved the formation of a complex between calixarene and Cu{sup 2+}. • Satisfactory analytical sensing characteristics for determining Cu{sup 2+} were obtained.

  16. PLODNOST HRVATSKE ŠARENE KOZE I PORODNA MASA JARADI

    OpenAIRE

    Beran, Mirna; Mioč, Boro; Barać, Zdravko; Vnučec, Ivan; Prpić, Zvonimir; Pavić, Vesna; Kasap, A.

    2011-01-01

    Hrvatska šarena koza je autohtona pasmina koja je nastala i uzgaja se na području hrvatskoga krša. Uglavnom je namijenjena za proizvodnju mesa, ponajviše visokokvalitetnih jarećih trupova. S obzirom da je reprodukcija osnova proizvodnje mesa, cilj ovog istraživanja bio je utvrditi određene reprodukcijske odlike hrvatske šarene koze (plodnost koza, veličinu legla, porodnu masu jaradi, omjer spolova) kao preduvjete učinkovitosti pasmine u proizvodnji mesa. Predmetno istraživanje obuhvaćalo je u...

  17. Relationship Between Structures and Reactivity of Polycyclic Arenes Toward Hydrogenation

    Institute of Scientific and Technical Information of China (English)

    倪中海; 张丽芳; 袁新华; 宗志敏; 魏贤勇

    2002-01-01

    Hydrogenation reactions of polycyclic arenes (Pas) were car ried out in the presence of Ni and sulfur at 300 ℃ to examine the structuralef fect of Pas on their reactivities toward hydrogenation. Hydrogen was observed to be transferred preferentially to some fixed positions in Pas and different Pas displayed some difference in hydrogenation reactivity. The results can be inte rpreted on the hydrogen-accepting ability of carbon atoms from different positi ons in Pas and the resonance stability of aryl radicals resulting from H-atom a ddition as well as the adsorption strength of Pas on catalyst surface.

  18. Nanoscaled carborane ruthenium(II-arene complex inducing lung cancer cells apoptosis

    Directory of Open Access Journals (Sweden)

    Yan Hong

    2011-02-01

    Full Text Available Abstract Background The new ruthenium(II-arene complex, which bearing a carborane unit, ruthenium and ferrocenyl functional groups, has a novel versatile synthetic chemistry and unique properties of the respective material at the nanoscale level. The ruthenium(II-arene complex shows significant cytotoxicity to cancer cells and tumor-inhibiting properties. However, ruthenium(II-arene complex of mechanism of anticancer activity are scarcely explored. Therefore, it is necessary to explore ruthenium(II-arene complex mechanism of anticancer activity for application in this area. Results In this study, the ruthenium(II-arene complex could significantly induce apoptosis in human lung cancer HCC827 cell line. At the concentration range of 5 μM-100 μM, ruthenium(II-arene complex had obvious cell cytotoxicity effect on HCC827 cells with IC50 values ranging 19.6 ± 5.3 μM. Additionally, our observations demonstrate that the ruthenium(II-arene complex can readily induce apoptosis in HCC827 cells, as evidenced by Annexin-V-FITC, nuclear fragmentation as well as DNA fragmentation. Treatment of HCC827 cells with the ruthenium(II-arene complex resulted in dose-dependent cell apoptosis as indicated by high cleaved Caspase-8,9 ratio. Besides ruthenium(II-arene complex caused a rapid induction of cleaved Caspase-3 activity and stimulated proteolytic cleavage of poly-(ADP-ribose polymerase (PARP in vitro and in vivo. Conclusion In this study, the ruthenium(II-arene complex could significantly induce apoptosis in human lung cancer HCC827 cell line. Treatment of HCC827 cells with the ruthenium(II-arene complex resulted in dose-dependent cell apoptosis as indicated by high cleaved Caspase-8,9 ratio. Besides ruthenium(II-arene complex caused a rapid induction of cleaved Caspase-3 activity and stimulated proteolytic cleavage of poly-(ADP-ribose polymerase (PARP in vitro and in vivo. Our results suggest that ruthenium(II-arene complex could be a candidate for further

  19. Los peligros volcánicos del Arenal

    Directory of Open Access Journals (Sweden)

    Sjöbohm Castillo, Linda Marie

    2007-06-01

    Full Text Available Este estudio fue realizado con el fin de establecer los riesgos asociados al volcán Arenal y la realización y utilización de los mapas de peligros volcánicos en la planificación de las áreas circundantes. Contiene información histórica de la actividad del volcán. Presenta los objetivos fundamentales de la producción de los mapas. Identifica los tipos de peligros que presenta el volcán en la actualidad y finalmente, informa sobre la construcción de los mapas de peligros volcánicos, tanto el de corto plazo como el de largo plazo This study was developed with the purpose of establishing the risks related to the Arenal Volcano and the development and use of volcanic danger maps in the planning of the areas around. It includes historic information about the volcano activity. It presents the main objective of doing the maps. It identifies the types of dangers the volcano presents in these days. Finally, it informs about the development of volcanic dangers maps, at short and long term

  20. Odd-numbered oxacalix[n]arenes (n = 5, 7): synthesis and solid-state structures.

    Science.gov (United States)

    Van Rossom, Wim; Robeyns, Koen; Ovaere, Magriet; Van Meervelt, Luc; Dehaen, Wim; Maes, Wouter

    2011-01-01

    The critical synthetic access to odd-numbered calix[n]arenes has evidently resulted in less attention for these macrocycles, although specific molecular recognition phenomena have been observed for some of them. A straightforward fragment coupling approach has been designed, applying kinetically controlled nucleophilic aromatic substitution reaction conditions, affording odd-numbered oxacalix[n]arenes (n = 5, 7) selectively in high yields. The solid-state conformational behavior and the oxacalix[n]arene cavity size were explored by single-crystal X-ray diffraction studies.

  1. Formation of upper rim acylated calix[4]arenes using a sacrifici al zinc anode

    OpenAIRE

    Louati, Alain; Vataj, Rame; Gabelica, Valérie; Lejeune, Manuel; MATT, DOMINIQUE

    2005-01-01

    A straightforward electrosynthetic method is described, which allows upper rim acylation of non-p-halogenated calix[4]-arenes. For example, a solution of tetrapropoxycalix[4]arene 4 was electrolysed in the presence of ZnBr2, in an undivided cell fitted with a sacrificial zinc anode using pure acetonitrile as solvent, yielding an organozinc species, which was then treated with acetyl chloride in the presence of a palladium catalyst to afford 5,11-diacety1-25,26,27,28-tetrapropoxycalix[4]arene ...

  2. Bimetallic ruthenium–tin chemistry: Synthesis and molecular structure of arene ruthenium complexes containing trichlorostannyl ligands

    OpenAIRE

    Therrien, Bruno; Thai, Trieu-Tien; Freudenreich, Julien; Süss-Fink, Georg; Shapovalov, Sergey S.; Pasynskii, Alexandr A.; Plasseraud, Laurent

    2012-01-01

    A series of neutral, anionic and cationic arene ruthenium complexes containing the trichlorostannyl ligand have been synthesised from SnCl2 and the corresponding arene ruthenium dichloride dimers [(η6-arene)Ru(μ2-Cl)Cl]2 (arene = C6H6, PriC6H4Me). While the reaction with triphenylphosphine and stannous chloride only gives the neutral mono(trichlorostannyl) complexes [(η6-C6H6)Ru(PPh3)(SnCl3)Cl] (1) and [(η6-PriC6H4Me)Ru(PPh3)(SnCl3)Cl] (2), the neutral di(trichlorostannyl) complex [(η6-PriC6H...

  3. Manganese-Mediated C-H Alkylation of Unbiased Arenes Using Alkylboronic Acids.

    Science.gov (United States)

    Castro, Susana; Fernández, Juan J; Fañanás, Francisco J; Vicente, Rubén; Rodríguez, Félix

    2016-06-27

    The alkylation of arenes is an essential synthetic step of interest not only from the academic point of view but also in the bulk chemical industry. Despite its limitations, the Friedel-Crafts reaction is still the method of choice for most of the arene alkylation processes. Thus, the development of new strategies to synthesize alkyl arenes is a highly desirable goal, and herein, we present an alternative method to those conventional reactions. Particularly, a simple protocol for the direct C-H alkylation of unbiased arenes with alkylboronic acids in the presence of Mn(OAc)3 ⋅2H2 O is reported. Primary or secondary unactivated alkylboronic acids served as alkylating agents for the direct functionalization of representative polyaromatic hydrocarbons (PAHs) or benzene. The results are consistent with a free-radical mechanism. PMID:27124250

  4. Functionalized O6-Corona[6]arenes: Synthesis, Structure, and Fullerene Complexation Property.

    Science.gov (United States)

    Ren, Wen-Sheng; Zhao, Liang; Wang, Mei-Xiang

    2016-07-01

    The synthesis, structure, and fullerene complexation property of novel and functionalized On-corona[n]arenes were reported. Based on the fragment coupling strategy, ester-containing On-corona[n]arenes (n = 6, 8) were obtained readily starting from 1,4-hydroquinone and diethyl 2,5-difluoroterephthalate. Reduction of esters with LiAlH4 produced almost quantitatively hydroxymethylated On-corona[n]arenes, which underwent etherification with MeI to afford methoxymethyl-substituted On-corona[n]arenes (n = 6, 8) in good yields. The macrocycles adopt unique corona-type conformation with a large cylindroid cavity. They are strong macrocyclic host molecules to form 1:1 complexes with fullerenes C60 and C70 in toluene with an associate constant up to (1.59 ± 0.04) × 10(5) M(-1). PMID:27324274

  5. Functionalized O6-Corona[6]arenes: Synthesis, Structure, and Fullerene Complexation Property.

    Science.gov (United States)

    Ren, Wen-Sheng; Zhao, Liang; Wang, Mei-Xiang

    2016-07-01

    The synthesis, structure, and fullerene complexation property of novel and functionalized On-corona[n]arenes were reported. Based on the fragment coupling strategy, ester-containing On-corona[n]arenes (n = 6, 8) were obtained readily starting from 1,4-hydroquinone and diethyl 2,5-difluoroterephthalate. Reduction of esters with LiAlH4 produced almost quantitatively hydroxymethylated On-corona[n]arenes, which underwent etherification with MeI to afford methoxymethyl-substituted On-corona[n]arenes (n = 6, 8) in good yields. The macrocycles adopt unique corona-type conformation with a large cylindroid cavity. They are strong macrocyclic host molecules to form 1:1 complexes with fullerenes C60 and C70 in toluene with an associate constant up to (1.59 ± 0.04) × 10(5) M(-1).

  6. Synthesis and Characterization of Mesoporous Silica Functionalized with Calix[4]arene Derivatives

    Directory of Open Access Journals (Sweden)

    Sana M. Alahmadi

    2012-10-01

    Full Text Available This work reports a new method to covalently attach calix[4]arene derivatives onto MCM-41, using a diisocyanate as a linker. The modified mesoporous silicates were characterized by fourier transform infrared spectroscopy (FTIR, thermal analysis (TGA and elemental analysis. The FTIR spectra and TGA analysis verified that the calix[4]arene derivates are covalently attached to the mesoporous silica. The preservation of the MCM-41 channel system was checked by X-ray diffraction and nitrogen adsorption analysis.

  7. Synthesis and Characterization of Mesoporous Silica Functionalized with Calix[4]arene Derivatives

    OpenAIRE

    Sana M. Alahmadi; Mohamad, Sharifah; Maah, Mohd Jamil

    2012-01-01

    This work reports a new method to covalently attach calix[4]arene derivatives onto MCM-41, using a diisocyanate as a linker. The modified mesoporous silicates were characterized by fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA) and elemental analysis. The FTIR spectra and TGA analysis verified that the calix[4]arene derivates are covalently attached to the mesoporous silica. The preservation of the MCM-41 channel system was checked by X-ray diffraction and nitrogen ads...

  8. Optical, electrical and sensing properties of β-ketoimine calix[4]arene thin films

    Energy Technology Data Exchange (ETDEWEB)

    Echabaane, M., E-mail: mosaab.echabaane@yahoo.fr [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Rouis, A. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Institut de Chimie and Biochimie Moléculaires and Supramoléculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Université Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ben Ouada, H. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia)

    2013-09-16

    Optical, electrical and ion sensing properties of β-ketoimine calix[4]arene thin films have been investigated. These calix[4]arene derivative films exhibit absorption spectra with a resolved electronic structure in the UV–vis and the energy gap was found to be 3.65 eV. Electrical properties of ITO/β-ketoimine calix[4]arene/Al devices have been investigated by I–V characteristics and impedance spectroscopy measurements. The conduction is governed by space-charge-limited current (SCLC) mechanism. The impedance spectroscopy study showed a hopping transport process, a typical behavior of disordered materials. The device was modeled by a single parallel resistor and capacitor network in series with a resistance. The β-ketoimine calix[4]arene was used for the conception of the novel optical chemical sensor and the detection of Cu{sup 2+} ions was monitored by UV–visible spectroscopy. The linear dynamic range for the determination of Cu{sup 2+} has been 10{sup −5}–10{sup −3.7} M with a detection limit of 10{sup −5} M. The characteristics of this optode such as regeneration, repeatability, reproducibility, short-term stability, life time and ion selectivity have been discussed. - Highlights: • We examine optical properties of β-ketoimine calix[4]arene ligand. • We investigate the electric properties of ITO/β-ketoimine calix[4]arene/Al device. • We study the sensing properties of optode films for the detection of copper (II)

  9. Photoinduced C-C Cross-Coupling of Aryl Chlorides and Inert Arenes

    Directory of Open Access Journals (Sweden)

    Lele Wang

    2016-01-01

    Full Text Available Here we report a facile, efficient, and catalyst-free method to realize C-C cross-coupling of aryl chlorides and inert arenes under UV light irradiation. The aryl radical upon homolytic cleavage of C-Cl bond initiated the nucleophilic substitution reaction with inert arenes to give biaryl products. This mild reaction mode can also be applied to other synthetic reactions, such as the construction of C-N bonds and trifluoromethylated compounds.

  10. Structural Determinants of p53-Independence in Anticancer Ruthenium-Arene Schiff-Base Complexes.

    Science.gov (United States)

    Chow, Mun Juinn; Babak, Maria V; Wong, Daniel Yuan Qiang; Pastorin, Giorgia; Gaiddon, Christian; Ang, Wee Han

    2016-07-01

    p53 is a key tumor suppressor gene involved in key cellular processes and implicated in cancer therapy. However, it is inactivated in more than 50% of all cancers due to mutation or overexpression of its negative regulators. This leads to drug resistance and poor chemotherapeutic outcome as most clinical drugs act via a p53-dependent mechanism of action. An attractive strategy to circumvent this resistance would be to identify new anticancer drugs that act via p53-independent mode of action. In the present study, we identified 9 Ru (II)-Arene Schiff-base (RAS) complexes able to induce p53-independent cytotoxicity and discuss structural features that are required for their p53-independent activity. Increasing hydrophobicity led to an increase in cellular accumulation in cells with a corresponding increase in efficacy. We further showed that all nine complexes demonstrated p53-independent activity. This was despite significant differences in their physicochemical properties, suggesting that the iminoquinoline ligand, a common structural feature for all the complexes, is required for the p53-independent activity. PMID:27174050

  11. Krista Aren & Raul Vaiksoo : Krista Aren : "Ühtegi tööd pole võimalik teha natuke" / Gitte Hint

    Index Scriptorium Estoniae

    Hint, Gitte

    2004-01-01

    Disainieriala lõpetanud Krista Aren kodu sisekujundamisest, klientidest, ehitajatest. Krista Arenist (sünd. 1961), tema töödest. Raul Vaiksoost (sünd. 1955), tema töödest. 1989. a. asutas R. Vaiksoo arhitektuuribüroo R. Projekt, kus töötab peaarhitektina. Ill.: foto K. Arenist ja R. Vaiksoost

  12. UTILIZATION OF AREN (Arenga pinnata Merr. SAWMILLING WASTE FOR EDIBLE MUSHROOM CULTIVATION MEDIA

    Directory of Open Access Journals (Sweden)

    Djarwanto

    2016-04-01

    Full Text Available Aren (Arenga pinnata Merr. is a multipurpose tree that can be utilized for palm sugar, alcoholic drinks, beverages and construction wood. The use of aren sawdust has not been studied intensively. This study examines the utilization of aren sawdust as cultivation media for edible mushrooms. Aren sawdust was mixed with rice bran, CaCO3, gypsum, fertilizers and distilled water before sterilization in 30 minutes pressurized autoclave at 1210C and 1.5atm. The mixed media was inoculated with pure cultures containing four mushrooms species (Pleurotus flabellatus, P. ostreatus, P. sajor-caju and Lentinula edodes and incubated for five weeks to allow mycelium growth producing fruit bodies. The fruit bodies were harvested everyday within four months and examined for its gained mushroom-weight and biological conversion efficiency/BE. The core part of aren trunk was cut into smaller pieces of 10 cm (width by 5 cm (thickness, by 120 cm (length. Each core sample was bored from the surface inward, creating holes with a particular distance apart. Each hole was inoculated with pure cultures containing 6 mushroom species (four species above, P. cystidiosus and Auricularia polytricha. The inoculated samples were slanted on bamboo support, and placed in a bamboo hut. Harvesting was carried out everyday after the fruiting body became mature and examined for its gained mushroom weight. Results show that the use of sawdust supplemented with nutritious material is more likely to improve the mushroom yield than that of aren sawn-timber core. In this case, the BE values with aren-sawdust media were 21.97-89.45% (P. flabellatus, 15.36-105.36% (P. ostreatus, 63.88-76.86% (P. sajor-caju, and up to 62.88% (L. edodes. Meanwhile, the yields (gained mushroom weight with aren sawn-timber media were 210g (P. ostreatus, 368g (P. flabellatus, 331g (P. sajor-caju and 48g (A. polytricha; however, P. cystidiosus and L. edodes inoculated on aren stem core failed to grow.

  13. X-ray guided 1H NMR analysis of pinched cone calix[4]arenes

    Science.gov (United States)

    Rashatasakhon, Paitoon; Jaiyu, Arisa; Rojanathanes, Rojrit; Muangsin, Nongnuj; Chaichit, Narongsak; Sukwattanasinitt, Mongkol

    2010-01-01

    The analysis of structural parameters of azobenzene- and stilbene-bridged calix[4]arene obtained from AM1 calculation are in good agreement with those obtained from X-ray crystallography. The bridge longer than 9.0 Å such as p,p- trans-azobenzene and p,p- trans-stilbene cannot be constructed over the narrow rim of calix[4]arene through two ethylene oxide linkers. The m,m-stilbene bridge is the most promising photo switch because its shorter cis stereoisomer (5.85 Å) allows calix[4]arene to assume the perfect cone conformation, whilst its longer trans stereoisomer (8.00 Å) forces calix[4]arene to adapt a pinched cone conformation. The pinched cone conformation has longer distances between the neighbouring phenoxyl groups causing the weaker intramolecular hydrogen bonding and the upfield shifts of the phenolic proton signals to below 7.00 ppm. This upfield shift is useful for quick identification of pinched cone conformation of new calix[4]arene compounds.

  14. Removal of chromate and phosphate anion from aqueous solutions using calix[4]aren receptors containing proton switchable units

    Energy Technology Data Exchange (ETDEWEB)

    Ertul, Seref; Bayrakci, Mevluet [University of Selcuk, Faculty of Science, Department of Chemistry, 42031 Campus, Konya (Turkey); Yilmaz, Mustafa, E-mail: myilmaz42@yahoo.com [University of Selcuk, Faculty of Science, Department of Chemistry, 42031 Campus, Konya (Turkey)

    2010-09-15

    In the present study four new calix[4]arene amide ionophores (4-7) have been prepared by aminolysis of calix[4]arene diester (3) and investigated their extraction ability toward phosphate and dichromate anions at different pH. The {sup 1}H NMR data showed that the synthesized compounds exist in the cone conformation. Liquid-liquid extraction experiments have been performed to evaluate the dichromate and phosphate anions extraction efficiency of both calix[4]arene bearing amide-pyridinium units (4-7) and the calix[4]arene derivative bearing aminomethyl pyridinium units (8, 9). It was observed that, compounds 4-7 exhibited lower affinity toward phosphate ions than the calix[4]arene derivative bearing amine pyridinium units (8, 9). The extraction of phosphate and dichromate anions by these compounds indicates that the partially protonated pyridyl or amino groups play the major role for the formation of hydrogen bonds and electrostatic interactions.

  15. The effect of p-tert-butylcalix[4]arene on radiation degradation of polypropylene

    International Nuclear Information System (INIS)

    Polypropylene(PP) containing cyclic phenolic antioxidant, p-tert-butylcalix[4] arene as additive was irradiated with γ-ray in air or in vacuum at ambient temperature. The mechanical properties, variation of IR spectra and decomposition temperature by thermal analysis were measured for the irradiated PP sheets. Compared with BHT, p-tert-butylcalix[4]arene showed radiation stabilization towards PP during and after irradiation, especially at a high dose. By means of ESR spectra and other spectra of formation of the stable calix[4]arene radical was confirmed. No decomposition species of the calixarene was observed with the dose≤1000 kGy and the dose rate of 6.5 x 103 kGy/h indicating the higher radiation-resistance of the calixarene structure

  16. Highly selective fluorescent chemosensor for Na+ based on pyrene-modified calix[4]arene derivative

    Institute of Scientific and Technical Information of China (English)

    WANG KeRang; GUO DongSheng; JIANG BangPing; LIU Yu

    2009-01-01

    A novel calix[4]arene derivative with pyrene fluorophores at the upper rim and tetraester ionophores at the lower rim was synthesized in six steps, and its structure was proved by NMR and ESi-MS spectro-scopies. Furthermore, the chemosensing behavior of the host compound for alkali and alkaline earth metal ions was investigated by fluorescence spectroscopy. The obtained results show that the calix-arene host can selectively bind sodium ion with the complexation stability constant of 2190 mol-1.L. The complexation with sodium ion can pronouncedly induce the excimer emission to decrease and the monomer emission to increase, whereas the addition of the other alkali and alkaline earth metal ions does not cause appreciable changes in the fluorescence spectrum of the host compound. The present calix[4]arene derivative displays potential application as fluorescent chemosensor for sodium ion.

  17. Molecular recognition study of ethosuximide by the supramolecular probe, p-t-butyl calix(8)arene

    Energy Technology Data Exchange (ETDEWEB)

    Meenakshi, C., E-mail: geethu.laxi@gmail.com [Department of Chemistry, Shri Meenakshi Government College for Women (Autonomous), Madurai 625002 (India); Sangeetha, P.; Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021 (India)

    2013-06-15

    The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule.

  18. Molecular recognition study of ethosuximide by the supramolecular probe, p-t-butyl calix(8)arene

    International Nuclear Information System (INIS)

    The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule

  19. Highly selective fluorescent chemosensor for Na~+ based on pyrene-modified calix[4]arene derivative

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A novel calix[4]arene derivative with pyrene fluorophores at the upper rim and tetraester ionophores at the lower rim was synthesized in six steps,and its structure was proved by NMR and ESI-MS spectro-scopies. Furthermore,the chemosensing behavior of the host compound for alkali and alkaline earth metal ions was investigated by fluorescence spectroscopy. The obtained results show that the calix-arene host can selectively bind sodium ion with the complexation stability constant of 2190 mol-1.L. The complexation with sodium ion can pronouncedly induce the excimer emission to decrease and the monomer emission to increase,whereas the addition of the other alkali and alkaline earth metal ions does not cause appreciable changes in the fluorescence spectrum of the host compound. The present calix[4]arene derivative displays potential application as fluorescent chemosensor for sodium ion.

  20. Removal of uranyl ions by p-hexasulfonated calyx[6]arene acid

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Ioana-Carmen [R and D National Institute for Metals and Radioactive Resources–ICPMRR, B-dul Carol I No.70, Sector 2, Bucharest 020917 (Romania); Petru, Filip [“C.D. Nenitescu” Institute of Organic Chemistry, Splaiul Independentei 202B, Sector 6, Bucharest 71141 (Romania); Humelnicu, Ionel [“Al.I. Cuza” University of Iasi, The Faculty of Chemistry, Bd. Carol-I No. 11, Iasi 700506 (Romania); Mateescu, Marina [National R and D Institute for Chemistry and Petrochemistry, Splaiul Independenţei No. 202, Bucharest 060021 (Romania); Militaru, Ecaterina [R and D National Institute for Metals and Radioactive Resources–ICPMRR, B-dul Carol I No.70, Sector 2, Bucharest 020917 (Romania); Humelnicu, Doina, E-mail: doinah@uaic.ro [“Al.I. Cuza” University of Iasi, The Faculty of Chemistry, Bd. Carol-I No. 11, Iasi 700506 (Romania)

    2014-10-15

    Radioactive pollution is a significant threat for the people’s health. Therefore highly effective radioactive decontamination methods are required. Ion exchange, biotechnologies and phytoremediation in constructed wetlands have been used as radioactive decontamination technologies for uranium contaminated soil and water remediation. Recently, beside those classical methods the calix[n]arenic derivatives’ utilization as radioactive decontaminators has jogged attention. The present work aims to present the preliminary research results of uranyl ion sorption studies on the p-hexasulfonated calyx[6]arenic acid. The effect of temperature, contact time, sorbent amount and uranyl concentration variation on sorption efficiency was investigated. Isotherm models revealed that the sorption process fit better Langmuir isotherm.

  1. Removal of uranyl ions by p-hexasulfonated calyx[6]arene acid

    Science.gov (United States)

    Popescu (Hoştuc), Ioana-Carmen; Petru, Filip; Humelnicu, Ionel; Mateescu, Marina; Militaru, Ecaterina; Humelnicu, Doina

    2014-10-01

    Radioactive pollution is a significant threat for the people’s health. Therefore highly effective radioactive decontamination methods are required. Ion exchange, biotechnologies and phytoremediation in constructed wetlands have been used as radioactive decontamination technologies for uranium contaminated soil and water remediation. Recently, beside those classical methods the calix[n]arenic derivatives’ utilization as radioactive decontaminators has jogged attention. The present work aims to present the preliminary research results of uranyl ion sorption studies on the p-hexasulfonated calyx[6]arenic acid. The effect of temperature, contact time, sorbent amount and uranyl concentration variation on sorption efficiency was investigated. Isotherm models revealed that the sorption process fit better Langmuir isotherm.

  2. The study of p-tert-butylcalix[n]arene on {gamma}-radiation stabilization of polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Feng Wen; Yuan Lihua; Zheng Shiyou; Huang Guanglin [Sichuan Univ., Chengdu (China); Qiao Jinliang [Beijing Research Institute of Chemical Industry, Beijing (China)

    2000-03-01

    The {gamma}-radiation effect of polyropylene was investigated in the presence of three kinds of p-tert-butylcalix[n]arene (n=4,6,8) in air or in vacuum at ambient temperature. The influence of radiation dose and store time upon the mechanical properties of the irradiated PP sheets were measured. The results showed that the radiation stabilization was reduced with the increase of the ring size of calixarenes. Based on the mass spectra and the analysis of post-irradiated product, the mechanism of radiation degradation of p-tert-butylcalix[4]arene has been proposed. (author)

  3. Synthesis and Chiral Recognition of a New Type of Chiral Calix[4]arene Derivatives

    Institute of Scientific and Technical Information of China (English)

    HE,Yong-Bing; LI,Jian-Feng; XIAO,Yuan-Jing; WEI,Lan-Hua; WU,Xiao-Jun; MENG,Ling-Zhi

    2003-01-01

    Two new chiral calix[4] arenes bearing chiral pendants, which were from by-product of the antibiotic industry, were synthesized and characterized by 1H NMR, MS-FAB and elemental analysis. Studies of 1H NMR of the two calix [4] arene derivatives indicate that they exist in cone conformation in solution. Results of chiral recognition of the two chiral ligands 2a and 2b towards the tartaric acid derivative 3 show that ligand 2a exhibited good chiral recognition abilities compared to ligand 2b.

  4. Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases

    Directory of Open Access Journals (Sweden)

    Saeed Taghvaee Ganjali

    2001-03-01

    Full Text Available Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2 is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these ligands indicates their potential for NLO applications.

  5. Arene-ruthenium(II) complexes with hydrophilic P-donor ligands: versatile catalysts in aqueous media.

    Science.gov (United States)

    Crochet, Pascale; Cadierno, Victorio

    2014-09-01

    In the last few years there has been increasing interest in the use of water as a reaction medium for catalysis, and therefore in designing water-soluble transition-metal catalysts. Half-sandwich (η(6)-arene)-ruthenium(ii) complexes are a versatile and well-known family of ruthenium compounds that exhibit a rich catalytic and coordination chemistry. This Perspective article focuses on the catalytic applications in aqueous media of (η(6)-arene)-ruthenium(ii) complexes containing water-soluble phosphines, and related hydrophilic P-donor ligands.

  6. Double Heteroatom Functionalization of Arenes Using Benzyne Three‐Component Coupling†

    Science.gov (United States)

    García‐López, José‐Antonio; Çetin, Meliha

    2015-01-01

    Abstract Arynes participate in three‐component coupling reactions with N, S, P, and Se functionalities to yield 1,2‐heteroatom‐difunctionalized arenes. Using 2‐iodophenyl arylsulfonates as benzyne precursors, we could effectively add magnesiated S‐, Se‐, and N‐nucleophilic components to the strained triple bond. In the same pot, addition of electrophilic N, S, or P reagents and a copper(I) catalyst trapped the intermediate aryl Grignard to produce a variety of 1,2‐difunctionalized arenes. PMID:25580700

  7. Encapsulation of chromen-4-one Schiff's bases by C-Hexylpyrogallol[4]arene and its structure

    Science.gov (United States)

    Chandrasekaran, Sowrirajan; Enoch, Israel V. M. V.

    2015-12-01

    In this paper, we report the encapsulation of Chromen-4-one Schiff's base derivatives with the host molecule C-Hexylpyrogallol[4]arene. The stoichiometry, binding constant, and the mode of association of the guest molecules with C-Hexylpyrogallol[4]arene are investigated by ultraviolet-visible absorption, steady-state and time-resolved fluorescence, and two dimensional Rotating-frame nuclear Overhauser spectroscopic techniques. The stoichiometry of the host-guest complexes is 1:2. The binding constants of the complexes are of the order of 104. The structures of the host-guest complexes are proposed.

  8. Permanent Encapsulation or Host–Guest Behavior of Aromatic Molecules in Hexanuclear Arene Ruthenium Prisms

    OpenAIRE

    Freudenreich, Julien; Barry, Nicolas P. E.; Süss-Fink, Georg; Therrien, Bruno

    2012-01-01

    Cationic arene ruthenium metallaprisms of the general formula [Ru6(p-cymene)6(tpt)2(OO∩OO)3]6+ {tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine; OO∩OO = 9,10-dioxo-9,10-dihydroanthracene-1,4-diolato [1]6+, 6,11-dioxo-6,11-dihydronaphthacene-5,12-diolato [2]6+} have been obtained from the corresponding dinuclear arene ruthenium complexes [Ru2(p-cymene)2(OO∩OO)Cl2] by reaction with tpt and silver trifluoromethanesulfonate. Aromatic molecules (phenanthrene, pyrene, triphenylene, coronene) present dur...

  9. The synthesis and bioevaluation of the dicyclic arene-homospermidine conjugates

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Four novel dicyclic arene-homospermidine conjugates (6a-d) were synthesized and evaluated for cytotoxicity in L1210, α-difluoromethylornithine (DFMO) treated L1210, melanoma B 16, spermidine (SPD) treated B 16, and Hela cells. In the DFMO-treated L1210 experiments, 6a-d were more sensitive to DFMO than naphthalene-homospermidine (6e), suggesting that 6a-d can utilize the polyamine transporter (PAT) to enter the cells as well as 6e. The diminished cytotoxicity in the SPD/B 16 experiments also supported this conclusion. In summary, the homospermidine is an efficacious vector to ferry dicyclic arenes into cells via PAT.

  10. Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

    Science.gov (United States)

    Baghdadi, S; Bouvier-Capely, C; Ritt, A; Peroux, A; Fevrier, L; Rebiere, F; Agarande, M; Cote, G

    2015-11-01

    Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present. The mineralisation protocol is usually based on a wet ashing step, followed by actinides co-precipitation and a furnace ashing step, before redissolution and the quantification of the actinides by the appropriate techniques. Amongst the existing methods to perform the actinides co-precipitation, alkali-earth (typically calcium) precipitation is widely used. In the present work, the extraction of uranium(VI), plutonium(IV) and americium(III) from the redissolution solutions (called "mineralised urines") on calix[6]arene columns bearing hydroxamic groups was investigated as such an extraction is a necessary step before their determination by ICP-MS or alpha spectrometry. Difficulties were encountered in the transfer of uranium(VI) from raw to mineralised urines, with yield of transfer ranging between 0% and 85%, compared to about 90% for Pu and Am, depending on the starting raw urines. To understand the origin of such a difficulty, the speciation of uranium (VI) in mineralised urines was investigated by computer simulation using the MEDUSA software and the associated HYDRA database, compiled with recently published data. These calculations showed that the presence of phosphates in the "mineralised urines" leads to the formation of strong uranyl-phosphate complexes (such as UO2HPO4) which compete with the uranium (VI) extraction by the calix[6]arene bearing hydroxamic groups. The extraction constant of uranium (VI) by calix[6]arene bearing hydroxamic groups was determined in a 0.04 mol L(-1) sodium nitrate solution (logK=4.86±0.03) and implemented in an extraction model taking into account the speciation in the aqueous phase. This model allowed to

  11. Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

    Science.gov (United States)

    Baghdadi, S; Bouvier-Capely, C; Ritt, A; Peroux, A; Fevrier, L; Rebiere, F; Agarande, M; Cote, G

    2015-11-01

    Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present. The mineralisation protocol is usually based on a wet ashing step, followed by actinides co-precipitation and a furnace ashing step, before redissolution and the quantification of the actinides by the appropriate techniques. Amongst the existing methods to perform the actinides co-precipitation, alkali-earth (typically calcium) precipitation is widely used. In the present work, the extraction of uranium(VI), plutonium(IV) and americium(III) from the redissolution solutions (called "mineralised urines") on calix[6]arene columns bearing hydroxamic groups was investigated as such an extraction is a necessary step before their determination by ICP-MS or alpha spectrometry. Difficulties were encountered in the transfer of uranium(VI) from raw to mineralised urines, with yield of transfer ranging between 0% and 85%, compared to about 90% for Pu and Am, depending on the starting raw urines. To understand the origin of such a difficulty, the speciation of uranium (VI) in mineralised urines was investigated by computer simulation using the MEDUSA software and the associated HYDRA database, compiled with recently published data. These calculations showed that the presence of phosphates in the "mineralised urines" leads to the formation of strong uranyl-phosphate complexes (such as UO2HPO4) which compete with the uranium (VI) extraction by the calix[6]arene bearing hydroxamic groups. The extraction constant of uranium (VI) by calix[6]arene bearing hydroxamic groups was determined in a 0.04 mol L(-1) sodium nitrate solution (logK=4.86±0.03) and implemented in an extraction model taking into account the speciation in the aqueous phase. This model allowed to

  12. Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

    International Nuclear Information System (INIS)

    Thin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy) -calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV–visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4]arene thin films based junction were studied by using current–voltage (I–V) characteristics and dielectric spectroscopy technique. I–V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (ε′), dielectric loss (ε″) and loss tangent (tan δ) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix

  13. Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

    Science.gov (United States)

    Rouis, A.; Davenas, J.; Bonnamour, I.; Ben Ouada, H.

    2015-10-01

    Thin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy)-calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV-visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4]arene thin films based junction were studied by using current-voltage (I-V) characteristics and dielectric spectroscopy technique. I-V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (ε‧), dielectric loss (ε″) and loss tangent (tan δ) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix.

  14. Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

    Energy Technology Data Exchange (ETDEWEB)

    Rouis, A., E-mail: rouisahlem2@yahoo.fr [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l’environnement, 5000 Monastir (Tunisia); Davenas, J. [Polymer Materials Engineering Laboratory IMP, UMR CNRS 5223, Université Claude Bernard Lyon 1, 15 boulevard Latarjet, 69622 Villeurbanne (France); Bonnamour, I. [Institut de Chimie & Biochimie Moléculaires & Supramoléculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Université Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ben Ouada, H. [Laboratoire des Interfaces et Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Avenue de l’environnement, 5000 Monastir (Tunisia)

    2015-10-01

    Thin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy) -calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV–visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4]arene thin films based junction were studied by using current–voltage (I–V) characteristics and dielectric spectroscopy technique. I–V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (ε′), dielectric loss (ε″) and loss tangent (tan δ) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix.

  15. Selective single crystal complexation of L- or D-leucine by p-sulfonatocalix[6]arene.

    Science.gov (United States)

    Atwood, Jerry L; Dalgarno, Scott J; Hardie, Michaele J; Raston, Colin L

    2005-01-21

    p-Sulfonatocalix[6]arene, organised in the 'double cone' conformation, has multi-guest capability binding either L- or D-leucine in a single crystal in a bi-layer type arrangement from a racemic mixture of the amino acid. PMID:15645029

  16. Structural Effects on the Langmuir Monolayers of Calix[4]arene Induced by Lower Rim Aromatic Substitution

    Institute of Scientific and Technical Information of China (English)

    HE Wei-Jiang; QIU Lin; LI Jun-Bai; ZHANG Yu; GUO Zi-Jian; ZHU Long-Gen

    2006-01-01

    The Langmuir monolayer properties of lower rim aromatically substituted calix[4]arenes, 5,11,17,23-tetra-tertbutyl-25,27-bis(2-naphth-1'-ylacetylaminoethoxy)-26,28-dihydroxylcalix[4]arene (BNAEC), 5,11,17,23-tetra-tertbutyl-25,27-bis(2-benzoylamino ethoxy)-26,28-dihydroxylcalix[4]arene (BBAEC) and 5,11,17,23-tetra-tert-butyl-25,27-bis(2-cinnamoylaminoethoxy)-26,28-dihydroxylcalix[4]arene (BCAEC), have been studied. Film balance measurements and Brewster angle microscopy (BAM) observation demonstrate that all the compounds can form Langmuir monolayers with different molecular limiting areas. BNAEC or BBAEC monolayer is able to form condensed domains during compression, while BCAEC monolayer can never form condensed domain. BNAEC monolayer is more readily to form condensed domain than BBAEC monolayer. Moreover, BNAEC monolayer can form the total condensed phase during compression even when T=28 ℃, while BBAEC monolayer can not when T> 10 ℃. The results imply that different lower rim aromatic substitutions affect essentially the intermolecular interaction and molecular packing in the monolayer at air/water interface.

  17. Interconnective host-guest complexation of ß-cyclodextrin-calix[4]arene couples

    NARCIS (Netherlands)

    Bugler, Jürgen; Sommerdijk, Nico A.J.M.; Visser, Antonie J.W.G.; Hoek, van Arie; Nolte, Roeland J.M.; Engbersen, Johan F.J.; Reinhoudt, David N.

    1999-01-01

    The two ß-cyclodextrin-calix[4]arene couples 1 and 2 were prepared as sensing molecules for the detection of organic analytes in water. Compounds 1 and 2 are amphiphilic in nature and form aggregates in aqueous solution. Compound 1 forms vesicles both in the absence and in the presence of guest spec

  18. η6-Arene complexes of ruthenium and osmium with pendant donor functionalities

    KAUST Repository

    Reiner, Thomas

    2010-11-01

    Conversion of 4′-(2,5-dihydrophenyl)butanol or N-trifluoroacetyl-2,5- dihydrobenzylamine with MCl3·n H2O (M = Ru, Os) affords the corresponding dimeric η6-arene complexes in good to excellent yields. Under similar reaction conditions, the amine functionalized arene precursor 2,5-dihydrobenzylamine yields the corresponding Ru(II) complex. For osmium, HCl induced oxidation leads to formation of [OsCl6] 2- salts. However, under optimized reaction conditions, conversion of the precursor 2,5-dihydrobenzylamine chloride results in clean formation of η6-arene Os(II) complex. X-ray structures of [(η6- benzyl ammonium)(dmso)RuCl2] and (2,5-dihydrobenzyl ammonium) 4[OsCl6]2confirm the spectroscopic data. High stability towards air and acid as well as enhanced solubility in water is observed for all η6-arene complexes. © 2010 Elsevier B.V. All rights reserved.

  19. Why Aren't Philosophers and Educators Speaking to Each Other? Some Reasons for Hope.

    Science.gov (United States)

    Ellett, Frederick S., Jr.

    2002-01-01

    Responds to Arcilla's article, "Why Aren't Philosophers and Educators Speaking to One Another?" noting complexities that complicate the answer and suggesting that they are indeed communicating if one accepts a broader definition of philosophers and educators. The essay asserts that little educational research and theory has had much influence on…

  20. Thiacalix(4)arene derivatives as radium ionophores: a study on the requirements for Ra2+ extraction

    NARCIS (Netherlands)

    Leeuwen, van Fijs W.B.; Beijleveld, Hans; Velders, Aldrik H.; Huskens, Jurriaan; Verboom, Willem; Reinhoudt, David N.

    2005-01-01

    The synthesis and NOE-based structural characterization is described of thiacalix[4]arene tricarboxylic acid ( 7), thiacalix[4]crown-5 and -6 monocarboxylic acids ( 2 and 5), and the bis(N-methylsulfonyl)thiacalix[4]crowns-5 and -6 ( 4a,b). The 226Ra2+ selectivity coefficients, log(KRaex/KMex), of t

  1. Oxatub[4]arene: a molecular "transformer" capable of hosting a wide range of organic cations.

    Science.gov (United States)

    Jia, Fei; Wang, Hao-Yi; Li, Dong-Hao; Yang, Liu-Pan; Jiang, Wei

    2016-04-14

    The molecular "transformer", oxatub[4]arene, was found to be able to host a wide range of organic cations. The strong binding ability is believed to originate from its four interconvertible and deep-cavity conformers. The binding behavior of such adaptable receptors may provide implications for molecular recognition in nature. PMID:26955919

  2. Benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2

    Institute of Scientific and Technical Information of China (English)

    Cheng Yi Zhang; Xin Qin Gao; Jiang Hua Zhang; Xiao Jun Peng

    2009-01-01

    A highly efficient benzylation of arenes and heteroarenes catalyzed by HfC14/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additionally, the HfO2 can be re-used after the reaction.

  3. Ruthenium(II) arene complexes with oligocationic triarylphosphine ligands: synthesis, DNA interactions and in vitro properties

    NARCIS (Netherlands)

    Snelders, D.J.M.; Casini, A.; Edafe, F.; van Koten, G.; Klein Gebbink, R.J.M.; Dyson, P.J.

    2011-01-01

    The synthesis, DNA binding properties and cytotoxicity of a series of Ru(II)-arene complexes containing oligocationic ammonium-functionalized triarylphosphines, of the type Ru(p-cymene)Cl2(L) (L ¼ oligocationic phosphine), are reported. The complexes are highly charged (the overall charge states bei

  4. One-pot synthesis of arene-fused 2-acylcyclohexenones from propargylic carboxylates

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    From readily available propargylic carboxylates, two sequential transformations―gold-catalyzed tandem reactions and Sc(OTf)3-catalyzed cyclization―in a one-pot process led to the formation of 2-acylcyclohexenones with an electron-rich arene ring fused at the 4,5-positions.

  5. One-pot synthesis of arene-fused 2-acylcyclohexenones from propargylic carboxylates

    Institute of Scientific and Technical Information of China (English)

    CAO SanSan; ZHANG LiMing

    2009-01-01

    From readily available propargylic carboxylates,two sequential transformations-gold-catalyzed tandem reactions and ScOTf3-catalyzed cyclization-in a one-pot process led to the formation of 2-acylcyclohexenones with an electron-rich arene ring fused at the 4,5-positions.

  6. Calix[4]arene supported clusters: a dimer of [Mn(III)Mn(II)] dimers

    DEFF Research Database (Denmark)

    Taylor, Stephanie M; McIntosh, Ruaraidh D; Beavers, Christine M;

    2011-01-01

    Phosphinate ligands allow for the transformation of a calix[4]arene supported [Mn(III)(2)Mn(II)(2)] tetramer cluster motif into an unusual [Mn(III)Mn(II)](2) dimer of dimers; the clusters self-assemble in the crystal to form bi-layer arrays reminiscent of the typical packing of calixarene solvates....

  7. Silver selective electrodes based on thioether functionalized calix[4]arenes as ionophores

    NARCIS (Netherlands)

    Malinowska, Elz˙bieta; Brzozka, Zbigniew; Kasiura, Krzysztof; Egberink, Richard J.M.; Reinhoudt, David N.

    1994-01-01

    Silver selective electrodes based on thioether functionalized calix[4]arenes 1 and 2 as ionophores were investigated. For both ionophores the selectivity coefficients (log kAg,M) were lower than −2.2 for Hg(II) and lower than −4.6 for other cations tested. The best results were obtained with membran

  8. Lead selective electrodes based on thioamide functionalized calix[4]arenes as ionophores

    NARCIS (Netherlands)

    Malinowska, Elz˙bieta; Brzozka, Zbigniew; Kasiura, Krzysztof; Egberink, Richard J.M.; Reinhoudt, David N.

    1994-01-01

    Lead selective electrodes based on a di- and tetrathioamide functionalized calix [4] arene as ionophores were investigated. The Pb(II)-response functions exhibited almost theoretical Nernstian slopes in the activity range 10¿6¿10¿2M of lead ions. For both ionophores a preference for lead over other

  9. Theoretical indications on the relationship between pyrogallol[4]arenes dynamics of assembling and geometry

    Directory of Open Access Journals (Sweden)

    Robert A. Cazar

    2014-05-01

    Full Text Available Pyrogallol[4]arenes are macrocycles with high potential as building blocks for nanocapsules. We theoretically studied the dimeric precursors of 2,8,14,20-tetramethylpyrogallol[4]arene and 2,8,10,14-tetraphenylpyrogallol[4] arene to understand the dynamics of assembly of these compounds, and calculated the potential energy curves along the torsion angle of the (R-pyrogallolCH–(R-pyrogallol dimeric bond at the B3LYP/6-311G(d,p level of theory. We found that the energy barriers for free rotation around the selected bond are 0.00133 Hartrees for the alkyl-substituted dimer and 0.77879 Hartrees for the aryl-substituted dimer. These values imply that the free rotation around the selected bond exists for the first dimer but not for the second one. Because the orientation of the substituent and the pyrogallol ring around this bond are likely to determine the geometry of the final structure, we propose that the alkyl-substituted compound will most likely adopt a crown-shaped geometry whereas the aryl-substituted compound will adopt a chair-shaped geometry. These predictions concur with experimental evidence, which shows that the geometry of pyrogallol[4]arenes depends on the substituents attached to them.

  10. Transition metal cations extraction by ester and ketone derivatives of chromogenic azocalix[4]arenes.

    Science.gov (United States)

    Ak, Metin; Taban, Deniz; Deligöz, Hasalettin

    2008-06-15

    The molecule of azocalix[n]arene is a macrocyclic used effectively in the complexation of the heavy metal pollutants (like silver and mercury). In this work, our main aim is to prepare new chromogenic azocalix[n]arene molecules to elaborate an extractant with high extractant selectivity for metal ions able to detect this type of pollutant. The solvent extraction properties of four acetyls, four methyl ketones and four benzoyls derivatives from azocalix[4]arenes which were prepared by linking 4-ethyl, 4-n-butyl, 4-acetamid anilin and 2-aminothiazol to calix[4]arene through a diazo-coupling reaction, the alkaline earth (Sr2+) and the transition (Ag+, Hg2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Cr3+) metal cations have been determined by extraction studies with metal picrates. Both ketones are better extractants than esters, and show a strong preference for Ag+, while Cu2+ and Cr3+ are the most extracted cation with the esters. Both acetyl and benzoyl esters are good carriers for Ag+ and Hg2+.

  11. Upper rim {alpha}-hydroxy-or {alpha}-amino phosphonic acid derivatives of calix (4) ARENES

    Energy Technology Data Exchange (ETDEWEB)

    Markovsky, L.N.; Kalchenko, V.I.; Solovyov, A.V.; Finocchiaro, P.; Failla, S.; Atamas, L.I.; Consiglio, G.; Tsymbal, I.F. [Institute of Organic Chemistry National Academy of Sciences of Ukraine (Ukraine)

    1998-10-01

    The synthesis and some stereochemical peculiarities of calix (4) arenes bearing at the upper rim of macrocycle alpha-hydroxy or alpha-amino phosphonic acid dialkyl ester fragments are described. The formation of the dimeric associates induced by intermolecular hydrogen bonds CH-OH...O=P has been also studied. (Author) 24 refs.

  12. Microwave-assisted facile and rapid Friedel-Crafts benzoylation of arenes catalysed by bismuth trifluoromethanesulfonate

    DEFF Research Database (Denmark)

    Tran, Phoung Hoang; Hansen, Poul Erik; Pham, Thuy Than;

    2014-01-01

    The catalytic activity of metal triflates was investigated in Friedel–Crafts benzoylation under microwave irradiation. Friedel–Crafts benzoylation with benzoyl chloride of a variety of arenes containing electron-rich and electron-poor rings using bismuth triflate under microwave irradiation is...

  13. Palladium-Catalyzed Desilylative Acyloxylation of Silicon-Carbon Bonds on (Trimethylsilyl)arenes: Synthesis of Phenol Derivatives from Trimethylsilylarenes.

    Science.gov (United States)

    Gondo, Keisuke; Oyamada, Juzo; Kitamura, Tsugio

    2015-10-01

    A strategy for desilylative acetoxylation of (trimethylsilyl)arenes has been developed in which (trimethylsilyl)arenes are converted into acetoxyarenes. The direct acetoxylation is performed in the presence of 5 mol % of Pd(OAc)2 and PhI(OCOCF3)2 (1.5 equiv) in AcOH at 80 °C for 17 h. The acetoxyarenes are obtained in good to high yields (67-98%). The synthetic utility is demonstrated with a one-pot transformation of (trimethylsilyl)arenes to phenols by successive acetoxylation and hydrolysis. Furthermore, desilylative acyloxylation of 2-(trimethylsilyl)naphthalene using several carboxylic acids has been conducted. PMID:26401835

  14. Synthesis and Characterization of New Polyimide Containing Calix[4]arenes in the Polymer Backbone with Transport Ability

    Institute of Scientific and Technical Information of China (English)

    LI Lei; XIAN Chun-ying; ZHENG Li-min

    2008-01-01

    New polyimide containing cvalix[4]arene moieties on the polymer backbone was successfully synthesized in N-methyl-2-pyrrolidone(NMP) by polycondensations of 3,3', 4, 4'- oxydiphthalic anhydride (ODPA) with the diaminocalix[4]arene monomer using 3,3'-dimethyl-4, 4'-diaminodiphenylmethane(DADPM) as a third comononmer.The polyimide prepared is soluble in common solvents, such as NMP, DMAc, DMF and chloroform. The polyimide films obtained have excellent thermal stability and mechanical property. At the same time, the liquid membrane transport of potassimn ions by the new polyimide was investigated, which testified that compared to ODPA-DADPM polyimide, the polyimide containing calix[4] arenes has the transport ability to metal ions in regard to bulky, cone-like calix [4] arene moieties.

  15. Arene ruthenium complexes with monoanionic carborane ligand [9-SMe2-7,8-C2B9H10]-

    International Nuclear Information System (INIS)

    Cation ruthenium complexes [(η-arene)Ru(η-9-SMe2-7,8-C2B9H10)]+ (arene = C6H6 (1), 1, 3, 5 - C6H3Me3 (2), Me = methyl), containing carborane ligand, were prepared with the yield of ∼ 50% by interaction between salt Na[9-SMe2-7,8-C2B9H10] and complexes [(η - arene)RuCl2]2. Products of the reactions were characterized by the methods of elementary analysis and 1H, 11B NMR. According to X-ray diffraction analysis data complex cation 1 has a sandwich structure. Distances from ruthenium atom to plane C2B3 in carborane ligand and to plane C6 of arene make up 1.630 and 1.732 A, respectively

  16. Derivation of structure-activity relationships from the anticancer properties of ruthenium(II) arene complexes with 2-aryldiazole ligands.

    Science.gov (United States)

    Martínez-Alonso, Marta; Busto, Natalia; Jalón, Félix A; Manzano, Blanca R; Leal, José M; Rodríguez, Ana M; García, Begoña; Espino, Gustavo

    2014-10-20

    The ligands 2-pyridin-2-yl-1H-benzimidazole (HL(1)), 1-methyl-2-pyridin-2-ylbenzimidazole (HL(2)), and 2-(1H-imidazol-2-yl)pyridine (HL(3)) and the proligand 2-phenyl-1H-benzimidazole (HL(4)) have been used to prepare five different types of new ruthenium(II) arene compounds: (i) monocationic complexes with the general formula [(η(6)-arene)RuCl(κ(2)-N,N-HL)]Y [HL = HL(1), HL(2), or HL(3); Y = Cl or BF4; arene = 2-phenoxyethanol (phoxet), benzene (bz), or p-cymene (p-cym)]; (ii) dicationic aqua complexes of the formula [(η(6)-arene)Ru(OH2)(κ(2)-N,N-HL(1))](Y)2 (Y = Cl or TfO; arene = phoxet, bz, or p-cym); (iii) the nucleobase derivative [(η(6)-arene)Ru(9-MeG)(κ(2)-N,N-HL(1))](PF6)2 (9-MeG = 9-methylguanine); (iv) neutral complexes consistent with the formulation [(η(6)-arene)RuCl(κ(2)-N,N-L(1))] (arene = bz or p-cym); (v) the neutral cyclometalated complex [(η(6)-p-cym)RuCl(κ(2)-N,C-L(4))]. The cytototoxic activity of the new ruthenium(II) arene compounds has been evaluated in several cell lines (MCR-5, MCF-7, A2780, and A2780cis) in order to establish structure-activity relationships. Three of the compounds with the general formula [(η(6)-arene)RuCl(κ(2)-N,N-HL(1))]Cl differing in the arene moiety have been studied in depth in terms of thermodynamic dissociation constants, aquation kinetic constants, and DNA binding measurements. The biologically most active compound is the p-cym derivative, which strongly destabilizes the DNA double helix, whereas those with bz and phoxet have only a small effect on the stability of the DNA double helix. Moreover, the inhibitory activity of several compounds toward CDK1 has also been evaluated. The DNA binding ability of some of the studied compounds and their CDK1 inhibitory effect suggest a multitarget mechanism for their biological activity. PMID:25302401

  17. Control of the rheological properties of clay nanosheet hydrogels with a guanidinium-attached calix[4]arene binder.

    Science.gov (United States)

    Lee, Ji Ha; Kim, Chaelin; Jung, Jong Hwa

    2015-10-21

    A 1,3-alternate calix[4]arene derivative 1 possessing four guanidinium moieties was synthesized as a molecular binder. The clay nanosheet (CNS) hydrogels were prepared upon addition of 1 and sodium polyacrylate (ASSP), and their mechanical properties were measured by rheometry. CNS hydrogels prepared by combining calix[4]arene 1 with dispersed CNSs surrounded by ASSPs showed an enhancement of mechanical properties such as viscosity and elasticity. PMID:26327603

  18. The Use of a Flexible Calix[4]arene Template to Stabilize a Cyclooctatetraindiyl Samarium-Potassium Complex

    Directory of Open Access Journals (Sweden)

    Geoffroy Guillemot

    2013-01-01

    Full Text Available A sandwich compound of cyclooctatetraendiyl (COT2− samarium-potassium was synthesized and analyzed using a flexible calix[4]arene dianion. This compound, [p-tBu-calix[4]-(OMe2(O2]arenediyl-samarium-(η8-cyclooctatetraendiyl-potassium (tetrahydrofurane3, is constructed as a linear sequence L-Sm--K-, where L, , and are specific ligands with L = O,O-dimethyl-calix[4]arene2−, = cyclo-octatetraendiyl, and = tetrahydrofurane templates.

  19. Carboxylate-Assisted Iridium-Catalyzed C-H Amination of Arenes with Biologically Relevant Alkyl Azides.

    Science.gov (United States)

    Zhang, Tao; Hu, Xuejiao; Wang, Zhen; Yang, Tiantian; Sun, Hao; Li, Guigen; Lu, Hongjian

    2016-02-24

    An iridium-catalyzed C-H amination of arenes with a wide substrate scope is reported. Benzamides with electron-donating and -withdrawing groups and linear, branched, and cyclic alkyl azides are all applicable. Cesium carboxylate is crucial for both reactivity and regioselectivity of the reactions. Many biologically relevant molecules, such as amino acid, peptide, steroid, sugar, and thymidine derivatives can be introduced to arenes with high yields and 100 % chiral retention. PMID:26712274

  20. Conformational isomerism in the solid-state structures of tetracaine and tamoxifen with para-sulphonato-calix[4]arene

    Science.gov (United States)

    Danylyuk, Oksana; Monachino, Melany; Lazar, Adina N.; Suwinska, Kinga; Coleman, Anthony W.

    2010-02-01

    The solid-state complexes between para-sulphonato-calix[4]arene and the drugs tamoxifen and tetracaine show an unusual 4:1 guest-host stoichiometry with formation of hydrophobic layer of drug molecules held between bilayers of para-sulphonato-calix[4]arene. In both structures each of the four independent drug molecules adopts different conformation due to the different mode of interaction with the anionic host, the neighbouring drug cations and water molecules.

  1. Synthesis and properties of calix[4]arene telluropodant ethers as Ag+ selective sensors and Ag+, Hg2+ extractants

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2009-10-01

    Full Text Available Three novel phenyltelluroalkoxyl functionalized tweezer-like calix[4]arenes 6–8 and two monophenyltelluropropoxyl functionalized calix[4]arenes 10 (cone conformer and 12 (partial cone conformer were synthesized and characterized. They are good Ag+-selective ionophores in ion-selective electrodes evaluated by electromotive force measurements of polymer membrane electrodes. The tweezer-like ionophores 6–8 showed excellent extraction ability towards Ag+ and Hg2+.

  2. First synthesis of a '1,2-diquinone-calix[4]arene'. Interaction of its reduced form with Ag+

    OpenAIRE

    Vataj, Rame; Ridaoui, Hassan; Louati, Alain; Gabelica, Valérie; Steyer, Stéphane; MATT, DOMINIQUE

    2002-01-01

    Electrochemical oxidation of 5,11,17,23-tetra-tert-butyl-25,26-bis(diphenylphosphinoylmethoxy)-27,28-dihydroxycalix[4]arene (3), a calixarene with two phosphoryl units appended on proximal positions, affords the corresponding '1,2-diquinonecalix[4]arene' (4). The formation of 4 results from nucleophilic attack of residual water on anodically generated diphenoxylium. cations. Preliminary voltammetric experiments in CH3CN on a platinum electrode showed that 4 is suitable for electrochemical det...

  3. Structural features and thermal stability of molecular complexes of 25,26,27,28-Tetrahydroxycalix[4]arene with solvents

    Science.gov (United States)

    Surov, O. V.; Voronova, M. I.; Plevina, E. V.; Barannikov, V. P.; Smirnov, P. R.; Mamardashvili, N. Zh.

    2014-08-01

    A single crystal of the complex 25,26,27,28-tetrahydroxycalix[4]arene with hexane is grown via slow evaporation of a solution, and its full structure is determined. A molecular complex of 25,26,27,28-tetrahydroxycalix[4]arene with toluene is prepared for the first time, and its thermal stability is studied. The kinetic curves of the sorption of saturated vapors of acetone, acetonitrile, n-hexane, and toluene on 25,26,27,28-tetrahydroxycalix[4]arene are experimentally obtained. It is shown that the sorption of acetonitrile vapors on 25,26,27,28-tetrahydroxycalix[4]arene is characterized by a pronounced maximum corresponding to a stoichiometry of 1: 1. It is assumed that the structural reorganization of 25,26,27,28-tetrahydroxycalix[4]arene results in the transport of acetonitrile molecules within the molecular crystal, followed by complexation to form a thermodynamically stable hexagonal structure. The high thermal stability of solvates of 25,26,27,28-tetrahydroxycalix[4]arene is found to be due to the strict proportionality of the form and size of a guest molecule to those of the cavity of a host molecule.

  4. Isostructural Heteronuclear (K+/M2+: M = Ni, Co, and Zn) One-Dimensional Coordination Polymers of Thiacalix[4]arene Tetraacetate

    International Nuclear Information System (INIS)

    Assembly of 1,3-alternate thiacalix[4]arene potassium tetraacetate with three transition metal salts afforded an isostructural metal-mediated heteronuclear coordination polymers. The present results illustrate how the appropriate modification of the 1,3-alternate thiacalix[4]arene derivative works as an approach in preparing desired metallosupra molecular networks. Further exploration of the synthesis and physical properties of novel metallosupra molecular network species based on the modification of the thiacalix[4]arene derivatives is underway

  5. 7,11,15,28-Tetrakis[(2-formylphenoxymethyl]-1,21,23,25-tetramethylresorcin[4]arene cavitand ethyl acetate clathrate at 173 K

    Directory of Open Access Journals (Sweden)

    Michael G. Mc Kay

    2009-04-01

    Full Text Available The title compound, C68H56O16, was synthesized as a novel synthetic intermediate towards deeper and more elaborate resorcin[4]arene cavitands. The structure is the first reported example of a resorcin[4]arene cavitand bearing aromatic aldehyde functional groups at the extra-annular rim of the molecule. The 2-formylphenoxy residues are found to assume two different orientations above the molecular cavity. One half of the resorcin[4]arene cavitand molecule appears in the asymmetric unit; the complete resorcin[4]arene cavitand structure was generated across a mirror plane. In addition, a highly disordered ethyl acetate solvent molecule is present within the molecular cavity.

  6. The magma budget of Volcan Arenal, Costa Rica from 1968 to 1980

    Science.gov (United States)

    Wadge, G.

    1983-01-01

    The magma volume emitted by Volcan Arenal, Costa Rica, has been calculated to be 304 x 10 to the 6th cu m. A near-continuous rise from very deep within the crust is proposed as an explanation for Arenal's magma supply, and the long-term seismic pattern is interpreted as individual batches of magma using previously fractured pathways. During a break in activity (1973) the effusion site moved from Crater A to Crater C, approximately 400 m higher. It is maintained that the steady downward tilting of the volcano's summit was caused by the loading of the volcano's western side by about 19 x 10 to the 6th cu m of lava. Also noted is the abrupt decrease in effusion rate compatible with the increased magmatic head needed to reach Crater C. It is concluded that the constancy of magma composition and effusion rate from 1974 to 1980 indicates a homogeneous magma reservoir.

  7. Highly selective hydrogenation of arenes using nanostructured ruthenium catalysts modified with a carbon–nitrogen matrix

    Science.gov (United States)

    Cui, Xinjiang; Surkus, Annette-Enrica; Junge, Kathrin; Topf, Christoph; Radnik, Jörg; Kreyenschulte, Carsten; Beller, Matthias

    2016-01-01

    Selective hydrogenations of (hetero)arenes represent essential processes in the chemical industry, especially for the production of polymer intermediates and a multitude of fine chemicals. Herein, we describe a new type of well-dispersed Ru nanoparticles supported on a nitrogen-doped carbon material obtained from ruthenium chloride and dicyanamide in a facile and scalable method. These novel catalysts are stable and display both excellent activity and selectivity in the hydrogenation of aromatic ethers, phenols as well as other functionalized substrates to the corresponding alicyclic reaction products. Furthermore, reduction of the aromatic core is preferred over hydrogenolysis of the C–O bond in the case of ether substrates. The selective hydrogenation of biomass-derived arenes, such as lignin building blocks, plays a pivotal role in the exploitation of novel sustainable feedstocks for chemical production and represents a notoriously difficult transformation up to now. PMID:27113087

  8. Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

    International Nuclear Information System (INIS)

    Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb2+, Cd2+, Mg2+ and Eu3+ ions at pH 6.8. The results showed a good selectivity response towards Eu3+. Low selectivity coefficients were observed for Cd2+ and Mg2+ where Pb2+ can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. - Highlights: ► We report optical sensing studies of chromogenic calixarene derivatives. ► We investigate optical interaction between azo-calix[4]arene and Eu3+. ► We study sensitivity and selectivity of optode films. ► We describe characteristics of optode films for determination of europium traces.

  9. Interaction of acridine-calix[4]arene with DNA at the electrified liquid liquid interface

    Energy Technology Data Exchange (ETDEWEB)

    Kivlehan, Francine [Tyndall National Institute, Lee Maltings, University College Cork, Cork (Ireland); Lefoix, Myriam; Moynihan, Humphrey A. [Department of Chemistry, Analytical and Biological Chemistry Research Facility, University College Cork, Cork (Ireland); Thompson, Damien; Ogurtsov, Vladimir I.; Herzog, Gregoire [Tyndall National Institute, Lee Maltings, University College Cork, Cork (Ireland); Arrigan, Damien W.M., E-mail: d.arrigan@curtin.edu.a [Tyndall National Institute, Lee Maltings, University College Cork, Cork (Ireland)

    2010-03-30

    The behaviour of an acridine-functionalised calix[4]arene at the interface between two immiscible electrolyte solutions (ITIES) is reported. Molecular modelling showed that the acridine-calix[4]arene has regions of significant net positive charge spread throughout the protonated acridine moieties, consistent with it being able to function as an anion ionophore. The presence of this compound in the organic phase facilitated the transfer of aqueous phase electrolyte ions. Upon addition of double stranded DNA to the aqueous phase, the transfer of electrolyte anions was diminished, due to DNA binding to the acridine moiety at the ITIES. The behaviour provides a basis for DNA hybridization detection using electrochemistry at the ITIES.

  10. Mono- and Bimetallic Ruthenium—Arene Catalysts for Olefin Metathesis: A Survey

    Science.gov (United States)

    Borguet, Yannick; Sauvage, Xavier; Demonceau, Albert; Delaude, Lionel

    In this chapter, we summarize the main achievements of our group toward the development of easily accessible, highly efficient ruthenium—arene catalyst precursors for olefin metathesis. Major advances in this field are presented chronologically, with an emphasis on catalyst design and mechanistic details. The first part of this survey focuses on monometallic complexes with the general formula RuCl2(p-cymene)(L), where L is a phosphine or N-heterocyclic carbene ancillary ligand. In the second part, we disclose recent developments in the synthesis and catalytic applications of homobimetallic ruthenium—arene complexes of generic formula (p-cymene)Ru(μ-Cl)3RuCl(η2-C2H4)(L) and their derivatives resulting from the substitution of the labile ethylene moiety with vinylidene, allenylidene, or indenylidene units

  11. Bis-tert-Alcohol-Functionalized Crown-6-Calix[4]arene: An Organic Promoter for Nucleophilic Fluorination.

    Science.gov (United States)

    Jadhav, Vinod H; Choi, Wonsil; Lee, Sung-Sik; Lee, Sungyul; Kim, Dong Wook

    2016-03-18

    A bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA) was designed and prepared as a multifunctional organic promoter for nucleophilic fluorinations with CsF. By formation of a CsF/BACCA complex, BACCA could release a significantly active and selective fluoride source for SN2 fluorination reactions. The origin of the promoting effects of BACCA was studied by quantum chemical methods. The role of BACCA was revealed to be separation of the metal fluoride to a large distance (>8 Å), thereby producing an essentially "free" F(-). The synergistic actions of the crown-6-calix[4]arene subunit (whose O atoms coordinate the counter-cation Cs(+)) and the terminal tert-alcohol OH groups (forming controlled hydrogen bonds with F(-)) of BACCA led to tremendous efficiency in SN2 fluorination of base-sensitive substrates.

  12. Intermolecular complexation thermodynamics between water-soluble calix[4]arenes and diazacycloalkanes

    International Nuclear Information System (INIS)

    Calorimetric titration experiments have been performed in pH 2.0 and 7.2 phosphate buffer solutions at 298.15 K to calculate the complex stability constants (K S) and thermodynamic parameters (ΔG deg , ΔH deg , and TΔS deg ) for the stoichiometric 1:1 inclusion complexation of water-soluble calix[4]arene tetrasulfonate (CAS) and thiacalix[4]arene tetrasulfonate (TCAS) with some diazacycloalkane guests, i.e. piperazine (1), homopiperazine (2) and 1,5-diazacyclooctane (3). The results indicated that complexes of CAS and TCAS with diazacycloalkane guests were enthalpy-stabilized, and an acidic environment was more favorable to host-guest complexation than a neutral one. CAS forms more stable complexes with guest molecules than TCAS due to the more favorable enthalpic gain

  13. Host-guest interaction of flavanone and 7-aminoflavone with C-Hexylpyrogallol[4]arene

    Science.gov (United States)

    Chandrasekaran, Sowrirajan; Enoch, Israel V. M. V.

    2014-11-01

    In this paper, we report the structures of the host-guest complexes of flavanone and 7-aminoflavone (guests) with C-Hexylpyrogallol[4]arene (host). The study of the host-guest binding is carried out using UV-Visible absorption, steady-state and time-resolved fluorescence, and 2D ROESY spectroscopy. The stoichiometry and the binding constant of the C-Hexylpyrogallol[4]arene-guest complexes are reported based on absorption and fluorescence titrations. Both flavanone and 7-aminoflavone form 1:1 complexes with the host with binding constant values of 1.71 × 104 mol-1 dm3 and 2.06 × 104 mol-1 dm3 respectively. Fluorescence quenching of the two flavonoids on complex formation occurs and the Stern-Volmer constants are reported. The mode of binding of flavanone and 7-aminoflavone with the host molecule is optimized with 2D ROESY and the structures of the inclusion complexes are proposed.

  14. RING-OPENING POLYMERIZATION OF TRIMETHYLENE CARBONATE BY CALIX[8]ARENE-NEODYMIUM

    Institute of Scientific and Technical Information of China (English)

    Ling Ge; Zhi-quan Shen; Yi-feng Zhang; Qiao-hong Huang

    2000-01-01

    Ring-opening polymerization of trimethylene carbonate (TMC) with a rare earth calixarene compound as catalyst has been studied for the first time. The effect of TMC/Nd (molar ratio) and polymerization conditions were investigated in detail. It was found that calix[8]arene-neodymium is a highly effective catalyst for the bulk polymerization of TMC and gives high molecular weight (Mv = 60,000) polymer. The optimum conditions of TMC polymerization were found to be as follows:TMC/Nd (molar ratio) = 2,000, 80℃, 16 h. The polymers were characterized by NMR, GPC and DSC. Studying the mechanism by NMR showed that the polymerization of TMC catalyzed by calix[8]arene-neodymium proceeds via a cationic mechanism.

  15. Metallic ruthenium nanoparticles derived from arene ruthenium complexes: synthesis, characterization and applications

    OpenAIRE

    Khan, Farooq-Ahmad; Süss-Fink, Georg

    2012-01-01

    The present work deals with the preparation of ruthenium nanoparticles using an organometallic approach. In the first part, the synthesis of ruthenium nanoparticles stabilized by mesogenic isonicotinic ester ligands is presented. We have been interested in the use of long-chain isonicotinic esters as lipohilic components in order to increase the anticancer activity of arene ruthenium complexes, while using them as stabilizers for ruthenium nanoparticles with the aim of exploring self-organiz...

  16. Porphyrinic supramolecular daisy chains incorporating pillar[5]arene-viologen host-guest interactions

    KAUST Repository

    Fathalla, Maher

    2015-05-18

    A porphyrin functionalised with pillar[5]arene and a viologen at its 5- and 15-meso positions assembles in a head-to-tail manner, producing linear supramolecular daisy chains in dichloromethane. At high concentrations, it forms an organogel which has been investigated by electron microscopy and rheological measurements, paving the way for the preparation of other functional supramolecular assemblies which harness viologen"⊂" pillararene host-guest interactions.

  17. Synthesis and self-assembly of thio derivatives of calix[4]arene on noble metal surfaces.

    Science.gov (United States)

    Genorio, Bostjan; He, Tao; Meden, Anton; Polanc, Slovenko; Jamnik, Janko; Tour, James M

    2008-10-21

    Self-assembled monolayers (SAMs) provide a simple route to functionalize electrode surfaces with organic molecules. Herein we use cavity-containing derivatives of calix[4]arenes in SAMs. Bound to noble metal surface, the assembled molecules are candidates to serve as molecular sieves for H 2 molecules and H (+) ions, which could have relevance for fuel cell applications. Tetra- O-alkylated calix[4]arenes with thiolacetate and thiolamide wide-rim anchoring groups in cone and partial-cone conformations were designed, synthesized and self-assembled onto Au, Pt, and Pd surfaces. The resulting SAMs were systematically examined. Single crystal X-ray diffraction of 5,11,17,23-tetrakis(thioacetyl)-25,26,27,28-tetra- i-propoxycalix[4]arene confirmed the cone conformation and revealed the cavity dimensions of the SAMs that were formed by immersing noble metal substrates (Au, Pt and Pd deposited on Si-wafers) in solutions of calix[4]arenes. Surface characterization techniques including ellipsometry, cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) were used, indicating that the metal surface is terminated with a monomolecular layer. Experimental thicknesses obtained from the ellipsometry are consistent with the calculated values. CV results showed 50 to 80% physical passivation against the Fe(CN) 6 (3-/4-) couple, implying an overall relatively low concentration of defects and pinholes in the films. The binding energies of the S2p core level in the XPS were consistent with the literature values and revealed that up to 3.2 out of four anchoring groups were bonded to the noble metal surface.

  18. LATEGLACIAL BATS FROM THE “M” LAYERS OF THE ARENE CANDIDE CAVE (LIGURIA, ITALY)

    OpenAIRE

    LEONARDO SALARI

    2010-01-01

    The Arene Candide Cave (Finale Ligure, Northern Italy) is considered one of the most important prehistoric site in Italy. The archaeological excavations conducted by the “Istituto Italiano di Paleontologia Umana” of Rome revealed 3 different horizons: an upper horizon with Holocene human presence dated from the Neolithic to the Byzantine period, and two underlying Pleistocene horizons with Gravettian and Epigravettian lithic artefacts. The stratigraphical sequence of the upper Palaeolithic is...

  19. Synthesis and properties of novel calix[4]arene derivatives bearing fluorogenic coumarin units

    Institute of Scientific and Technical Information of China (English)

    He Wen Wang; Ya Qing Feng; Jin Qiang Xue; Chan Xiao

    2008-01-01

    Four novel calix[4]arene derivatives 5-8 bearing four fluorogenic coumarin units attached via imino group acting also as binding sites at the upper rim have been prepared and characterized by IR, 1H NMR and MS. Compounds 5-8 adopt a cone conformation. Their complexation properties to different heavy and transition metal ions have been studied by UV-vis spectroscopy. Compounds 5, 6, 8 show selective recognition to Fe3+ and Cr3+.

  20. Molecular design of Calix[4]arene derivatives for uranyl ion extraction from aqueous media

    International Nuclear Information System (INIS)

    Uranyl ion extraction is an important part of nuclear waste reprocessing. Use of organic ligands having chelating property with uranyl ions is a promising tool in this area, because of the possibility to improve the selectivity and the affinity of the ligands towards uranyl ions. In this study, Calix[4]arene derivatives containing B, Al, C, Si, N, P, O and S elements in bridging positions were designed and their chelating energetics with uranyl cation are calculated by means of DFT methods.

  1. Antiseptic properties of two calix[4]arenes derivatives on the human coronavirus 229E.

    Science.gov (United States)

    Geller, C; Fontanay, S; Mourer, M; Dibama, H Massimba; Regnouf-de-Vains, J-B; Finance, C; Duval, R E

    2010-12-01

    Facing the lack in specific antiviral treatment, it is necessary to develop new means of prevention. In the case of the Coronaviridae this family is now recognized as including potent human pathogens causing upper and lower respiratory tract infections as well as nosocomial ones. Within the purpose of developing new antiseptics molecules, the antiseptic virucidal activity of two calix[4]arene derivatives, the tetra-para-sulfonato-calix[4]arene (C[4]S) and the 1,3-bis(bithiazolyl)-tetra-para-sulfonato-calix[4]arene (C[4]S-BTZ) were evaluated toward the human coronavirus 229E (HCoV 229E). Comparing these results with some obtained previously with chlorhexidine and hexamidine, (i) these two calixarenes did not show any cytotoxicity contrary to chlorhexidine and hexamidine, (ii) C[4]S showed as did hexamidine, a very weak activity against HCoV 229E, and (iii) the C[4]S-BTZ showed a stronger activity than chlorhexidine, i.e. 2.7 and 1.4log₁₀ reduction in viral titer after 5min of contact with 10⁻³mol L⁻¹ solutions of C[4]S-BTZ and chlorhexidine, respectively. Thus, the C[4]S-BTZ appeared as a promising virucidal (antiseptic) molecule.

  2. Novel water-soluble b-cyclodextrin-calix[4]arene couples as fluorescent sensor molecules for the detection of neutral analytes

    NARCIS (Netherlands)

    Bügler, Jürgen; Engbersen, Johan F.J.; Reinhoudt, David N.

    1998-01-01

    The synthesis and the host-guest chemistry of two novel fluorescent B-cyclodextrin-calix[4]arene couples 1 and 2 is described. The compounds were prepared by coupling a B-cyclodextrin linked with an aminoxylyl spacer with two different calix[4]arene building blocks each bearing a fluorophore. The fl

  3. [Kinetics of inhibitory effect of calix[4]arene C-90 on activity of transporting plasma membrane Ca2+, Mg2+-ATPase of smooth muscle cells].

    Science.gov (United States)

    Veklich, T O; Shkrabak, O A; Mazur, Iu Iu; Rodik, R V; Kal'chenko, V I; Kosterin, S O

    2014-01-01

    In experiments on the suspension of myometrium cell plasma membrane, processed by 0.1% digitonin, the inhibitory action of calix[4]arene C-90 (5,11,17,23-tetra(threeftor)methyl(phenilsulphonilimino)-methylamino-25,26,27,28-tetrapropoxy-calix[4]arene) on the activity of Ca2+,Mg2+-ATPase was investigated. The authors also examined the influence of calix[4]arene in different concentration on affinity of enzyme (Ca2,Mg2+-ATPase) for the ATP and ions of Mg and Ca, and its influence on cooperative effect and maximum velocity of ATP hydrolysis. It is shown that calix[4]arene does not influence the affinity of Ca2+,Mg2+-ATPase for the ATP, which means that these two compounds have different binding centers. Also calix[4]arene has no influence on affinity and cooperative effect of Ca ions, if it is used in concentration lower than 50 μM. Calix[4]arene slightly increases coefficient of Ca2+,Mg2+-ATPase activation by magnesium chloride. In all three cases, where ATP, Mg and Ca ions are used to test the impact of calix[4]arene, maximum velocity of ATP hydrolysis significantly decreases. All these results clarify that calix[4]arene implements its inhibitory action through mechanism of uncompetitive inhibition of Ca2+,Mg2+-ATPase activity.

  4. Synthesis, spectral and structural studies of water soluble arene ruthenium (II) complexes containing 2,2′-dipyridyl-N-alkylimine ligand

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Kaminsky, W.

    A series of water soluble complexes of general formula [(Eta sup(6)-arene) Ru ((C sub(5) H sub(4) N) sub(2) CNRi) Cl) PF sub(6) have been prepared by the reaction of [[(Eta sup(6)- arene) RuCl sub(2)) sub(2)) with appropriate 2,2’-dipyridyl...

  5. Sensitive fluorescence probes for dihydrogen phosphonate anion based on calix[4]arene bearing naphthol-hydrazone groups

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    t-Butyl and t-pentylcalix[4]arenes bearing two 2-naphthol-1-hydrazone groups at the lower rim were synthesized,and showed excited-state intermolecular proton transfer fluorescent signal with basic anion.They are more sensitive to dihydrogen phosphate anion than to fluoride anion,although the latter has stronger basicity.Compared with t-butylcalix[4]arene bearing two 2-naphthol-1-hydrazone groups,t-pentylcalix[4]arenes derivative has a larger fluorescent difference between dihydrogen phosphate and fluoride anion.This finding may be used to analyze dihydrogen phosphate anion in the presence of fluoride anion and provide a new approach for designing fluorescence probes that are highly selective for H2PO4-.

  6. Influence of the π-coordinated arene on the anticancer activity of ruthenium(II carbohydrate organometallic complexes

    Directory of Open Access Journals (Sweden)

    Muhammad eHanif

    2013-10-01

    Full Text Available The synthesis and in vitro cytotoxicity of a series of RuII(arene complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well with cellular accumulation. The most lipophilic compound bearing a biphenyl moiety and a cyclohexylidene-protected carbohydrate is the most cytotoxic with unprecedented IC50 values for the compound class in three human cancer cell lines. This compound shows reactivity to the DNA model nucleobase 9-ethylguanine, but does not alter the secondary structure of plasmid DNA indicating that other biological targets are responsible for its cytotoxic effect.

  7. 25,26,27,28-Tetra­kis(3-bromo­benzyl­oxy)calix[4]arene

    OpenAIRE

    Lee, Eunji; Moon, Suk-Hee; Kim, Tae Ho; Park, Ki-Min

    2011-01-01

    In the title compound, C56H44Br4O4, the calix[4]arene unit displays the 1,2-alternate conformation with crystallograpically imposed inversion symmetry. The four phen­oxy rings of the calix[4]arene unit are twisted about the mean plane defined by the four methyl­ene C atoms bridging the benzene rings, with dihedral angles of 46.73 (6) and 66.11 (5)°. The dihedral angle between adjacent phen­oxy rings is 74.75 (7)°. The two pendant bromo­phenyl rings on the same side of the calix[4]arene unit a...

  8. Synthesis, Structure and Ion Extraction Properties of Novel Monooxa-diselkylene-1,ω-dioxy Substituted Calix[4]arene Derivatives

    Institute of Scientific and Technical Information of China (English)

    QIN Da-Bin; ZENG Xian-Shun; XU Feng-Bo; LI Qing-Shan; ZHANG Zheng-Zhi

    2006-01-01

    Novel macrocyclic monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a were synthesized by the reaction of calix[4]arene dibromides 1-5 with the disodium salt of bis(2-selenylethyl)ether in the yields between 28% and 64%. Their structures were characterized by proton and carbon NMR spectra. X-Ray structure analysis of 1a further confirmed the cone conformation of compounds 1a-5a. An interesting host-guest complex of 1a with dichloromethane via CH/π and Cl/π interactions was elucidated. Extraction experiments showed that these novel monooxa-diselkylene-1,ω-dioxy substituted calix[4]arene derivatives 1a-5a had strong extraction ability towards mercury ion. The interaction of Hg2+with the calix ligand has also been investigated by 1H NMR titration.

  9. Molecular recognition of curcumin (Indian Ayurvedic medicine) by the supramolecular probe, p-t-butyl calix(8)arene

    Science.gov (United States)

    Meenakshi, C.; Jayabal, P.; Ramakrishnan, V.

    2014-06-01

    The thermodynamic property of the host-guest complexes formed between the curcumin, component of Indian Ayurvedic medicine turmeric, a drug molecule, with the supra molecule, p-t-butyl calix(8)arene was studied. p-t-Butyl calix(8)arene has been used as a host molecule and curcumin as a guest molecule. Optical absorption spectral studies were carried out to investigate the molecular recognition properties of p-t-butyl calix(8)arene with curcumin. The stochiometry of the host-guest complexes formed and the binding constant were determined. An interesting 1:1 and 4:1 stochiometric host-guest complexes were formed. Job's continuous method of variation and Benesi-Hildebrand expression were used for the determination of binding constant and the stochiometry of the host-guest complex formed.

  10. Cobalt-chitosan: Magnetic and biodegradable heterogeneous catalyst for selective aerobic oxidation of alkyl arenes and alcohols

    Indian Academy of Sciences (India)

    Ahmad Shaabani; Mahmoud Borjian Boroujeni; Mona Hamidzad Sangachin

    2015-11-01

    A novel and biodegradable cobalt-chitosan as a magnetic heterogeneous catalyst was synthesized and characterized by XPS, FT-IR, EDX and TEM. Catalytic performance of cobalt- chitosan was tested by aerobic oxidation of alkyl arenes and alcohols. The results show that the catalyst exhibits excellent conversion for selective aerobic oxidation of various alkyl arenes, primary and secondary alcohols with air as the only oxidant. The catalyst can be easily separated by magnetic devices and reused for 5 runs without appreciable loss of activity.

  11. Catalytic, Interrupted Formal Homo-Nazarov Cyclization with (Hetero)arenes: Access to α-(Hetero)aryl Cyclohexanones.

    Science.gov (United States)

    Williams, Corey W; Shenje, Raynold; France, Stefan

    2016-09-16

    The first examples of a Lewis-acid catalyzed (hetero)arene interrupted, formal homo-Nazarov cyclization have been disclosed. Using SnCl4 as the catalyst, alkenyl cyclopropyl ketones undergo ring-opening cyclization to form six-membered cyclic oxyallyl cations. Subsequent intermolecular Friedel-Crafts-type arylation with various electron-rich arenes and heteroarenes provides functionalized α-(hetero)arylated cyclohexanones, a scaffold present in many natural products and bioactive compounds, in yields up to 88% and diastereomeric ratios up to 12:1. Regiospecific arylation occurs at the α-carbon of the oxyallyl cation due to polarization caused by the ester group. PMID:27529123

  12. A New Type of Dibenzoyl Tartaric Acid Selective Electrode Baded on Polymer Membrane Containing Calix[4] arene lonophore

    Institute of Scientific and Technical Information of China (English)

    Meng; Ling-zhi; Mei; Gong-xiong; 等

    2003-01-01

    A new type of dibenzoyl tartaric acid selective electrode has been developed. Three double-arm calix [4] arene derivatives were employed as the neutral ionophores. The poly(vinyl chloride) membrane electrode containing an amide derivative of calix [4] arene as the neutral carrier and a dibutyl phthalate as the plasticizer exhibited the highest sensitivity for dibenzoyl tartaric acid. The slope of linear portion was 27.8mV per concertration decade. The electrode has a fast response and a long lifetime.

  13. A New Type of Dibenzoyl Tartaric Acid Selective Electrode Based on Polymer Membrane Containing Calix[4]arene Ionophore

    Institute of Scientific and Technical Information of China (English)

    Meng Ling-zhi; Mei Gong-xiong; He Yong-bing; Li Jiang-feng

    2003-01-01

    A new type of dibenzoyl tartaric acid selective electrode has been developed. Three double-arm calix[4]arene derivatives were employed as the neutral ionophores. The poly(vinyl chloride) membrane electrode containing an amide derivative of calix[4]arene as the neutral carrier and a dibutyl phthalate as the plasticizer exhibited the highest sensitivity for dibenzoyl tartaric acid. The slope of linear portion was 27.8 mV per concertration decade. The electrode has a fast response and a long lifetime.

  14. Dual triggering of DNA binding and fluorescence via photoactivation of a dinuclear ruthenium(II) arene complex.

    Science.gov (United States)

    Magennis, Steven W; Habtemariam, Abraha; Novakova, Olga; Henry, John B; Meier, Samuel; Parsons, Simon; Oswald, Iain D H; Brabec, Viktor; Sadler, Peter J

    2007-06-11

    The dinuclear RuII arene complexes [{(eta6-arene)RuCl}2(mu-2,3-dpp)](PF6)2, arene=indan (1), benzene (2), p-cymene (3), or hexamethylbenzene (4) and 2,3-dpp=2,3-bis(2-pyridyl)pyrazine, have been synthesized and characterized. Upon irradiation with UVA light, complexes 1 and 2 readily underwent arene loss, while complexes 3 and 4 did not. The photochemistry of 1 was studied in detail. In the X-ray structure of [{(eta6-indan)RuCl}2(mu-2,3-dpp)](PF6)2 (1), 2,3-dpp bridges two RuII centers 6.8529(6) A apart. In water, aquation of 1 in the dark occurs with replacement of chloride with biexponential kinetics and decay constants of 100+/-1 min-1 and 580+/-11 min-1. This aquation was suppressed by 0.1 M NaCl. UV or visible irradiation of 1 in aqueous or methanolic solution led to arene loss. The fluorescence of the unbound arene is approximately 40 times greater than when it is complexed. Irradiation of 1 also had a significant effect on its interactions with DNA. The DNA binding of 1 is increased after irradiation. The non-irradiated form of 1 preferentially formed DNA adducts that only weakly blocked RNA polymerase, while irradiation of 1 transformed the adducts into stronger blocks for RNA polymerase. The efficiency of irradiated 1 to form DNA interstrand cross-links was slightly greater than that of cisplatin in both 10 mM NaClO4 and 0.1 M NaCl. In contrast, the interstrand cross-linking efficiency of non-irradiated 1 in 10 mM NaClO4 was relatively low. An intermediate amount of cross-linking was observed when the sample of DNA already modified by non-irradiated 1 was irradiated. DNA unwinding measurements supported the conclusion that both mono- and bifunctional adducts with DNA can form. These results show that photoactivation of dinuclear RuII arene complexes can simultaneously produce a highly reactive ruthenium species that can bind to DNA and a fluorescent marker (the free arene). Importantly, the mechanism of photoreactivity is also independent of oxygen. These

  15. The synthesis of new amphiphilic p-tert-butylthiacalix[4]arenes containing peptide fragments and their interaction with DNA.

    Science.gov (United States)

    Padnya, Pavel L; Andreyko, Elena A; Mostovaya, Olga A; Rizvanov, Ildar Kh; Stoikov, Ivan I

    2015-06-01

    New water-soluble p-tert-butylthiacalix[4]arenes containing peptide and quaternary ammonium fragments in cone and 1,3-alternate conformations were synthesized and characterized. The interaction of the macrocycles with DNA was studied by UV-spectroscopy, DLS and TEM. It was shown that the interaction of the self-associates based on p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim with glycine and quaternary ammonium fragments in cone and 1,3-alternate conformations with DNA led to the formation of particles of about 99-192 nm in size.

  16. Enantioselective Recognition of Calix [4] arene Derivative Bearing Bicyclic Guanidinium for D/L Amino Acid Zwitterions

    Institute of Scientific and Technical Information of China (English)

    刘芳; 陆国元; 何卫江; 王震生; 朱龙根

    2001-01-01

    The p-tetra-tert-butyl calix[4]arene derivatives ( 3 and 4 )with(S,S) chiral bicyclic guanidinium, as the receptors of amino acid zwitterions, have been synthesized via a O-alkylation reaction of p-tetra-tert-rutyi calix [4] arene with chloromethly chiral bicyclic guanidinium 2 in the presence of anhydrous K2CO3 in acetonitrile.The results obtained from liquid-liquid competitive extraction experiments indicate that the two receptors may selectively recognize L-aromatic amino acids, and that the enantioselective recognizability of the receptor 4 with two chiral bicyclic guanidinium units reachs up to about 90% for L-Phe.

  17. Synthesis and cationic selectivity studies of novel calix[4]arene derivatives containing heteroatom at the lower rim

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of calixarene derivatives 2-5 containing heteroatom at the lower rim have been synthesized. 1H NMR studies and crystallographic structures demonstrated that the calix[4]arene derivatives adopted cone conformations. Their cationic binding abilities and selectivities towards heavy and transition metal ions have been evaluated by solvent extraction of aqueous metal picrates. The obtained results indicated that the introduction of nitrogen, sulfur, and/or phosphor atoms to the calix[4]arene framework could effectively enhance their binding ability and selectivity for heavy and transition metal ions, such as Pb2+ or Ag+.

  18. New Neutral Receptors for Fluoride Based on Calix[4]arene Bearing Thiourea and Amide

    Institute of Scientific and Technical Information of China (English)

    刘顺英; 徐括喜; 何永炳; 秦海娟; 孟令芝

    2005-01-01

    Two-armed neutral anion receptors (4,5), calix[4]arenes beating thiourea and amide binding sites, were prepared and examined their anion-binding ability by the UV-vis spectra. The results of non-linear curve fitting and Job plot indicate that 4 or 5 forms 1:1 stoichiometry complex with fluoride by hydrogen bonding interactions. Receptors 4 and 5 have an excellent selectivity for fluoride but have no binding ability with acetate, dihydrogen phosphate and the halogen anions (Cl-,Br-,I-).

  19. Study on Laccase-Catalyzed Oxidation of Disubstituted Ferrocene and π-arene-π-cyclopentadienyliron Derivatives

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    It is studied that Rhus vernicifera laccase catalyzed oxidation of 26 disubstituted ferrocene and its metal complexes, π-arene-π-cyclopentadienyliron derivatives and metal meso-(tetra-4-sulfanatophenyl)porphyrin in the diethylene glycol monobutyl ether (DGBE)/phosphate buffer (V/V,1/5).It is found that 1,1'-bishydroxylmethy1 ferrocene etc 16 compounds are new substrates of laccase. The relation of structure and function of substrates is discussed. The affective factors of laccase-catalyzed oxidation of 1,1'-bishydroxylmethyl ferrocene--pH, temperature, substrate concentration, laccase quantity and surfactant were investigated further.

  20. Calix[4]arene based selective fluorescent chemosensor for organic acid recognition

    Institute of Scientific and Technical Information of China (English)

    Runhe WANG; Jianhua BU; Junmin LIU; Shijun LIAO

    2008-01-01

    A novel calix[4]arene,based fluorescent chemosensor bearing a 2,aminopyridine moiety and a naphthalenic fluorophore was synthesized The chemical structure of the product was elucidated by FT,IR, MS,FAB, NMR and elemental analyses. Then, the properties and identification mechanism of the synthesized chemosensor were investigated. The results show that the chemosensor exhibits selective fluorescent quenching in the presence of aromatic organic acid in acetonitrile solution, and that the binding ability of the chemosensor with organic acid is in the order of p,cyanic,benzyl acid>p,chloric,benzyl acid>p,methoxyl,benzyl acid>benzyl acid.

  1. Noncovalent Complexation of Monoamine Neurotransmitters and Related Ammonium Ions by Tetramethoxy Tetraglucosylcalix[4]arene

    Science.gov (United States)

    Torvinen, Mika; Kalenius, Elina; Sansone, Francesco; Casnati, Alessandro; Jänis, Janne

    2012-02-01

    The noncovalent complexation of monoamine neurotransmitters and related ammonium and quaternary ammonium ions by a conformationally flexible tetramethoxy glucosylcalix[4]arene was studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. The glucosylcalixarene exhibited highest binding affinity towards serotonin, norepinephrine, epinephrine, and dopamine. Structural properties of the guests, such as the number, location, and type of hydrogen bonding groups, length of the alkyl spacer between the ammonium head-group and the aromatic ring structure, and the degree of nitrogen substitution affected the complexation. Competition experiments and guest-exchange reactions indicated that the hydroxyl groups of guests participate in intermolecular hydrogen bonding with the glucocalixarene.

  2. Olefin Metathesis With Ruthenium-Arene Catalysts Bearing N-Heterocyclic Carbene Ligands

    Science.gov (United States)

    Delaude, Lionel; Demonceau, Albert

    In this chapter, we summarize the main results of our investigations on the ring-opening metathesis polymerization (ROMP) of cyclooctene catalyzed by various ruthenium (Ru)-arene complexes bearing imidazolin-2-ylidene, imidazolidin- 2-ylidene, or triazolin-5-ylidene ligands. Three major findings emerged from this study. First, we underscored the intervention of a photochemical activation step due to visible light illumination. Second, we established that the presence of an endocyclic double bond in the carbene ligand central heterocycle was not crucial to achieve high catalytic efficiencies. Third, we demonstrated that ortho-metallation of the N-heterocyclic carbene (NHC) ligand by the Ru center led to inactive catalysts.

  3. Benzylic Phosphates in Friedel-Crafts Reactions with Activated and Unactivated Arenes: Access to Polyarylated Alkanes.

    Science.gov (United States)

    Pallikonda, Gangaram; Chakravartya, Manab

    2016-03-01

    Easily reachable electron-poor/rich primary and secondary benzylic phosphates are suitably used as substrates for Friedel-Crafts benzylation reactions with only 1.2 equiv activated/deactivated arenes (no additional solvent) to access structurally and electronically diverse polyarylated alkanes with excellent yields and selectivities at room temperature. Specifically, diversely substituted di/triarylmethanes are generated within 2-30 min using this approach. A wide number of electron-poor polyarylated alkanes are easily accomplished through this route by just tuning the phosphates. PMID:26835977

  4. Stereoselective Arene-Forming Aldol Condensation: Synthesis of Axially Chiral Aromatic Amides.

    Science.gov (United States)

    Fäseke, Vincent C; Sparr, Christof

    2016-06-13

    The increasing awareness of the importance of amide atropisomers prompts the development of novel strategies for their selective preparation. Described herein is a method for the enantioselective synthesis of atropisomeric aromatic amides by an amine-catalyzed arene-forming aldol condensation. The high reactivity of the glyoxylic amide substrates enables a remarkably efficient construction of a new aromatic ring, which proceeds within minutes at ambient temperature to afford products with excellent stereoselectivity. The high rotational barriers of the reduced products highlight the utility of this stable, spatially organized chiral scaffold. PMID:27166995

  5. Stereoselective Arene-Forming Aldol Condensation: Synthesis of Configurationally Stable Oligo-1,2-naphthylenes.

    Science.gov (United States)

    Lotter, Dominik; Neuburger, Markus; Rickhaus, Michel; Häussinger, Daniel; Sparr, Christof

    2016-02-18

    Structurally well-defined oligomers are fundamental for the functionality of natural molecular systems and key for the design of synthetic counterparts. Herein, we describe a strategy for the efficient synthesis of individual stereoisomers of 1,2-naphthylene oligomers by iterative building block additions and consecutive stereoselective arene-forming aldol condensation reactions. The catalyst-controlled atropoenantioselective and the substrate-controlled atropodiastereoselective aldol condensation reaction provide structurally distinct ter- and quaternaphthalene stereoisomers, which represent configurationally stable analogues of otherwise stereodynamic, helically shaped ortho-phenylenes. PMID:26799152

  6. Molecularly Imprinted Polymer with Calix[4]arene Derivative for the Recognition of Acetanilide

    Institute of Scientific and Technical Information of China (English)

    LU, Chun-Yang(卢春阳); HE, Hai-Cheng(何海成); HE, Xi-Wen(何锡文); ZENG, Xian-Shun(曾宪顺)

    2004-01-01

    Two molecularly imprinted polymers binding to analgesic acetanilide were prepared using either dual functional monomers of calix[4]arene derivative and acrylamide or single monomer acrylamide, respectively. The polymers were ground, sieved and investigated by equilibrium binding experiment to evaluate their recognition properties for the template and other substrates. Scatchard analysis showed that homogeneous recognition sites were formed in the imprinted polymer matrix. Our results demonstrated that the polymer using two functional monomers exhibited better selectivity for the template. This study may open new frontiers for the development and application of imprinted polymers, such as drug separation and purification.

  7. Laser Spectroscopic and Theoretical Studies of Encapsulation Complexes of Calix[4]arene

    OpenAIRE

    Kaneko, Shohei; Inokuchi, Yoshiya; Ebata, Takayuki; Aprà, Edoardo; Xantheas, Sotiris S.

    2011-01-01

    The complexes between the host calix[4]arene (C4A) and various guest molecules such as NH3, N2, CH4, and C2H2 have been investigated via experimental and theoretical methods. The S1-S0 electronic spectra of these guest-host complexes are observed by mass-selected resonant two-photon ionization (R2PI) and laser induced fluorescence (LIF) spectroscopy. The infrared (IR) spectra of the complexes formed in molecular beams are obtained by IR-UV double resonance (IR-UV DR) and IR photodissociation ...

  8. Biological activity of ruthenium and osmium arene complexes with modified paullones in human cancer cells

    OpenAIRE

    Mühlgassner, Gerhard; Bartel, Caroline; Schmid, Wolfgang F.; Jakupec, Michael A.; Arion, Vladimir B; BERNHARD K. KEPPLER

    2012-01-01

    In an attempt to combine the ability of indolobenzazepines (paullones) to inhibit cyclin-dependent kinases (Cdks) and that of platinum-group metal ions to interact with proteins and DNA, ruthenium(II) and osmium(II) arene complexes with paullones were prepared, expecting synergies and an increase of solubility of paullones. Complexes with the general formula [MIICl(η 6-p-cymene)L]Cl, where M = Ru (1, 3) or Os (2, 4), and L = L 1 (1, 2) or L 2 (3, 4), L 1  = N-(9-bromo-7,12-dihydroindolo[3,2-d...

  9. Synthesis and Structure of an Octopus-like Octapropargyl Tetra-iso-butyl-resorcin[4]arene

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang; LIU Yu-Jie; ZHANG Qian-Feng

    2005-01-01

    Treatment of tetra-iso-butyl-resorcin[4]arene 1 with propargyl bromide in the presence of K2CO3 as base gave an octopus-like octapropargyl tetra-iso-butyl-resorcin[4]arene 2 (C68H72O8, Mr = 1017.26) in a quantitative yield.Single-crystal structure of 2 was determined by X-ray crystallography.2 crystallizes in the monoclinic system, space group P21/n with a =13.3247(6), b = 24.7929(11), c = 19.1810(9)(。A), β= 109.272(1)°, V= 5981.5(5)(。A)3, Dc.= 1.130 g/cm3, μ = 0.073 mm-1, F(000) = 2176 and Z = 4.Overall structure of 2 reveals an octopus-like resorcinarene with eight propargyl groups in different directions.The resorcinarene adopts the boat conformation where the iso-butyl residues act as four-legged piano stool.The two opposite aryl rings of the macrocyclic framework are almost coplanar, and the two others facing each other are perpendicular to this plane.

  10. Thin-skinned mass-wasting responsible for edifice-wide deformation at Arenal Volcano

    Directory of Open Access Journals (Sweden)

    Susanna Kathryn Ebmeier

    2014-12-01

    Full Text Available The shape and stability of a volcano’s edifice depends on the relationship between eruption rate and the loss or redistribution of material due to erosion, mass-wasting or deformation. This work provides measurements of deformation and shallow mass-wasting at a stratovolcano immediately after an extended period of growth, and demonstrates that high rates of deformation can be associated with shallow edifice processes. We measure displacements and surface property changes on the upper flanks of Arenal, Costa Rica, after a ~40 year period of edifice growth. We present high-resolution satellite radar imagery of the 2011-2013 period that provides evidence of frequent rockfalls and of at least 16 slow-moving, shallow landslides (estimated to be 5-11 m thick, total volume = 2.4×107 m3 DRE. The 2012 Nicoya Earthquake (Mw 7.4 had no measurable impact on the velocities of sliding units at Arenal, but did result in an increase in the area affected by rockfall.

  11. Radiosensitisation of human colorectal cancer cells by ruthenium(II) arene anticancer complexes

    Science.gov (United States)

    Carter, R; Westhorpe, A; Romero, MJ; Habtemariam, A; Gallevo, CR; Bark, Y; Menezes, N; Sadler, PJ; Sharma, RA

    2016-01-01

    Some of the largest improvements in clinical outcomes for patients with solid cancers observed over the past 3 decades have been from concurrent treatment with chemotherapy and radiotherapy (RT). The lethal effects of RT on cancer cells arise primarily from damage to DNA. Ruthenium (Ru) is a transition metal of the platinum group, with potentially less toxicity than platinum drugs. We postulated that ruthenium-arene complexes are radiosensitisers when used in combination with RT. We screened 14 ruthenium-arene complexes and identified AH54 and AH63 as supra-additive radiosensitisers by clonogenic survival assays and isobologram analyses. Both complexes displayed facial chirality. At clinically relevant doses of RT, radiosensitisation of cancer cells by AH54 and AH63 was p53-dependent. Radiation enhancement ratios for 5–10 micromolar drug concentrations ranged from 1.19 to 1.82. In p53-wildtype cells, both drugs induced significant G2 cell cycle arrest and apoptosis. Colorectal cancer cells deficient in DNA damage repair proteins, EME1 and MUS81, were significantly more sensitive to both agents. Both drugs were active in cancer cell lines displaying acquired resistance to oxaliplatin or cisplatin. Our findings broaden the potential scope for these drugs for use in cancer therapy, including combination with radiotherapy to treat colorectal cancer. PMID:26867983

  12. Cadmium-sensitive electrode based on tetracetone derivatives of p-tert-butylcalix[8]arene

    Energy Technology Data Exchange (ETDEWEB)

    Dernane, C. [Université de Jijel, Laboratoire de Matériaux: Elaborations-Propriétés-Applications, BP 98, Ouled Aissa, 18000 Jijel (Algeria); Zazoua, A., E-mail: azazoua@yahoo.fr [Université de Jijel, Laboratoire de Matériaux: Elaborations-Propriétés-Applications, BP 98, Ouled Aissa, 18000 Jijel (Algeria); Kazane, I. [Université de Jijel, Laboratoire de Matériaux: Elaborations-Propriétés-Applications, BP 98, Ouled Aissa, 18000 Jijel (Algeria); Jaffrezic-Renault, N. [Université de Lyon, LSA-UMR 5180 CNRS, Université Claude Bernard Lyon 1, 69622 Villeurbanne cedex (France)

    2013-10-15

    The performance of a cadmium-sensitive electrode based on the tetracetone derivatives of p-tert butylcalix[8]arene was investigated. The ion-sensitivity of the calix[8]arene was examined via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectrometry, UV/Vis spectroscopy and FT-IR spectroscopy. The sensitive membrane containing the active ionophore was cast onto the surface of a gold electrode. The electrode exhibited a linear relationship between the charge transfer resistance (R{sub ct}) and the logarithm of the detected ion concentration. The cathodic peak at a potential of 0.56 V increased linearly as the Cd{sup 2+} ion concentration increased. The detection limit of the device reached 10{sup −7} M with high sensitivity toward cadmium. - Highlights: • The performances of cadmium-sensitive electrode were investigated. • The sensitive membrane was casted on the surface of a gold electrode. • The electrode showed a linear relationship between the R{sub ct} and the ion concentration. • The detection limit of the device was 10{sup −7} M with high sensitivity toward cadmium.

  13. Characterization of an azo-calix[4]arene-based optical sensor for Europium (III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Echabaane, M., E-mail: mosaab.echabaane@gmail.com [Laboratoire d' interfaces et Materiaux Avances (LIMA) Faculte des sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Rouis, A. [Laboratoire d' interfaces et Materiaux Avances (LIMA) Faculte des sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Institut de Chimie and Biochimie Moleculaires and Supramoleculaires (ICBMS), UMR CNRS 5246, 43 Boulevard du 11 Novembre 1918, Universite Claude Bernard Lyon 1, 69100 Villeurbanne (France); Ouada, H. Ben [Laboratoire d' interfaces et Materiaux Avances (LIMA) Faculte des sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia)

    2012-07-01

    Selective and sensitive optical sensor membranes (optodes) were elaborated to detect cations in aqueous solutions. The sensing films are based on chromogenic calix[4]arene derivatives. The optode membranes were studied using UV/Vis absorption spectroscopy measurements. The sensitivity of the optode has been tested for Pb{sup 2+}, Cd{sup 2+}, Mg{sup 2+} and Eu{sup 3+} ions at pH 6.8. The results showed a good selectivity response towards Eu{sup 3+}. Low selectivity coefficients were observed for Cd{sup 2+} and Mg{sup 2+} where Pb{sup 2+} can be considered as interfering ions. The characteristics of this optode such as response time, regeneration, reproducibility and lifetime are discussed. - Highlights: Black-Right-Pointing-Pointer We report optical sensing studies of chromogenic calixarene derivatives. Black-Right-Pointing-Pointer We investigate optical interaction between azo-calix[4]arene and Eu{sup 3+}. Black-Right-Pointing-Pointer We study sensitivity and selectivity of optode films. Black-Right-Pointing-Pointer We describe characteristics of optode films for determination of europium traces.

  14. Theoretical Studies on the Intermolecular Interactions of Aza-calix[2]arene[2]-triazines with RDX

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-Mei; SHI Wen-Jing; ZHAO Shu-Sen; REN Fu-De; CAO Duan-Lin

    2011-01-01

    Six fully optimized structures of the aza-calix[2]arene[2]-triazines/RDX supramolecular complexes have been obtained at the DFT-B3LYP/6-311++G** level, and the corresponding intermolecular interactions have been investigated using the B3LYP, mPWPW91 and MP2 methods at the 6-311++G** level, respectively. The natural bond orbital (NBO) and atoms in molecules (AIM) analyses have been performed to reveal the origin of interactions. To our interest, the result indicates that the strongest interaction is up to -22.34 kJ/mol after basis set superposition error (BSSE) and zero point energy (ZPE) correction at the MP2/6-311++G** level. Furthermore, the intermolecular interactions between aza-calix[2]arene[2]-triazines with the substituted amidos and RDX are stronger than those of other complexes. Thus, the complexes with amidos can be used as the candidates to increase the stability of explosive and eliminate the explosive wastewater.

  15. Ir/Sn dual-reagent catalysis towards highly selective alkylation of arenes and heteroarenes with benzyl alcohols

    Indian Academy of Sciences (India)

    Sujit Roy; Susmita Podder; Joyanta Choudhury

    2008-09-01

    A catalytic combination of [Ir(COD)Cl]2-SnCl4 efficiently promotes the reactions of arenes and heteroarenes with 1°/2°/3° benzyl alcohols as the alkylating agents to afford the corresponding diarylmethane and triarylmethane derivatives in high yields. The scope and limitation of the reaction with respect to catalyst and substrates variation has been studied in detail.

  16. Complexation of uranium with 1, 3, 5-trimethoxy 2, 4, 6-tricarboxymethoxy-P-tert-butyl calix(6) arene

    International Nuclear Information System (INIS)

    Complexation behaviour of UO22+ with 1,3,5-trimethoxy 2,4,6-tricarboxymethoxy-p-tert-butyl calix[6]arene under varying conditions of pH and acetate ion concentration has been studied. These studies indicate that extraction mechanism of uranium is influenced by the presence of Na+ ion. (author)

  17. A New Strategy for Architecture of Robust Monolayer Based on Binuclear Palladium (II) Complex of Calix[4]arene Derivative

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A monolayer which is formed by a binuclear palladium complex of low rim methionine-disubstituted calix[4]arene exhibits extraordinary cohesiveness. Cohesiveness measurement and Brewster Angle Microscopy observation show that the monolayer is uniform and robust. This film is probably formed by self-assembly of precursor complex through strong chloride ion bridge between palladium centers.

  18. Para-ter-butyl of calix(4)arene with acetamide-ether as inorganic-organic receiver

    International Nuclear Information System (INIS)

    A new functionalized calix(4)arene was designed and constructed with predetrmined properties to form lanthanides complexes and to sensibilize its luminescent properties. This, in addition to sensibilize that photophysical property and once formed the complex resulted a good receiver of organic molecules as it is demonstrated the crystal structure of the lutetium complex. (Author)

  19. Sequential FRET processes in calix[4]arene-linked orange-red-green perylene bisimide dye zigzag arrays

    NARCIS (Netherlands)

    C. Hippius; I.H.M. van Stokkum; M. Gsänger; M.M. Groeneveld; R.M. Williams; F. Würthner

    2008-01-01

    Perylene bisimide-calix[4]arene arrays composed of up to three different types of perylene bisimide chromophores (orange, red, and green PBIs) have been synthesized. Within these arrays, the individual chromophoric building blocks are positioned in defined spatial orientation and are easily replacea

  20. Ground- and excited-state pinched cone equilibria in calix[4]arenes bearing two perylene bisimide dyes

    NARCIS (Netherlands)

    C. Hippius; I.H.M. van Stokkum; E. Zangrando; R.M. Williams; M. Wykes; D. Beljonne; F. Würthner

    2008-01-01

    We report oil a series of bis-chromophoric compounds o2c, g2c, and r2c, afforded by linking two identical orange, green, or red perylene bisimide (PBI) units, respectively, through a calix[4]arene spacer unit. The PBI units are characterized by their increasing sterical demand from a planar conforma

  1. Self-assembly of amphiphilic anionic calix[4]arenes and encapsulation of poorly soluble naproxen and flurbiprofen.

    Science.gov (United States)

    Barbera, Lucia; Gattuso, Giuseppe; Kohnke, Franz H; Notti, Anna; Pappalardo, Sebastiano; Parisi, Melchiorre F; Pisagatti, Ilenia; Patanè, Salvatore; Micali, Norberto; Villari, Valentina

    2015-06-21

    Supramolecular aggregates formed through the association of an amphiphilic tetra-O-butylsulfonate calix[4]arene 1 were investigated in aqueous solution by a combination of different techniques (NMR, DLS and AFM). The ability of the micellar aggregates of calixarene 1 to increase the solubility of poorly water-soluble drugs was studied.

  2. Self-assembled arene-ruthenium-based rectangles for the selective sensing of multi-carboxylate anions.

    Science.gov (United States)

    Vajpayee, Vaishali; Song, Young Ho; Lee, Min Hyung; Kim, Hyunuk; Wang, Ming; Stang, Peter J; Chi, Ki-Whan

    2011-07-01

    Novel arene-ruthenium [2+2] metalla-rectangles 4 and 5 have been synthesized by self-assembly using dipyridyl amide ligand 3 and arene-ruthenium acceptors (arene: benzoquinone (1), naphthacenedione (2)) and characterized by NMR spectroscopy and ESI-MS. The solid-state structure of 5 was determined by X-ray diffraction and shows encapsulated diethyl ether molecule in the rectangular cavity of 5. The luminescent 5 was further used for anion sensing with the amidic linkage serving as a hydrogen-bond donor site for anions and the ruthenium moiety serving as a signaling unit. A UV/Vis titration study demonstrated that although 5 interacts very weakly with common monoanions as well as with flexible dicarboxylate anions such as malonate and succinate, it displays significant binding affinity (K>10(3) in MeOH) for rigid multi-carboxylate anions such as oxalate, citrate, and tartrate, exhibiting a 1:1 stoichiometry. It has been suggested that 1:1 bidentate hydrogen bonding assisted by appropriate geometrical complementarity is mainly responsible for the increased affinity of 5 towards such anions. A fluorescence titration study revealed a large fluorescence enhancement of 5 upon binding to multi-carboxylate anions, which can be attributed to the blocking of the photoinduced electron-transfer process from the arene-Ru moiety to the amidic donor in 5 as a result of hydrogen bonding between the donor and the anion.

  3. CMPO-substituted calix[6]- and calix[8]arene extractants for the separation of An{sup 3+}/Ln{sup 3+} from radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Sansone, Francesco; Fontanella, Marco; Casnati, Alessandro; Ungaro, Rocco [Dipartimento di Chimica Organica e Industriale, Universita di Parma, V.le G. P. Usberti 17/A, I-43100 Parma (Italy); Boehmer, Volker; Saadioui, Mohamed [Fachbereich Chemie, Pharmazie und Geowissenschaften, Abteilung Lehramt Chemie, Johannes Gutenberg-Universitaet, Duesbergweg 10-14, D-55099 Mainz (Germany); Liger, Karine; Dozol, Jean-Fran is [CEA/DEN Cadarache, DED/SEP/LCD, 13108 Saint Paul lez Durance (France)

    2006-07-01

    Three calix[6]arene derivatives (1a-c) and two calix[8]arene derivatives (2a,b), with six and eight CMPO residues, respectively, attached to the narrow/lower rim via ether links, were synthesised. Preliminary liquid-liquid extraction studies for Eu(III) and Ann(III) from aqueous nitric acid to o-nitrophenyl-hexyl ether reveal remarkable properties with respect to efficiency and selectivity, especially for the tert-butyl-calix[6]arene derivative with a -(CH{sub 2}){sub 3}-spacer. (authors)

  4. Complex behavior and source model of the tremor at Arenal volcano, Costa Rica

    Science.gov (United States)

    Lesage, Philippe; Mora, Mauricio M.; Alvarado, Guillermo E.; Pacheco, Javier; Métaxian, Jean-Philippe

    2006-09-01

    Typical records of volcanic tremor and explosion quakes at Arenal volcano are analyzed with a high-resolution time-frequency method. The main characteristics of these seismic signals are: (1) numerous regularly spaced spectral peaks including both odd and even overtones; (2) frequency gliding in the range [0.9-2] Hz of the fundamental peak; (3) frequency jumps with either positive or negative increments; (4) tremor episodes with two simultaneous systems of spectral peaks affected by independent frequency gliding; (5) progressive transitions between spasmodic tremor and harmonic tremor; (6) lack of clear and systematic relationship between the occurrence of explosions and tremor. Some examples of alternation between two states of oscillation characterized by different fundamental frequencies are also observed. Some tremor and explosion codas are characterized by acoustic and seismic waves with identical spectral content and frequency gliding, which suggests a common excitation process. We propose a source model for the tremor at Arenal in which intermittent gas flow through fractures produces repetitive pressure pulses. The repeating period of the pulses is stabilized by a feedback mechanism associated with standing or traveling waves in the magmatic conduit. The pressure pulses generate acoustic waves in the atmosphere and act as excitation of the interface waves in the conduit. When the repeating period of the pulses is stable enough, they produce regularly spaced spectral peaks by the Dirac comb effect and hence harmonic tremor. When the period stability is lost, because of failures in the feedback mechanism, the tremor becomes spasmodic. The proposed source model of tremor is similar to the sound emission process of a clarinet. Fractures in the solid or viscous layer capping the lava pool in the crater act as the clarinet reed, and the conduit filled with low velocity bubbly magma is equivalent to the pipe of the musical instrument. The frequency gliding is

  5. SYNTHESIS AND SPECTRAL-LUMINESCENT PROPERTIES OF CALIX[4]ARENES MODIFIED WITH CARBOXYLIC, PHTHALIMIDE AND AMINOETHOXY-GROUPS, AND THEIR LANTHANIDE-CONTAINING COMPLEXES

    OpenAIRE

    Fadeyev, Y. M.; Snurnikova, O. V.; Lukyanenko, O. P.; Alyeksyeyeva, O. O.; Rusakova, N. V.

    2015-01-01

    p-tert-Butylcalix[4]arene derivatives modified with carboxylic, phthalimide and aminoethoxy-groups on the lower rim as well as their lanthanide (ytterbium and lutetium) complexes were synthesized. Spectral-luminescent properties of obtained compounds were analyzed.

  6. Study on the inclusion interaction of p-sulfonated calix[ n]arenes with Vitamin K 3 using methylene blue as a spectral probe

    Science.gov (United States)

    Lu, Qin; Gu, Jiashan; Yu, Huapeng; Liu, Chun; Wang, Lun; Zhou, Yunyou

    2007-09-01

    The characteristics of host-guest complexation between p-sulfonated calix[ n]arene ( SCnA, n = 4, 6) and Vitamin K 3 ( VK3) were investigated by fluorescence spectrometry and absorption spectrometry using methylene blue ( MB) as a probe. Interaction with MB and SCnA led to an obvious decrease in fluorescence intensity of MB, accompanying with shifts of emission peaks. Absorption peaks also showed interesting changes; however, when VK3 was added, fluorescence intensity and absorbance recovered and a slight and slow red shift was observed. The obtained results showed that the inclusion ability of p-sulphonated calix[ n]arenes towards VK3 was the order: p-sulphonated calix[6]arene ( SC6A) > p-sulphonated calix[4]arene ( SC4A). Relative mechanism was proposed to explain the inclusion process.

  7. Surface Morphology and Coordination Chemistry of 4-Isopropylcalix[4]Arene as an Ionophore with Chromium (III) in Fabrication of Cr3+ Selective Membrane Sensor

    International Nuclear Information System (INIS)

    The present work deals with a poly (vinyl chloride) based selective membrane incorporating 4-Isopropylcalix[4]arene as an ionophore which has been prepared and explored as Cr3+ cation selective sensor. The strengths of the ion-ionophore (Cr3+ - 4- Isopropylcalix[4]arene) interactions and the role of ionophore on membrane performance has been studied. The ligand coordination with the ion investigated via IR and UV-Vis spectroscopy. (author)

  8. Tetranuclear manganese(II) complexes of sulfonylcalix[4]arene macrocycles: synthesis, structure, spectroscopic and magnetic properties.

    Science.gov (United States)

    Lamouchi, Meriem; Jeanneau, Erwann; Pillonnet, Anne; Brioude, Arnaud; Martini, Matteo; Stéphan, Olivier; Meganem, Faouzi; Novitchi, Ghenadie; Luneau, Dominique; Desroches, Cédric

    2012-03-01

    Two tetranuclear manganese(II) complexes {K(+)[Mn(4)(ThiaSO(2))(2)(OH)](-)} (1) and {K(+)[Mn(4)(ThiaSO(2))(2)(F)](-)} (2) have been synthesized under solvothermal conditions in methanol with p-tert-butylsulfonylcalix[4]arene (ThiaSO(2)). For both complexes, the structure has been established from single-crystal X-ray diffraction. The two complexes are best described as manganese squares sandwiched between two thiacalixarene macrocycles. In both complexes, in the center of the square formed by the four manganese(II) atoms, the unexpected presence of μ(4)-OH(-) or μ(4)-F(-) gives a negative charge to the cluster. The two tetranuclear complexes exhibit strong orange luminescence behavior resulting from the symbiosis between the ThiaSO(2) and the Mn(2+). Despite similar chemical formulation, (1) and (2) present difference in emission intensity and lifetime τ. PMID:22266843

  9. Antiproliferative activity of ruthenium(ii) arene complexes with mono- and bidentate pyridine-based ligands.

    Science.gov (United States)

    Richter, Stefan; Singh, Sushma; Draca, Dijana; Kate, Anup; Kumbhar, Anupa; Kumbhar, Avinash S; Maksimovic-Ivanic, Danijela; Mijatovic, Sanja; Lönnecke, Peter; Hey-Hawkins, Evamarie

    2016-08-16

    A series of Ru(II) arene complexes of mono- and bidentate N-donor ligands with carboxyl or ester groups and chlorido ancillary ligands were synthesised and structurally characterised. The complexes have a distorted tetrahedral piano-stool geometry. The binding interaction was studied with calf thymus DNA (CT-DNA) by absorption titration, viscosity measurement, thermal melting, circular dichroism, ethidium bromide displacement assay and DNA cleavage of plasmid DNA (pBR322), investigated by gel electrophoresis. The dichlorido complexes bind covalently to DNA in the dark, similar to cisplatin, while the monochlorido complexes bind covalently on irradiation, similar to cisplatin analogues. The compounds are selectively cytotoxic against several tumour cell lines and show specific nonlinear correlation between dose and activity. This phenomenon is closely related to their potential to act preferentially as inhibitors of cell division. PMID:27264161

  10. Selective Electrochemical Recognition of o-Phenylenediol by a Novel Calix[4]arene Derivative

    Institute of Scientific and Technical Information of China (English)

    L(U), Jian-Quan; ZHANG, Hai-Li; LU, Ping

    2007-01-01

    A new type of calixarene-modified electrode has been prepared by directly coating the surface of a glassy carbon electrode with tetrahydrofuran solution containing 25,26,27,28-tetra-(3-amidino thiopropoxy)-5,11,17,23-tetratert-butylcalix[4]arene, and applied to the investigation of electrochemical behavior of phenylenediols. The results showed that the modified electrode could selectively recognize o-phenylenediol, making the over-potential of o-phenylenediol dropped and peak current increased greatly. The anodic peak current is proportional to the concentration of o-phenylenediol in the range of 1.0 × 10-5-1.0 × 10-4 mol· L-1 with the detection limit (S/N= 3) of 1.0 ×10-7 mol·L-1. The recognizing mechanism, including electrochemical process and binging sites, was also discussed using voltammetry.

  11. The Olefin Metathesis Reactions Combined with Organo-Iron Arene Activation Towards Dendrimers, and Polymers

    Science.gov (United States)

    Astruc, Didier; Martinez, Victor

    The subjects treated in the two lectures of the North Atlantic Treaty Organization (NATO) summer course are (1) the combination of arene activation and perfunctionalization using organo-iron chemistry with olefin metathesis incuding metathesis of dendritic polyolefin molecules; (2) the synthesis of metallodendritic benzylidene complexes that catalyse ring-opening metathesis polymerization (ROMP) under ambient conditions and the formation of dendritic stars; (3) the use of stoichiometric and catalytic electron-transfer processes with standard reservoirs of electrons (reductants) or electron holes (oxidants) iron complexes to achieve noteworthy metathesis reactions or synthesize compounds that are useful in metathesis. Only the two first topics are treated in this chapter, and interested readers can find references concerning the third aspect called in the introduction and subsequently cited in the reference list.

  12. Supramolecular Drug Delivery Systems Based on Water-Soluble Pillar[n]arenes.

    Science.gov (United States)

    Wu, Xuan; Gao, Lei; Hu, Xiao-Yu; Wang, Leyong

    2016-06-01

    Supramolecular drug delivery systems (SDDSs), including various kinds of nanostructures that are assembled by reversible noncovalent interactions, have attracted considerable attention as ideal drug carriers owing to their fascinating ability to undergo dynamic switching of structure, morphology, and function in response to various external stimuli, which provides a flexible and robust platform for designing and developing functional and smart supramolecular nano-drug carriers. Pillar[n]arenes represent a new generation of macrocyclic hosts, which have unique structures and excellent properties in host-guest chemistry. This account describes recent progress in our group to develop pillararene-based stimuli-responsive supramolecular nanostructures constructed by reversible host-guest interactions for controllable anticancer drug delivery. The potential applications of these supramolecular drug carriers in cancer treatment and the fundamental questions facing SDDSs are also discussed.

  13. Extraction and Binding Efficiency of Calix[8]arene Derivative Toward Selected Transition Metals

    Directory of Open Access Journals (Sweden)

    Imdadullah Qureshi

    2008-12-01

    Full Text Available In this article we have explored the extraction efficiency as well as binding ability of calix[8]arene derivative (3 for selected transition metal ions (Co2+, Cd2+, Ni2+, Pb2+ and Cu2+. Picrate salt solutions of these metals were used in the liquid-liquid extraction experiments. It is apparent from the results that ligand 3 shows appreciable high extraction of transition metal cations, with the relative order Pb2+>Cu2+>Ni2+>Co2+>Cd2+ being observed. Highest extraction efficiency has been observed for Pb2+ and Cu2+ i.e. 95 and 91% respectively. The significant extraction and complexation ability for these metal ions may be attributed to the nature, size, structure and geometry of both ligand and metal ions.

  14. X-Ray structure and cytotoxic activity of a picolinate ruthenium(II–arene complex

    Directory of Open Access Journals (Sweden)

    IVANKA IVANOVIĆ

    2011-01-01

    Full Text Available A ruthenium(II–arene complex with picolinic acid, [(η6-p-cymeneRuCl(pico]∙H2O, was prepared by the reaction of [(η6-p-cymeneRuCl2]2 with picolinic acid in a 1:2 molar ratio in 2-propanol. The compound was characterized by elemental analysis, and IR and NMR spectroscopy. X-ray diffraction analysis showed that the molecule adopts a “three-leg piano-stool” geometry, which is common for this type of complexes. The cytotoxic activity of the complex was tested in two human cancer cell lines HeLa (cervix and FemX (melanoma by MTT assay. The IC50 values were at 82.0 and 36.2 µmol dm-3 for HeLa and FemX cells, respectively.

  15. Mercedes García-Arenal, coord., Al-Andalus allende el-Atlántico

    OpenAIRE

    Aubaile-Sallenave, Françoise

    2007-01-01

    Allende el Atlántico est l’une des publications marquantes que l’Unesco a réalisée en Espagne pour commémorer l’année 1492. Cet ouvrage collectif, qui comprend quatorze articles de spécialistes coordonnés par Mercedes García Arenal, présente divers aspects de la contribution de la culture arabo-andalouse à la culture hispanique – en ce qui concerne la vie sociale la navigation, le cheval, l’agriculture, l’irrigation, les plantes et leurs corollaires, l’alimentation, la médecine, l’habitat – e...

  16. Molecular modeling of complexation behavior of p-tert-butylcalix[5]arene derivative toward butylammonium ions

    International Nuclear Information System (INIS)

    Using several molecular modeling programs we have performed computer simulations to investigate the complexation behaviors of an ester derivative of p-ter-butylcalix[5]arene (1e) toward a variety of butyl-ammonium ions. Semi-empirical AM1 method was used for calculating the binding energies and the formation enthalpies. MM and CVFF forcefields for molecular mechanics calculations were adapted to express the complexation energies of the host. Molecular dynamics were performed to the calculated complex systems to simulate the ionophoric behavior of the host-guest complexes. The absolute Gibbs free energies of the host (1e) complexed with four kinds of butylammonium ions have been calculated using the Finite Difference Thermodynamic Integration (FDTI) method in Discover. Calculation results show that the trend in complex formation is n-BuNH3+> iso-BuNH3+>> sec-BuNH3+> tert-BuNH3+, which is in good agreement with the experimental results

  17. Pillar[5]arene-Based Glycoclusters: Synthesis and Multivalent Binding to Pathogenic Bacterial Lectins.

    Science.gov (United States)

    Buffet, Kevin; Nierengarten, Iwona; Galanos, Nicolas; Gillon, Emilie; Holler, Michel; Imberty, Anne; Matthews, Susan E; Vidal, Sébastien; Vincent, Stéphane P; Nierengarten, Jean-François

    2016-02-24

    The synthesis of pillar[5]arene-based glycoclusters has been readily achieved by CuAAC conjugations of azido- and alkyne-functionalized precursors. The lectin binding properties of the resulting glycosylated multivalent ligands have been studied by at least two complementary techniques to provide a good understanding. Three lectins were selected from bacterial pathogens based on their potential therapeutic applications as anti-adhesives, namely LecA and LecB from Pseudomonas aeruginosa and BambL from Burkholderia ambifaria. As a general trend, multivalency improved the binding to lectins and a higher affinity can be obtained by increasing to a certain limit the length of the spacer arm between the carbohydrate subunits and the central macrocyclic core.

  18. Enhancement of cytotoxicity by combining pyrenyl-dendrimers and arene ruthenium metallacages.

    Science.gov (United States)

    Pitto-Barry, Anaïs; Zava, Olivier; Dyson, Paul J; Deschenaux, Robert; Therrien, Bruno

    2012-07-01

    Three generations of pyrenyl bis-MPA dendrimers with two different end-groups, acetonide (pyr(Gn)) or alcohol (pyr(Gn-OH)) (n = 1-3), were synthesized, and the pyrenyl group of the dendritic molecules was encapsulated in the arene ruthenium metallacages, [Ru(6)(p-cymene)(6)(OO∩OO)(3)(tpt)(2)](6+) (OO∩OO = 5,8-dioxydo-1,4-naphtaquinonato (donq) [1](6+) and 6,11-dioxydo-5,12-naphtacenedionato (dotq) [2](6+); tpt =2,4,6-tri(pyridin-4-yl)-1,3,5-triazine). The host-guest properties of [guest⊂1](6+) and [guest⊂2](6+) were studied in solution by NMR and UV-vis spectroscopic methods, thus allowing the determination of the affinity constants. Moreover, the cytotoxicity of these water-soluble host-guest systems and the pyrenyl-dendrimers was evaluated on human ovarian cancer cells. PMID:22716166

  19. Sol-Gel-Coated Calix[4]arene Fiber for Solid-Phase Microextraction

    Institute of Scientific and Technical Information of China (English)

    LiXiu-juan; XiaoRui-min; LiHai-bing; ZengZhao-rui

    2003-01-01

    5, 11, 17, 23-tetra-tert-butyl-25, 27-diethoxy-26, 28-dihydroxycalix [4] arene/hydroxy-terminated silicone oil coated fiber was first prepared and applied for solid-phase microextraction with sol-gel technology. The properties of the new coating were investigated by analysis of benzene derivatives, polycyclic aromatic hydrocarbons and aromatic amines.The fiber is characterized by good sensitivity and selectivity to these aromatics. The fiber has stable performance at a high temperature of 380℃ and after a long solvent immersing,thus its lifetime is very long. It shows good fiber-to-fiber and batch-to-batch reproducibility. Furthermore, broad linear ranges and low detection limits are also its characteristics.

  20. Supported organoactinide complexes as heterogeneous catalysts. A kinetic and mechanistic study of facile arene hydrogenation

    International Nuclear Information System (INIS)

    This contribution reports a kinetic and mechanistic study of arene hydrogenation by the supported organoactinide complexes Cp'Th(benzyl)3/DA (1/DA), Th(1,3,5-CH2C6H3Me2)4/DA (2/DA), and Th(η3-allyl)4/DA (3/DA) where Cp' = η5-Me5C5 and DA = dehydroxylated γ-alumina. In slurry reactions (90 degrees C, PH2 = 180 psi), the activity for benzene hydrogenation follows the order 1/DA t value for 3/DA of ∼25,000 h-1 active site-1. This approaches or exceeds most conventional platinum metal catalysts in efficacy for benzene reduction. Partially hydrogenation products cannot be detected at partial conversions, and there is no D2 incorporated in the unconverted benzene. D2 is not delivered to a single benzene face, but rather a 1:3 mixture of all-cis and cis,cis,trans,cis,trans isotopomers is formed. Active site characterizations using D2O poisoning, hydrogenolysis, and CH3Cl dosing indicate that ≤8 ± 1% of the Th surface sites are responsible for the bulk of the benzene hydrogenation. EPR and XPS studies provide no evidence for surface Th oxidation states less than +4. As a function of arene, the relative rates of Th(η3-C3H5)4/DA-catalyzed hydrogenation are benzene > toluene > p-xylene > naphthalene, with the regiochemistry of p-xylene reduction similar to that for benzene. Experiments with 1:1 benzene-p-xylene mixtures reveal that benzene is preferentially hydrogenated with almost complete exclusion of p-xylene (∼97:3), inferring that the benzene binding constant to the active sites is ∼6.7x that of p-xylene. 51 refs., 8 figs., 2 tabs

  1. Sensor for Silver(I Ion Based on Schiff-base-p-tertbutylcalix[4]arene

    Directory of Open Access Journals (Sweden)

    M. Kumar

    2002-10-01

    Full Text Available The preparation of polymer membrane selective to silver ion and its application to ion-selective electrode is reported here. PVC membrane contain silver-selective calix[4]arene derivative as ionophore. The membrane electrode is highly selective to silver ion and exhibit good linear response over a wide concentration range of 1.0×10-1 to 1.0×10-5M AgNO3 with Nernstian slope of 58.9 mV per decade. The detection limit of electrode is 6.31×10-6 M .The calix[4]arene based membrane electrode exhibit enhanced selectivities for silver ion over other cations; log KPotAg,Na = -2.35, log KPotAg,K= -2.65, log KPotAg,Mg = -4.57, log KPotAg,Ba = -4.10, log KPotAg,Cd = -3.42, log KPotAg,Pb = -3.45.Even the strongest interferent Hg2+ do not interfere to great extent, log KPotAg,Hg = -2.0.The electrode response is stable over wide pH range of 1.0-6.0. The response time of the sensor is 30 seconds and the membrane can be used for more than 6 months without observing any divergence. The sensor can also be applied as an indicator electrode for potentiometric titration of Ag+ ions with Cl-. It is possible to determine Ag(I in the natural water spiked with silver with this electrode assembly.

  2. Electron transport properties of some new 4-tert-butylcalix[4]arene derivatives in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Leontie, Liviu, E-mail: lleontie@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, B-dul Carol I, Nr. 11, 700506 Iasi (Romania); Danac, Ramona [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, B-dul Carol I, Nr. 11, 700506 Iasi (Romania); Girtan, Mihaela [Laboratoire LPhiA, Angers University, 2, Bd. Lavoisier, 49045, Angers (France); Carlescu, Aurelian; Rambu, Alicia Petronela; Rusu, Gheorghe I. [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, B-dul Carol I, Nr. 11, 700506 Iasi (Romania)

    2012-07-16

    Temperature dependences of electric conductivity and thermoelectric power of some recently synthesized organic compounds, 4-tert-butylcalix[4]arene derivatives, are studied. Thin-film samples (d = 0.10-0.40 {mu}m) spin-coated from chloroform solutions onto glass substrates were used. Organic films with reproducible electron transport properties can be obtained if, after deposition, they are submitted to a heat treatment within temperature range of 295-575 K. The studied polycrystalline compounds show typical p-type semiconductor behavior. The activation energy of the electric conduction ranges between 0.82 and 1.12 eV, while the ratio of charge carrier mobilities was found in the range of 0.83-0.94. Some correlations between semiconducting parameters and molecular structure of the organic compounds have been discussed. In the higher temperature ranges (T > 420 K), the electron transport in examined compounds can be interpreted in terms of the band gap representation model, while in the lower temperature range, the Mott's variable-range hopping conduction model was found to be appropriate. The investigated compounds hold promise for thermistor applications. - Highlights: Black-Right-Pointing-Pointer 4-tert-butylcalix(4)arene derivatives in thin films are p-type semiconductors. Black-Right-Pointing-Pointer The electron transfer is favored by their extended conjugation and packing capacity. Black-Right-Pointing-Pointer The band gap representation is suitable in the higher temperature range. Black-Right-Pointing-Pointer The Mott's VRH conduction model may be applied in the lower temperature range. Black-Right-Pointing-Pointer As-prepared organic compounds are promising for thermistor applications.

  3. Palladium-catalyzed Cs2CO3-promoted arylation of unactivated C(sp(3))-H bonds by (diacetoxyiodo)arenes: shifting the reactivity of (diacetoxyiodo)arenes from acetoxylation to arylation.

    Science.gov (United States)

    Gou, Quan; Zhang, Zhao-Fu; Liu, Zhi-Cheng; Qin, Jun

    2015-03-20

    PdCl2(CH3CN)2-catalyzed arylation of unactivated C(sp(3))-H bonds using (diacetoxyiodo)arenes as arylation reagents is reported. The reactivity of (diacetoxyiodo)arenes as arylation reagents is enabled in the presence of Cs2CO3 under the reaction conditions. This arylation method is highly efficient and occurs without the use of silver salt. The reaction tolerates a broad substrate scope that was not demonstrated by other silver salt-free C(sp(3))-H bond arylation conditions. The synthetic utility of the method is further illustrated in the synthesis of the psychotropic drug phenibut. A detailed mechanism study has been conducted to understand the reaction pathway. PMID:25763683

  4. Glycine Betaine Recognition through Cation−π Interactions in Crystal Structures of Glycine Betaine Complexes with C-Ethyl-pyrogallol[4]arene and C-Ethyl-resorcin[4]arene as Receptors

    Directory of Open Access Journals (Sweden)

    Ikuhide Fujisawa

    2013-04-01

    Full Text Available The glycine betaine (betaine, interacts with several types of proteins with diverse structures in vivo, and in the contact regions, the aromatic rings of protein residues are frequently found beside the trimethylammonium group of betaine, implying the importance of the cation−π interactions in recognition of this molecule. The crystal structures determined by X-ray crystallography of the complexes of betaine and C-ethyl-pyrogallol[4]arene (pyrogallol cyclic tetramer: PCT and betaine and C-ethyl-resorcin[4]arene (resorcinol cyclic tetramer: RCT mimic the conformations of betaine and protein complexes and show that the clathrate conformations are retained by the cation−π interactions. The difference of the conformation feature of betaine in the Protein Data Bank and in the Cambridge Structural Database was found by chance during the research and analyzed with the torsion angles.

  5. Synthetic studies on axial chiral biaryls and functional materials utilizing arene-metal complexes; aren kinzokusakutai no tokusei wo riyo shita jikufusai biariru, oyobi shinki kinosei zairyo no gosei kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, Motokazu [Osaka Prefecture University, Osaka (Japan). Faculty of Integrated Arts and Sceinces

    1999-12-16

    Axially chiral biaryls compounds are of importance not only as chiral ligands for asymmetric reactions but also as biologically active natural products, e. g., korupensamine, michellamine and vancomycin. (Arene) chromium complex exists in two enantiomeric forms based on a planar chirality. Axially chiral biaryls were stereoselectively prepared by palladium(0)-catalyzed cross-coupling of (aryl halide)Cr(CO){sub 3} complexes with arylboronic acids. This method was applied for the total synthesis of antimaralial agent korupensamine A, naphthyltetrahydro-isoquinoline alkaloid. Furthermore, chiral 1,2-diols and diamines are important compounds for asymmetric reactions. These enantionerically pure 1,2-diols and 1,2-diamines were stereoselectively prepared by pinacol coupling of planar chiral chromium complexes of benzaldehydes and benzaldimines with samarium iodide. Moreover, non-biaryl axial compounds, N,N-dialkyl 2,6-disubstituted benzamides were synthesized in enantiomerically pure form utilizing planar chiral arene chromium complex. (author)

  6. The effect of temperatures and γ-ray irradiation on silica-based calix[4]arene-R14 adsorbent modified with surfactants for the adsorption of cesium from nuclear waste solution

    Science.gov (United States)

    Chen, Zi; Wu, Yan; Wei, Yuezhou

    2014-10-01

    1,3-[(2,4-Diethylheptylethoxy)oxy]-2,4-crown-6-Calix[4]arene(Calix[4]arene-R14), used as an extractant of Cs(I) from nitric acid, modified by dodecanol and dodecyl benzenesulfonic acid (DBS), was loaded into the pores of macroporous silica-based polymer support (SiO2-P) particles. To evaluate the stability of the adsorbent, the adsorption data at different temperatures (298-323 K) and γ-ray absorbed doses (10-200 kGy) were analyzed by the Langmuir isotherm. The minimum adsorbed amount was calculated to be 0.121 mmol g-1 at 323 K, approximately 23% reduction compared to 298 K. The maximum adsorbed amount of not-irradiated adsorbent with 0.156 mmol g-1 decreased by 20% than that irradiated in 0.5 M HNO3. The thermodynamic parameters have revealed that this adsorption reaction is an exothermic and spontaneous process. The reduction in 3 M HNO3 was about 45% by the comparison between the before- and after-irradiation. It was found that both the concentrations of HNO3 and DBS have significant influence on the degradation of the adsorbents.

  7. Tubular Structures Self-Assembled from a Bola-Amphiphilic Pillar[5]arene in Water and Applied as a Microreactor.

    Science.gov (United States)

    Chen, Rener; Jiang, Huajiang; Gu, Haining; Zhou, Qizhong; Zhang, Zhen; Wu, Jiashou; Jin, Zhengneng

    2015-09-01

    Various nanomorphologies were obtained by simply changing the fabrication conditions, such as the pH of the system, different solvent, or different concentration, of bola-amphiphilic pillar[5]arene Bola-AP5. Importantly, hybrid microtubules as a microreactor were successfully prepared by directly reducing AuCl4(-) on the surface of Bola-AP5-based tubular structures in water. PMID:26275020

  8. Solid Lipid Nanoparticle-Based Calix[n]arenes and Calix-Resorcinarenes as Building Blocks: Synthesis, Formulation and Characterization

    OpenAIRE

    Coleman, Anthony W.; Imed Montasser; Patrick Shahgaldian; Florent Perret

    2013-01-01

    Solid lipid nanoparticles (SLNs) have attracted increasing attention during recent years. This paper presents an overview about the use of calix[n]arenes and calix-resorcinarenes in the formulation of SLNs. Because of their specific inclusion capability both in the intraparticle spaces and in the host cavities as well as their capacity for functionalization, these colloidal nanostructures represent excellent tools for the encapsulation of different active pharmaceutical ingredients (APIs) in ...

  9. A study of the layer structure in a calix-8-arene Langmuir–Blodgett film by reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    McCartney, C.M.; Cowlam, N.; Richardson, T. [Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH (United Kingdom); Davis, F., E-mail: f.davis@cranfield.ac.uk [Cranfield Health, Cranfield University, Bedford, MK43 0AL (United Kingdom); Stirling, C.J.M. [Department of Chemistry, University of Sheffield, Sheffield, S3 7HF (United Kingdom); Gibaud, A. [Laboratoire P.E.C. Rayons-X, Faculté des Sciences, Université du Maine, 72085 Le Mans Cedex 9 (France); Nabok, A.V. [MERI, Sheffield Hallam University, Sheffield, S1 1WB (United Kingdom)

    2013-01-01

    X-ray reflectometry measurements have been made on Langmuir–Blodgett films of tertiary-octyl calix-8-arene. The samples have additional cadmium ions incorporated in the film and the typical X-ray reflectivity profile exhibits both interference fringes and a well defined Bragg peak. The total film thickness and the bilayer spacing were obtained from these. Simulations of the experimental reflectivity profile were made for three structural models, using a program based on Parratt's recursive relations. The traditional “bowl and chain” conformation and the “wheel-like” pleated loop conformation of calix-8-arene were both unable to provide an effective model for the structure of the multilayer film. In contrast, the more complex “pinched loop” molecular conformation produced a film with the correct total thickness and bilayer spacing. The reflectivity profile calculated from this model was in excellent agreement with the experimental profile. The principle features of the model are a partial interdigitation of the hydrophobic R-groups and an interpenetration of the hydrocarbon X-groups, which leads to a high value of electronic scattering length density in the plane of the incorporated cadmium ions. - Highlights: ► X-ray reflectometry measurements made on Langmuir–Blodgett films of calix-8-arene ► Simulations of the reflectivity profile made for three structural models ► Pinched loop conformation of calix-8-arene produced correct thickness and spacing ► Calculated and experimental profiles in excellent agreement for pinched loop ► Profile incompatible with “bowl and chain” and pleated loop conformations.

  10. Neue potenziell sensoraktive Calix[4]arene mit spezifischer Substitution am oberen und unteren Kelchrand sowie in lateraler Kelchposition

    OpenAIRE

    Gruber, Tobias

    2009-01-01

    Gegenstand dieser Arbeit ist die Entwicklung, Synthese und Charakterisierung von fluorogenen Calixaren-Wirtverbindungen. An die zunächst synthetisierten kopplungsfähigen Calix[4]arene mit gezielt eingestellter Lipophilie wurden in einem zweiten Schritt Dansyl- bzw. Pyrenylreste kovalent angeknüpft. Auf diesem Wege gelang es, dreizehn Zielverbindungen darzustellen, die sich in ihrer konformativen Flexibilität unterscheiden und durch eine ausgewogene Hydrophilie-Lipophilie-Balance in der Lage s...

  11. The design and simulation of TCR(thyristor control reactor) reactive power compensation system based on Arene

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-fang; ZHANG Li; JIANG Jian-guo; WANG Ru-lin

    2004-01-01

    Inevitably, the question of reactive power compensation was aroused by applied of power electronics. Based on the study of the instantaneous reactive power theory, the designs of TCR(thyristor control reactor) thyristor control reactor reactive power compensation system and TCR single closed loop strategy was proposed. In addition, as digital simulation software, Arene was applied to simulate the Jining coal mine No.2 system. The simulation results validate that the design is effective to improve power factor and stabilization of the system.

  12. Toward Acetylcholine Sensor Devices: Facile Synthesis of 2-Cyanoresorcin[4 ] arene and Its High Affinity toward Acetylcholine

    Institute of Scientific and Technical Information of China (English)

    TAN Song-De; WEI Ying; WANG Bo; XU Zun-Le; CHEN Wen-Hua

    2003-01-01

    @@ The biological importance of acetylcholine spurs the efforts to construct its synthetic receptors with the aims to develop acetylcholine sensor devices. Among the various building blocks used to synthesize artificial acetylcholine receptors, resorcin [4 ]arenes, [1] which can be conveniently obtained from the acid-catalyzed condensation of resorcinol with aldehyde, were shown to serve as one of the most strongest synthetic receptors for choline type guests.

  13. Synthesis of a novel calix[4]arene-based fluorescent ionophore and its metal ions recognition properties

    Institute of Scientific and Technical Information of China (English)

    Qiang Peng; Xing Hua Tang

    2009-01-01

    A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and synthesized. Its molecular structure was confirmed by 1H NMR and element analysis. The resulting material shows specific fluorescent behavior toward the Zn2+ ion among the other divalent metal ions, such as Co2+, Ni2+, Cu2+. The primary results indicate this ionophore material is a potential material for developing efficient fluorescent Zn2+ chemosensors.

  14. Influences of Hard Donor on Cation Selectivities Closing to Soft Selenium Donor in Tweezer-like Calix[4]arene Receptors

    Institute of Scientific and Technical Information of China (English)

    LIU,Chang-Ying(刘长鹰); ZHANG,Zheng-Zhi(张正之); QIN,Da-Bin(秦大斌); LENG,Xue-Bing(冷雪冰); CHEN,Lang-Xing(陈朗星); ZENG,Xian-Shun(曾宪顺); XU,Feng-Bo(徐凤波); LI,Qing-Shan(李庆山); HE,Xi-Wen(何锡文); ZHANG,Wen-Qin(张文勤)

    2004-01-01

    Three novel 25,27-dihydroxy-26,28-bis(3-benzylselenopropoxy)-5,11,17,23-tetra-tert-butylcalix[4]-arene (2),25,27-dihydroxy-26,28-bis[3-(2-hydroxyethylseleno)propoxy]-5,11,17,23-tetra-tert-butyl-calix[4]arene (3) and 25,27-dihydroxy-26,28-bis(3-propylselenopropoxy)-5,11,17,23-tetra-tert-butyl-calix[4]arene (4) were synthesized for the comparison of their ion-selectivity in ion-selective electrodes (ISE). X-ray structure of the CH/π complex of 4·CH2Cl2 was elucidated. ISEs based on 2-4 as neutral ionophores were prepared, and their selectivity coefficients for Ag+ (log Kpot Ag,M) were investigated against some main group metal ions and transition metal ones using the fixed interference method (FIM). These ISEs showed excellent Ag+ selectivity over most of the interfering cations examined. It is evident that the stronger Hg2+ interference may not be produced while hard donors (hydroxy) are close to the soft selenium donors.

  15. Synthesis and Characterization of Tetravalent Cerium Complexes with p-Tert-butylcalix[n]arenes (n=4, 6, 8)

    Institute of Scientific and Technical Information of China (English)

    张亚文; 严纯华; 增田嘉孝

    2002-01-01

    Three Ce4+ complexes Ce(p-tert-butylcalix[4]arene)*(dmf)4*H2O (complex A), Ce(p-tert-butylcalix[6]arene)2*(dmf)10 (complex B) and Ce(p-tert-butylcalix[8]arene)*(dmf)4 (complex C) were prepared from N,N-dimethylforamide (dmf) solution of Ce(NO3)3. Their thermal stability, optical properties and coordination features were investigated with thermogravimetric and differential thermal analysis, ultraviolet and visible spectrophotometer, fluorescence spectrophotometer, infrared spectroscopy, and 1H NMR spectrometer. In the solvents of C6H6, 1,2-dichloroethane and dmf, complexes A and B can exhibit a ligand to metal charge transfer transition lying in ca. 20000 cm-1 in the electronic spectra. Complex A displays a dimeric structure in C6D6 solution. Ce4+ ions in the complexes are coordinated by phenolic groups of the ligands, oxygen atoms of dmf molecules, and / or OH- ions.

  16. Light-Induced C-H Arylation of (Hetero)arenes by In Situ Generated Diazo Anhydrides.

    Science.gov (United States)

    Cantillo, David; Mateos, Carlos; Rincon, Juan A; de Frutos, Oscar; Kappe, C Oliver

    2015-09-01

    Diazo anhydrides (Ar-N=N-O-N=N-Ar) have been known since 1896 but have rarely been used in synthesis. This communication describes the development of a photochemical catalyst-free C-H arylation methodology for the preparation of bi(hetero)aryls by the one-pot reaction of anilines with tert-butyl nitrite and (hetero)arenes under neutral conditions. The key step in this procedure is the in situ formation and subsequent photochemical (>300 nm) homolytic cleavage of a transient diazo anhydride intermediate. The generated aryl radical then efficiently reacts with a (hetero)arene to form the desired bi(hetero)aryls producing only nitrogen, water, and tert-butanol as byproducts. The scope of the reaction for several substituted anilines and (hetero)arenes was investigated. A continuous-flow protocol increasing selectivity and safety has been developed enabling the experimentally straightforward preparation of a variety of substituted bi(hetero)aryls within 45 min of reaction time. PMID:26239967

  17. Synthesis of doubly ethyl-bridged bis(p-sulfonatocalix[4]arene) and its supramolecular polymerization with viologen dimer.

    Science.gov (United States)

    Wang, Kun-Peng; Guo, Dong-Sheng; Zhao, Hong-Xia; Liu, Yu

    2014-04-01

    A water-soluble supramolecular polymer with a high degree of polymerization and viscosity has been constructed based on the strong host-guest interaction between p-sulfonatocalix[4]arenes (SC4As) and viologen. A homoditopic doubly ethyl-bridged bis(p-sulfonatocalix[4]arene) (d-SC4A) was prepared and its binding behavior towards methyl viologen compared with the singly ethyl-bridged bis(p-sulfonatocalix[4]arene) (s-SC4A) by NMR spectroscopy and isothermal titration calorimetry. By employing a viologen dimer (bisMV(4+)) as the homoditopic guest, two linear AA/BB-type supramolecular polymers, d-SC4A⊃bisMV(4+) and s-SC4A⊃bisMV(4+), were successfully constructed. Compared with s-SC4A⊃bisMV(4+), d-SC4A⊃bisMV(4+) shows much higher solubility and viscosity, and has also been characterized by viscosity, diffusion-ordered NMR spectroscopy, dynamic light scattering, and atomic force microscopy measurements. Furthermore, the polymer is responsive to electrostimulus as viologen is electroactive, which was studied by cyclic voltammetry. This study represents a proof-of-principle as the polymer can potentially be applied as a self-healing and degradable polymeric material.

  18. Theoretical study on interactions of fluorinated organomercurials with arene and gold fragments.

    Science.gov (United States)

    Mendizabal, Fernando; Miranda-Rojas, Sebastián; Barrientos, Lorena

    2015-10-21

    The electronic structure and spectroscopic properties of [Hg(C6F5)2]2-{L}, [Hg3(o-C6F4)3]2·{L} (L = naphthalene, biphenyl, fluorene) and [Hg3(o-C6F4)3]{Au3(μ-C(OEt)=NC6H4CH3)3}n (n = 1, 2) adducts were studied at the HF, MP2, SCS-MP2, DFT and DFT-D3 levels. The intermolecular interactions among the fragments were analyzed using the levels of calculations proposed. The energy decomposition analysis at the TPSS-D3 level was used to define the dominant components of the interaction. The van der Waals interactions between mercury and arene (Hg-arene) were found to be the main short-range stability contribution in the [Hg(C6F5)2]2-{L} and [Hg3(o-C6F4)3]2·{L} complexes. At the MP2, SCS-MP2 and DFT-D3 levels, equilibrium Hg-C distances are between 360 and 310 pm. The pair-wise energies were found to be between 18.0 and 6.0 kJ mol(-1). In the [Hg3(o-C6F4)3]{Au3(μ-C(OEt)=NC6H4CH3)3}n (n = 1, 2) complexes the metallophilic intermolecular interaction is Hg-Au. Pair-wise energies of 85.7, 39.4, 78.1 and 57.9 kJ mol(-1) were found at the MP2, SCS-MP2, TPSS-D3 and PBE-D3 levels using the [Hg3(o-C6F4)3]{Au3(μ-C(OEt)=NC6H4CH3)3} model. The same trend is maintained for the [Hg3(o-C6F4)3]{Au3(μ-C(OEt)=NC6H4CH3)3}2 model: 73.4, 29.3, 70.6 and 61.3 kJ mol(-1) by MP2, SCS-MP2, TPSS-D3 and PBE-D3, respectively. The absorption spectra of these complexes were calculated using the single excitation time-dependent method at the TPSS-D3 level to validate the models against the experimental data.

  19. Synthesis, characterization and biological evaluation of novel Ru(II)-arene complexes containing intercalating ligands.

    Science.gov (United States)

    Nikolić, Stefan; Rangasamy, Loganathan; Gligorijević, Nevenka; Aranđelović, Sandra; Radulović, Siniša; Gasser, Gilles; Grgurić-Šipka, Sanja

    2016-07-01

    Three new ruthenium(II)-arene complexes, namely [(η(6)-p-cymene)Ru(Me2dppz)Cl]PF6 (1), [(η(6)-benzene)Ru(Me2dppz)Cl]PF6 (2) and [(η(6)-p-cymene)Ru(aip)Cl]PF6 (3) (Me2dppz=11,12-dimethyldipyrido[3,2-a:2',3'-c]phenazine; aip=2-(9-anthryl)-1H-imidazo[4,5-f] [1,10] phenanthroline) have been synthesized and characterized using different spectroscopic techniques including elemental analysis. The complexes were found to be well soluble and stable in DMSO. The biological activity of the three complexes was tested in three different human cancer cell lines (A549, MDA-MB-231 and HeLa) and in one human non-cancerous cell line (MRC-5). Complexes 1 and 3, carrying η(6)-p-cymene as the arene ligand, were shown to be toxic in all cell lines in the low micromolar/subnanomolar range, with complex 1 being the most cytotoxic complex of the series. Flow cytometry analysis revealed that complex 1 caused concentration- and time-dependent arrest of the cell cycle in G2-M and S phases in HeLa cells. This event is followed by the accumulation of the sub-G1 DNA content after 48h, in levels higher than cisplatin and in the absence of phosphatidylserine externalization. Fluorescent microscopy and acridine orange/ethidium bromide staining revealed that complex 1 induced both apoptotic and necrotic cell morphology characteristics. Drug-accumulation and DNA-binding studies performed by inductively coupled plasma mass spectrometry in HeLa cells showed that the total ruthenium uptake increased in a time- and concentration-dependent manner, and that complex 1 accumulated more efficiently than cisplatin at equimolar concentrations. The introduction of a Me2dppz ligand into the ruthenium(II)-p-cymene scaffold was found to allow the discovery of a strongly cytotoxic complex with significantly higher cellular uptake and DNA-binding properties than cisplatin. PMID:26818702

  20. Highly Efficient C--N Bond Forming Reactions in Water Catalyzed by Copper(I) Iodide with Calix[4]arene Supported Amino Acid Ionic Liquid%Highly Efficient C--N Bond Forming Reactions in Water Catalyzed by Copper(I) Iodide with Calix[4]arene Supported Amino Acid Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    黄利; 金灿; 苏为科

    2012-01-01

    A novel and effective protocol has been developed for the Ullmann-type C--N coupling reaction catalyzed by calix[4]arene supported amino acid ionic liquid and copper(I) iodide in water under microwave irradiation condition The protocol uses ealix[4]arene supported amino acid ionic liquid as double function of the ligand and phase-transfer catalyst, and shows good tolerance in good to excellent yields.

  1. Parent Involvement.

    Science.gov (United States)

    LaCrosse, Ed

    The paper discusses the rationale and guidelines for parent involvement in HCEEP (Handicapped Children's Early Education Program) projects. Ways of assessing parents' needs are reviewed, as are four types of services to meet the identified needs: parent education, direct participation, parent counseling, and parent provided programs. Materials and…

  2. Triflate-functionalized calix[6]arenes as versatile building-blocks: application to the synthesis of an inherently chiral Zn(ii) complex.

    Science.gov (United States)

    Zahim, Sara; Lavendomme, Roy; Reinaud, Olivia; Luhmer, Michel; Evano, Gwilherm; Jabin, Ivan

    2016-02-14

    Cavity-based metal complexes can find many applications notably in the fields of catalysis and biomimicry. In this context, it was shown that metal complexes of calix[6]arenes bearing three aza-coordinating arms at the small rim provide excellent structural models of the poly-imidazole sites found in the active site of many metallo-enzymes. All these N-donor ligands were synthesized from the 1,3,5-tris-methoxy-p-tBu-calix[6]arene platform, which presents some limitations in terms of functionalization. Therefore, there is a need for the development of new calix[6]arene-based building-blocks selectively protected at the small rim. Herein we describe the regioselective one step synthesis of two calix[6]arenes decorated with triflate groups, i.e. X6H4Tf2 and X6H3Tf3, from the parent calix[6]arene X6H6. It is shown that the triflate groups can either act as protecting or deactivating groups, allowing the elaboration of sophisticated calixarene-based systems selectively functionalized at the large and/or at the small rim. In addition, X6H3Tf3 is functionalized on the A, B, and D rings and thus gives access to inherently chiral compounds, as demonstrated by the synthesis of a rare example of inherently chiral cavity-based metal complex. PMID:26751614

  3. Synthesis and structural properties of 5,17-bis (N-methyl-N-arylaminocarbonyl)calix[4]arenes. Directing the substituents toward the cavity by use of the cis-generating property of the N-methylaminocarbonyl linker

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Larsen, Mogens; Jørgensen, Mikkel;

    1998-01-01

    A series of cone 5,17-bis(N-arylaminocarbonyl)calix[4]arenes were synthesized and N-methylated using an easy and high-yielding methylation procedure. The structures of the cone 5,17-bis(Nmethyl-N-arylaminocarbonyl)calix[4]arenes were studied in solution by NMR spectroscopy and in the solid state ...

  4. New π-arene ruthenium(II) piano-stool complexes with nitrogen ligands.

    Science.gov (United States)

    Grau, Jordi; Noe, Verónica; Ciudad, Carles; Prieto, Maria J; Font-Bardia, Mercè; Calvet, Teresa; Moreno, Virtudes

    2012-04-01

    The synthesis, characterization, DNA interaction and antiproliferative behavior of new π-arene ruthenium(II) piano-stool complexes with nitrogen ligands are described. Three series of organometallic compounds of formulae [RuCl(2)(η(6)-p-cym)L] were synthesized (with L=2-, 3- or 4-methylpyridine; L=2,3-, 2,4-, 2,5-, 3,4-, 3,5-dimethylpyridine and L=1,2-, 1,3- 1,4-methylaminobenzene). The crystal structures of [RuCl(2)(p-cym)(4-methylpyridine)], [RuCl(2)(p-cym)(3,4-dimethylpyridine)] and [RuCl(2)(p-cym)(1,4-methylaminobenzene)] were resolved and the characterization was completed by spectroscopic UV-vis, FT-IR and (1)H NMR studies. Electrochemical experiments were performed by cyclic voltammetry to estimate the redox potential of the Ru(II)/Ru(III) couple. The interaction with plasmid pBR322 DNA was studied through the examination of the electrophoretical mobility and atomic force microscopy, and interaction with ct-DNA by circular dichroism, viscosity measurements and fluorescence studies based on the DNA-ethidium bromide complex. The antiproliferative behavior of the series with L=methylpyridine was assayed against two tumor cell lines, i.e. LoVo and MiaPaca. The results revealed a moderate cytotoxicity with a higher activity for the LoVo cell line compared to the MiaPaca one. PMID:22387934

  5. Crystal structures of two thiacalix[4]arene derivatives anchoring four thiadiazole groups

    Indian Academy of Sciences (India)

    Bang-Tun Zhao; Zhen Zhou; Zhen-Ning Yan

    2009-11-01

    The crystal structures of two thiacalixarene derivatives anchoring thiadiazole functional groups at lower rim, C60H72O4S12N8 (1), C64H80O4S12N8 (2), have been determined by single crystal X-ray diffraction. The thiacalix[4]arene framework in both 1 and 2 adopts the 1,3-alternate conformation. Compound 1 forms a 1-D chain by weak hydrogen bonding (C-H$\\cdots$N) interactions between two thiadiazole groups in two different molecules. The chains are further connected to form a 2-D network through sulfur-sulfur (S$\\cdots$S) interactions. The lattice water molecules which exist as dimers by forming hydrogen bonds (O-H$\\cdots$O) promote a 3-D supramolecular structure through weak hydrogen bonding (O-H$\\cdots$S) interactions between the lattice water dimers and the 2-D networks. On the other hand, compound 2, based on dimer which is formed by weak hydrogen bonding (C-H$\\cdots$S) interactions, is extended to a 1-D chain through sulfur-sulfur (S$\\cdots$S) interactions. The dimers of lattice methanol molecules linked by hydrogen bonds (O-H$\\cdots$O) act as bridges to link the 1-D chains into a 2-D network through weak hydrogen bonding (C-H$\\cdots$N) interactions.

  6. Biocompatible polyurethane/thiacalix[4]arenes functionalized Fe3O4 magnetic nanocomposites: Synthesis and properties.

    Science.gov (United States)

    Mohammadi, Abbas; Barikani, Mehdi; Lakouraj, Moslem Mansour

    2016-09-01

    In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use. PMID:27207044

  7. LATEGLACIAL BATS FROM THE “M” LAYERS OF THE ARENE CANDIDE CAVE (LIGURIA, ITALY

    Directory of Open Access Journals (Sweden)

    LEONARDO SALARI

    2010-03-01

    Full Text Available The Arene Candide Cave (Finale Ligure, Northern Italy is considered one of the most important prehistoric site in Italy. The archaeological excavations conducted by the “Istituto Italiano di Paleontologia Umana” of Rome revealed 3 different horizons: an upper horizon with Holocene human presence dated from the Neolithic to the Byzantine period, and two underlying Pleistocene horizons with Gravettian and Epigravettian lithic artefacts. The stratigraphical sequence of the upper Palaeolithic is divided in two groups of strata separated by a depositional gap: the “P” complex, divided in 13 layers, dated from 25,620 to 18,560 years BP, and the 5 “M” layers dated between 11,750 and 9,980 years BP (14C non-calibrated dating.In this paper the fossil bone remains of bats from “M” layers are described. Fifteen taxa, divided into 3 families and 6 genera have been identified: Rhinolophus ferrumequinum, R. mehelyi, R. euryale, R. hipposideros, Myotis myotis, M. blythii, M. capaccinii, M. emarginatus, M. mystacinus s.l., Myotis sp. (small sized, Plecotus auritus s.l., Nyctalus lasiopterus, N. noctula, Barbastella barbastellus and Miniopterus schreibersii. Comments for each of these taxa on current ecological and geographical distributions are presented, together with some osteometric measures and recent data referred to Late Pleistocene fossils bats in Italy. Finally, the value of this bat tanathocoenoses as a microclimatic, environmental, and human activity indicators is discussed. SHORT NOTE

  8. Hybrid liposomal PEGylated calix[4]arene systems as drug delivery platforms for curcumin.

    Science.gov (United States)

    Drakalska, Elena; Momekova, Denitsa; Manolova, Yana; Budurova, Dessislava; Momekov, Georgi; Genova, Margarita; Antonov, Liudmil; Lambov, Nikolay; Rangelov, Stanislav

    2014-09-10

    The tremendous therapeutic potential of curcumin as a chemopreventive, antineoplastic and chemosensitizing agent has failed to progress towards clinical development and commercialization due to its unfavorable physicochemical properties, low aqueous solubility, chemical instability, and pharmacokinetics. The present contribution is focused on the feasibility of using PEGylated calixarene, in particular polyoxyethylene-derivatized tert-butylcalix[4]arene, to prepare various platforms for delivery of curcumin such as inclusion complex, supramolecular aggregates, and hybrid liposomal systems. The inclusion complex is characterized by UV-vis and FT-IR spectroscopy as well as thermal gravimetrical analysis and differential scanning calorimetry. At concentrations exceeding the critical micellization concentration of PEGylated calixarene, the tremendous solubility enhancement of curcumin is attributed to additional solubilization and hydrophobic non-covalent interactions of the drug with supramolecular aggregates. A hybrid liposomal system is created via encapsulation of the inclusion complex in dipalmitoylphosphatidylcholine:cholesterol liposomes. Bare and liposomal curcumin:BEC-X inclusion complexes, as well as free curcumin were additionally investigated for cytotoxicity and apoptogenic activity against human tumor cell lines.

  9. Calix[4]arene based dipodal receptor nanohybrids for selective determination of chloride ions in aqueous media.

    Science.gov (United States)

    Kaur, Harpreet; Singh, Jasminder; Chopra, Shweta; Kaur, Navneet

    2016-01-01

    A chemical sensor based on p-tert butyl calix[4]arene has been synthesized and characterized using an assortment of spectroscopic techniques such as (1)H NMR, (13)C NMR, and elemental analysis. For sensor application, organic nanoparticles (N1) of 1 have been primed by implementing re-precipitation technique, which were further employed for preparing organic-inorganic hybrid (H1) by decorating N1 with gold nanoparticles. Both N1 and H1 were characterized using UV-visible, fluorescence, and DLS studies. Photo-physical changes due to anion binding with H1 were scrutinized using UV-visible absorption spectrometer and found it to promptly and selectively recognize Cl(-) ions in aqueous media. Thus, H1 can be effectively used for recognition of Cl(-) ions in aqueous media over a wide pH range, in samples of real time importance with a detection limit of 2.84×10(-9) M with a linear detection range up to 50 μM.

  10. Host-guest interaction between water-soluble calix[6]arene hexasulfonate and p-nitrophenol

    International Nuclear Information System (INIS)

    The inclusion complexation of calix[6]arene hexasulfonate with p-nitrophenol has been studied by photoluminescence (PL), differential scanning calorimetry (DSC) and quantum-chemical methods in aqueous media. The results indicate 1:1 complex stoichiometry. The directly measured molar enthalpy of inclusion shows strong interaction between the host and the guest, however the entropy change of the complex formation is negative and quite high. Therefore, the Gibbs free enthalpy change of the complex formation is small resulting in a relatively low complex stability. This well-known enthalpy-entropy-compensation effect is probably due to the increased freedom of guest molecules relative to the host calixarenes and also due to the increased disorder of solvent molecules after the complex has been dissociated. The good correlation between the van't Hoff enthalpy determined by PL studies and the calorimetric enthalpy reflects the two-state character of complexation. Quantum-chemical investigation suggests π-π interaction between the host and the guest in agreement with earlier results

  11. Fabrication of Calix[4]arene Derivative Monolayers to Control Orientation of Antibody Immobilization

    Directory of Open Access Journals (Sweden)

    Hongxia Chen

    2014-03-01

    Full Text Available Three calix[4]arene (Cal-4 derivatives which separately contain ethylester (1, carboxylic acid (2, and crownether (3 at the lower rim with a common reactive thiol at the upper rim were synthesized and constructed to self-assembled monolayers (SAMs on Au films. After spectroscopic characterization of the monolayers, surface coverage and orientation of antibody immobilized on the Cal-4 derivative SAMs were studied by surface plasmon resonance (SPR technique. Experimental results revealed that the antibody could be immobilized on the Cal-4 derivatives spontaneously. The orientation of absorbed antibody on the Cal-4 derivative SAMs is related to the SAM’s dipole moment. The possible orientations of the antibody immobilized on the Cal-4 derivative 1 SAM are lying-on or side-on, while on the Cal-4 derivative 2 and Cal-4 derivative 3 head-on and end-on respectively. These experimental results demonstrate the surface dipole moment of Cal-4 derivative appears to be an important factor to antibody orientation. Cal-4 derivatives are useful in developing site direct protein chips.

  12. SYNTHESIS OF RUTHENIUM(0) DIENES FROM ([2.2]PARACYCLOPHANE)(ARENE) RUTHENIUM(II) COMPLEXES AND THEIR SUBSEQUENT REACTIONS TO FORM HIGHLY FLUXIONAL AGOSTICS

    OpenAIRE

    Steed, J. W.; Tocher, D. A.

    1994-01-01

    Action of Na[BH4] on the ([2.2]Paracyclophane)(arene)ruthenium(II) complexes [Ru(eta6-C16H16)(n6-arene)][BF4]2 (arene = p-cymene 1a, durene 1b, pentamethylbenzene 1c, and hexamethylbenzene 1d) results exclusively in reduction of the metal centre and addition of two hydrides to the non-cyclophane ring, giving the neutral 1,3-diene compounds [Ru(0)(eta6-C16H16)(eta4-diene)](diene = MeC6H6CHMe2 2a, C6Me4H4 2b, C6Me5H3 2c, C6Me6H2 2d). These results contrast with several previous studies on Ru(II...

  13. Impedimetric Sensing Proprieties of ITO Electrodes Functionalized with PEDOT:PSS/Azo-Calix[4]Arene for the Detection of Al3+ Ions Under Light Excitation

    Science.gov (United States)

    Echabaane, M.; Rouis, A.; Mahjoub, M. A.; Bonnamour, I.; Ben Ouada, H.

    2016-08-01

    This study describes an investigation of the sensitivity of the azo-calix[4]arene/poly(3,4-ethylenedioxythiophene)/poly-(styrenesulfonate) (PEDOT:PSS) thin film deposited on the indium tin oxide (ITO) electrode surface toward aluminum ions (Al3+) under light excitation. Thin films were deposited by the spin-coating technique. Adhesion of these films to the ITO surface was highlighted by performing contact angle measurements. Then, interfaces of the azo-calix[4]arene/PEDOT:PSS thin film were characterized by impedance measurements using electrochemical impedance spectroscopy. Obtained impedance spectra were fitted using an equivalent circuit. Finally, evolutions of the different components of this circuit were studied. These evolutions show that the sensitivity of the azo-calix[4]arene/PEDOT:PSS/ITO electrode is remarkably improved under illumination.

  14. Formation and proof of stable bi-, tri- and tetraradical polyanions during the electrochemical reduction of cone-polynitrocalix[4]arenes. An ESR-UV-vis spectroelectrochemical study

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: The first intermediates of electrochemical reduction of nitro compounds in nonaqueous DMF are stable radical anions. In the series of mono-, di-, tri- and tetranitro calix[4]arenes each nitro group represents a reduction center, therefore the question about the spin state of intermediary anions arises. In this communication, the voltammetric and coulometric investigation of these compounds is performed together with the spectral measurements (ESR and UV-vis). The in-situ spectroelectrochemical approach proved that during reduction, in all polynitro radicalic intermediates the electrons remain unpaired and thus relatively stable mono-, di-, tri- and tetraradical mono-, di-, tri- and tetraanions, respectively, can be electrochemically generated in aprotic DMF from polynitrocalix[4]arenes. This finding confirms that the nitrophenyl units in polynitrocalix[4]arenes are completely independent and no mutual electronic communication takes place among them

  15. Separation of uranium from aqueous solutions using calix[6]arenes in liquid-liquid extraction as well as solid phase extraction; Abtrennung von Uran aus waessriger Loesung durch Calix[6]arene mittels Fluessig-Fluessig-Extraktion sowie Festphasen-Extraktion

    Energy Technology Data Exchange (ETDEWEB)

    Schmeide, K.; Geipel, G.; Bernhard, G.

    2004-11-01

    The suitability of different calyx[n] arene types for uranyl extraction from liquid solutions was examined by means of liquid-liquid extraction using aqueous phases and organic solvents of varying compositions. It was found that COOH-derivatised calyx[6] arenes have good extraction properties and can even be used in the acid pH range. The use of calixarene-modified fleeces for the separation of uranyl from aqueous phases was examined in batch experiments with pH and uranyl concentration as variables and in the presence or absence of competing ions. The results showed that calixarene-modified fleeces can be used for uranium separation starting from pH 4. At pH 5, up to a maximum of 7.6 x 10{sup -7} mol uranium can be bound per 1 g of calixarene-modified fleece. The separation of uranyl from synthetic pit waters was examined as a means of testing the separation capacity of calixarene-modified fleeces in environmentally sensitive waters. Studies on the reversibility of uranium bonding to calixarene-treated polyester fleeces have shown that under environmentally realistic conditions (neutral pH range) the uranium is firmly bound to the calixarene-modified fleeces and cannot be mobilised. By contrast, in acidic environments calixarene-modified fleeces are capable of near-complete regeneration. Such regenerated textile filter materials can then be used for further uranium separation cycles. [German] Die Eignung verschiedener Calix[n]aren-Typen fuer die Uranylextraktion aus waessriger Loesung wurde mittels Fluessig-Fluessig-Extraktion unter Variation der Zusammensetzung der waessrigen Phase und des organischen Loesungsmittels untersucht. Es konnte gezeigt werden, dass COOH-derivatisierte Calix[6]arene gute Extraktionseigenschaften aufweisen und selbst im sauren pH-Bereich angewendet werden koennen. Die Uranylabtrennung aus waessriger Loesung durch calixarenmodifizierte Vliese wurde in Abhaengigkeit des pH-Wertes und der Uranylkonzentration in Abwesenheit und Gegenwart von

  16. Pd-Catalyzed C-H Alkylation of Arenes Using PyrDipSi, a Transformable and Removable Silicon-Tethered Directing Group.

    Science.gov (United States)

    Sarkar, Dhruba; Gevorgyan, Vladimir

    2016-08-01

    An efficient Pd-catalyzed ortho-C-H alkylation reaction of arenes using a transformable and removable Si-tethered pyridyldiisopropylsilyl (PyrDipSi) directing group has been developed. In addition, the PyrDipSi directing group allows for an efficient sequential double-fold C-H alkylation/oxygenation of arenes to produce meta-alkylated phenols. This directing group can easily be removed or converted into valuable functionalities, such as aryl, iodo, boronic ester, or phenol. PMID:27272930

  17. Novel Pyrene-armed Calix[4]arenes through Triazole Connec-tion: Ratiometric Fluorescent Chemosensor for Zn2+ and Promising Structure for Integrated Logic Gates

    Institute of Scientific and Technical Information of China (English)

    ZHU Lin-Na; GONG Shao-Long; GONG Shu-Ling; YANG Chu-Luo; QIN Jin-Gui

    2008-01-01

    Two novel pyrene-armed calix[4]arenes by triazole connection were synthesized using "click" chemistry. Com-pound 1 with two pyrene subunits appended to the lower rims of the calix[4]arene shows ratiometric fluorescence response toward Zn2+, and selective fluorescence quenching toward heavy metal ions such as Cu2+, Hg2+ and pb2+; while compound 2 with one pyrene subunit exhibits significant fluorescence quenching toward Cu2+ and moderate quenching behaviour toward Hg2+. By utilizing the different fluorescence behavior of 1 toward Zn2+and Cu2+, inhi-bition (INH) and not or (NOR) logic gates were established.

  18. O-H...π(arene) intermolecular hydrogen bonding in the structure of 1,1,2-triphenylethanol

    OpenAIRE

    Ferguson, George; Gallagher, John F.; Glidewell, Christopher; Zakaria, Choudhury M.

    1994-01-01

    The 1,1,2-triphenylethanol molecule, Ph2(PhCH2)COH (I), forms centrosymmetric dimers in the solid state. The shortest O-..O separation, 5.837 (3)A,, is too long for any O--H..-O hydrogen-bond formation. Instead, there are O--H~..π(arene) interactions between the hydroxyl group of one molecule and a phenyl group of a centrosymmetrically related molecule. The O...C and H-..C distances between the hydroxyl group and the closest phenyl-ring C atom are 3.525 (4) and 2.73 (4...

  19. Synthesis and application of p-tert-butylcalix[8]arene immobilized material for the removal of azo dyes

    International Nuclear Information System (INIS)

    Graphical abstract: The sorption of selected azo dyes is highly pH dependent and newly immobilized material 4 is potentially more effective sorbent as compared to pure silica (1) as well as p-tert-butylcalix[8]arene (3). Research highlights: → Sorption behavior investigation of p-tert-butyl-calix[8]arene immobilized material4. → Azo dyes (i.e. RB-5 and RR-45) were used as sorbate. → Optimization of different parameters to evaluate sorption performance of material 4. → Sorption efficiency of resin 4 for RB-5 and RR-45 azo dyes is highly pH dependent. → The sorption data was evaluated by sorption isotherms. - Abstract: The present study describes synthesis of a new resin through immobilization of p-tert-butylcalix[8]arene onto silica and its application for the removal of azo dyes from aqueous media as well as from textile effluents. The newly synthesized material 4 is characterized by FT-IR spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Reactive Black-5 (RB-5) and Reactive Red-45 (RR-45) azo dyes were used as sorbate. Batch wise sorption experiments were conducted to optimize various experimental parameters such as the effect of sorbent dosage, electrolyte, pH, dye concentration, and contact time. The optimized pH for the effective removal of RB-5 and RR-45 dyes was 9 and 3, respectively. The increase in material 4 dosage increased the percent sorption. Both Langmuir and Freundlich isotherm models were applied to experimental data and Langmuir isotherm model found to be best fit. The results revealed that material 4 was potentially more effective sorbent for the sorption of selected azo dyes as compared to pure silica and p-tert-butylcalix[8]arene. The field studies also supported the effectiveness of material 4, which could be useful for the removal of both the dyes and also for the normalization of pH, TDS, conductivity and salinity near to the drinking water.

  20. Syntheses and metal ions recognition of dendritic calix[n]arenes(n=6,8)amide derivative

    Institute of Scientific and Technical Information of China (English)

    WANG Yunyan; CAI Yahua; YAN Chaoguo

    2007-01-01

    Dendritic p-t'butylcalix[n]arene amide derivatives with terminal amino groups of the first and second generations were synthesized by using divergent methods from ammonolysis of ethyl calixarylacetate with 1,6-diaminohexane and Michael addition of methyl acrylate.Their structures were confirmed by IR,1H NMR.The recognition properties of these amide derivatives for several kinds of metal ions were studied with UV-Vis spectroscopy.The results showed a great affinity for soft Ag+ and UO22+ ions and formed 1:2 or 1:3 stoichiometric complexes.

  1. A new ion selective electrode for cesium (I) based on calix[4]arene-crown-6 compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramanjaneyulu, P.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094 (India); Kumar, Abha Naveen [Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094 (India); Sayi, Y.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094 (India); Ramakumar, K.L., E-mail: klram@barc.gov.in [Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400094 (India); Nayak, S.K.; Chattopadhyay, S. [Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400094 (India)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer First report on Cs(I)-ISE employing 25,27-bis(1-octyloxy)calix[4]arene-crown-6. Black-Right-Pointing-Pointer Higher sensitivity and selectivity achieved by minimizing trans-membrane fluxes. Black-Right-Pointing-Pointer 10 months life time is longest reported so far for membrane based Cs-ISE. Black-Right-Pointing-Pointer Cesium is chemically toxic displaces potassium from muscles and red blood cells. Black-Right-Pointing-Pointer Its monitoring in environment is essential. - Abstract: A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium has been developed. 25,27-Dihydroxycalix[4]arene-crown-6 (L1), 5,11,17,23-tetra-tert-butyl-25,27-dimethoxycalix[4]arene-crown-6 (L2) and 25,27-bis(1-octyloxy)calix[4]arene-crown-6 (L3) were investigated for their use as ionophores. The cation exchange resin DOWEX-50W was used to maintain low activity Cs{sup +} in inner filling solution to improve the performance. The best response for cesium was observed with L3 along with optimized membrane constituents and composition. Excellent Nernstian response (56.6 mV/decade of Cs(I)) over the concentration range 10{sup -7} to 10{sup -2} M of Cs(I) was obtained with a fast response time of less than 10 s. Detection limit for Cs(I) using the present ISE is 8.48 Multiplication-Sign 10{sup -8} M Cs(I). Separate solution method (SSM) was applied to ascertain the selectivity for Cs(I) over alkali, alkaline earth and transition metal ions. The response of ISE for Cs(I) was fairly constant over the pH range of 4-11. The lifetime of the electrode is 10 months which is the highest life for any membrane based Cs-ISE so far developed. The concentration of cesium ion in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing AAS.

  2. Binding of Coumarin 334 with β-Cyclodextrin and with C-Hexylpyrogallol[4]arene: Opposite Fluorescence Behavior

    OpenAIRE

    Chandrasekaran Sowrirajan; Enoch Israel Vijayaraj Muthu Vijayan

    2013-01-01

    We report here the structure of the host-guest complexes of Coumarin 334 (C334) with β-cyclodextrin (β-CD) and with C-hexylpyrogallol[4]arene (C-HPA) and the effect of acidity on the neutral-cation equilibrium of C334 in water and in the presence of the host molecules. The structures of the host-guest complexes are proposed on the basis of the change of fluorescence on the addition of β-CD or C-HPA to C334 and by 2D ROESY spectroscopy. Opposite fluorescence behaviors, that is, quenching of fl...

  3. Investigation of the inclusion behavior between p-sulfoniccalix[8]arene and norfloxacin by fluorescence spectroscopy

    International Nuclear Information System (INIS)

    The host-guest complexation between p-sulfoniccalix[8]arene (SC8A) and norfloxacin (NFLX) in aqueous solution was investigated by fluorescence spectroscopy. Strong fluorescence intensity of the NFLX aqueous solution alone and obvious fluorescence quenching of NFLX solution in the presence of SC8A were observed. The fluorescence lifetimes of NFLX and SC8A-NFLX inclusion complex were determined and the effect of temperature on SC8A-NFLX inclusion complex was studied. The static quenching of the inclusion was obtained, that is the SC8A can form a nonfluorescent ground-state inclusion complex with NFLX. As the results show, the combined ratio (n) was 1:1 and association constant K was 1.17x105 L/mol. Based on the experimental results, the mechanism of the inclusion complex was explored. The space matching, electrostatic force and hydrogen bond play important effects in the inclusion process. Subsequently, the addition of bovine serum albumin (BSA) solution led to the recovery of fluorescence intensity. It is indicated that BSA can liberate the NFLX into the solution by destructing the SC8A-NFLX inclusion complex. Hence SC8A may be used for controlled-release drug delivery in the pharmaceutical industry. - Highlights: → Fluorescence lifetimes of NFLX and SC8A-NFLX inclusion complex were determined. → Mechanism of the SC8A-NFLX inclusion complex was explored. → It is proved that SC8A can form a nonfluorescent ground-state inclusion complex with NFLX.

  4. Biological activity of ruthenium and osmium arene complexes with modified paullones in human cancer cells.

    Science.gov (United States)

    Mühlgassner, Gerhard; Bartel, Caroline; Schmid, Wolfgang F; Jakupec, Michael A; Arion, Vladimir B; Keppler, Bernhard K

    2012-11-01

    In an attempt to combine the ability of indolobenzazepines (paullones) to inhibit cyclin-dependent kinases (Cdks) and that of platinum-group metal ions to interact with proteins and DNA, ruthenium(II) and osmium(II) arene complexes with paullones were prepared, expecting synergies and an increase of solubility of paullones. Complexes with the general formula [M(II)Cl(η(6)-p-cymene)L]Cl, where M=Ru (1, 3) or Os (2, 4), and L=L(1) (1, 2) or L(2) (3, 4), L(1)=N-(9-bromo-7,12-dihydroindolo[3,2-d][1]-benzazepin-6(5H)-yliden-N'-(2-hydroxybenzylidene)azine and L(2)=N-(9-bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-yl)-N'-[3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl-methylene]azinium chloride (L(2)(*)HCl), were now investigated regarding cytotoxicity and accumulation in cancer cells, impact on the cell cycle, capacity of inhibiting DNA synthesis and inducing apoptosis as well as their ability to inhibit Cdk activity. The MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay yielded IC(50) values in the nanomolar to low micromolar range. In accordance with cytotoxicity data, the BrdU assay showed that 1 is the most and 4 the least effective of these compounds regarding inhibition of DNA synthesis. Effects on the cell cycle are minor, although concentration-dependent inhibition of Cdk2/cyclin E activity was observed in cell-free experiments. Induction of apoptosis is most pronounced for complex 1, accompanied by a low fraction of necrotic cells, as observed by annexin V-fluorescein isothiocyanate/propidium iodide staining and flow cytometric analysis. PMID:23037896

  5. Synthesis, Structure, and Molecular Recognition of S6 - and (SO2 )6 -Corona[6](het)arenes: Control of Macrocyclic Conformation and Properties by the Oxidation State of the Bridging Heteroatoms.

    Science.gov (United States)

    Guo, Qing-Hui; Zhao, Liang; Wang, Mei-Xiang

    2016-05-10

    We report herein the synthesis, structure, and molecular recognition of S6 - and (SO2 )6 -corona[6](het)arenes, and demonstrate a unique and efficient strategy of regulating macrocyclic conformation and properties by adjusting the oxidation state of the heteroatom linkages. The one-pot nucleophilic aromatic substitution reaction of 1,4-benzenedithiol derivatives, biphenyl-4,4'-dithiol and 9,9-dipropyl-9H-fluorene-2,7-dithiol with 3,6-dichlorotetrazine afforded S6 -corona[3]arene[3]tetrazines. These compounds underwent inverse-electron-demand Diels-Alder reaction with enamines and norbornadiene to produce S6 -corona[3]arene[3]pyridazines. Facile oxidation of sulfide linkages yielded (SO2 )6 -corona[3]arene[3]pyridazines. All corona[6](het)arenes adopted generally hexagonal macrocyclic ring structures; however, their electronic properties and conformation could be fine-tuned by altering the oxidation state of the sulfur linkages. Whereas (SO2 )6 -corona[3]arene[3]pyridazines were electron-deficient, S6 -corona[3]arene[3]pyridazines acted as electron-rich macrocyclic hosts that recognized various organic cations in both aqueous and organic solutions.

  6. Hetero-bimetallic Complex of a 2D Coordination Network Constructed by Sodium Ion and p-Sulfonatothiacalix[4]arene

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A 2D coordination polymer built by sodium ion and water-soluble p-sulfonato thiacalix(4)arene of trivalent yttrium complex [Na(H2O)2Y(H2O)6(DMF) (p-sulfonatothiaca lix(4)arene)]·9H2O is reported.The complex belongs to the monoclinic system, space group P21/c, with a =16.703(3),b = 17.819(4), c = 17.357(4)(A), β= 106.23(3)°,Z= 4,V= 4960.0(17)(A)3, Mr = 1304.08,Dc = 1.746 g/cm3,μ= 1.624 mm-1, F(000) = 2688, the final R = 0.0398 and wR = 0.1132 for 7534 observed reflections with I>2σ(I).One yttrium(Ⅲ) ion is coordinated by the thiacalixarene ligand via the sulfonato group, and also ligated by an oxygen atom of a DMF molecule occupying the cavity of thiacalixarene and six aqua ligands.

  7. Thiacalix[4]arene-tetra-(quinoline-8- sulfonate): a Sensitive and Selective Fluorescent Sensor for Co (II).

    Science.gov (United States)

    Modi, Krunal; Panchal, Urvi; Dey, Shuvankar; Patel, Chirag; Kongor, Anita; Pandya, Himanshu A; Jain, V K

    2016-09-01

    A novel fluorescent thiacalix[4]arene-tetra-(quinoline-8-sulfonate) (TCTQ8S) was synthesized by condensation of thiacalix[4]arene (TCA) and 8-quinoline sulfonyl chloride(8QSC). TCTQ8S was characterized by ESI-MS, (1)H-NMR and (13)C-NMR spectroscopic methods. TCTQ8S was found to be an efficient "turn-off" fluorescent sensor for the selective and sensitive recognition of Co(II) ions. The Job's plot measurement reveals a 1:1 stoichiometric ratio. The designed chemosensor exhibited high selectivity toward Co(II) ions vs. other tested metal ions, with a detection limit of up to 1.038 × 10(-9) M. The binding constant and quantum yield for the complex were also determined. Molecular docking studies have been successfully performed to support 1:1 binding of TCTQ8S with the Co(II) metal ion. TCTQ8S was evaluated for real sample analysis on water sample for the detection of Co(II). Graphical Abstract Thiacalix derivatized fluorescent sensor for the selective detection of Co(II). PMID:27392975

  8. Host–guest interactions between 4-sulfonatocalix[8]arene and 1-alkyl-3-methylimidazolium type ionic liquids

    International Nuclear Information System (INIS)

    Highlights: ► 1-Alkyl-3-methylimidazolium forms 1:1 and 2:1 complexes with sulfonatocalix[8]arene. ► Length of the alkyl group of the guest barely affects the stability of 1:1 complex. ► ΔG of 2:1 association goes through a minimum in the series of the guests. ► ΔH and ΔS of 1:1 binding show parallel decrease as the alkyl group of is lengthened. ► ΔH and ΔS of 2:1 inclusion reach minimum in the homologous series of guests. - Abstract: The inclusion of 1-alkyl-3-methylimidazolium ions (Cnmim+) in 4-sulfonatocalix[8]arene was studied by isothermal titration calorimetry in aqueous solution at 298 K. Sequential formation of 1:1 and 2:1 complexes occurred in enthalpy driven reactions. The alteration of the molecular structure of the guest barely affected the driving force of the confinement of the first Cnmim+. However, the binding affinity of the second Cnmim+ went through a maximum when the number of carbon atoms in the side chain was increased. The enthalpy and entropy change diminished linearly with the length of the aliphatic substituent of Cnmim+ for 1:1 complexation, but reached a minimum for the hexyl homologue in the case of 2:1 inclusion. Linear entropy–enthalpy correlations were found with smaller slope and intercept for the second binding step.

  9. Transition Metal Complexes of Calix[4]arene: Theoretical Investigations into Small Guest Binding within the Host Cavity.

    Science.gov (United States)

    Murphy, Paul; Dalgarno, Scott J; Paterson, Martin J

    2016-02-11

    The ability to selectively detect or store small molecules, such as gases, is of enormous commercial potential. Calixarenes have been studied extensively as host molecules; however, recent synthetic advances have seen the formation of new polymetallic calixarene clusters, which have not yet been explored for such purposes. We therefore present a theoretical study, using Density Functional Theory, to thoroughly investigate the binding preferences of calix[4]arene, with a variety of transition metal cations coordinated to the calixarene tetraphenolic pocket, toward a series of important small molecules, H2S, SO2, H2O, O2, H2, N2, N2O, CO2, NH3, and HCN. It was found that the inclusion of a metal atom at the lower-rim of the calixarene caused significant strengthening of binding energy with all of the small molecules in our study as compared to metal-free calixarene. The guests, SO2 and NH3, were found to bind strongest with H2 binding weakest. Our calculations predict that simply introducing metal coordination of any type to calix[4]arene will make the largest difference to the binding energies. Subsequently changing the type, oxidation state, or the spin state of the metal coordinated to the calixarene tetraphenolic pocket was found to have a lesser effect on these. PMID:26783648

  10. (Eta6-arene) ruthenium(II) complexes and metallo-papain hybrid as Lewis acid catalysts of Diels-Alder reaction in water.

    OpenAIRE

    Talbi, Barisa; Haquette, Pierre; Martel, Annie; Montigny, Frédéric de; Fosse, Céline; Cordier, Stéphane; Roisnel, Thierry; Jaouen, Gérard; Salmain, Michèle

    2010-01-01

    International audience Covalent embedding of a (eta(6)-arene) ruthenium(II) complex into the protein papain gives rise to a metalloenzyme displaying a catalytic efficiency for a Lewis acid-mediated catalysed Diels-Alder reaction enhanced by two orders of magnitude in water.

  11. Densely packed Gd(III)-chelates with fast water exchange on a calix[4]arene scaffold: a potential MRI contrast agent

    NARCIS (Netherlands)

    Schühle, D.T.; Polášek, M.; Lukeš, I.; Chauvin, T.; Tóth, E.; Schatz, J.; Hanefeld, U.; Stuart, M.C.A.; Peters, J.A.

    2009-01-01

    A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the corresponding Gd-complex was characterized with respect to its suitability as MRI contrast agent. The compound forms spherical micelles in water with a cmc of 35 mMand a radius of 8.2 nm. The relaxivity of

  12. Liposomes with conjugates of a calix[4]arene and a Gd-DOTA derivative on the outside surface: An efficient potential contrast agent for MRI

    NARCIS (Netherlands)

    Schühle, D.T.; Van Rijn, P.; Laurent, S.; Van der Elst, L.; Muller, R.N.; Stuart, M.C.A.; Schatz, J.; Peters, J.A.

    2010-01-01

    Paramagnetic liposomes used as contrast agents in magnetic resonance imaging (MRI) often suffer from low efficacies because of slow water diffusion through the membrane. We present an approach to overcome this limitation by incorporation of a calix[4]arene based agent that expresses the chelates tow

  13. Densely packed Gd(III)-chelates with fast water exchange on a calix[4]arene scaffold : a potential MRI contrast agent

    NARCIS (Netherlands)

    Schuhle, Daniel T.; Polasek, Miloslav; Lukes, Ivan; Chauvin, Thomas; Toth, Eva; Schatz, Juergen; Hanefeld, Ulf; Stuart, Marc C. A.; Peters, Joop A.

    2010-01-01

    A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the corresponding Gd-complex was characterized with respect to its suitability as MRI contrast agent. The compound forms spherical micelles in water with a cmc of 35 mu M and a radius of 8.2 nm. The relaxivity

  14. Liposomes with conjugates of a calix[4]arene and a Gd-DOTA derivative on the outside surface; an efficient potential contrast agent for MRI

    NARCIS (Netherlands)

    Schuhle, Daniel T.; van Rijn, Patrick; Laurent, Sophie; Vander Elst, Luce; Muller, Robert N.; Stuart, Marc C. A.; Schatze, Juergen; Peters, Joop A.

    2010-01-01

    Paramagnetic liposomes used as contrast agents in magnetic resonance imaging (MRI) often suffer from low efficacies because of slow water diffusion through the membrane. We present an approach to overcome this limitation by incorporation of a calix[4]arene based agent that expresses the chelates tow

  15. Crystal Structures of Two Calix[4]arene Isomers with Benzaldehyde Moiety and Their Photophysical Properties with Terbium(Ⅲ) Ions

    Institute of Scientific and Technical Information of China (English)

    王浩; 张衡益; 刘育

    2005-01-01

    Two calix[4]arene isomers with benzaldehyde moieties, i.e., 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(o-formyl-phenoxy)ethoxy]-26,28-dihydroxycalix[4]arene (3) and 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(p-formylphenoxy)-ethoxy]-26,28-dihydroxycalix[4]arene (4), were synthesized according to a newly designed route in high yields, and their crystal structures have been determined by X-ray crystallographic study. The photophysical behavior on complexation of calix[4]arene derivatives 3 and 4 with terbium(Ⅲ) nitrate was investigated in anhydrous acetonitrile at 25℃ by UV-Vis and fluorescence spectroscopies. The crystallographic structure of 3 indicated that the eight oxygen atoms formed a preorganized ionophoric cavity due to intramolecular π-π stacking, which could encapsulate lanthanide ions tightly. In sharp contrast, the compound 4 formed a linear array by intermolecular π-π stacking, hence the oxygen atoms of pendant arms could not coordinate with metal ions, giving a poor binding ability to Tb3+. The absorption spectra of 3 with Tb3+ showed clearly a new broad intense absorption at 385nm. Interestingly, the narrow emission line spectrum has also been observed for compound 3 with Tb3+, and the results obtained were discussed from the viewpoint of energy transfer mechanism between host structures and the properties of lanthanide ions.

  16. Transduction of selective recognition by preorganized ionophores, K+ selectivity of the different 1,3-diethoxycalix[4]arene crown ether conformers

    NARCIS (Netherlands)

    Brzozka, Zbigniew; Lammerink, Ben; Reinhoudt, David N.; Ghidini, Eleonora; Ungaro, Rocco

    1993-01-01

    Three different conformers of 1,3-diethoxy-p-tert-butylcalix[4]arene crown ethers have been used to study the effect of the ionophore preorganization on the potentiometric K+-selectivity. Selectivities were measured for chemically modified field effect transistors (CHEMFETs) and membrane ion-selecti

  17. Novel diglycolamide functionalized calix[4]arenes for actinide extraction and supported liquid membrane studies: Part II. Role of substituents in the pendent arms and mass transfer modeling I

    NARCIS (Netherlands)

    Ansari, S.A.; Mohapatra, P.K.; Iqbal, M.; Kandwal, P.; Huskens, J.; Verboom, W.

    2013-01-01

    Several calix[4]arene-functionalized diglycolamide (C4DGA) ligands were evaluated for the extraction as well as supported liquid membrane (SLM) transport of actinides and fission product elements from nitric acid feed solutions. The extraction efficiency of the C4DGA ligands for Am(III) was orders o

  18. Spectrofluorimetric determination of benzoimidazolic pesticides: Effect of p-sulfonatocalix[6]arene and cyclodextrins

    Energy Technology Data Exchange (ETDEWEB)

    Pacioni, Natalia L.; Sueldo Occello, Valeria N. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Lazzarotto, Marcio [Departamento de Quimica Organica, Instituto de Quimica, Universidade Federal do Rio Grande do Sul-UFRGS, 15003 Porto Alegre, R.S. (Brazil); Veglia, Alicia V. [Instituto de Investigaciones en Fisico Quimica de Cordoba (INFIQC), Departamento de Quimica Organica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)], E-mail: aveglia@fcq.unc.edu.ar

    2008-08-22

    The effect of the addition of a macrocyclic host (H) such as p-sulfonatocalix[6]arene (C6S), native and modified cyclodextrins (CDs), on the fluorescence of benzoimidazolic fungicides (P), like Benomyl (BY) and Carbendazim (CZ), has been studied. The fluorescence of BY in water at pH 1.000 and 25.0 deg. C was increased in the presence of C6S, {alpha}CD and hydroxypropyl-{beta}-CD (HPCD). The association constants determined by fluorescence enhancement showed weak interactions (K{sub A} {approx} 10{sup 1} to 10{sup 2} M{sup -1}) between the fungicide with both CDs, whereas they were stronger with C6S (K{sub A} {approx} 10{sup 5} M{sup -1}). Molecular recognition of BY for C6S was mainly attributed to electrostatic interactions, and for CDs to the hydrophobic effect and hydrogen bond formation. On the other hand, the fluorescent behaviour of CZ in the presence of C6S at pH 6.994 was interpreted as the formation of two complexes with 1:1 (P:H) and 1:2 (P:H{sub 2}) stoichiometry, the latter being less fluorescent than the free analyte. Relative fluorescence quantum yield ratios between the complexed and free BY ({phi}{sup P:H}/{phi}{sup P}) were 2.00 {+-} 0.05, 1.40 {+-} 0.03 and 2.8 {+-} 0.4 for C6S, {alpha}CD and HPCD, respectively. The analytical parameters improved in the presence of C6S and CDs. The best limit of detection (L{sub D}, ng mL{sup -1}) was 17.4 {+-} 0.8 with HPCD. The proposed method with C6S and HPCD was successfully applied to fortified samples of tap water and orange flesh extract with good recoveries (91-106%) and R.S.D. ({<=}2%) by triplicate analysis. The method is rapid, direct and simple and needs no previous degradation or derivatization reaction.

  19. Crystal structures of resorcin[4]arene and pyrogallol[4]arene complexes with DL-pipecolinic acid. Model compounds for the recognition of the pipecolinyl ring, a key fragment of FK506, through C-H⋯π interaction

    Science.gov (United States)

    Fujisawa, Ikuhide; Kitamura, Yuji; Kato, Ryo; Murayama, Kazutaka; Aoki, Katsuyuki

    2014-01-01

    Resorcin[4]arene (resorcinol cyclic tetramer, abbreviated as RCT) or pyrogallol[4]arene (pyrogallol cyclic tetramer, PCT) form host-guest 1:1 complexes with DL-pipecolinic acid (DL-pipeH), RCT·DL-pipeH·EtOH·8H2O (1), PCT DL-pipeH·EtOH·4H2O (2), and PCT·DL-pipeH·3H2O (3), whose crystal structures have been determined. In each complex, the pipeH ligand is incorporated into the bowl-shaped cavity of the RCT or PCT host molecules through C-H⋯π interactions between alkyl protons of the piperidine ring of pipeH and π-rings of RCT or PCT, forming an [(RCT/PCT)·pipeH] structural fragment. In 1 and 3, two [(RCT/PCT) pipeH] fragments self-associate across an inversion center to form a guest-mediated, obliquely declined dimeric structure [(RCT/PCT)·L-pipeH·D-pipeH (RCT/PCT)]. In 2, each PCT-capped pipeH ligand bridges to two adjacent PCT molecules to form guest-mediated, optically-discrete helical polymers [PCT·L-pipeH]n or [PCT·D-pipeH]n. An 1H NMR experiment shows that the complexation through C-H⋯π interaction between the piperidine ring of pipeH and π-rings of RCT or PCT occurs also in solution, with the binding constants of 9.7 ± 0.6 M-1 for RCT and 26.5 ± 1.5 M-1 for PCT. These complexes provide a synthetic model for the recognition of the pipecolinyl-ring moiety, a key constituent of immunosuppressant drugs such as FK506, FK520 or rapamycin, by their binding proteins through C-H⋯π interaction.

  20. Effect of the Piperazine Unit and Metal-Binding Site Position on the Solubility and Anti-Proliferative Activity of Ruthenium(II)- and Osmium(II)- Arene Complexes of Isomeric Indolo[3,2-c]quinoline—Piperazine Hybrids

    OpenAIRE

    Filak, Lukas K.; Kalinowski, Danuta S.; Bauer, Theresa J.; Richardson, Des R.; Arion, Vladimir B

    2014-01-01

    In this study, the indoloquinoline backbone and piperazine were combined to prepare indoloquinoline–piperazine hybrids and their ruthenium- and osmium-arene complexes in an effort to generate novel antitumor agents with improved aqueous solubility. In addition, the position of the metal-binding unit was varied, and the effect of these structural alterations on the aqueous solubility and antiproliferative activity of their ruthenium- and osmium-arene complexes was studied. The indoloquinoline–...

  1. Hexameric Capsules Studied by Magic Angle Spinning Solid-State NMR Spectroscopy: Identifying Solvent Molecules in Pyrogallol[4]arene Capsules.

    Science.gov (United States)

    Avram, Liat; Goldbourt, Amir; Cohen, Yoram

    2016-01-18

    Powders of pyrogallol[4]arene hexamers were produced by evaporation from organic solvents and were studied, for the first time, by magic angle spinning solid-state NMR (MAS ssNMR). Evaporation selectively removed non-encapsulated solvent molecules leaving stable hexameric capsules encapsulating solvent molecules. After exposure of the powder to solvent vapors, (1)H/(13)C heteronuclear correlation MAS ssNMR experiments were used to assign the signals of the external and encapsulated solvent molecules. The formed capsules were stable for months and the process of solvent encapsulation was reversible. According to the ssNMR experiments, the encapsulated solvent molecules occupy different sites and those sites differ in their mobility. The presented approach paves the way for studying guest exchange, guest affinity, and gas storage in hexamers of this type in the solid state.

  2. Photo-physical and complexation properties of chromogenic azo-calix[4]arene: Application to the detection of Eu 3+

    Science.gov (United States)

    Ebdelli, Rihab; Rouis, Ahelm; Mlika, Rym; Bonnamour, Isabelle; Ben Ouada, Hafedh; Davenas, Joel

    2011-12-01

    A studies of a tetrakis(phenylazo)calix[4]arene derivative have been developed for cation recognition. The complexation properties of this ligand towards transition metal ions have been investigated by UV-Visible and fluorescence spectroscopies. It has been found that the ligand has remarkable complexation ability for transition metal Ni 2+, Co 2+, Hg 2+, heavy metal ions Al 3+ and Pb 2+ with an exceptional high affinity for the lanthanide Eu 3+ ion. The stoichiometric ratio of the complexation between the ionophore and Eu 3+ ions in acetonitrile solution has been determined by applying the molar ratio method. The complexes formed are ML 2 and ML in neutral and in basic medium respectively. The recognition properties between the thin film and the ions have also been studied. The complexation properties of the ligand with Eu 3+ ion has been confirmed by fluorescence spectroscopy.

  3. Synthesis, characterization and ion recognition studies of lower rim 1,3-di{rhodamine} conjugate of calix[4]arene

    Indian Academy of Sciences (India)

    Jugun Prakash Chinta; Jayaraman Dessingou; Chebrolu Pulla Rao

    2013-11-01

    An amido-linked rhodamine conjugate of calix[4]arene, L has been synthesized and characterized. Metal ion recognition properties of L have been studied by emission and absorption techniques with 14 different metal ions including the transition ones. Results show that, L exhibits ratiometric emission intensity towards Hg2+, Fe2+, Fe3+, Cu2+, Pb2+ and Zn2+. Composition of the complex formed in the solution has been found to be 1:2 (L:M+), based on the Job’s plot. The L can also act as a chemosensor for Hg2+ through naked eye detection. Fluorescence quenching observed at 485 nm follows an order, Hg2+>>Fe3+∼Cu2+>Zn2+>Pb2+>Ca2+, while the enhancement observed at 580 nm follows, Hg2+>>Fe2+∼Pb2+>Zn2+. Mode of interaction of M+ with L is by the ring opening of spirolactam moiety.

  4. Solid Lipid Nanoparticle-Based Calix[n]arenes and Calix-Resorcinarenes as Building Blocks: Synthesis, Formulation and Characterization

    Directory of Open Access Journals (Sweden)

    Anthony W. Coleman

    2013-11-01

    Full Text Available Solid lipid nanoparticles (SLNs have attracted increasing attention during recent years. This paper presents an overview about the use of calix[n]arenes and calix-resorcinarenes in the formulation of SLNs. Because of their specific inclusion capability both in the intraparticle spaces and in the host cavities as well as their capacity for functionalization, these colloidal nanostructures represent excellent tools for the encapsulation of different active pharmaceutical ingredients (APIs in the area of drug targeting, cosmetic additives, contrast agents, etc. Various synthetic routes to the supramolecular structures will be given. These various routes lead to the formulation of the corresponding SLNs. Characterization, properties, toxicological considerations as well as numerous corresponding experimental studies and analytical methods will be also exposed and discussed.

  5. Malonamide, phosphine oxide and calix[4]arene functionalized ionic liquids: synthesis and extraction of actinides and lanthanides

    International Nuclear Information System (INIS)

    Radioactive waste treatment is a crucial problem nowadays. This work was dedicated to the development of the new extracting systems for radionuclides on the basis of 'green' solvents Ionic Liquids (Ils). For this purpose Ils were functionalized with various extracting patterns: phosphine oxide, carbamoyl phosphine oxide groups and malonamide fragment. Also the calix[4]arene platforms were used for the synthesis of functionalized ionic liquids (Fils) and their precursors. The Fils of both types cationic and anionic have been obtained. The synthesized Fils were tested for the liquid-liquid extraction of radionuclides. lt was found that extraction well occurs due to the extracting patterns, however a charge of a modified ion influences extraction.The various extracting experiments and mathematical modelling have been performed to determine the mechanisms of extraction. These studies showed that each extracting system is characterized by a different set of extracting equilibria, based mostly on cationic exchange. (author)

  6. Ring-Opening Polymerisation of rac-Lactide Using a Calix[4]arene-Based Titanium (IV Complex

    Directory of Open Access Journals (Sweden)

    Marco Frediani

    2010-01-01

    Full Text Available cone-25,27-Dipropyloxy-26,28-dioxo-calix[4]arene titanium (IV dichloride (1 has been assessed in the ring-opening polymerisation of rac-lactide (L,D-LA. The polymers formed (PLDA turned out to display an isotactic stereoblock microstructure (determined by NMR despite the fact that the catalyst has C2v symmetry. Two techniques were applied for initiating the polymerisation reaction, microwave irradiation, and conventional thermal treatment. The polymers obtained were all characterised by NMR, IR, HPLC-SEC, DSC, and MALDI-TOF analysis. The use of microwave irradiation, applied for the first time to calixarene-based catalysts in the presence of the rac-lactide monomer, increased the polymerisation rate compared with that obtained by the other method. On the other hand, standard thermal treatment enabled a slightly better control than microwave irradiation over the molecular weight and molecular weight distribution of the polylactides formed.

  7. Separation of Salbutamol by Nano-baskets of Calix[4]arene Bearing Sulfonyl-carboxamides in Partial-cone Conformation

    Institute of Scientific and Technical Information of China (English)

    MOKHTARI Bahram; POURABDOLLAH Kobra

    2012-01-01

    Salbutamol,which increases the muscle mass and decreases the adipose tissue,is misused as nutrient repartitioning agent in the livestock.The novelty of this work is the determination of salbutamol in the livestock meat via new bonded-phases bearing eight derivatives ofp-tert-calix[4]arene in partial-cone conformation.The new synthesized bonded-phases were characterized and optimized.The bonding interactions of solute and stationary-phases were examined and the main interactions were reported.The salbutamol levels in six samples of livestock meat were analyzed and the results reveal that for the best bonded-phases,the limit of detection(LOD) and limit of quantitation (LOQ) were 0.02 and 0.06 μg/mL,respectively.

  8. The Synthesis of Diquinone and Dihydroquinone Derivatives of Calix[4]arene and Electrochemical Characterization on Au(111) surface.

    Science.gov (United States)

    Genorio, Boštjan

    2016-01-01

    Several new electroactive diquinone and dihydroquinone derivatives of calix[4]arene bearing anchor functional groups were designed, synthesized and characterized. A method for selective protection of the hydroquinone -OH groups with trimethylsilyl groups (TMS) either on lower-rim or on upper-rim was developed. Four selected molecules - with sulfide anchor groups and carboxylic anchor groups - were adsorbed onto Au(111) single crystal surface using ex-situ and insitu self-assembly methods. Adsorbed molecules were then electrochemically probed with cyclic voltammetry. All adsorbed molecules showed redox response which changed during cycling. After conditioning CVs stabilized and showed two distinct current peaks for all molecules. Synthesized and electrochemically probed molecules are of interest to: Li-ion batteries (as cathode materials and overcharge protection), beyond Li-ion batteries and redox-flow batteries. PMID:27640377

  9. Syntheses and Properties of New Pendant-armed Calix[ 4 ] areneDerivatives as Cesium Selective Ionophore

    Institute of Scientific and Technical Information of China (English)

    XING Yah-Jun; ZHOU Zhi-Xian; WU Yang-Jie

    2001-01-01

    Two new pendant-armed calix[4] arene derivatives 5 and 6 have been synthesized.The study of alkali metal picrates ex- traction indicates that both compounds show prefereoce of ce- sium cation, compounnd 6 in 1,3-altermate conformation has better extractibility for Cs+ than compound 5.The coordina- tion behavior of compound 6 with cesium cation was studied by 1H NMR spectroscopy.The Cs+ selective elctrode based on compound 6 exhibits a linear, near Nernstian response characteristics, the slope is 56.4 mV/decade in the concentra- tion range of 10-4-10-1 mol/L, the selectivity coefficient (log Kdot,Na.) is -3.39.

  10. Stabilized rhodium(0) nanoparticles: a reusable hydrogenation catalyst for arene derivatives in a biphasic water-liquid system.

    Science.gov (United States)

    Schulz, J; Roucoux, A; Patin, H

    2000-02-18

    A colloidal system based on an aqueous suspension of rhodium(o) nanoparticles proved to be an efficient catalyst for the hydrogenation of arene derivatives under biphasic conditions. The rhodium nanoparticles (2-2.5 nm) were synthesized by the reduction of RhCl3 x 3H2O with sodium borohydride and were stabilized by highly water-soluble N-alkyl-N-(2-hydroxyethyl)ammonium salts (HEA-Cn). These surfactant molecules were characterized by measurements of the surface tension and the aqueous dispersions with rhodium were observed by transmission electron cryomicroscopy. The catalytic system is efficient under ultramild conditions, namely room temperature and 1 atm H2 pressure. The aqueous phase which contains the protected rhodium(0) colloids can be reused without significant loss of activity. The microheterogeneous behavior of this catalytic system was confirmed on a mercury poisoning experiment.

  11. Insights into the Intramolecular Properties of η6-Arene-Ru-Based Anticancer Complexes Using Quantum Calculations

    Directory of Open Access Journals (Sweden)

    Adebayo A. Adeniyi

    2013-01-01

    Full Text Available The factors that determine the stability and the effects of noncovalent interaction on the η6-arene ruthenium anticancer complexes are determined using DFT method. The intramolecular and intra-atomic properties were computed for two models of these half-sandwich ruthenium anticancer complexes and their respective hydrated forms. The results showed that the stability of these complexes depends largely on the network of hydrogen bonds (HB, strong nature of charge transfer, polarizability, and electrostatic energies that exist within the complexes. The hydrogen bonds strength was found to be related to the reported anticancer activities and the activation of the complexes by hydration. The metal–ligand bonds were found to be closed shell systems that are characterised by high positive Laplacian values of electron density. Two of the complexes are found to be predominantly characterised by LMCT while the other two are predominately characterised by MLCT.

  12. Origin of the {sup 238}U-{sup 230}Th disequilibrium in magmas from subduction zones: the Arenal example; Origine du desequilibre {sup 238}U-{sup 230}TH dans les magmas des zones de subduction: exemple de l`Arenal

    Energy Technology Data Exchange (ETDEWEB)

    Villemant, B. [Paris-6 Univ., 75 (France)

    1996-12-31

    The existence in some volcanic products of strong excess of {sup 238}U with respect to {sup 230}Th is one of the characteristics of volcanic arc magmas. These excesses are generally attributed to fluid additions inside mantellic sources before magma segregation, differentiation and eruption. These fluids should be linked to the dehydration of the subducted rocks. These hypotheses are essentially based on correlations between {sup 10}Be, {sup 87}Sr anomalies, Ba/La ratios and on the distribution of volcanic centers with respect to the subduction zone. Recent studies suggest an evolution of the composition of volcanic sources in Central America from a depleted mantle type (MORB) in the North (Nicaragua) to a less transformed enriched type (OIB) in the South (Costa Rica). The Arenal volcano belongs to a transition zone between these two types. The preliminary study of trace elements and {sup 238}U-{sup 230}Th disequilibria in recent volcanic products (1968-1993) indicates a more complex situation. At least two different mantle sources were successively involved characterized by different Th/La and La/Yb ratios and very different to the OIB type. Also most lavas are in equilibrium with {sup 238}U/{sup 232}Th ratios of about 1.2 to 1.3. However, in eruptive cycle, some lavas are characterized by a strong {sup 238}U excess with respect to {sup 230}Th with cannot be linked to the sources, even when modified by fluids in depth. These results are interpreted in terms of heterogeneities of mantle sources and low depths late interactions with hydrothermal fluids during eruptions. Abstract only. (J.S.). 2 refs.

  13. Host-guest interactions between 4-sulfonatocalix[8]arene and 1-alkyl-3-methylimidazolium type ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Wintgens, Veronique; Amiel, Catherine [Systemes Polymeres Complexes, ICMPE, 2 rue Henri Dunant, 94320 Thiais (France); Biczok, Laszlo, E-mail: biczok.laszlo@ttk.mta.hu [Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 17, 1525 Budapest (Hungary); Miskolczy, Zsombor; Megyesi, Monika [Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 17, 1525 Budapest (Hungary)

    2012-11-20

    Highlights: Black-Right-Pointing-Pointer 1-Alkyl-3-methylimidazolium forms 1:1 and 2:1 complexes with sulfonatocalix[8]arene. Black-Right-Pointing-Pointer Length of the alkyl group of the guest barely affects the stability of 1:1 complex. Black-Right-Pointing-Pointer {Delta}G of 2:1 association goes through a minimum in the series of the guests. Black-Right-Pointing-Pointer {Delta}H and {Delta}S of 1:1 binding show parallel decrease as the alkyl group of is lengthened. Black-Right-Pointing-Pointer {Delta}H and {Delta}S of 2:1 inclusion reach minimum in the homologous series of guests. - Abstract: The inclusion of 1-alkyl-3-methylimidazolium ions (C{sub n}mim{sup +}) in 4-sulfonatocalix[8]arene was studied by isothermal titration calorimetry in aqueous solution at 298 K. Sequential formation of 1:1 and 2:1 complexes occurred in enthalpy driven reactions. The alteration of the molecular structure of the guest barely affected the driving force of the confinement of the first C{sub n}mim{sup +}. However, the binding affinity of the second C{sub n}mim{sup +} went through a maximum when the number of carbon atoms in the side chain was increased. The enthalpy and entropy change diminished linearly with the length of the aliphatic substituent of C{sub n}mim{sup +} for 1:1 complexation, but reached a minimum for the hexyl homologue in the case of 2:1 inclusion. Linear entropy-enthalpy correlations were found with smaller slope and intercept for the second binding step.

  14. Synthesis and complexation properties towards uranyl cation of carboxylic acid derivatives of p-tert-butyl-calix[6]arene; Synthese et proprietes complexantes vis-a-vis de l'ion uranyle de derives carboxyliques du p-tert-butyl-calix[6]arene

    Energy Technology Data Exchange (ETDEWEB)

    Souane, R

    2005-03-15

    In the fuel reprocessing plants radioactive metals, and more particularly, uranium in UO{sub 2}{sup 2+} form in the various installations, have many varied physico-chemical forms and there is a risk of exposure and internal contamination in the nuclear industry. It is necessary to exert a medical control to ensure the protection of the health of the workers. This medical control is done by dosing uranyl cation in the urine of the exposed people. This work forms part of this context. Indeed, we prepared a ligand able to complex the ion uranyl and which is also to be grafted on a solid support. In the family of calixarenes, the calix[6]arenes functionalized by three or four carboxylic functions were selected like chelating molecules of the ion uranyl. The properties of complexation of these calixarenes were studied by potentiometry in methanol, under these conditions balances of protonation and complexation were determined and the constant partners were obtained using the Hyperquad program. We synthesized tri-carboxylic calix[6]arenes comprising of the groupings nitro (NO{sub 2}) in para position of phenol in order to see the influence of a substitution in para position on the complexation. We also synthesized calix[6]arenes tetra-carboxylic in order to show the role of an additional carboxylic acid grouping. The potentiometric study determined thermodynamic parameters of protonation and complexation of carboxylic calix[6]arenes. The results of the complexation highlighted which complex UO{sub 2}L corresponding to the ligand para-tert-butyl-calix[6]arene tetra-acid is more stable than that corresponding to the ligand mono-nitro calix[6]arene tri-acid ({delta}log{beta}110 = 4.3), and than the effect of the groupings nitro in para position has low influence on the complexation of UO{sub 2}{sup 2+}. This makes it possible to consider as possible the grafting of the calix[6]arenes which one knows the behaviour of trapping. To this end we synthesized the ligand 23

  15. Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu2+

    Science.gov (United States)

    Nemati, Mohammad; Zadmard, Reza; Mohadjerani, Maryam

    2016-01-01

    Summary Functionalization of calix[4]arene with amidofluorene moieties at the lower rim led to formation of the 1,3-diconjugate of calix[4]arene L as a novel fluorescent chemosensor for Cu2+. The receptor molecule L exhibited a pronounced selectivity towards Cu2+ over other mono and divalent ions. The formation of the complex between L and Cu2+ was evaluated by absorption, fluorescence and 1H NMR spectroscopy. The sensor L showed a remarkable color change from colorless to purple and a fluorescence quenching only upon interaction with Cu2+. The 1:1 stoichiometry of the obtained complex has been determined by Job’s plot. The association constant determined by fluorescence titration was found to be 1.8 × 106 M−1. The sensor showed a linear response toward Cu2+ in the concentration range from 1 to 10 µM with a detection limit of 9.6 × 10−8 M.

  16. Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu(2.).

    Science.gov (United States)

    Hosseinzadeh, Rahman; Nemati, Mohammad; Zadmard, Reza; Mohadjerani, Maryam

    2016-01-01

    Functionalization of calix[4]arene with amidofluorene moieties at the lower rim led to formation of the 1,3-diconjugate of calix[4]arene L as a novel fluorescent chemosensor for Cu(2+). The receptor molecule L exhibited a pronounced selectivity towards Cu(2+) over other mono and divalent ions. The formation of the complex between L and Cu(2+) was evaluated by absorption, fluorescence and (1)H NMR spectroscopy. The sensor L showed a remarkable color change from colorless to purple and a fluorescence quenching only upon interaction with Cu(2+). The 1:1 stoichiometry of the obtained complex has been determined by Job's plot. The association constant determined by fluorescence titration was found to be 1.8 × 10(6) M(-1). The sensor showed a linear response toward Cu(2+) in the concentration range from 1 to 10 µM with a detection limit of 9.6 × 10(-8) M. PMID:27559419

  17. Kinetics and mechanism studies on scandium calix[6]arene complex initiating ring-opening polymerization of 2,2-dimethyltrimethylene carbonate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Scandium p-tert-butylcalix[6]arene complex has been synthesized from scandium isopropoxide and p-tert-butylcalix[6]arene and used as a single component initiator for the first time. The polymerization of 2,2-dimethyltrimethylene carbonate (DTC) using this complex can proceed under mild conditions. Poly (2,2-dimethyltrimethylene carbonate) (PolyDTC) with weight-average molecular weight of 33700 and molecular weight distribution of 1.21 can be prepared. Kinetics study indicates that the polymerization rate is first order with respect to both monomer and initiator concentrations, and the apparent activation energy of the polymerization is 22.7 kJ/mol. 1H NMR spectrum of the polymer reveals that the monomer ring opens via acyl-oxygen bond cleavage leading to an active center of Sc-O.

  18. Methodology for estimating aquifer recharge direct mfisurado system by the method of ripple of free (WTF) surface Mina Arenal departamento de Rivera

    International Nuclear Information System (INIS)

    The study area is framed in the so-called Crystal Island Rivera region of economic importance to Uruguay considering the gold occurrences . The company Uruguay Mineral Exploration Inc. (UME ) develops prospective exploration projects in the region since 1997 The discovery of a deposit of gold ore results in the opening of the Arenal mine near the town of Minas de Corrales, Department Rivera .Income groundwater to the quarry would affect the progress of the mineral extractive work to control this situation and monitors the evolution of a monitoring program is established with the potentiometric measurement levels and hydrological variables meteorelógicas.The data obtained allowed to estimate the direct recharge of the aquifer system in the area comprising the operational work of the Arenal mine, by applying the method of free surface fluctuation (WTF ) .The WTF method provides an estimate of groundwater recharge by analyzing water level fluctuations in observation wells

  19. Synthesis of a Tweezer-like Bis(phenylthiapropoxy)calix[4]arene as a Cation/π Enhanced Sensor for Ion-Selective Electrodes

    Institute of Scientific and Technical Information of China (English)

    SUN,Hao(孙浩); ZHANG,Zheng-Zhi(张正之); ZENG,Xian-Shun(曾宪顺); LU,Jian-Quan(吕监泉); LENG,Xue-Bing(冷雪冰); CHEN Qi-Fa(陈企发); XU,Feng-Bo(徐风波); LI,Qing-Shan(李庆山); HE,Xi-Wen(何锡文); ZHANG,Wen-Qin(张文勤)

    2002-01-01

    Two novel 25,27-dihydroxy-26,28-bis(3-phenylthiapropoxy)-calix[4]arene (3) and 25,27-dihydroxy-26,28-bis(3-phenylthiapropoxy)-5,11, 17, 23-tetra-tert-butylcalix[4] arene (4) were synthesized for the evaluation of their ion-selectivity in ion-selective electrodes (ISEs). ISEs based on 3 and 4 as neutral ionophores were prepared, and their selectivity coefficients for Ag+ (lg Kpot Ag,M) were investigated against other alkali metal,alkaline-earth metal, aluninum, thallium(Ⅰ), lead and some transition metal ions using the separate solution method (SSM). These ISEs showed excellent Ag + selectivity over most of the interfering cations examined, except for Hg2 + and Fe2 + having relative smaller interference (lgKpot Ag,M≤ -2.1).

  20. Interaction of Sulfonated Calix [n] arenes with Rhodamine B and Its Application to Determine Acetylcholine in a Real Neutral Aqueous Medium

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yong-Jun; XU,Jian; 等

    2002-01-01

    Complexation between Rhodamine B(RB) and sulfonated calix [n] arenes (SCnA) were studied by means of UV-vis spectroscopy and fluorescence spectroscopy.In the presence of sulfonated calix [n] arenes,the absorption hand of Rhodamine B shifts to longer wavelength and its intensity decreases.The formation of a host-guest type complex also results in the fluorescence quenching of Rhodamine B.The accociation constants for the RB/SCn A complexes increase in the order of SC4A

  1. Synthesis of a Tweezer—like Bis(Phenylthiapropoxy)calix[4]—arene as a Cation/π Enhanced Sensor for Ion—Selective Electrodes

    Institute of Scientific and Technical Information of China (English)

    孙浩; 曾宪顺; 吕监泉; 陈企发; 徐风波; 李庆山; 何锡文; 张文勤

    2002-01-01

    Two novel 25,27-dihydroxy-26,28-bis(3-phenylthiapropxy)-calix[4]arene(3) and 25,27-dihydroxy-26,28-bis(3-phenylthiapropoxy)-5,11,17,23-tetra-tert-butylcalix[4] arene (4) were synthesized for the evaluation of their ion-selectivity in ion-selective electrodes(ISEs).ISEs based on 3 and 4 as neutral ionophores were prepared,and their selectivity coefficients for Ag (lg KAg,Mpot)were investigated against other alkali metal,alkaline-earth metal,aluminum,thallium(Ⅰ),Lead and some transition metal ions using the separate solution method (SSM).These ISEs showed excellent Ag seletivity over most of the interfering cations examined,except for Hg2 and Fe2 having relative smaller interference(lg KAg,Mpot≤-2.1).

  2. Di-ionizable p-tert-butylcalix[4]arene-1,2-crown-3 ligands in cone and 1,2-alternate conformations: synthesis and metal ion extraction.

    Science.gov (United States)

    Zhang, Dongmei; Cao, Xiaodan; Purkiss, David W; Bartsch, Richard A

    2007-04-21

    Novel di-ionizable p-tert-butylcalix[4]arene-1,2-crown-3 ligands in cone and 1,2-alternate conformations were prepared as potential metal ion extractants. Selective bridging of proximal hydroxyl groups of the calix[4]arene platform by a crown-3 polyether unit was achieved under Mitsunobu reaction conditions. In addition to the carboxylic acid group, the acidity tunable N-(X)sulfonyl oxyacetamide functions [OCH(2)C(O)NHSO(2)X] with X group variation from methyl to phenyl to p-nitrophenyl to trifluomethyl were used as the proton-ionizable groups. Conformations and regioselectivities of the new ligands were established by (1)H and (13)C NMR spectroscopy. Competitive solvent extractions of alkali metal cations and of alkaline earth metal cations from aqueous solutions into chloroform were performed, as were single species extractions of lead(ii) and mercury(ii).

  3. Deciphering Noncovalent Interactions Accompanying 7,7,8,8-Tetracyanoquinodimethane Encapsulation within Biphene[n]arenes: Nucleus-Independent Chemical Shifts Approach.

    Science.gov (United States)

    Lande, Dipali N; Rao, Soniya S; Gejji, Shridhar P

    2016-07-18

    Binding of novel biphene[n]arene hosts to antiaromatic 7,7,8,8-tetracyanoquinodimethane (TCNQ) are investigated by DFT. Biphene[4]arene favors the inclusion complex through noncovalent interactions, such as hydrogen bonding, π-π stacking, C-H⋅⋅⋅π, and C-H⋅⋅⋅H-C dihydrogen bonding. Donor-acceptor complexation renders aromatic character to the guest through charge transfer. The formation of TCNQ anionic radicals through supramolecular π stacking significantly influences its chemical and photophysical behavior. Electron density reorganization consequent to encapsulation of TCNQ reflects in the shift of characteristic vibrations in the IR spectra. The accompanying aromaticities arising from the induced ring currents are analyzed by employing nucleus-independent chemical shifts based profiles. PMID:27028656

  4. Noncritically phase-matched second harmonic generation of blue light in Si[O]N-calix[4] arene slab type waveguides

    NARCIS (Netherlands)

    Wörhoff, K.; Noordman, O.F.J.; Lambeck, P.V.; Hulst, van N.F.; Albers, H.

    1996-01-01

    Phase-matching (TM(0)(omega) --> TM(1)(2 omega)) devices for generation of blue light using Si[0]N and optically nonlinear calix[4]arene layers are designed, fabricated and tested. The devices show second harmonic peak power of 17 mW at 472.9 nm and 4.5 W at 481.6 nm after 10 mm propagation length o

  5. p-Phosphonic acid calix[8]arene assisted dispersion and stabilisation of pea-pod C60@multi-walled carbon nanotubes in water.

    Science.gov (United States)

    Chen, Xianjue; Gibson, Christopher T; Britton, Joshua; Eggers, Paul K; Wahid, M Haniff; Raston, Colin L

    2015-02-11

    A facile approach has been developed for non-covalently stabilising pristine C60 and multi-walled carbon nanotubes (MWCNTs) in water in the presence of p-phosphonic acid calix[8]arene, along with the formation of a 'pea-pod' encapsulation of the fullerene inside the MWCNTs. Aqueous dispersions of the different carbon nano-materials are readily decorated with palladium nanoparticles.

  6. Self assembly of C-methyl resorcin[4]arene with coumarin and thiocoumarin: A nanotubular array with a near perfect lock and key fit

    Indian Academy of Sciences (India)

    Lepakshaiah Mahalakshmi; Partha P Das; Tayur N Guru Row

    2008-01-01

    The host-guest complex of -methyl resorcin[4]arene with coumarin and thiocoumarin has been characterized by single crystal X-ray diffraction technique. Structural analysis shows that the host forms an infinitie nanotubular array in which the guest coumarin shows a `head to tail’ arrangement of dimers held together by $\\ldots$ interaction in the host framework. Similar structural motif is observed when thiocoumarin used as a guest.

  7. Photoassisted Synthesis of Complex Molecular Architectures: Dearomatization of Benzenoid Arenes with Aza-o-xylylenes via an Unprecedented [2+4] Reaction Topology.

    Science.gov (United States)

    Kuznetsov, Dmitry M; Mukhina, Olga A; Kutateladze, Andrei G

    2016-06-01

    A new method was developed for the photoinduced dearomatization of arenes through an intramolecular cycloaddition with aza-o-xylylenes generated by excited-state intramolecular proton transfer (ESIPT) in the readily available photoprecursors. The [2+4] topology of this cycloaddition is unprecedented for photo-dearomatizations of benzenoid aromatic carbocycles. It provides rapid access to novel heterocycles, cyclohexadieno-oxazolidino-quinolinols, as valuable synthons for a broad range of post-photochemical transformations. PMID:27097759

  8. Two novel fluorescent calix[4]arene derivatives with benzoazole units in 1,3-alternate conformation for selective recognition to Fe~(3+) and Cr~(3+)

    Institute of Scientific and Technical Information of China (English)

    He Wen Wang; Ya Qing Feng; Chen Chen; Jin Qiang Xue

    2009-01-01

    Two novel fluorescent calix[4]arene derivatives 1a and 1b with benzoxazole or benzothiazole units in 1,3-alternate conformation have been synthesized and characterized by IR, ~1H NMR, ~(13)C NMR and MS. Their complexation properties to different heavy and transition metal ions have been studied by UV-vis spectroscopy and fluorescence spectrometer. Compounds la and lb show selective recognition to Fe~(3+) and Cr~(3+).

  9. Nilai Ekonomi dan Sebaran Aren(Arenga pinnata).(Studi Kasus Desa Suka Maju dan Desa Bukum ,Kecamatan Sibolagit, Kabupaten Deli Serdang).

    OpenAIRE

    Purba, Erickson

    2015-01-01

    Aren (Arenga pinnata) is a forest plant that has many benefits but can not be used optimally by the forest dwellers. This study aimed to determine the distribution of palm and palm economic value. Sampling was done by purposive sampling technique. Based on research by the distribution of palm is known and dominant groups grow altitude of 600-800 meters above sea level, while the highest economic value of palm sugar used is red and the lowest economic value is wine . 091201131

  10. Thiacalix[4]arene derivatives as extractants for metal ions in aqueous solutions: Application to the selective facilitated transport of Ag(I)

    International Nuclear Information System (INIS)

    The complexation abilities of different thiacalix[4]arene derivatives towards some rare earth metal ions, metallic pollutants, and noble metals have been investigated in liquid-liquid experiments. Thiacalix[4]arene dissolved in chloroform effectively extracts Pd(II) (in acidic chloride media) and also Ag(I), Cd(II), Sm(III) and Ce(III), all buffered at pH 6 or 8. The modification of this compound to form an amide derivative results in an effective extraction of noble metals, ranked according to Au(III) > Pd(II) > Pt(IV) > Ag(I). Moreover, a supported liquid membrane system for silver transport has been developed based on thiacalix[4]arene dissolved in NPOE, and parameters affecting its efficiency have been investigated, such as the stripping composition and the pH of the feed solution. Finally, the selectivity of the membrane system has been evaluated by using as feed sources mixtures of silver and other metal ions

  11. Synthesis of 18F-Arenes from Spirocyclic Iodonium(III) Ylides via Continuous-Flow Microfluidics

    Science.gov (United States)

    Calderwood, Samuel; Collier, Thomas Lee; Gouverneur, Véronique; Liang, Steven H.; Vasdev, Neil

    2016-01-01

    Spirocyclic hypervalent iodine(III) ylides have proven to be synthetically versatile precursors for efficient radiolabelling of a diverse range of non-activated (hetero)arenes, highly functionalised small molecules, building blocks and radiopharmaceuticals from [18F]fluoride ion. Herein, we report the implementation of these reactions onto a continuous-flow microfluidic platform, thereby offering an alterative and automated synthetic procedure of a radiopharmaceutical, 3-[18F]fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile ([18F]FPEB) and a routinely used building block for click-radiochemistry, 4-[18F]fluorobenzyl azide. This new protocol was applied to the synthesis of [18F]FPEB (radiochemical conversion (RCC) = 68 ± 5%) and 4-[18F]fluorobenzyl azide (RCC=68 ± 5%; isolated radiochemical yield = 24±0%). We anticipate that the high throughput microfluidic platform will accelerate the discovery and applications of 18F-labelled building blocks and labelled compounds prepared by iodonium ylide precursors as well as the production of radiotracers for preclinical imaging studies.

  12. Arene C(sp(2))-H Metalation at Ni(II) Modeled with a Reactive PONCPh Ligand.

    Science.gov (United States)

    Jongbloed, Linda S; García-López, Diego; van Heck, Richard; Siegler, Maxime A; Carbó, Jorge J; van der Vlugt, Jarl Ivar

    2016-08-15

    Coordination of the reactive phosphinitopyridylphenyl PONCPh ligand L(H) to NiBr2 initially yields paramagnetic brown NiBr2(L(H)) (1), but addition of triethylamine results in fast and facile cyclometalation at Ni(II), giving NiBr(κ(3)-P,N,C-L) (2) as well-defined species. This is a rare example of direct cyclometalation at Ni(II) from a C-H bond in a ligand structure other than encumbering ligands (e.g., ECE pincers). Diamagnetic yellow complex 2 reacts instantaneously with HBF4 to give purple [NiBr(κ(3)-P,N-L(H))]BF4 (3). A very unusual (an)agostic Ni(CPh-H) interaction in the solid-state structure of 3 was unequivocally demonstrated using single-crystal X-ray crystallography and was interpreted by density functional theory calculations (quantum theory of atoms in molecules and electron localization function analysis). These compounds may be viewed as models for key intermediates in the Ni-catalyzed C-H functionalization of arenes. PMID:27479533

  13. InSAR, GPS, triangulation and EDM combination in a 3D velocity field: Insight from Arenal volcano

    Science.gov (United States)

    Muller, Cyril; del Potro, Rodrigo; Biggs, Juliet; Gottsmann, Joachim; Ebmeier, Susanna; Van der Laat, Rodolfo

    2014-05-01

    Geodetic techniques provide useful information to detect and assess geophysical processes occurring at volcanoes. When the deformation signal is large, standard analyses and modelling can be carried out. However, when surface movements are subtle and several processes occur simultaneously, stochastic and multi-techniques assessment is required. Here we present a methodology that combines GPS, triangulation, trilateration and InSAR in a 3D velocity surface without any prior specific source assumption. The methodology is in 5 steps: design of the geodetic monitoring network, acquisition and post-processing of deformation observations, spatial integration, time series computation and finally spatial and temporal measurement integration. We apply this methodology to Arenal volcano in Costa Rica and provide an unprecedented insight of the volcano's deformation. The most significant improvements of this method are the reduction of campaign logistics, the unambiguous detection of the outliers, an increase in accuracy, a 3D velocity field accounting for all techniques and measurements. Although, the methodology is applied to GPS, triangulation, trilateration and INSAR geodetic networks with a steady motion, it has the potential to be extended to other geodetic techniques and where transient deformations are ongoing. The described methodology can be applied in volcano monitoring worldwide.

  14. A new arene-Ru based supramolecular coordination complex for efficient binding and selective sensing of green fluorescent protein.

    Science.gov (United States)

    Mishra, Anurag; Ravikumar, Sambandam; Song, Young Ho; Prabhu, Nadarajan Saravanan; Kim, Hyunuk; Hong, Soon Ho; Cheon, Seyeon; Noh, Jaegeun; Chi, Ki-Whan

    2014-04-28

    A new dipyridyl ligand is encoded with 120° angularity between its coordination vectors by using a central pyridine carboxamide scaffold to orient two 4-(pyridin-4-ylethynyl)phenyl moieties. The N,N'-bis(4-(pyridin-4-ylethynyl)phenyl)pyridine-2,6-dicarboxamide ligand undergoes self-assembly with a diruthenium arene complex to furnish a [2 + 2] metallacycle with a wedge-like structure. The metallacycle binds to the enhanced green fluorescent protein (EGFP) variant of GFP, resulting in steady-state spectral changes in UV-Vis absorption and emission experiments. These studies indicate that the metallacycle induces conformation changes to the EGFP, disrupting the tripeptide chromophore. Furthermore, gel electrophoresis, circular dichroism and atomic force microscopy studies indicate that binding ultimately leads to aggregation of the protein. Computational investigations indicate a favorable interaction, predominantly between the metallacycle and the Arg168 residue of the EGFP. An interaction with Arg168 and related residues was previously observed for an emission-attenuating antibody, supporting that these interactions induce changes to the photophysical properties of EGFP by disrupting the tripeptidechromophore in a similar manner. Additionally, we have also described the quenching study of the reporter GFP protein in vivo by a new metal complex using reflected fluorescence microscopy. We anticipate that such metal complexes which can passively diffuse into the cells in vivo can serve as potential tools in molecular and drug targeting based biological studies.

  15. Electrochemistry of tert-Butylcalix[8]arene-C(60) Films Using a Scanning Electrochemical Microscope-Quartz Crystal Microbalance.

    Science.gov (United States)

    Cliffel, D E; Bard, A J; Shinkai, S

    1998-10-01

    The electrochemical reduction of tert-butylcalix[8]arene-C(60) particle films was studied using the scanning electrochemical microscope combined with a quartz crystal microbalance (QCM) for several electrolytes in MeCN. Complexation of the fullerene within the film results in a negative shift of the peak potential of the first cathodic wave by about 400 mV compared to the reduction of a pure C(60) film. The QCM indicates a mass loss during reduction of the film. Even in electrolytes where C(60) anions normally remain in the surface film, a loss of fullerene electrochemical activity occurs. The complex breaks apart upon reduction of the fullerene center, with the fullerene escaping from the calixarene basket into the MeCN solution, leaving the calixarene as an insoluble film on the electrode surface. These results show that the π electron sharing of the complex is decreased by the additional electron density added to the fullerene by reduction to C(60)(-). PMID:21651251

  16. Computations between metallocalix(4)arene host and a series of four oil-based fuel pollutant guests

    International Nuclear Information System (INIS)

    Calculations using PM3 and mechanics methods on metallocalix(4)arene hosts (1-10) and substituted dibenzothiophene guests (A-D), which are generally known as oil-based fuel pollutants, show that host-guest formation is energetically favored. Calculations have been carried out for both 1/1 and 1/4 ratios of host/guest. There is no direct bonding between the metal center of the host and the sulfur of the guest in the host-guest complex. Sterically hundered dibenzothiophene guests show similar energies to the unhindered analogs. For calix(4)arenas (5-10) in partial cone conformations and having hydrogen rather than p-tert-butyl groups on the wide rim, host-guest formation occurs within the narrow rim rather than the wide rim. Host-guest association appears to occur via Pie-Pie interactions between host and guest phenyl groups rather than via metal-sulfur bonding. The study has importance especially in oil refining to obtain environmentally safe fuel oils and help supramolecular chemists in designing and synthesizing more sophisticated host molecules for the removal of sulfur from crude oil / refinery oil. (author)

  17. Binding of Coumarin 334 with β-Cyclodextrin and with C-Hexylpyrogallol[4]arene: Opposite Fluorescence Behavior

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Sowrirajan

    2013-01-01

    Full Text Available We report here the structure of the host-guest complexes of Coumarin 334 (C334 with β-cyclodextrin (β-CD and with C-hexylpyrogallol[4]arene (C-HPA and the effect of acidity on the neutral-cation equilibrium of C334 in water and in the presence of the host molecules. The structures of the host-guest complexes are proposed on the basis of the change of fluorescence on the addition of β-CD or C-HPA to C334 and by 2D ROESY spectroscopy. Opposite fluorescence behaviors, that is, quenching of fluorescence in β-CD and enhancement of fluorescence in C-HPA are observed. Time-resolved fluorescence analysis is done for the complexation, and biexponential decay pattern is observed. The possible strong inclusion complexation with C-HPA is explained. The ground and the excited state pKa values for the protonation equilibrium of C334 in water and the difficulty of protonation in the presence of the host molecules are discussed.

  18. Influence of alkali and alkaline earth ions on the -alkylation of the lower rim phenolic-OH groups of -tert-butyl-calix[4]arene to result in amide-pendants: Template action of K+ and the structure of K+ bound tetra-amide derivative crystallized with a -tert-butylcalix[4]arene anion

    Indian Academy of Sciences (India)

    Amjad Ali; Chebrolu P Rao; Philippe Guionneau

    2008-03-01

    Role of alkali and alkaline earth ions on the formation of calix[4]arene-amide derivatives through -alkylation of the lower rim phenolic-OH groups in general and template action of K+ in particular have been explored. Na+ and K+ ions among alkali, and Ca2+ and Sr2+ ions among alkaline earth have shown tetra-amide derivatives bound to metal ion species. Among all these, potassium salts act as template and yields a K+ bound tetra-amide derivative where the charge is counter balanced by a calix[4] arene-monoanion and the product is crystallographically characterized. Change in the amide precursor used in these -alkylation reactions has no effect on the type of the amide derivative formed. Also demonstrated is a direct one-step reaction for the preparation of 1,3-di-amide derivative in high yield and low reaction period using CsHCO3.

  19. Synthesis of Calix[4]arene with ω-Chloroalkyl Groups at the Lower Rim%ω-氯代烷氧基杯[4]芳烃的合成

    Institute of Scientific and Technical Information of China (English)

    陈远荫; 胡旭波; 胡为民; 周宜遂; 卢雪然

    1997-01-01

    杯[4]芳烃以Cl(CH2CH2O)nTs(n=1,2)烷基化.得到65~87%的下缘带有2-氯乙氧基和2-(2-氯乙氧基)乙氧基杯[4]芳烃.%Calix[4]arenes with 2-chloroethoxy and 2-(2-chloroethoxy)ethoxy functonal groups at the lower rim were prepared in 65~87% yields via etherification of calix[4]arenes with Cl(CH2CH2O)nTs.

  20. Impedance spectroscopic investigation of the effect of thin azo-calix[4]arene film type on the cation sensitivity of the gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mlika, R., E-mail: mlikarym@yahoo.fr [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Rouis, A. [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Universite de Lyon, Institut de Chimie et Biochimie Moleculaires et Supramoleculaires, Universite Claude Bernar, Lyon 1, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne (France); Ouada, H. Ben [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia)

    2011-10-10

    In this work, we report the impedance spectroscopic investigation of the effect of the thin film type on the selectivity of gold/azo-calix[4]arene electrodes. For this purpose, two C1 and C3 azo-calix[4]arene derivative molecules, used as thin films, are deposited by spin-coating process on the gold surface. These thin films were first studied using contact angle measurements. This revealed a less hydrophobic character for C3 thin film, which has been attributed to the presence of hydroxyl groups at the lower rim. The sensitivity study, by Electrochemical Impedance Spectroscopy (EIS), towards Cu{sup 2+} and Eu{sup 3+} cations, has showed that the C3 thin film is more sensitive and selective towards Eu{sup 3+} than C1. This best performance is due to the presence of two ester groups acting as clips and leading to more complexation stability. The EIS results were modeled by an appropriate equivalent circuit for the aim of elucidating electrical properties of thin films. This modeling has exposed that C3 thin film presents lower ionic conductivity and limited diffusion phenomenon at the interface. Highlights: {yields} C1 and C3 azo-calix[4]arenes thin films are deposited on the gold surface. {yields} The lower hydrophobicity for C3 was attributed to the presence of hydroxyl groups. {yields} The C3 thin film is more sensitive and selective towards Eu{sup 3+} than C1 one. {yields} This best performance is due to the presence of two ester groups acting as clips.

  1. Un testimoni sobre la vida de Santa Ximenis d'Arenós i sobre l'origen del Libre de Les Dones

    OpenAIRE

    Izquierdo Molinas, Eva

    2010-01-01

    L’estudi de la documentació relacionada amb Sanxa Ximenis d’Arenós, comtessa de Prades, permet de conèixer molt millor les seves activitats i els seus moviments en els últims anys de la seva vida, quan va entrar en contacte amb Eiximenis, que li va dedicar el "Llibre de les dones". L’edició i l’estudi, sobretot, d’un plet relacionat amb la separació del comte Pere de Prades i de Sanxa Ximenis, la seva esposa, que va acabar fent vida en el convent de les clarisses de València, proporciona nove...

  2. Un testimoni sobre la vida de Sanxa Ximenis d'Arenós i sobre l'origen del "Llibre de les dones"

    OpenAIRE

    Eva Izquierdo Molinas

    2014-01-01

    L’estudi de la documentació relacionada amb Sanxa Ximenis d’Arenós, comtessa de Prades, permet de conèixer molt millor les seves activitats i els seus moviments en els últims anys de la seva vida, quan va entrar en contacte amb Eiximenis, que li va dedicar el "Llibre de les dones". L’edició i l’estudi, sobretot, d’un plet relacionat amb la separació del comte Pere de Prades i de Sanxa Ximenis, la seva esposa, que va acabar fent vida en el convent de les clarisses de València, proporciona nove...

  3. A Hydrogen Ion-Selective Poly(Vinyl Chloride) Membrane Electrode Based on Calix[4]arene as a Perchlorate Ion-Selective Electrode

    OpenAIRE

    CANEL, Esin; ERDEN, Sevcan; ÖZEL, Ayça DEMİREL; MEMON, Sahahabuddin

    2008-01-01

    A hydrogen ion-selective electrode was prepared using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanometoxy-calix[4]arene and the possibility of its use as a perchlorate ion-selective electrode was investigated using its characteristic of becoming perchlorate sensitive in acidic regions. The electrode of the optimum characteristic had a composition of 1% ionophore, 66% o-NPOE, and 33% PVC. This electrode exhibited a linear response over the range 1.0 \\times 10-1-1.0 \\times 10-5 M o...

  4. Synthesis of novel p-tert-butylcalix[4]arene Schiff bases and their complexes with C60, potential HIV-Protease inhibitors

    Science.gov (United States)

    Khadra, Khalid Abu; Mizyed, Shehadeh; Marji, Deeb; Haddad, Salim F.; Ashram, Muhammad; Foudeh, Ayat

    2015-02-01

    Some p-tert-butylcalix[4]arene Schiff base crown ethers were synthesized, characterized using 1H, 13C-NMR, DEPT 135 and Mass spectrometry. Their complexes with C60 were isolated and characterized. The inhibition effect of these complexes on HIVP was studied and found that complexes of 9 and 10 have comparable Ki values to Pepstatine which is known as HIVP inhibitor and used as a control. The synthesis of the ligands, complexes and the inhibition behavior are discussed in this article.

  5. Fluorinated arene, imide and unsaturated pyrrolidinone based donor acceptor conjugated polymers: Synthesis, structure-property and device studies

    Science.gov (United States)

    Liyanage, Arawwawala Don Thilanga

    After the discovery of doped polyacetylene, organic semiconductor materials are widely studied as high impending active components in consumer electronics. They have received substantial consideration due to their potential for structural tailoring, low cost, large area and mechanically flexible alternatives to common inorganic semiconductors. To acquire maximum use of these materials, it is essential to get a strong idea about their chemical and physical nature. Material chemist has an enormous role to play in this novel area, including development of efficient synthetic methodologies and control the molecular self-assembly and (opto)-electronic properties. The body of this thesis mainly focuses on the substituent effects: how different substituents affect the (opto)-electronic properties of the donor-acceptor (D-A) conjugated polymers. The main priority goes to understand, how different alkyl substituent effect to the polymer solubility, crystallinity, thermal properties (e.g.: glass transition temperature) and morphological order. Three classes of D-A systems were extensively studied in this work. The second chapter mainly focuses on the synthesis and structure-property study of fluorinated arene (TFB) base polymers. Here we used commercially available 1,4-dibromo-2,3,5,6-tetrafluorobenzene (TFB) as the acceptor material and prepare several polymers using 3,3'-dialkyl(3,3'-R2T2) or 3,3'-dialkoxy bithiophene (3,3'-RO2T2) units as electron donors. A detail study was done using 3,3'-bithiophene donor units incorporating branched alkoxy-functionalities by systematic variation of branching position and chain length. The study allowed disentangling the branching effects on (i) aggregation tendency, intermolecular arrangement, (iii) solid state optical energy gaps, and (iv) electronic properties in an overall consistent picture, which might guide future polymer synthesis towards optimized materials for opto-electronic applications. The third chapter mainly focused on

  6. p-sulfonated calix[8]arene functionalized graphene as a "turn on" fluorescent sensing platform for aconitine determination.

    Science.gov (United States)

    Yang, Long; Xie, Xiaoguang; Cai, Le; Ran, Xin; Li, Yucong; Yin, Tianpeng; Zhao, Hui; Li, Can-Peng

    2016-08-15

    This work reports a novel method for the determination of aconitine through the competitive host-guest interaction between p-sulfonated calix[8]arene (SCX8) and signal probe/target molecules by using SCX8 functionalized reduced graphene oxide (SCX8-RGO) as a receptor. Three dyes (ST, RhB, BRB) and aconitine were selected as the probe and target molecules, respectively. The formation of SCX8-RGO·ST, SCX8-RGO·RhB, and SCX8-RGO·BRB complexes greatly decreases the fluorescence emission of ST, RhB, and BRB. The aconitine/SCX8 complex possesses a higher binding constant than ST/SCX8, RhB/SCX8, and BRB/SCX8 complexes, thus the dye in the SCX8 cavity can be replaced by aconitine to revert the fluorescence emission of SCX8-RGO·dye, leading to a "switch-on" fluorescence response. The fluorescence intensity of SCX8-RGO·ST, SCX8-RGO·RhB, and SCX8-RGO·BRB complexes increased linearly with increasing concentration of aconitine ranging from 1.0 to 14.0μM, 2.0-16.0μM, and 1.0-16.0μM, respectively. Based on the competitive host-guest interaction, the proposed detection method for aconitine showed detection limits of 0.28μM, 0.60μM, and 0.37μM, respectively, and was successfully applied for the determination of aconitine in human serum samples with good recoveries from 95.1% to 104.8%. The proposed method showed high selectivity for aconitine beyond competitive binding analytes. In addition, the inclusion complex of the SCX8/aconitine was studied by the molecular docking and molecular dynamics simulation, which indicated that the phenyl ester group of the aconitine molecule was included into the SCX8 cavity. PMID:27085945

  7. Interfacial Recognition of Acetylcholine by an Amphiphilic p-Sulfonatocalix[8]arene Derivative Incorporated into Dimyristoyl Phosphatidylcholine Vesicles

    Directory of Open Access Journals (Sweden)

    Yasuhiro Ooi

    2008-10-01

    Full Text Available Dodecyl ether derivatives 1-3 of p-sulfonatocalix[n]arene were incorporated into dimyristoyl phosphatidylcholine (DMPC vesicles, and their binding abilities for acetylcholine (ACh were examined by using steady-state fluorescence/fluorescence anisotropy and fluorescence correlation spectroscopy (FCS. For the detection of ACh binding to the DMPC vesicles containing 5 mol % of 1-3, competitive fluorophore displacement experiments were performed, where rhodamine 6G (Rh6G was used as a fluorescent guest. The addition of Rh6G to the DMPC vesicles containing 3 resulted in a decrease in the fluorescence intensity of Rh6G with an increase of its fluorescence anisotropy, indicating that Rh6G binds to the DMPC-3 vesicles. In the case of DMPC-1 and DMPC-2 vesicles, significant changes in the fluorescence spectra of Rh6G were not observed. When ACh was added to the DMPC-3 vesicles in the presence of Rh6G ([3]/[Rh6G]=100, the fluorescence intensity of Rh6G increased with a decrease in its fluorescence anisotropy. From the analysis of fluorescence titration data, the association constants were determined to be 7.1×105 M-1 for Rh6G-3 complex and 1.1×102 M-1 for ACh-3 complex at the DMPC-3 vesicles. To get a direct evidence for the binding of Rh6G and its displacement by ACh at the DMPC-3 vesicles, diffusion times of the Rh6G were measured by using FCS. Binding selectivity of the DMPC-3 vesicles for ACh, choline, GABA, L-aspartic acid, L-glutamic acid, L-arginine, L-lysine, L-histamine and ammonium chloride was also evaluated using FCS.

  8. Strontium (II-Selective Potentiometric Sensor Based on Ester Derivative of 4-tert-butylcalix(8arene in PVC Matrix

    Directory of Open Access Journals (Sweden)

    Jitendra R. Raisoni

    2004-08-01

    Full Text Available Abstract: Membranes of 4-tert-butylcalix(8arene-octaacetic acid octaethyl ester (I as an electroactive material, sodium tetraphenyl borate (NaTPB as an anion excluder, and tri-n-butyl phosphate (TBP as a solvent mediator in poly(vinyl chloride (PVC matrix have been tried for a strontium-selective sensor. The best performance was exhibited by the membrane having a composition 5:100:150:2 (I: PVC: TBP: NaTPB (w/w. This sensor exhibits a good potentiometric response to Sr2+ over a wide concentration range (3.2 × 10 –5 –1.0 × 10 –1 M with a Nernstian slope (30 mV/ decade. The response time of the sensor is 10 s and it has been used for a period of four months without any drift in potentials. The selectivity coefficient values are in the order of 0.01 for mono-, bi-, and trivalent cations which indicate a good selectivity for Sr2+ over a large number of cations. The useful pH range for the sensor was found to be 3-10 and it works well in mixtures with non-aqueous content up to 25 % (v/v. The sensor has been used as an indicator electrode in the potentiometric titration of Sr2+ against EDTA.

  9. Fluorophores as Chemosensors for Sr(sup 2+) and Cs(sup +) Based on Calix[4]arenes and Coumarin Reporter Groups

    Energy Technology Data Exchange (ETDEWEB)

    Gorestzki, Gudrun; Brown, Gilbert M.; Bonnesen, Peter V.

    2003-09-10

    Fluorescent sensors are being developed for Cs + and Sr2+ which combine a molecular recognition element with an optical transduction element. Such sensors will be needed for real-time application in the characterization of nuclear waste and waste process streams. The fluorescent method is very important due to its high sensitivity and direct visual perception even in highly dilute solutions and its potential for remote application utilizing fiber optics. Crown ether bridged calix[4]arenes have been widely used as a three-dimensional platform for selective metal ion recognition. Coumarins show interesting photochemical and photophysical properties and are widely used in laser dye applications. These fluorescence probes increase their dipolar moment when excited. We will report the synthesis of calix[4]arene-crown-6 derivatives possessing 1,3-alternate conformation and incorporating a coumarin based fluorescence reporter group. Selectivity for Sr2+ over Cs + is obtained by using azacrowns and the sensitivity will be determined by varying the donor atom set as well as the substitution pattern of the coumarin.

  10. Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu2+

    Science.gov (United States)

    Nemati, Mohammad; Zadmard, Reza; Mohadjerani, Maryam

    2016-01-01

    Summary Functionalization of calix[4]arene with amidofluorene moieties at the lower rim led to formation of the 1,3-diconjugate of calix[4]arene L as a novel fluorescent chemosensor for Cu2+. The receptor molecule L exhibited a pronounced selectivity towards Cu2+ over other mono and divalent ions. The formation of the complex between L and Cu2+ was evaluated by absorption, fluorescence and 1H NMR spectroscopy. The sensor L showed a remarkable color change from colorless to purple and a fluorescence quenching only upon interaction with Cu2+. The 1:1 stoichiometry of the obtained complex has been determined by Job’s plot. The association constant determined by fluorescence titration was found to be 1.8 × 106 M−1. The sensor showed a linear response toward Cu2+ in the concentration range from 1 to 10 µM with a detection limit of 9.6 × 10−8 M. PMID:27559419

  11. One-dimensional Hydrogen-bonded Polymer Based on Tetra-iso-butyl-resorcin[4]arene and 2,6-Diacetylpyridine

    Institute of Scientific and Technical Information of China (English)

    刘书群; 姚文锐; 张千峰

    2005-01-01

    The co-crystallization of tetra-iso-butyl-resorcin[4]arene 1 and 2,6-diacetyl- pyridine (Ac2py) from MeCN/CH2Cl2 yielded a multi-component complex 1(Ac2py(2H2O(0.5Me-CN 2, in which the upper rim of 1 is extended supramolecularly by way of hydrogen bonds. Complex 2 (C52H66.5N1.5O14) crystallizes in monoclinic, space group P21/m with a = 10.845(9), b = 20.805(17), c = 12.881(11) (A), β = 103.884(19)o, V = 2821(4) (A)3, Dc = 1.102 g/cm3 and Z = 2. The molecular structure shows that the two adjacent double-stranded arrays as well as linear and zigzag chains generated from Ac2py and water bridging to two resorcin[4] arene molecules, respectively, facilitate self-inclusion of one-dimensional hydrogen-bonded polymer.

  12. Self-inclusion of a New Calix[4]arene Derivative via Associated Acetonitrile: X-ray Diffraction and Density Functional Theory Studies

    Institute of Scientific and Technical Information of China (English)

    杨高升; 缪韧; 李一志; 金晨; 洪瑾; 郭子建; 朱龙根

    2005-01-01

    A new calix[4]arene derivative, 11,23-bis(hydroxyiminomethyl)-25,27-dihydroxy-26,28-di-n-propoxycalix[4]-arene (B), was synthesized and a compound, with composition of Bo2CH3CN, was fully characterized. 1H NMR showed that B in the B*2CH3CN adopts a cone conformation. X-ray diffraction analysis confirmed the conformation found in solution. In the crystal network, self-inclusion phenomenon is present in a dimeric unit of B*2CH3CN via embedding each other. The noncovalent interaction energies were calculated at B3LYP/6-311G(d) level and corrected by basis set superposition error (BSSE). In half a dimeric unit, one CH3CN is stabilized via hydrogen bonding formed between nitrogen atom of the acetonitrile and one hydroxyimino group, with bonding energy of -5.02 kJ·mol-1, and the other one stabilized by hydrogen bonding formed between nitrogen atom of the acetonitrile and the other hydroxyimino group, with bonding energy of - 14.23 kJ·mol-1, and by inclusion to hydrophobiccavity of the other half of the dimeric unit via C-H…π interaction, with bonding energy of -3.77 kJ·mol-1 doubling of which is a driving force for embedding two B*2CH3CN together.

  13. Development of Conductometric Sensor Based on 25,27-Di-(5-thio-octyloxy)calix[4]arene-crown-6 for Determination of Ammonium.

    Science.gov (United States)

    Saiapina, O Y; Kharchenko, S G; Vishnevskii, S G; Pyeshkova, V M; Kalchenko, V I; Dzyadevych, S V

    2016-12-01

    The conductometric sensor based on 25,27-di-(5-thio-octyloxy)calix[4]arene-crown-6 was developed for the quantitative analysis of ammonium. The calixarene was immobilized on the surface of the planar interdigitated electrodes by attachment of its dialkyl sulfide groups to the surface of the gold electrodes. The intrinsic ability of the calixarene to capture ammonium was studied in the conductometric measuring mode and by the electrochemical impedance spectroscopy. The developed sensor showed high selectivity to ammonium in the presence of mono-, di-, and trivalent cations. Selective and highly sensitive detection of ammonium resulted from the complexation between the ammonium ions and a crown-ether fragment of the upper rim of the 25,27-di-(5-thio-octyloxy)calix[4]arene-crown-6 macrocycle. The developed sensor had high signal repeatability. Its sensitivity was found to be satisfactory for the forthcoming sensor application in the water-sample analysis; the linear range was 0.01-1.5 mM and limit of detection 10 μM. PMID:26911569

  14. Arene ruthenium(II) azido complexes incorporating N intersection O chelate ligands: Synthesis, spectral studies and 1,3-dipolar-cycloaddition to a coordinated azide in ruthenium(II) compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Kaminsky, W.

    The arene ruthenium(II) azido compounds [{(p-cymene)Ru(N^O)N3}] have been prepared by the reaction of [{(p-cymene)Ru(mewN3)Cl}2] with the corresponding ligands. The ruthenium azido compounds [{(p...

  15. Lithium-ion induced conformational change of 5,17-bis(9-fluorenyl)-25,26,27,28-tetrapropoxy calix[4]arene resulting in an egg-shaped dimeric clathrate

    DEFF Research Database (Denmark)

    Faldt, A.; Krebs, Frederik C; Jørgensen, Mikkel

    2000-01-01

    Synthesis and structural investigation of a 5,17-bis(9-fluorenyl)-25,26,27,28-tetrapropoxy calix[4]arene and its lithium complex salt that forms a dimeric clathrate with a molecule of solvent inside a cavity. At least three different interactions were identified as being responsible for the...

  16. There aren't plenty more fish in the sea: a causal network approach.

    Science.gov (United States)

    Nikolic, Milena; Lagnado, David A

    2015-11-01

    The current research investigated how lay representations of the causes of an environmental problem may underlie individuals' reasoning about the issue. Naïve participants completed an experiment that involved two main tasks. The causal diagram task required participants to depict the causal relations between a set of factors related to overfishing and to estimate the strength of these relations. The counterfactual task required participants to judge the effect of counterfactual suppositions based on the diagrammed factors. We explored two major questions: (1) what is the relation between individual causal models and counterfactual judgments? Consistent with previous findings (e.g., Green et al., 1998, Br. J. Soc. Psychology, 37, 415), these judgments were best explained by a combination of the strength of both direct and indirect causal paths. (2) To what extent do people use two-way causal thinking when reasoning about an environmental problem? In contrast to previous research (e.g., White, 2008, Appl. Cogn. Psychology, 22, 559), analyses based on individual causal networks revealed the presence of numerous feedback loops. The studies support the value of analysing individual causal models in contrast to consensual representations. Theoretical and practical implications are discussed in relation to causal reasoning as well as environmental psychology. PMID:25597224

  17. Crown bridged thiacalix[4]arenes as cesium-selective ionophores in solvent polymeric membrane electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Bereczki, Robert [Technical Analytical Research Group of the Hungarian Academy of Sciences, Department of General and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellert ter 4, H-1111 Budapest (Hungary); Csokai, Viktor [Department of Organic Chemical Technology, Budapest University of Technology and Economics, Muegyetem rkp.3, H-1111 Budapest (Hungary); Gruen, Alajos [Department of Organic Chemical Technology, Budapest University of Technology and Economics, Muegyetem rkp.3, H-1111 Budapest (Hungary); Bitter, Istvan [Department of Organic Chemical Technology, Budapest University of Technology and Economics, Muegyetem rkp.3, H-1111 Budapest (Hungary); Toth, Klara [Technical Analytical Research Group of the Hungarian Academy of Sciences, Department of General and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellert ter 4, H-1111 Budapest (Hungary)]. E-mail: ktoth@mail.bme.hu

    2006-05-31

    Novel 1,3-alternate thiacalix[4]mono- and biscrown-6 ethers were studied as ionophores in poly(vinyl chloride) membrane electrodes. Their selectivity behavior was characterized with respect to large number of cations, including potential interferents in environmental samples, and the membrane composition was optimized for cesium ion response. Among the ionophores, 1,3-alternate thiacalix[4]mono(crown-6) ether showed, especially high selectivity for cesium over other alkali-metal ions. Transition and heavy metal ions did not interfere seriously with the electrode response, which indicates that the bridging sulfur atoms do not take part in the ion recognition process. The potentiometric cesium responses of all electrodes involved in this study were found close to Nernstian and the detection limits were lower than 10{sup -7} M. The Cs{sup +}/Na{sup +} selectivity of the different ionophore-based sensors and the solvent extraction ability of the ligands were interpreted based on the respective constants of complex formation.

  18. Eye Involvement in TSC

    Science.gov (United States)

    ... of the eyes) should prompt inquiries into the family history and TSC involvement. Also, ophthalmologists should remember that mental handicap is ... or depigmented area and should inquire about the family’s history and any possible involvement in TSC. **This publication from the Tuberous Sclerosis ...

  19. Building Parent Involvement

    Science.gov (United States)

    Nelson, Richard C.; Bloom, John W.

    1973-01-01

    Discussed is the rationale behind parent involvement in guidance and educational activities, together with specific suggestions for involving parents with other adults (parent advisory committees, informal coffees, Transactional analysis (groups etc.), with children (story hours, trips, demonstrations, counseling booths, testing, interviewing,…

  20. Doctors' involvement in torture

    DEFF Research Database (Denmark)

    Sonntag, Jesper

    2008-01-01

    Doctors from both non-democratic and democratic countries are involved in torture. The majority of doctors involved in torture are doctors at risk. Doctors at risk might compromise their ethical duty towards patients for the following possible reasons: individual factors (such as career, economic...

  1. Self-Assembly of New Arene-Ruthenium Rectangles Containing Triptycene Building Block and Their Application in Fluorescent Detection of Nitro Aromatics

    Science.gov (United States)

    Dubey, Abhishek; Mishra, Anurag; Min, Jin Wook; Lee, Min Hyung; Kim, Hyunuk; Stang, Peter J.; Chi, Ki-Whan

    2014-01-01

    A suite of two new tetraruthenium metallarectangles 5 and 6 have been obtained from [2 + 2] self-assemblies between dipyridylethynyltriptycene 2 and one of the two dinuclear arene ruthenium clips, [Ru2 (μ-η4-OO∩OO) (η6-p-cymene)2][OTf]2 ; (OO∩OO = oxalate 3; 6,11-dihydroxy-5,12-naphthacenedionato (dotq) 4; OTf = triflate). These molecular rectangles are fully characterized by 1H NMR spectroscopy, electrospray mass spectrometry. A single crystal of 6 was suitable for X-ray diffraction structural characterization. These new metallarectangles showed fluorescence behavior in solution, have been examined for emission quenching effects with various aromatic compounds, and show high quenching selectivity and sensitivity towards nitroaromatics, particularly picric acid and trinitrotoluene. Excited-state charge transfer from the rectangles to nitro aromatic substrates can be used to develop selective fluorescent sensors for nitro aromatics. PMID:26321767

  2. A new Hg(2+) -selective fluorescent sensor based on a 1,3-alternate thiacalix[4]arene anchored with four 8-quinolinoloxy groups.

    Science.gov (United States)

    Praveen, L; Ganga, V B; Thirumalai, R; Sreeja, T; Reddy, M L P; Varma, R Luxmi

    2007-08-01

    A new thiacalix [4]arene derivative in a 1,3-alternate conformation bearing four quinolinoloxy groups through propyl chains has been synthesized, and its metal ion-binding and fluorescence-sensing properties were investigated in both THF and 10% H2O-THF systems. The designed ligand exhibited pronounced Hg2+ -selective on-off type fluoroionophoric properties among the representative transition and heavy metal ions including Cu2+. The detection limit for Hg2+ was found to be 2.0 x 10(-6) M in the mixed H2O-THF system. Detailed spectral studies including 1H NMR and MALDI-TOF mass spectroscopy reveal the unusual formation of a tetramercury complex with the ligand, in which the four propyl arms containing the quinolinoloxy groups adopt a "tetrapodand" conformation enclosing one Hg2+ ion each in the four cavities thus formed. PMID:17608414

  3. Unusual mode of protein binding by a cytotoxic π-arene ruthenium(ii) piano-stool compound containing an O,S-chelating ligand.

    Science.gov (United States)

    Hildebrandt, Jana; Görls, Helmar; Häfner, Norman; Ferraro, Giarita; Dürst, Matthias; Runnebaum, Ingo B; Weigand, Wolfgang; Merlino, Antonello

    2016-08-01

    A new pseudo-octahedral π-arene ruthenium(ii) piano-stool compound, containing an O,S-bidentate ligand (compound 1) and showing significant cytotoxic activity in vitro, was synthesized and characterized. In solution stability and interaction with the model protein bovine pancreatic ribonuclease (RNase A) were investigated by using UV-Vis absorption spectroscopy. Its crystal structure and that of the adduct formed upon reaction with RNase A were obtained by X-ray crystallography. The comparison between the structure of purified compound 1 and that of the fragment bound to RNase A reveals an unusual mode of protein binding that includes ligand exchange and alteration of coordination sphere geometry. PMID:27427335

  4. Unusual mode of protein binding by a cytotoxic π-arene ruthenium(ii) piano-stool compound containing an O,S-chelating ligand.

    Science.gov (United States)

    Hildebrandt, Jana; Görls, Helmar; Häfner, Norman; Ferraro, Giarita; Dürst, Matthias; Runnebaum, Ingo B; Weigand, Wolfgang; Merlino, Antonello

    2016-08-01

    A new pseudo-octahedral π-arene ruthenium(ii) piano-stool compound, containing an O,S-bidentate ligand (compound 1) and showing significant cytotoxic activity in vitro, was synthesized and characterized. In solution stability and interaction with the model protein bovine pancreatic ribonuclease (RNase A) were investigated by using UV-Vis absorption spectroscopy. Its crystal structure and that of the adduct formed upon reaction with RNase A were obtained by X-ray crystallography. The comparison between the structure of purified compound 1 and that of the fragment bound to RNase A reveals an unusual mode of protein binding that includes ligand exchange and alteration of coordination sphere geometry.

  5. Interaction of Sulfonated Calix[n]arenes with Rhodamine B and Its Application to Determine Acetylcholine in a Real Neutral Aqueous Medium

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yong-Jun(张拥军); CAO,Wei-Xiao(曹维孝); XU,Jian(徐坚)

    2002-01-01

    Complexation between Rhodamine B (RB) and sulfonated calix [n]arenes (SCnA) were studied by means of UV-vis spectroscopy and fluorescence spectroscopy. In the presence of sulfonated calix[n ]arones, the absorption band of Rhodamine B shifts to longer wavelength and its intensity decreases. The formation of a host-guest type complex also results in the fluorescence quenching of Rhodamine B. The association constants for the RB/SCnA complexes increase in the order of SC4A <SC6A < SC8A and show dependence on the size of the cavities of the calixarenes. The fluorescence is selectively regenerated by adding acetylcholine. Based on this observation, a method to determine acetylcholine in a real neutral aqueous medium was developed.

  6. Synthesis and characterization of a Bi10O8(OAr)16 oxo-cluster supported by p-tert-butylcalix[5]arene ligands.

    Science.gov (United States)

    Mendoza-Espinosa, Daniel

    2016-09-14

    Reaction of a non-dried monobenzylated [(t)BuC5(OBn)(OH)4] ligand with excess of Bi[N(SiMe3)2]3 yields a mixture of the dimeric complex 1 [Bi{(t)BuC5(OBn)(OH)}]2 in 12% yield and complex 2 [Bi10O8{(t)BuC5(OBn)(OH)}4] in 48% yield. The highly symmetric complex 2 features a Bi10O8(OAr)16 central core with tetra-, hexa- and heptacoordinated bismuth(iii) centers, and (μ2)-(μ4) bridging oxygen atoms all arranged in a I4 symmetrical pattern. Cluster 2 represents the largest bismuth oxo-cluster supported by calix[n]arene ligands reported to date. PMID:27484218

  7. 3-(Dicyanomethylidene)indan-1-one-Functionalized Calix[4]arene-Calix[4]pyrrole Hybrid: An Ion-Pair Sensor for Cesium Salts.

    Science.gov (United States)

    Yeon, Yerim; Leem, Soojung; Wagen, Corin; Lynch, Vincent M; Kim, Sung Kuk; Sessler, Jonathan L

    2016-09-01

    A chromogenic calix[4]arene-calix[4]pyrrole hybrid ion pair receptor bearing an indane substituent at a β-pyrrolic position has been prepared. On the basis of solution-phase UV-vis spectroscopic analysis and (1)H NMR spectroscopic studies carried out in 10% methanol in chloroform, receptor 1 is able to bind only cesium ion pairs (e.g., CsF, CsCl, and CsNO3) but not the constituent cesium cation (as its perchlorate salt) or the F(-), Cl(-), or NO3(-) anions (as the tetrabutylammonium salts). It thus displays rudimentary AND logic gate behavior. Receptor 1 shows a colorimetric response to cesium ion pairs under conditions of solid-liquid (nitrobenzene) and liquid-liquid (D2O-nitrobenzene-d5) extraction. PMID:27533478

  8. Involved Node Radiation Therapy

    DEFF Research Database (Denmark)

    Maraldo, Maja V; Aznar, Marianne C; Vogelius, Ivan R;

    2012-01-01

    PURPOSE: The involved node radiation therapy (INRT) strategy was introduced for patients with Hodgkin lymphoma (HL) to reduce the risk of late effects. With INRT, only the originally involved lymph nodes are irradiated. We present treatment outcome in a retrospective analysis using this strategy...... in a cohort of 97 clinical stage I-II HL patients. METHODS AND MATERIALS: Patients were staged with positron emission tomography/computed tomography scans, treated with adriamycin, bleomycin, vinblastine, and dacarbazine chemotherapy, and given INRT (prechemotherapy involved nodes to 30 Gy, residual masses...

  9. Rare earth (Eu3+, Tb3+) mesoporous hybrids with calix[4]arene derivative covalently linking MCM-41: Physical characterization and photoluminescence property

    International Nuclear Information System (INIS)

    MCM-41 mesoporous silica has been functionalized with two kinds of macrocylic calixarene derivatives Calix[4] and Calix[4]Br (Calix[4]=P-tert-butylcalix[4]arene, Calix[4]Br=5.11,17.23-tetra-tert-butyl-25.27-bihydroxy- 26.28-bibromopropoxycalix[4]arene) through condensation approach of tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as a template. Novel organic-inorganic mesoporous luminescent hybrid containing RE3+ (Eu3+, Tb3+) complexes covalently attached to the functionalized ordered mesoporous MCM-41, which are designated as RE-Calix[4]-MCM-41 and RE-Calix[4]Br-MCM-41, respectively, are obtained by sol-gel process. It is found that they all have high surface area, uniform in the mesostructure and good crystallinity. Measurement of the photoluminescence properties show the mesoporous material covalently bonded Tb3+ complexes (Tb-Calix[4]-MCM-41 and Tb-Calix[4]Br-MCM-41) exhibit the stronger characteristic emission of Tb3+ and longer lifetime than the corresponding Eu-containing materials Eu-Calix[4]-MCM-41 and Eu-Calix[4]Br-MCM-41 due to the triplet state energy of modified organic ligands Calix[4]-Si and Calix[4]Br-Si match with the emissive energy level of Tb3+ very well. - Graphical abstract: MCM-41 mesoporous silica is functionalized with two kinds of macrocylic calixarene derivatives and luminescent organic-inorganic mesoporous hybrids containing Ln3+ complexes covalently attached to the functionalized ordered mesoporous MCM-41. Highlights: → Novel linkages of functionalized calixarene derivative. → New rare earth mesoporous hybrids. → Luminescence in visible region.

  10. Comparison of hydration reactions for "piano-stool" RAPTA-B and [Ru(η6- arene)(en)Cl]+ complexes: Density functional theory computational study

    Science.gov (United States)

    Chval, Zdeněk; Futera, Zdeněk; Burda, Jaroslav V.

    2011-01-01

    The hydration process for two Ru(II) representative half-sandwich complexes: Ru(arene)(pta)Cl2 (from the RAPTA family) and [Ru(arene)(en)Cl]+ (further labeled as Ru_en) were compared with analogous reaction of cisplatin. In the study, quantum chemical methods were employed. All the complexes were optimized at the B3LYP/6-31G(d) level using Conductor Polarizable Continuum Model (CPCM) solvent continuum model and single-point (SP) energy calculations and determination of electronic properties were performed at the B3LYP/6-311++G(2df,2pd)/CPCM level. It was found that the hydration model works fairly well for the replacement of the first chloride by water where an acceptable agreement for both Gibbs free energies and rate constants was obtained. However, in the second hydration step worse agreement of the experimental and calculated values was achieved. In agreement with experimental values, the rate constants for the first step can be ordered as RAPTA-B > Ru_en > cisplatin. The rate constants correlate well with binding energies (BEs) of the Pt/Ru-Cl bond in the reactant complexes. Substitution reactions on Ru_en and cisplatin complexes proceed only via pseudoassociative (associative interchange) mechanism. On the other hand in the case of RAPTA there is also possible a competitive dissociation mechanism with metastable pentacoordinated intermediate. The first hydration step is slightly endothermic for all three complexes by 3-5 kcal/mol. Estimated BEs confirm that the benzene ligand is relatively weakly bonded assuming the fact that it occupies three coordination positions of the Ru(II) cation.

  11. Microwave-Assisted Synthesis of Arene Ru(II Complexes Induce Tumor Cell Apoptosis Through Selectively Binding and Stabilizing bcl-2 G-Quadruplex DNA

    Directory of Open Access Journals (Sweden)

    Yanhua Chen

    2016-05-01

    Full Text Available A series of arene Ru(II complexes coordinated with phenanthroimidazole derivatives, [(η6-C6H6Ru(lCl]Cl(1b L = p-ClPIP = 2-(4-Chlorophenylimidazole[4,5f] 1,10-phenanthroline; 2b L = m-ClPIP = 2-(3-Chlorophenylimidazole[4,5f] 1,10-phenanthroline; 3b L = p-NPIP = 2-(4-Nitrophenylimidazole[4,5f] 1,10-phenanthroline; 4b L = m-NPIP = 2-(3-Nitrophenyl imidazole [4,5f] 1,10-phenanthroline were synthesized in yields of 89.9%–92.7% under conditions of microwave irradiation heating for 30 min to liberate four arene Ru(II complexes (1b, 2b, 3b, 4b. The anti-tumor activity of 1b against various tumor cells was evaluated by MTT assay. The results indicated that this complex blocked the growth of human lung adenocarcinoma A549 cells with an IC50 of 16.59 μM. Flow cytometric analysis showed that apoptosis of A549 cells was observed following treatment with 1b. Furthermore, the in vitro DNA-binding behaviors that were confirmed by spectroscopy indicated that 1b could selectively bind and stabilize bcl-2 G-quadruplex DNA to induce apoptosis of A549 cells. Therefore, the synthesized 1b has impressive bcl-2 G-quadruplex DNA-binding and stabilizing activities with potential applications in cancer chemotherapy.

  12. Pancreatic Involvement in Melioidosis

    Directory of Open Access Journals (Sweden)

    Vui Heng Chong

    2010-07-01

    Full Text Available Context Melioidosis is endemic to tropical regions and, despite the common occurrence of intra-abdominal abscesses, pancreatic involvement in melioidosis has not previously been reported. Objective We report our experience with pancreatic melioidosis. Patients All 65 patients treated for melioidosis who had computed tomography (CT scans were identified from prospective databases and were retrospectively reviewed. Main outcome measures A detailed review of cases with pancreas involvement was carried out. Results There were four cases (three males and one female; median age 29.5 years, range: 25-48 years with pancreatic melioidosis, giving a prevalence of 6.2%. All had predisposing conditions (two had poorly controlled diabetes mellitus and two had thalassemia for melioidosis. Fever (100%, anorexia (100%, weight loss (100%, rigor (75% and abdominal pain (75% were the most common symptoms at presentation and the median duration of symptoms before presentation was six weeks (range: 2-8 weeks. All pancreatic abscesses were detected on CT scan. Multiple foci involvement was common (3 to 6 sites: blood (4 patients, liver (3 patients, psoas muscle (2 patients, spleen (2 patients, infected ascites (2 patients and lung (1 patient. Pancreatic involvement ranged from multi-focal micro-abscesses to focal large abscesses and involved all parts of the pancreas (body 100%, head 75% and tail 50%. Associated pancreatic findings included splenic vein thrombosis, peripancreatic inflammation and peripancreatic fat streaking. All the pancreatic abscesses were resolved with antibiotics without requiring pancreatic abscess drainage (including one patient who died from disseminated melioidosis. Conclusion Pancreatic involvement typically occurs as part of multi-organ involvement and commonly manifests as multifoci micro-abscesses. Associated pancreatic abnormalities were also common. All responded to treatment without requiring drainage

  13. [Pulmonary involvements of sarcoidosis].

    Science.gov (United States)

    Ohmichi, M; Hiraga, Y; Hirasawa, M

    1990-01-01

    We reported about intrathoracic changes and prognosis of 686 patients with sarcoidosis diagnosed in our hospital between 1963 and 1988. We evaluated CT findings in 135 patients with sarcoidosis and found pulmonary involvements in 81. We analyzed CT findings according to the classification by Tuengerthal which classified radiographic findings combining ILO classification of pneumoconiosis and characteristic findings of bronchovascular sheath with sarcoidosis. The CT findings were as follows: small opacities (44 out of 81 cases, 54.3%), large opacities (37 cases, 46.7%). Additional findings were as follows: peribronchial marking (42 cases, 51.9%), contraction (17 cases, 21.0%), pleural involvement (9 cases, 11.1%), bulla (5 cases, 6.2%). The characteristic CT findings of serious sarcoidosis were extasis of bronchus, thickening of the bronchial wall, unclearness of vascular shadow, atelectasis and thickening of pleura. Concerning the prognosis of pulmonary involvement, according to age, patients younger than 30 years old at initial diagnosis were better than those of 30 years and over in terms of disappearance of pulmonary involvements. According to stage, patients of stage I and stage II were better than those of stage III. Among the patients we were able to observe chest X-ray findings during five years according to the character of shadow, ill-defined shadow of small opacities and rounded shadows of large opacities had a higher disappearance rate of pulmonary involvements than irregular shadows of large opacities, atelectasis and contraction.

  14. Involvement, Tate and me

    OpenAIRE

    Slater, Alix; Armstrong, Kate

    2010-01-01

    The involvement construct has been explored in relation to products, services and leisure but not in an art museum context. The purpose of this paper is to address this theoretical gap by drawing on the marketing and leisure literature to understand members’ consumption of Tate using the involvement construct. Tate, a portfolio of four art museums in the UK has more than 90,000 members that receive a benefits package in return for a membership fee. Data were collected using an interpretive, q...

  15. Unprovability results involving braids

    CERN Document Server

    Carlucci, Lorenzo; Weiermann, Andreas

    2007-01-01

    We construct long sequences of braids that are descending with respect to the standard order of braids (``Dehornoy order''), and we deduce that, contrary to all usual algebraic properties of braids, certain simple combinatorial statements involving the braid order are true, but not provable in the subsystems ISigma1 or ISigma2 of the standard Peano system.

  16. Promoting vital involvement.

    Science.gov (United States)

    Kivnick, Helen Q; Stoffel, Sharon A

    2002-09-01

    Health care for the elderly generally focuses on health problems. This approach ignores the strengths and resources that maximize a person's autonomy, integrity, and ability to make contributions to society; and it exacerbates poor health. Vital involvement practice (VIP) is an approach to caring for the elderly that emphasizes an individual's capabilities by exploring factors both internal and external to the individual. VIP is identified as a model for health care providers that will improve the health and quality of life of elderly patients. PMID:12387120

  17. Involvement in Physical Activity

    Directory of Open Access Journals (Sweden)

    James Gavin

    2013-04-01

    Full Text Available A total of 1,096 adolescents participated in 123 focus groups regarding the perceived outcomes of their involvement in sports and physical activity (PA. The groups, segmented by grade level, sex, and school types, were conducted in both public and private high schools in Montreal, Quebec. We sought to understand, through the participants’ own words, their perception of the outcome matrix of involvement in sports and PA. Focus group questions emphasized changes that adolescents associated with such engagement. In particular, participants were asked how sports and PA might influence behaviors, emotional states, personal characteristics, and other outcomes. Twelve themes were identified in the responses: Positive Health and Physical Changes (18.5%, Activity-Related Positive Emotions (15.6%, and Personal Learning (11.3% were most prevalent in the discussions. A cluster of deeper personal changes thematically described as Self-Identity, Autonomy, and Positive Character Development accounted for another 16.5% of the responses. Relatively few commentaries emphasized negative effects (7.1%. Converting the proportions of qualitative data into a quantitative index allowed us to analyze potential differences in emphasis according to sex, age, and school type. Though a few significant findings emerged, the larger pattern was of a uniform perceptual map across the variables for this adolescent sample. Implications drawn from this investigation highlight the need to clearly articulate concrete pathways to positive nonphysical changes (e.g., mood states, autonomy, positive character development from engagements in sports and PA.

  18. Involvement Without Participation?

    DEFF Research Database (Denmark)

    Olsén, Peter

    2012-01-01

    environment did not improve; on the contrary, it deteriorated. The article highlights cultural and structural obstacles to the process, including an inadequate understanding of organisational learning and a narrow focus on market and competition. The endeavours did not consistently increase delegation......The article presents a case study of a knowledge-intensive company that launched a 2-year project to improve their psychosocial working environment. All parties agreed on the project, and the methods used aimed to promote the involvement of the employees. Surprisingly, the psychosocial working...... and participation. In order to develop a more sustainable and viable psychosocial working environment, a broader and more democratic notion of organisational learning and managing is proposed....

  19. Emergency preparedness involves cooperation

    International Nuclear Information System (INIS)

    The measures of the Finnish authorities in radiation emergency situations are summarised in the article. The emphasis of emergency measures has sifted to peace-time accident preparedness. The potential radiation risk sources include nuclear power plant accidents, passing nuclear-driven ships, radioactive wastes etc. In Finland the Ministry of the Interior is the highest authority in matters of radiation control and preparedness. For analysing radiation situations and ensuring compliance with recommended actions, the Ministry relies on the Finnish Centre for Radiation and Nuclear Safety and the Finnish Meteorological Institute as its main expert bodies. Other authorities, such as Defence Forces and fire departments, also play an important role in situations involving a radiation hazard

  20. Effectiveness of citizen involvement

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, L. [Prince William Sound Regional Citizen' s Advisory Council, Anchorage, AK (United States)

    2006-07-01

    This paper reviewed the rise of citizen involvement in industry that affects their community. Following the Exxon Valdez oil spill (EVOS) in 1989, the Oil Pollution Act of 1990 provided funding by industry for a citizens group to provide oversite of the Alyeska Pipeline Service Agency terminal and associated tankers. That role is currently filled by the Prince William Sound Regional Citizen's Advisory Council, a volunteer organization that represents communities that were affected by the EVOS. The history of the Prince William Sound Regional Citizen's Advisory Council was discussed along with its structure, funding and overview of projects and research into safer transportation of oil, better oil spill response capabilities and improved environmental protection practices. Some of the successes involving citizen input include the requirement that all tankers going into Prince William Sound be double hull by 2015; a world-class system of tugs escorting tankers in Prince William Sound; installation of an ice-detection radar on a small island near the site of the EVOS; a guidebook for communities affected by man-made disasters; identification of nearshore locations that should be the first to be protected in the case of another spill; and, the installation of a system to capture crude oil vapors when tankers take on cargo. Other projects underway include the study of invasive species that can be transported in the ballast water of tankers, efficacy of dispersants, soil contamination at the tanker loading site, emissions of hazardous air pollutants from ballast water treatment processes, and continual review of emergency response plans. In the 17 years since the formation of the Prince William Sound Regional Citizen's Advisory Council, it has been shown that communication and transparency are the keys to solving complacency, which is believed to have been a contributing factor to the EVOS. 3 refs.

  1. Self-assembled Thiolated Calix[n]arene (n=4, 6, 8) Films on Gold Electrodes and Application for Electrochemical Determination Dopamine

    International Nuclear Information System (INIS)

    Highlights: • TCnA/GE was prepared by using a simple self-assembled strategy. • Multilayer self-assembled films of TCnA molecules were fabricated on GE. • TCnA/GE exhibited high supramolecular recognition and enrichment capability. • TC8A/GE showed excellent electrochemical performance for DA. - Abstract: In this study, gold electrodes (GE) modified with three kinds of thiolated calix[4,6,8]arenes (TCnA: TC4A, TC6A, TC8A) were successfully prepared using a simple self-assembly strategy. Three self-assembled films were characterized by cyclic voltammetry measurement, electrochemical impedance spectroscopy, static contact angle measurement and atomic force microscopy. The results confirmed that TCnA molecules effectively absorbed onto the surface of gold electrodes to fabricate the multilayer self-assembled films. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurement showed that the TCnA/GE exhibited high supramolecular recognition and enrichment capability and consequently displayed good electrochemical response toward dopamine (DA). Especially, TC8A/GE exhibited an excellent electrochemical performance for DA with high current densities of 1.5 mA mmol−1 L cm−2, broad linear range (1 × 10−6 to 1 × 10−3 mol L−1) and low detection limit (5 × 10−7 mol L−1). The mechanism of supramolecular recognition and enrichment capability of TCnA/GE was discussed

  2. Spectrofluorimetric study on the inclusion interaction between vitamin K 3 with p-( p-sulfonated benzeneazo)calix[6]arene and determination of VK 3

    Science.gov (United States)

    Zhou, Yunyou; Xu, Hongwei; Wu, Lian; Liu, Chun; Lu, Qin; Wang, Lun

    2008-11-01

    The characteristics of host-guest complexation between p-( p-sulfonated benzeneazo) calix[6]arene (SBC6A) and vitamin K 3 (VK 3) were investigated by fluorescence spectrometry. A 1:1 stoichiometry for the complexation was established and was verified by Job's plot. An association constant of 4.95 × 10 3 L mol -1 at 20 °C was calculated by applying a deduced equation. The interaction mechanism of the inclusion complex was discussed. It was found that the fluorescence of SBC6A could be remarkably quenched by an appropriate amount of VK 3 especially when non-ionic surfactant Triton X-100 existed. According to the obtained results, a novel sensitive spectrofluorimetric method for the determination of VK 3 based on supramolecular complex was developed with a linear range of 5.0 × 10 -7-3.0 × 10 -5 mol L -1 and a detection limit of 2.0 × 10 -7 mol L -1. The proposed method was used to determine VK 3 in commercial preparations with satisfactory results.

  3. Calix[4]arene functionalized gold nanoparticles for colorimetric and bare-eye detection of iodide in aqueous media and periodate aided enhancement in sensitivity

    International Nuclear Information System (INIS)

    A water- soluble p-sulphonatocalix[4]arene was synthesized and anchored onto the surface of gold nanoparticles (AuNPs) in aqueous medium. The conjugate was characterized by IR, UV–Vis and TEM analysis. This material responds to iodide in giving a color change from pink to blue which is easily detectable with bare eyes. While periodate itself does not cause any spectral changes, a substantial spectral change can be seen in the presence of traces of iodide. The lower detection limit for iodide in the absence of periodate is 2.5 μM, which is further lowered to 80 nM in presence of periodate. A mechanistic study revealed that the chemisorption of the ions I− and I3−, formed by the reaction I− and periodate on the surface of AuNPs resulted in spontaneous oxidation of the anions. The electron transfer changes the size and morphology of the nanoparticles and results in the color change. The method is specific for iodide. It was successfully applied to the determination of I− in (spiked) waters and in solutions of iodized edible salt. (author)

  4. Bifunctional supramolecular systems on the platform of p-sulfonatothiacalix[4]arene containing photochromic mononitrosyl Ru (II) and paramagnetic aqua Gd or Dy complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kushch, L.A., E-mail: lkushch@icp.ac.r [Institute of Problems of Chemical Physics RAS, 142432 Chernogolovka, MD, Semenov av.1 (Russian Federation); Yagubskii, E.B.; Dmitriev, A.I.; Morgunov, R.B. [Institute of Problems of Chemical Physics RAS, 142432 Chernogolovka, MD, Semenov av.1 (Russian Federation); Emel' yanov, V.A. [Institute of Inorganic Chemistry, Sibirian Division of RAS, 630090 Novosibirsk (Russian Federation); Mustafina, A.R.; Gubaidullin, A.T.; Burilov, V.A.; Solovieva, S.E. [A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' (Russian Federation); Schaniel, D.; Woike, Th. [1. Physical Institute University of Cologne, Cologne (Germany)

    2010-06-01

    Two bifunctional supramolecular systems [RuNO(NH{sub 3}){sub 4}OH]{sup 2+}.[RuNO(NH{sub 3}){sub 4}H{sub 2}O]{sup 3+}.Gd{sup 3+}(H{sub 2}O){sub 6}.2[TCAS]{sup 4-}.4H{sub 2}O (1) and [RuNO(NH{sub 3}){sub 4}OH]{sup 2+}.[RuNO(NH{sub 3}){sub 4}H{sub 2}O]{sup 3+}.Dy{sup 3+}(H{sub 2}O){sub 6}.2[TCAS]{sup 4-}.4H{sub 2}O (2) on the platform of p-sulfonatothiacalix[4]arene containing photochromic mononitrosyl Ru and paramagnetic rare-earth (Gd{sup 3+}, Dy{sup 3+}) cations have been synthesized. The crystal structures of 1 and 2 are discussed. Their photochromic, magnetic and photomagnetic properties studied by IR and SQUID experimental techniques are presented

  5. A Bifunctional Thioether Linked Coumarin Appended Calix[4]arene Acquires Selectivity Toward Cu(2+) Sensing on Going from Solution to SAM on Gold.

    Science.gov (United States)

    Samanta, Kushal; Rao, Chebrolu Pulla

    2016-02-10

    A bifunctional calix[4]arene molecule bearing coumarin moiety on the lower rim and thioether moiety on the upper rim (L1), has been synthesized and well characterized by (1)H, (13)C NMR and mass spectrometry. Suitably functionalized coumarin moieties are well suited for selective recognition of various cations and anions. Among the 10 different metal ions studied, only Cu(2+) and Fe(3+) exhibit appreciable changes in the absorption spectra owing to the availability of functional moieties present at both the lower as well as the upper rim of free L1 in acetonitrile solution. To bring better selectivity, we blocked one of these functional moieties by coating on to a surface so that only the other one is exposed to the environment for sensing. Such a study carried out in the present case using the self-assembled monolayer (SAM) of L1 on Au(111) resulted in selective sensing of Cu(2+) over several other metal ions as studied by surface plasmon resonance (SPR). The SAM of L1 on Au(111) was confirmed by different techniques, such as grazing incidence FT-IR, contact angle measurement, cyclic voltammetry and scanning tunneling microscopy. Thus, L1 is proven to be a suitable sensor for Cu(2+) when attached to gold surface.

  6. Temperature effects on the retention of n-alkanes and arenes in helium-squalane gas-liquid chromatography. Experiment and molecular simulation.

    Science.gov (United States)

    Wick, Collin D; Siepman, J Ilja; Klotz, Wendy L; Schure, Mark R

    2002-04-19

    Experiments and molecular simulations were carried out to study temperature effects (in the range of 323 to 383 K) on the absolute and relative retention of n-hexane, n-heptane, n-octane, benzene, toluene and the three xylene isomers in gas-liquid chromatography. Helium and squalane were used as the carrier gas and retentive phase, respectively. Both the experiments and the simulations show a markedly different temperature dependence of the retention for the n-alkanes compared to the arenes. For example, over the 60 K temperature range studied, the Kovats retention index of benzene is found to increase by about 16 or 18+/-10 retention index units determined from the experiments or simulations, respectively. For toluene and the xylenes, the experimentally measured increases are similar in magnitude and range from 14 to 17 retention index units for m-xylene to o-xylene. The molecular simulation data provide an independent method of obtaining the transfer enthalpies and entropies. The change in retention indices is shown to be the result of the larger entropic penalty and the larger heat capacity for the transfer of the alkane molecules.

  7. Positioning a Carbon-Fluorine Bond over the π Cloud of an Aromatic Ring: A Different Type of Arene Activation.

    Science.gov (United States)

    Holl, Maxwell Gargiulo; Struble, Mark D; Singal, Prakhar; Siegler, Maxime A; Lectka, Thomas

    2016-07-11

    It is known that the fluoro group has only a small effect on the rates of electrophilic aromatic substitutions. Imagine instead a carbon-fluorine (C-F) bond positioned tightly over the π cloud of an aryl ring-such an orthogonal, noncovalent arrangement could instead stabilize a positively charged arene intermediate or transition state, giving rise to novel electrophilic aromatic substitution chemistry. Herein, we report the synthesis and study of molecule 1, containing a rigid C-F⋅⋅⋅Ar interaction that plays a prominent role in both its reaction chemistry and spectroscopy. For example, we established that the C-F⋅⋅⋅Ar interaction can bring about a >1500 fold increase in the relative rate of an aromatic nitration reaction, affording functionalization on the activated ring exclusively. Overall, these results establish fluoro as a through-space directing/activating group that complements the traditional role of fluorine as a slightly deactivating aryl substituent in nitrations. PMID:27145463

  8. Friedel-Crafts Alkylation of Arenes with 2-Halogeno-2-CF3-styrenes under Superacidic Conditions. Access to Trifluoromethylated Ethanes and Ethenes.

    Science.gov (United States)

    Sandzhieva, Maria A; Kazakova, Anna N; Boyarskaya, Irina A; Ivanov, Alexandr Yu; Nenajdenko, Valentine G; Vasilyev, Aleksander V

    2016-06-17

    The formation of the corresponding benzyl cations [ArHC(+)-CH(X)CF3] takes place under protonation of E-/Z-2-halogeno-2-CF3 styrenes [ArCH═C(X)CF3, X = F, Cl, Br] in superacids. The structures of these new electrophiles were studied by means of NMR and theoretical DFT calculations. According to these data, in the case of bromo derivatives, the formed cations, most probably, exist as cyclic bromonium ions; however, in the cases of chloro and fluoro derivatives, open forms are more preferable. Subsequent reaction of these benzyl cations with arenes proceeds as Friedel-Crafts alkylation to afford 1,1-diaryl-2-halo-3,3,3-trifluoropropanes [Ar(Ar')CH-CH(X)CF3] in high yields (up to 96%) as a mixture of two diastereomers. The prepared halogenopropanes were easily converted into the corresponding mixtures of E-/Z-trifluoromethylated diarylethenes [Ar(Ar')C═CCF3] (in yields up to 96%) by dehydrohalogenation with base (KOH or t-BuOK). The mechanism of elimination (E2 and Ecb) depends on the nature of the leaving group and reaction conditions. PMID:27227747

  9. Calix[8]arene functionalized single-walled carbon nanohorns for dual-signalling electrochemical sensing of aconitine based on competitive host-guest recognition.

    Science.gov (United States)

    Yang, Long; Ran, Xin; Cai, Le; Li, Yucong; Zhao, Hui; Li, Can-Peng

    2016-09-15

    A dual-signalling electrochemical approach has been developed towards aconitine based on competitive host-guest interaction by selecting methylene blue (MB) and p-sulfonated calix[8]arene functionalized single-walled carbon nanohorns (SCX8-SWCNHs) as the "reporter pair". Upon the presence of aconitine to the performed SCX8-SWCNHs·MB complex, the MB molecules are displaced by aconitine. This results in a decreased oxidation peak current of MB and the appearance of an oxidation peak of aconitine, and the changes of these signals correlate linearly with the concentration of aconitine. A linear response range of 1.00-10.00μM for aconitine with a low detection limit of 0.18μM (S/N=3) was obtained by using the proposed method. This method could be successfully utilized to detect aconitine in serum samples. This dual-signalling sensor can provide more sensitive target recognition and will have important applications in the sensitive and selective electrochemical detection of aconitine. PMID:27135940

  10. Synthesis of water-soluble CdSe quantum dots by ligand exchange with p-sulfonatocalix(n)arene (n = 4, 6) as fluorescent probes for amino acids

    International Nuclear Information System (INIS)

    A simple, rapid ligand exchange route to prepare highly fluorescent, stable and water-soluble CdSe quantum dots (QDs) is reported by using p-sulfonatocalix(n)arene (SFCA(n), n = 4 or 6) instead of original trioctylphosphine oxide (TOPO) ligands. The ligands were found to have a profound effect on the luminescence response of QDs to amino acids. The SFCA(4) coated CdSe QDs were sensitive to methionine. On the other hand, SFCA(6) coated CdSe QDs turned out to be sensitive to phenylalanine. To demonstrate the detection capability of these new probes, SFCA(n) (n = 4, 6) coated CdSe QDs were used to detect methionine and phenylalanine in physiological buffer solution. Under optimal conditions, the relative fluorescence intensities of the SFCA(n) coated QDs (n = 4, 6) increased linearly with increasing concentration of amino acids. Methionine and phenylalanine enhanced the luminescence of SFCA(n) coated QDs with a concentration dependence that was best described by a Langmuir-type equation. The possible mechanism is also discussed

  11. A mixed DFT-MD methodology for the in silico development of drug releasing macrocycles. Calix and thia-calix[N]arenes as carriers for Bosutinib and Sorafenib.

    Science.gov (United States)

    Galindo-Murillo, Rodrigo; Aguilar-Suárez, Luis Enrique; Barroso-Flores, Joaquín

    2016-04-15

    Interaction energies between a family of 36 calix[n]arenes, their corresponding thia- analogues, and two commercially available second generation tyrosine kinase III inhibitors-Bosutinib and Sorafenib-were calculated through DFT methods at the B97D/6-31G(d,p) level of theory, based on Natural Population Analysis, for the in silico development of suitable drug carriers based on the aforementioned macrocycles which can increase their bioavailability and in turn their pharmaceutical efficiency. Molecular Dynamics simulations (production runs: +500 ns) using the General Amber Force Field were also carried out in order to assess the releasing process of these drugs in an explicit aqueous environment. In total, 144 host-guest complexes are examined. According to our results, five-membered SO3 H and i-Pr functionalized-calixarenes are the best candidates for Sorafenib-carriers while six-membered ones SO3 H and C2 H4 NH2 functionalized- are the lead candidates for Bosutinib-carriers. © 2015 Wiley Periodicals, Inc. PMID:26714797

  12. Detection of cationic guest molecules by quenching of luminescence of a self-assembled host molecule consisting of terbium(III) and calix[4]arene-p-tetrasulfonates

    International Nuclear Information System (INIS)

    By self-assembly in aqueous solution, calix- (CAS) and thiacalix[4]arene-p-tetrasulfonate (TCAS) formed luminescent complexes TbIII.(CAS)2 and TbIII.TCAS, respectively, which were utilized as a host for cationic guests. Addition of 1-ethylpyridinium guest quenched luminescence of TbIII.(CAS)2 in accordance with the Stern-Volmer (SV) relation with a low detection limit (D.L.) of 5.94 x 10-8 M (S/N = 3, M ≡ mol dm-3). On the other hand, 1-ethylquinolinium quenched luminescence of TbIII.TCAS most efficiently, affording a very low D.L. (6.71 x 10-10 M). The agreement of the SV coefficients obtained with luminescent intensity (KSV,all = 6.74 x 106 M-1) and lifetime (KSV,Tb = 6.50 x 106 M-1) implied that dynamic quenching of 5D4 excited state of TbIII was predominant in the quenching processes. The quenching rate was estimated to be kq,Tb = 9.94 x 109 M-1 s-1, which was as fast as diffusion-limited rate. Quenching of TbIII.(CAS)2 was also applied to detection of NAD+, with a D.L. of 2.78 x 10-7 M.

  13. Opportunities Offered by Chiral η6-Arene/N-Arylsulfonyl-diamine-RuII Catalysts in the Asymmetric Transfer Hydrogenation of Ketones and Imines

    Directory of Open Access Journals (Sweden)

    Libor Červený

    2011-06-01

    Full Text Available Methods for the asymmetric transfer hydrogenation (ATH of ketones and imines are still being intensively studied and developed. Of foremost interest is the use of Noyori’s [RuCl(η6-arene(N-TsDPEN] complexes in the presence of a hydrogen donor (i-PrOH, formic acid. These complexes have found numerous practical applications and have been extensively modified. The resulting derivatives have been heterogenized, used in ATH in water or ionic liquids and even some attempts have been made to approach the properties of biocatalysts. Therefore, an appropriate modification of the catalyst that suits the specific requirements for the reaction conditions is very often readily available. The mechanism of the reaction has also been explored to a great extent. Model substrates, acetophenone (a ketone and 6,7-dimethoxy-1-methyl-3,4-dihydroisoquinoline (an imine, are both reduced by this Ru catalytic system with almost perfect selectivity. However, in each case the major product is a different enantiomer (S- for an alcohol, R- for an amine when the S,S-catalyst is used, which demanded an in-depth mechanistic investigation. Full-scale molecular modelling of this system enabled us to visualize the plausible 3D structures of the transition states, allowing the proposition of a viable explanation of previous experimental findings.

  14. Synthesis and Structural Characterization of an Arene-ruthenium Complex [(η6-p-cymene)Ru(μ-N3) (N3)]2

    Institute of Scientific and Technical Information of China (English)

    LIU Yang-Li; WU Fang-Hui; DUAN Tai-Ke; ZHANG Qian-Feng

    2009-01-01

    An arene-ruthenium dimeric complex, [(η6-p-cymene)Ru(μ-N3) (N3)]21, was synthe-sized from the reaction of [(η6-p-cymene)Ru(μ-Cl)(Cl)]2 with an excess NaN3 and charac-terized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1 with a=8.2321(8), b=8.2155(8), c=9.9976(11) A,α=81.786(5), β=82.906(5), γ=77.134(5)°, V=649.46(11) A3, Z=1,Mr=638.68, Dc=1.633 g/cm3,μ(MoKd)=1.195 mm-1, F(000)=320, S=0.974, the final R=0.0282 and wR=0.0644 for 2363 observed reflections with I > 2σ(I) and 157 variables. The neutral molecule is dimeric with two azide ligands bridging two ruthenium atoms to adopt an octahedral coordination geometry. The average RuNt (terminal) and Ru-Nb (bridge) bond lengths are 2.092(3)and 2.147(2) A,, respectively.

  15. Synthesis of a New Calix[4]Arene and Its Application in Construction of a Highly Selective Silver Ion-Selective Membrane Electrode

    Directory of Open Access Journals (Sweden)

    Saeed Taghvaei-Ganjali

    2009-01-01

    Full Text Available A PVC membrane sensor for Ag (I ions has been prepared. The membrane has 5, 11, 17, 23-tetra-tert-butyl-25-(3-N, N-diethyldithio carbamoylpropoxy-26,27,28-tris-propoxy calix[4]arene (CAD as a carrier. It was found that the sensor exhibits a Nernstian response for Ag+ ions over a wide concentration range (10−2–10−6 M. Additionally, it illustrates a fast response time (about 5 seconds, and it can be used for at least 2 months without any considerable divergence in potentials. The nature of the plasticizer, the additive, the concentration of internal solutions in the electrodes, and the composition of the membrane were investigated. Furthermore, the suggested membrane electrode revealed good selectivities for Ag+ over a variety of other metal cations, and it could be used in the pH range of 3.0–7.0. Eventually, it was successfully applied as an indicator electrode for the potentiometric titration of Ag+ ion with NaCl.

  16. Solid-phase Microextraction with Benzoxy-calix[6]arene Fiber Coupled to Gas Chromatography for the Analysis of Polycyclic Aromatic Hydrocarbons in Water

    Institute of Scientific and Technical Information of China (English)

    YE Chang-wen; ZHANG Xue-na; HUANG Jiang-yan; LI Xiu-juan; PAN Si-yi

    2011-01-01

    Headspace solid-phase microextraction(HS-SPME) with sol-gel calix[6]arene-containing fiber followed by gas chromatography with a flame ionization detector was used to examine the composition and distribution of seven polycyclic aromatic hydrocarbons(PAHs) in water. The novel SPME fiber exhibited higher extraction efficien cy to PAHs compared with poly(dimethylsiloxane) and other calixarene-containing fibers. Extraction/retention me chanism based on the interactions between calixarenes and PAHs was discussed. Owing to the good selectivity and high extraction capability of this calixarene fiber, low detection limits were obtained in a range of 0.34—6.50 ng/L and the relative standard deviation values were ≤ 12.3% for all of the analytes. The linear ranges of the proposed method were five orders of magnitude for the tested compounds, with linear correlation coefficients(r) greater than 0.998. The method was applied to the determination of polycyclic aromatic hydrocarbons in nine water sources in Wuhan City, China. Standard addition method was selected for the quantification and the recovery values were in a satisfactory range. Total PAHs concentrations in the nine surface water samples were found to vary between unde tectable and 8.840 μg/L with two-and three-ring PAHs predominating.

  17. [Nail involvement in leprosy].

    Science.gov (United States)

    Belinchón Romero, I; Ramos Rincón, J M; Reyes Rabell, F

    2012-05-01

    Leprosy, a disease caused by Mycobacterium leprae, primarily affects the skin and nerves, but the nails are also involved in as many as 3 out of 4 patients .The factors that trigger nail changes in leprosy are numerous and include repeated trauma, neuropathy, vascular impairment, infections, lepra reactions, and the drugs used to manage the disease. The changes most often reported include subungual hematomas, onycholysis, onychauxis, onychogryphosis, pterygium unguis, and onychoheterotopia, most of which can be attributed to nerve damage and trauma. Furthermore, the acro-osteolysis that occurs in the advanced stages of the disease may present with brachyonychia, racquet nails, or even anonychia. Infections of the nail bed leading to paronychia and onychomycosis should also be taken into account in leprosy. Other typical changes include longitudinal striae, pitting, macrolunula, Terry nails, leukonychia, hapalonychia, and Beau lines. In this review, we describe the principal nail changes associated with leprosy. These changes, which are highly varied and diverse in origin, are in fact a reflection of the significant morbidity caused by M. leprae infection.

  18. Games are motivating, aren´t they? Disputing the arguments for digital game-based learning

    NARCIS (Netherlands)

    Westera, Wim

    2015-01-01

    The growing popularity of game-based learning reflects the burning desire for exploiting the involving and motivating characteristics of games for serious purposes. A wide range of arguments for using games for teaching and learning can be encountered in scientific papers, policy reports, game revie

  19. Applying Employee Involvement in Schools.

    Science.gov (United States)

    Mohrman, Susan Albers; And Others

    1992-01-01

    The applicability of employee-involvement approaches to the management of schools is explored, describing three approaches (parallel-suggestion involvement, job involvement, and high involvement). Design issues (technology; organizational structure; leadership; organizational boundaries, customer definition, and relation to stakeholder; measures;…

  20. Multidrug toxicity involving sumatriptan.

    Science.gov (United States)

    Knittel, Jessica L; Vorce, Shawn P; Levine, Barry; Hughes, Rhome L; Bosy, Thomas Z

    2015-01-01

    A multidrug fatality involving sumatriptan is reported. Sumatriptan is a tryptamine derivative that acts at 5-HT(1B/1D) receptors and is used for the treatment of migraines. The decedent was a 21-year-old white female found dead in bed by her spouse. No signs of physical trauma were observed and a large number of prescription medications were discovered at the scene. Toxicological analysis of the central blood revealed sumatriptan at a concentration of 1.03 mg/L. Following therapeutic dosing guidelines, sumatriptan concentrations do not exceed 0.095 mg/L. Sumatriptan was isolated by solid-phase extraction and analyzed using liquid chromatography-tandem mass spectrometry in multiple reaction monitoring mode. A tissue distribution study was completed with the following concentrations measured: 0.61 mg/L in femoral blood, 0.56 mg/L in iliac blood, 5.01 mg/L in urine, 0.51 mg/kg in liver, 3.66 mg/kg in kidney, 0.09 mg/kg in heart, 0.32 mg/kg in spleen, 0.01 mg/kg in brain, 15.99 mg/kg in lung and 78.54 mg/45 mL in the stomach contents. Carisoprodol, meprobamate, fluoxetine, doxylamine, orphenadrine, dextromethorphan and hydroxyzine were also present in the blood at the following concentrations: 3.35, 2.36, 0.63, 0.19, 0.06, 0.55 and 0.16 mg/L. The medical examiner ruled the cause of death as acute mixed drug toxicity and the manner of death as accident. PMID:25324526

  1. Games are motivating, aren´t they? Disputing the arguments for digital game-based learning

    OpenAIRE

    Wim Westera

    2015-01-01

    The growing popularity of game-based learning reflects the burning desire for exploiting the involving and motivating characteristics of games for serious purposes. A wide range of arguments for using games for teaching and learning can be encountered in scientific papers, policy reports, game reviews and advertisements. With contagious enthusiasm, the proponents of game-based learning make their claims for using games to improve education. However, standing up for a good cause is easily repl...

  2. The Nature of Aqueous Solutions of a Cationic Calix[4]arene: A Comparative Study of Dye–Calixarene and Dye–Surfactant Interactions

    Directory of Open Access Journals (Sweden)

    V. I. Kalchenko

    2006-08-01

    Full Text Available Among different types of calixarenes, the water–soluble ones are of especial interestbecause of their possible applications in biochemical research. In order to elucidate the natureof aqueous solutions of a cationic amphiphilic calixarene, substituted tetrapropoxycalix[4]arene bearing hydrophilic choline groups at the upper rim, we studied vis–spectroscopically the influence of the above system on the acid–base behavior of threeindicator dyes, namely, 2,4-dinitrophenol, bromophenol blue, and N,N/-dioctadecylrhodamine,at constant ionic strength of 0.05 M, maintained with NaCl addition. Simultaneously,‘apparent’ ionization constants, Kaa , of the same dyes were determined in the presence ofcommon cationic surfactant micelles. Within the concentration range from 1.0×10–5 to 0.01 M,the aforementioned water–soluble calixarene displays effects similar to those of micelles ofcetyltrimethylammonium bromide (or chloride. The shifts of the absorption and emissionbands in the visible region, as well as the alterations of the Kaa values against the ‘aqueous’ones appeared to be very similar in aqueous solutions of both calix[4]arene and cationicsurfactant. A conclusion can be made about aggregation (or association, i.e., micelleformation of the cationic calix[4]arene under study.

  3. Reactions of N,3-diarylpropiolamides with arenes under superelectrophilic activation: synthesis of 4,4-diaryl-3,4-dihydroquinolin-2(1H)-ones and their derivatives

    Science.gov (United States)

    Gurskaya, Larisa Yu; Belyanskaya, Diana S; Ryabukhin, Dmitry S; Nilov, Denis I; Boyarskaya, Irina A

    2016-01-01

    Summary The reaction of 3-aryl-N-(aryl)propiolamides with arenes in TfOH at room temperature for 0.5 h led to 4,4-diaryl-3,4-dihydroquinolin-2-(1H)-ones in yields of 44–98%. The obtained dihydroquinolinones were further transformed into the corresponding N-acyl or N-formyl derivatives. For the latter, the superelectrophilic activation of the N-formyl group by TfOH in the reaction with benzene resulted in the formation of N-(diphenylmethyl)-substituted dihydroquinolinones. PMID:27340485

  4. Chelation-assisted Pd-catalysed ortho-selective oxidative C-H/C-H cross-coupling of aromatic carboxylic acids with arenes and intramolecular Friedel-Crafts acylation: one-pot formation of fluorenones.

    Science.gov (United States)

    Sun, Denan; Li, Bijin; Lan, Jingbo; Huang, Quan; You, Jingsong

    2016-03-01

    Pd-Catalysed ortho-selective oxidative C-H/C-H cross-coupling of aromatic carboxylic acids with arenes and subsequent intramolecular Friedel-Crafts acylation has been accomplished for the first time through a chelation-assisted C-H activation strategy. Starting from the readily available substrates, a variety of fluorenone derivatives are obtained in one pot. The direct use of naturally occurring carboxylic acid functionalities as directing groups avoids unnecessary steps for installation and removal of an extra directing group. PMID:26861768

  5. Ion selective electrode for cesium based on 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene

    Energy Technology Data Exchange (ETDEWEB)

    Ramanjaneyulu, P.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India); Singh, Parminder [Department of Chemistry, Indian Institute of Technology, New Delhi 110016 (India); Sayi, Y.S. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India); Chawla, H.M. [Department of Chemistry, Indian Institute of Technology, New Delhi 110016 (India); Ramakumar, K.L., E-mail: klram@barc.gov.in [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India)

    2010-03-15

    A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium was fabricated with 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene as ionophore. Different membrane constituents were investigated to realise optimum performance of the ISE developed. Of the four plasticizers and two ion additives studied, the best response was observed with membrane having 2-nitro phenyl octyl ether (oNPOE) as plasticizer and potassium tetrakis (perchloro phenyl) borate (KTpClPB) as ion additive. Linear response over concentration range of 10{sup -5}-10{sup -1} M CsCl was obtained. The Nernstian slope of the response was 56 mV per decade for Cs with a response time less than 20 s. Matched potential method has been applied to find out the selectivity for Cs over several ions like Rb{sup +}, K{sup +}, Na{sup +}, NH{sub 4}{sup +}, Sr{sup 2+}, Ba{sup 2+}, Ca{sup 2+}, Mg{sup 2+}, Cu{sup 2+}, Pb{sup 2+}, Zn{sup 2+}, Ni{sup 2+} and Ce{sup 3+}. The response of ISE for Cs{sup +} was fairly constant over the pH range of 3-11. The lifetime of the electrode is 9 months which is the longest life for any membrane-based Cs-ISE so far developed. The concentration of cesium in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing atomic absorption spectrometry.

  6. Direct no-carrier-added {sup 18}F-labelling of arenes via nucleophilic substitution on aryl(2-thienyl)iodonium salts

    Energy Technology Data Exchange (ETDEWEB)

    Ross, T.L.

    2006-01-15

    For in vivo imaging of molecular processes via positron emission tomography (PET) radiotracers of high specific activity are demanded. In case of the most commonly used positron emitter fluorine-18, this is only achievable with no-carrier-added [{sup 18}F]fluoride, which implies nucleophilic methods of {sup 18}F-substitution. Whereas electron deficient aromatic groups can be labelled in one step using no-carrier-added [{sup 18}F]fluoride, electron rich {sup 18}F-labelled aromatic molecules are only available by multi-step radiosyntheses or carrier-added electrophilic reactions. Here, diaryliodonium salts represent an alternative, since they have been proven as potent precursor for a direct nucleophilic {sup 18}F-introduction into aromatic molecules. Furthermore, as known from non-radioactive studies, the highly electron rich 2-thienyliodonium leaving group leads to a high regioselectivity in nucleophilic substitution reactions. Consequently, a direct nucleophilic no-carrier-added {sup 18}F-labelling of electron rich arenes via aryl(2-thienyl)iodonium precursors was developed in this work. The applicability of direct nucleophilic {sup 18}F-labelling was examined in a systematic study on eighteen aryl(2-thienyl)iodonium salts. As electron rich precursors the ortho-, meta- and para-methoxyphenyl(2-thienyl)iodonium bromides, iodides, tosylates and triflates were synthesised. In addition, para-substituted (R=BnO, CH{sub 3}, H, Cl, Br, I) aryl(2-thienyl)iodonium bromides were prepared as precursors with a systematically varying electron density. As first approach, the general reaction conditions of the nucleophilic {sup 18}F-substitution procedure were optimised. The best conditions for direct nucleophilic no-carrier-added {sup 18}F-labelling via aryl(2-thienyl)iodonium salts were found with dimethylformamide as solvent, a reaction temperature of 130{+-}3 C and 25 mmol/l as concentration of the precursor. (orig.)

  7. Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, F. de M. [Instituto Nacional de Investigaciones Nucleares, La Marquesa, Ocoyoacac (Mexico). Dept. de Quimica; Varbanov, S. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Organic Chemistry with Center of Phytochemistry; Buenzli, J.C.G. [Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland). Inst. of Chemical Sciences and Engineering; Rivas-Silva, J.F.; Ocana-Bribiesca, M.A. [Instituto de Fisica de la BUAP, Puebla (Mexico); Cortes-Jacome, M.A.; Toledo-Antonio, J.A. [Instituto Mexicano del Petroleo/Programa de Ingenieria Molecular (Mexico)

    2012-07-01

    The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1:1 and 1:2 (M:L) complexes with a tetra-phosphinoylated p-tert-butylcalix[4]arene, B{sub 4}bL{sup 4}: UO{sub 2}(NO{sub 3}){sub 2}(B{sub 4}bL{sup 4}){sub n} . xH{sub 2}O (n = 1, x = 2, 1; n = 2, x = 6, 2). Spectroscopic data point to the inner coordination sphere of 1 containing one monodentate nitrate anion, one water molecule and the four phosphinoylated arms bound to UO{sub 2}{sup 2+} while in 2, uranyl is only coordinated to calixarene ligands. In both cases the U(VI) ion is 8-coordinate. Uranyl complexes display enhanced metal-centred luminescence due to energy transfer from the calixarene ligands; the luminescence decays are bi-exponential with associated lifetimes in the ranges 220 {mu}s < {tau}{sub s} < 250 {mu}s and 630 {mu}s < {tau}{sub L} < 640 {mu}s, pointing to the presence of two species with differently coordinated calixarene, as substantiated by a XPS study of U(4f{sub 5/2,7/2}), O(1s) and P(2p) levels on solid state samples. The extraction study of UO{sub 2}{sup 2+} cation and trivalent rare-earth (Y, La, Eu) ions from acidic nitrate media by B{sub 4}bL{sup 4} in chloroform shows the uranyl cation being much more extracted than rare earths. (orig.)

  8. Electronic structure, molecular electrostatic potential and spectral characteristics of pillar[6]arene hosts and their complexes with n-octyltriethylammonium ions.

    Science.gov (United States)

    Peerannawar, Swarada R; Gejji, Shridhar P

    2012-06-28

    Electronic structure, charge distribution and (1)H NMR in pillar[6]arene (P6) conformers, their diisobutoxy derivatives and their host-guest complexes have been investigated by employing the density functional theory. It has been shown that a P6 conformer obtained by flipping of alternate hydroquinone units turns out to be of lowest energy, owing to the hydrogen bonded network at both rims of the host. As opposed to this, a conformer void of hydrogen bonding interactions has largely been destabilized. The O-HO interactions are analyzed using molecular electrostatic potential topography as a tool. Modification of a P6 host by substituting a diisobutoxy group at reactive phenols (DIBP6) renders rigid pillar-shape architecture to the host in which electron-rich regions are localized within the cavity and near portals. Complexation of n-octyltriethylammonium ions (n-OTEA) with P6 and DIBP6 reveals qualitatively different binding patterns. It has been shown that the conformer in which n-OTEA penetrates from the lower rim of the host and partially encapsulates within the P6 cavity turns out to be 1.4 kJ mol(-1) lower in energy than the complex showing complete guest encapsulation. Host-guest binding patterns, viz. encapsulation or portal interactions, can be distinguished from (1)H NMR chemical shifts. The shielding of ethyl and n-octyl chain protons in an n-OTEA⊂DIBP6 complex points to encapsulation of the guest which has been rationalized from natural bond orbital analyses. These inferences are in consonance with (1)H NMR experiments. PMID:22596047

  9. Near-Infrared Fluorescence Detection of Acetylcholine in Aqueous Solution Using a Complex of Rhodamine 800 and p-Sulfonato-calix[8]arene

    Directory of Open Access Journals (Sweden)

    Takashi Jin

    2010-03-01

    Full Text Available The complexing properties of p-sulfonatocalix[n]arenes (n = 4: S[4], n = 6: S[6], and n = 8: S[8] for rhodamine 800 (Rh800 and indocyanine green (ICG were examined to develop a near-infrared (NIR fluorescence detection method for acetylcholine (ACh. We found that Rh800 (as a cation forms an inclusion complex with S[n], while ICG (as a twitter ion have no binding ability for S[n]. The binding ability of Rh800 to S[n] decreased in the order of S[8] > S[6] >> S[4]. By the formation of the complex between Rh800 and S[8], fluorescence intensity of the Rh800 was significantly decreased. From the fluorescence titration of Rh800 by S[8], stoichiometry of the Rh800-S[8] complex was determined to be 1:1 with a dissociation constant of 2.2 mM in PBS. The addition of ACh to the aqueous solution of the Rh800-S[8] complex caused a fluorescence increase of Rh800, resulting from a competitive replacement of Rh800 by ACh in the complex. From the fluorescence change by the competitive fluorophore replacement, stoichiometry of the Rh800-ACh complex was found to be 1:1 with a dissociation constant of 1.7 mM. The effects of other neurotransmitters on the fluorescence spectra of the Rh800-S[8] complex were examined for dopamine, GABA, glycine, and L-asparatic acid. Among the neurotransmitters examined, fluorescence response of the Rh800-S[8] complex was highly specific to ACh. Rh800-S[8] complexes can be used as a NIR fluorescent probe for the detection of ACh (5 × 10-4−10-3 M in PBS buffer (pH = 7.2.

  10. Detailed mechanism of the ligand-to-metal energy transfer of silica-coated Tb(III) complex with p-sulfonatothiacalix[4]arene

    Energy Technology Data Exchange (ETDEWEB)

    Safiullin, Georgy M. [Zavoisky Physical -Technical Institute of Kazan Scientific Center of Russian Academy of Sciences (Russian Federation); Nikiforov, Victor G., E-mail: vgnik@mail.ru [Zavoisky Physical -Technical Institute of Kazan Scientific Center of Russian Academy of Sciences (Russian Federation); Davydov, Nikolay A.; Mustafina, Asiya R.; Soloveva, Svetlana Ye. [Arbuzov Organic and Physical Chemistry Institute of Kazan Scientific Center of Russian Academy of Sciences (Russian Federation); Lobkov, Vladimir S.; Salikhov, Kev M. [Zavoisky Physical -Technical Institute of Kazan Scientific Center of Russian Academy of Sciences (Russian Federation); Konovalov, Alexander I. [Arbuzov Organic and Physical Chemistry Institute of Kazan Scientific Center of Russian Academy of Sciences (Russian Federation)

    2015-01-15

    The energy transfer mechanism, which provides the feeding of the excited {sup 5}D{sub 4} level of Tb(III), has been studied by photoluminescence spectroscopy in the Tb(III) complex with p-sulfonato-thiacalix[4]arene doped into the silica nanoparticles. The quantitative evaluation of the rate constants of each energy transfer step highlights two channels of the energy transfer from the singlet ligand-centered level to the {sup 5}D{sub 4} level. The channel one occurs via the triplet ligand level S{sub 1}→T{sub 1}→{sup 5}D{sub 4}, the second channel comes about via the higher levels of Tb(III) S{sub 1}→{sup 5}D{sub 3}→{sup 5}D{sub 4}. The latter channel determines the rate of the luminescence decay of the {sup 5}D{sub 4} level. The high luminescence efficiency and enhanced thermo- and photo-stabilities make the Tb(III) complexes doped into the silica nanoparticles a promising nanomaterial for medical and bioanalytical applications. - Highlights: • Tb(III) complexes doped into the silica nanoparticles display high luminescence. • Rate constants of energy transfer providing feeding of {sup 5}D{sub 4} level of Tb(III) were obtained. • Two different channels of energy transfer from singlet ligand level to {sup 5}D{sub 4} level are revealed. • Luminescence of silica coated Tb(III) complexes exhibits high thermo- and photo-stabilities.

  11. Palladium-Catalyzed Reaction of Haloarenes with Diarylethynes: Synthesis, Structural Analysis, and Properties of Methylene-Bridged Arenes.

    Science.gov (United States)

    Lee, Che-Wei; Liu, En-Chih; Wu, Yao-Ting

    2015-11-01

    Fluorenes and methylene-bridged polyarenes were easily and efficiently synthesized from haloarenes (or aryl triflates) and diarylethynes by a one-pot, two-step procedure. This protocol involves the palladium-catalyzed cycloisomerization and a subsequent base-mediated retro-aldol condensation. A major advantage is that the starting materials need not have ortho functional groups to complete the annulation. The backbone of the designed products was enlarged using dihaloarenes, highly π-conjugated haloarenes, or diarylalkynes. The mechanism of the formation of benzo[a]fluorene was investigated. The bowl-shaped structure of methylene-bridged indenocorannulene was verified by X-ray crystallography. The photophysical and electrochemical properties of the products thus prepared were investigated. PMID:26451853

  12. Aqua(μ-cone-26,28-dibutoxy-25,27-bis{N-[5-(dimethylaminonaphthalene-1-sulfonyl]carbamoylmethoxy}-5,11,17,23-tetrakis(1,1-dimethylethylcalix[4]arene(2−disodium acetonitrile tetrasolvate

    Directory of Open Access Journals (Sweden)

    Pogisego Dinake

    2012-04-01

    Full Text Available The structure of the title complex, [Na2(C80H98N4O10S2(H2O]·4CH3CN, obtained after crystallization from acetonitrile, contains two formula units in the asymmetric unit (Z′ = 2 and an estimated four molecules of acetonitrile per calixarene moiety. It is unusual for two Na+ ions to occupy the lower rims of the cone calix[4]arene, as in this case, with one Na+ ion forming two O→ Na+ coordinate bonds with the two butoxy groups and four such bonds with the two N-dansyl carboxamide groups, forming six dative bonds between Na+ and O. On the other hand, the other Na+ ion forms only five O→Na+ coordinate bonds on the far end of the calix[4]arene lower rim, bringing the two dansyl groups in close proximity with each other. There also appears to be an O→Na+ coordination coming from a dangling water molecule. The structure contained both resolved and poorly resolved solvent molecules. The latter were treated using the SQUEEZE routine in PLATON [Spek (2009. Acta Cryst. D65, 148–155].

  13. 杯[4]芳烃衍生物一维超分子的晶体结构研究%Crystal Structure of a Novel Supramolecular Calix[4]arene Derivative with 1D Structure

    Institute of Scientific and Technical Information of China (English)

    邢彦军; 杜晨霞; 周稚仙; 吴养洁

    2001-01-01

    A new calix[4]arene derivative, 5,11,17,23-tetra-tert-butyl-25,27-dihydroxy-26,28-bis[2-(methoxycarbonyl)benzyloxy]calix[4]arene was synthesized. The X-ray crystal structure of the title compound has been determined. It crystallizes in the monoclinic with space group C2/c, a=1.262 8(3) nm, b=2.535 0(5) nm, c=2.095 7(4) nm,  β=103.36(3)°, V=6.528(2) nm3, Z=4, Dc=1.203 g/cm3, F(000)=2 488, R=0.114 3, wR2=0.297 9, Δρmax=0.329×103 e/nm3, Δρmin=-0.256×103 e/nm3. The crystal structure of the title compound shows that in the molecule there are hydrogen bonds between proximal hydroxyl and ether functional groups [O(H)—O: 0.300 4 nm]. The benzoic ether site in the title molecule may be considered as a π-conjugated system, therefore, the intermolecular π-π interaction exists between two benzoic ether site of the adjacent molecules, which caused the formation of a one-dimensional saw-toothed supramolecule.

  14. 多硝基芳烃的电火花感度和热安定性关系%A New Aspect of Relationships between Electric Spark Sensitivity and Thermal Stability of Some Polynitro Arenes

    Institute of Scientific and Technical Information of China (English)

    Svatopluk Zeman

    2008-01-01

    An ESZ KTTV instrument of a new, relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes, expressed as spark energy, EES, required for 50-percent initiation probability. The thermal stability thresholds, Tmax, were calculated from the published Arrhenius parameters of monomolecular thermal decomposition of the studied compounds, predominantly obtained under the conditions of the Russian manometric method. An approximate relationship has been found between the ln EES values and threshold Tmax values. In the sense of this relationship, the compounds studied fall into several sub-groups. The reason of the said diversification lies in the decomposition reaction rate at the temperature of onset of their thermal decomposition. It has been found that in each sub-group increasing thermal stability of polynitro arenes is accompanied by increasing electric spark sensitivity of these substances. This fact must be taken into account if we deal with the problem of electric spark energy transfer into the reaction centre of the molecule.

  15. Nitril Grubu Tasıyan Kaliks[4]aren ve Polimer Destekli Türevinin Sentezi ve Civa Taşıma Özelliklerinin Karşılaştırılması

    Directory of Open Access Journals (Sweden)

    Gülderen UYSAL AKKUŞ

    2009-04-01

    Full Text Available Bu çalışma 5,11,17,23-tetra-ter-bütil-25,27-bis(3siyanopropoksikaliks[4]aren (2 ve bunun birden fazla kaliksaren birimininin bir arada olduğu uygun polimerik yapısının sentezini ve ekstraksiyon özelliklerini içermektedir. Başlangıç maddesi olarak kullanılan p-ter-bütilkaliks[4]aren literatürdeki metotlara göre sentezlendi. Daha sonra bu bileşiğe literatürdeki metotlar uyarlanarak 2 nolu bileşik elde edildi. Polimerik yapı (3 bileşik 2 ile Merrifield reçinesinin reaksiyonuyla elde edildi. Son olarak bu bileşiklerin faz-transfer çalışmaları sıvı-sıvı ekstraksiyon metodu kullanılarak gerçekleştirildi. Ekstraksiyon sonuçlarından görülmektedir ki monomer 2 Hg+2 katyonuna karşı bir seçicilik göstermektedir. Halbuki, bunun polimeri (3 Ni2+ hariç seçilen metallerin hepsini iyi bir şekilde organik faza taşımaktadır.

  16. Electrochemical synthesis of Ag nanoparticles supported on glassy carbon electrode by means of p-isopropyl calix[6]arene matrix and its application for electrocatalytic reduction of H2O2

    International Nuclear Information System (INIS)

    The silver nanoparticles were prepared on the glassy carbon (GC) electrode, modified with p-iso propyl calix[6]arene, by preconcentration of silver ions in open circuit potential and followed by electrochemical reduction of silver ions. The stepwise fabrication process of Ag nanoparticles was characterized by scanning electron microscopy and electrochemical impedance spectroscopy. The prepared Ag nanoparticles were deposited with an average size of 70 nm and a homogeneous distribution on the surface of electrode. The observed results indicated that the presence of calixarene layer on the electrode surface can control the particle size and prevent the agglomeratione and electrochemical deposition is a promising technique for preparation of nanoparticles due to its easy-to-use procedure and low cost of implementation. Cyclic voltammetry experiments showed that Ag nanoparticles had a good catalytic ability for the reduction of hydrogen peroxide (H2O2). The effects of p-isopropyl calix[6]arene concentration, applied potential for reduction of Ag+, number of calixarene layers and pH value on the electrocatalytic ability of Ag nanoparticles were investigated. The present modified electrode exhibited a linear range from 5.0 × 10-5 to 6.5 × 10-3 M and a detection limit 2.7 × 10-5 M of H2O2 (S/N = 3) using amperometric method.

  17. Games are motivating, aren´t they? Disputing the arguments for digital game-based learning

    Directory of Open Access Journals (Sweden)

    Wim Westera

    2015-06-01

    Full Text Available The growing popularity of game-based learning reflects the burning desire for exploiting the involving and motivating characteristics of games for serious purposes. A wide range of arguments for using games for teaching and learning can be encountered in scientific papers, policy reports, game reviews and advertisements. With contagious enthusiasm, the proponents of game-based learning make their claims for using games to improve education. However, standing up for a good cause is easily replaced with the unconcerned promotion and spread of the word, which tends to make gaming an article of faith. This paper critically examines and re-establishes the argumentation used for game-based learning and identifies misconceptions that confuse the discussions. It reviews the following claims about game-based learning: 1 games foster motivation, 2 play is a natural mode of learning, 3 games induce cognitive flow, which is productive for learning, 4 games support learning-by-doing, 5 games allow for performance monitoring, 6 games offer freedom of movement and the associated problem ownership, 7 games support social learning, 8 games allow for safe experimentation, 9 games accommodate new generations of learners, who have grown up immersed in digital media, and 10 there are many successful games for learning. Assessing the validity of argumentation is considered essential for the credibility of game-based learning as a discipline.

  18. Musculoskeletal involvement in systemic sclerosis.

    Science.gov (United States)

    Randone, Silvia Bellando; Guiducci, Serena; Cerinic, Marco Matucci

    2008-04-01

    Musculoskeletal involvement is more frequent than expected in patients with systemic sclerosis (SSc) and is a major cause of disability, even if the prognosis of the disease largely depends on visceral involvement. The most common clinical feature of musculoskeletal involvement is arthralgia; less frequent features are arthritis, flexion contractures, stiffness (affecting predominantly fingers, wrists and ankles), proximal muscle weakness (mainly of the shoulder and hip) and tendon sheath involvement. Tendon friction rubs are predictive of poor prognosis. If musculoskeletal involvement is suspected, serum creatinine phosphokinase, aldolase, lactate dehydrogenase, alkaline phosphate, rheumatoid factor and anticyclic citrullinated peptide autoantibodies should be checked routinely. Treatment for muscle involvement has not yet been considered adequately and, in the future, it is to be hoped that clinical trials will identify new drugs to control this aspect of SSc, which seriously compromises patients' quality of life. PMID:18455689

  19. Determination of the extractive capacity of para-tert butyl calix[8]arene octa-phosphinoylated towards uranyl ions from an aqueous-acidic-salty medium

    International Nuclear Information System (INIS)

    The extraction properties of octa-phosphinoylated para-tert butyl calix[8]arene (prepared in the laboratory) in chloroform towards uranyl ions from an aqueous-acidic-salty medium (HNO3-3.5 NaNO3) containing uranyl nitrate salt, was investigated. Two spectroscopic techniques UV/Vis and Luminescence were used for this study. The latter permitted analyze the fluorescence from the uranyl ions influenced by the surrounding medium. Both permitted to learn about the power of this calixarene as extractant towards the mentioned ions. Its extraction ability or capability using this calixarene at 5.91 x 10-4 M towards the uranyl ions was 400% as determined by UV/Vis while fluorescence revealed 100% of uranyl ion extraction. A closed analysis of the results obtained by using these techniques revealed that the stoichiometry of the main extracted species was 1calixarene:2 uranyl ions. The loading capacity of the calixarene ligand towards the uranyl ions was also investigated using both techniques. UV/Vis resulted to be inadequate for quantifying exactly the loading capacity of the calixarene whereas luminescence was excellent indeed, using a 5.91 x 10-4 M calixarene concentration, its loading capacity was 0.157 M of free uranyl ions from 0.161 M of uranyl ions present in the aqueous-acidic-salty medium. The extracts from the ability and capacity studies were concentrated to dryness, purified and the dried extracts were analyzed by infrared and neutron activation analysis. By these techniques it was demonstrated that during the extraction of the uranyl ions by the calixarene ligand they form thermodynamically and kinetically stable complexes, since in the solid state, the 1:2, calixarene; uranyl ions stoichiometry was kept with the minimum formula: (UO2)2B8bL8(NO3)4(H2O)4CHCl3(CH3OH)3 the methanol molecules come from its purification. It is proposed that B8bL8 calixarene in chloroform medium is a good extractant for the treatment of nuclear wastes or radioactive wastes containing

  20. Preparing Teachers for Parent Involvement.

    Science.gov (United States)

    Safran, Daniel

    This paper examines the potential impact of parent involvement in the formal education of their children and suggests ways that teacher education can be restructured to prepare teachers to work with parents. This paper attempts to answer five questions: (1) Why should parents be involved in the formal education of their children? (2) Why should…

  1. Disseminated tuberculosis with rare involvements

    International Nuclear Information System (INIS)

    We report a case of disseminated tuberculosis involving the middle ear, the central nervous system, the spine and the lung. The tuberculous epidural abscess and otomastoiditis don't have any specific imaging features. But their coexistence with an other tuberculous involvement might suggest their tuberculous nature. The epidural abscess may result from direct extension from otomastoiditis. (authors)

  2. Direct Employee Involvement Quality (DEIQ)

    NARCIS (Netherlands)

    Torka, Nicole; Woerkom, van Marianne; Looise, Jan-Kees

    2008-01-01

    This paper focuses on one aspect of human resource management (HRM) that is important for innovative employee behaviour: direct employee involvement quality (DEIQ). However, research has also shown that employee involvement is often in serious need of improvement. This paper presents evidence from t

  3. Employee involvement: motivation or manipulation?

    Science.gov (United States)

    McConnell, C R

    1998-03-01

    Employee involvement is subject to a great deal of verbal tribute; there is hardly a manager at work today who will not praise the value of employee input. However, many employee involvement efforts leave employees feeling more manipulated than motivated. This occurs because supervisors and managers, while expecting employees to change the way they work, are themselves either unwilling to change or remain unconscious of the need to change. The result is that, although employee input is regularly solicited in a number of forms, it is often discounted, ignored, or altered to fit the manager's preconceptions. Often the employee is left feeling manipulated. Since the opportunity for involvement can be a strong motivator, it becomes the manager's task to learn how to provide involvement opportunity in manipulative fashion. This can be accomplished by providing involvement opportunity accompanied by clear outcome expectations and allowing employees the freedom to pursue those outcomes in their own way.

  4. Who and What does involvement

    DEFF Research Database (Denmark)

    Hansen, Jeppe Oute; Petersen, Anders; Huniche, Lotte

    2016-01-01

    This article gives an account of aspects of a multi-sited field study of involvement of relatives in Danish psychiatry. By following metaphors of involvement across three sites of the psychiatric systema family site, a clinical site and a policy sitethe first author (J.O.) investigated how...... theoretical perspective laid out by Ernesto Laclau and Chantal Mouffe, the aim of this study is to show how the dominant discourse about involvement at the political and clinical sites is constituted by understandings of mentally ill individuals and by political objectives of involvement. The analysis...... elucidates how a psycho-ideological discourse positions the mentally ill person as weak, incapable, and ineffective. By contrast, the supporting relative is positioned as a strong, capable, and effective co-therapist. Furthermore, the analysis considers how this dominant discourse of involvement...

  5. GOVERNMENT INVOLVEMENT IN CONSUMPTION BEHAVIOUR

    OpenAIRE

    CRISTINA ZAMFIR; IOANA LUPAŞC; ADRIAN LUPAŞC

    2010-01-01

    In this article, we will follow the involvement that the government has, through its expenses, on the consumption behavior. The involvement that the government has in the consumption behavior is made through fees and taxes that are applied on income. Fees and taxes are applied to the different forms of income but in this article we will be focused only on the influence of them on wages. In order to analyze the involvement of government expenses on consumption behavior an utility model will be...

  6. 1,3-Diamido-calix[4]arene conjugates of amino acids: recognition of -COOH side chain present in amino acids, peptides, and proteins by experimental and computational studies.

    Science.gov (United States)

    Acharya, Amitabha; Ramanujam, Balaji; Chinta, Jugun Prakash; Rao, Chebrolu P

    2011-01-01

    Lower rim 1,3-diamido conjugates of calix[4]arene have been synthesized and characterized, and the structures of some of these have been established by single crystal XRD. The amido-calix conjugates possessing a terminal -COOH moiety have been shown to exhibit recognition toward guest molecules possessing -COOH moiety, viz., Asp, Glu, and reduced and oxidized glutathione (GSH, GSSG), by switch-on fluorescence in aqueous acetonitrile and methanol solutions when compared to the control molecules via forming a 1:1 complex. The complex formed has been shown by mass spectrometry, and the structural features of the complexes were derived on the basis of DFT computations. The association constants observed for the recognition of Asp/Glu by Phe-calix conjugate, viz., 532/676 M(-1), are higher than that reported for the recognition of Val, Leu, Phe, His, and Trp (16-63 M(-1)) by a water-soluble calixarene (Arena, G., et al. Tetrahedron Lett. 1999, 40, 1597). For this recognition, there should be a free -COOH moiety from the guest molecule. AFM, SEM, and DLS data exhibited spherical particles with a hundred-fold reduction in the size of the complexes when compared to the particles of the precursors. These spherical particles have been computationally modeled to possess hexameric species reminiscent of the hexameric micellar structures shown for a Ag(+) complex of a calix[6]arene reported in the literature (Houmadi, S., et al. Langmuir 2007, 23, 4849). Both AFM and TEM studies demonstrated the formation of nanospheres in the case of GSH-capped Ag nanoparticles in interaction with the amido-calix conjugate that possesses terminal -COOH moiety. The AFM studies demonstrated in this paper have been very well applied to albumin proteins to differentiate the aggregational behavior and nanostructural features exhibited by the complexes of proteins from those of the uncomplexed ones. To our knowledge, this is the first report wherein a amido-calix[4]arene conjugate and its amino acid

  7. Effect of the piperazine unit and metal-binding site position on the solubility and anti-proliferative activity of ruthenium(II)- and osmium(II)- arene complexes of isomeric indolo[3,2-c]quinoline-piperazine hybrids.

    Science.gov (United States)

    Filak, Lukas K; Kalinowski, Danuta S; Bauer, Theresa J; Richardson, Des R; Arion, Vladimir B

    2014-07-01

    In this study, the indoloquinoline backbone and piperazine were combined to prepare indoloquinoline-piperazine hybrids and their ruthenium- and osmium-arene complexes in an effort to generate novel antitumor agents with improved aqueous solubility. In addition, the position of the metal-binding unit was varied, and the effect of these structural alterations on the aqueous solubility and antiproliferative activity of their ruthenium- and osmium-arene complexes was studied. The indoloquinoline-piperazine hybrids L(1-3) were prepared in situ and isolated as six ruthenium and osmium complexes [(η(6)-p-cymene)M(L(1-3))Cl]Cl, where L(1) = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-2-N-amine, M = Ru ([1a]Cl), Os ([1b]Cl), L(2) = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-4-N-amine, M = Ru ([2a]Cl), Os ([2b]Cl), L(3) = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-8-N-amine, M = Ru ([3a]Cl), Os ([3b]Cl). The compounds were characterized by elemental analysis, one- and two-dimensional NMR spectroscopy, ESI mass spectrometry, IR and UV-vis spectroscopy, and single-crystal X-ray diffraction. The antiproliferative activity of the isomeric ruthenium and osmium complexes [1a,b]Cl-[3a,b]Cl was examined in vitro and showed the importance of the position of the metal-binding site for their cytotoxicity. Those complexes containing the metal-binding site located at the position 4 of the indoloquinoline scaffold ([2a]Cl and [2b]Cl) demonstrated the most potent antiproliferative activity. The results provide important insight into the structure-activity relationships of ruthenium- and osmium-arene complexes with indoloquinoline-piperazine hybrid ligands. These studies can be further utilized for the design and development of more potent chemotherapeutic agents. PMID:24927493

  8. User Involvement And Entrepreneurial Action

    Directory of Open Access Journals (Sweden)

    Eva Heiskanen

    2007-01-01

    Full Text Available Involving users in the innovation process is a subject of much research, experimentation, and debate. Less attention has been given to the limits to user involvement that ensue from specific organizational characteristics. This article explores barriers to the utilization of users’ input in two small companies developing interactive digital applications. We contrast our findings to earlier research involving large companies to identify features of entrepreneurial sensemaking and action that influence the utilization of users’ input. We find that the small companies follow a distinct action rationality, leading to rapid implementation of some user inputs, and defensiveness toward others. Both sets of data also reveal common features that are often overlooked in the literature. We reconceptualize user involvement as a form of interaction between users and innovating companies that is facilitated and constrained by micro-sociological processes, on the one hand, and the nature of the competitive environment, on the other.

  9. Cervicobrachial involvement in diabetic radiculoplexopathy.

    Science.gov (United States)

    Katz, J S; Saperstein, D S; Wolfe, G; Nations, S P; Alkhersam, H; Amato, A A; Barohn, R J

    2001-06-01

    Diabetic radiculoplexopathy is commonly viewed as a condition affecting the lower extremities. However, other regions may also be affected and the presence of upper extremity involvement has rarely been emphasized. Our goal was to illustrate the clinical features of arm involvement in this condition. Of 60 patients with diabetic lumbosacral radiculoplexopathy, we identified 9 who also had upper extremity involvement. The study included 8 men and 1 woman, ranging in age from 36 to 71 years. Upper limb involvement developed simultaneously with the onset of lower limb disorder in 1 patient, preceded it by 2 months in another patient, and occurred between 3 weeks and 15 months later in the remaining 7. In 5 cases, arm involvement developed after symptoms in the legs began to improve. The upper extremity weakness affected the hands and forearms most severely. It was unilateral in 5 patients and bilateral but asymmetric in 4. Pain was often present, but it was not a prominent feature. In most patients, neurologic deficits in the arms improved spontaneously after 2-9 months. We conclude that diabetic radiculoplexopathy may involve the cervical region before, after, or simultaneously with the lumbosacral syndrome. The upper limb process is similar to that in the legs, with subacutely progressive weakness and pain followed by spontaneous recovery. PMID:11360263

  10. Análisis y evaluación de la vulnerabilidad de la población de La Fortuna de San Carlos a la actividad volcànica del Volcán Arenal, Costa Rica.

    OpenAIRE

    Berrocal Vargas, Milena

    2008-01-01

    El Volcán Arenal es un joven estratovolcán (7ka) localizado en el noroeste de Costa Rica. Inicio su presente ciclo eruptivo el 29 de Julio de 1968 con una gran explosión lateral que mató alrededor de 90 personas. En el momento inicial de la erupción los alrededores del volcán estaban ocupados principalmente por fincas ganaderas. Hoy día, 40 años después de constante actividad volcánica las tierras dedicadas a la ganadería en los alrededores del volcán han retrocedido como principal actividad ...

  11. 1,3-Alternate conformer 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetra-kis-(4-methyl-sulfanylbenz-yloxy)-2,8,14,20-tetra-thia-calix[4]arene.

    Science.gov (United States)

    Gao, Qingsong; Xie, Dexun; An, Delie

    2013-01-01

    The title thia-calix[4]arene derivative, C72H80O4S8, adopts a 1,3-alternate conformation, where the four 4-methyl-sul-fan-yl-benzyl groups are located alternately at the two sides of a virtual plane defined by the four bridging S atoms. In the crystal, there are no significant inter-molecular inter-actions present. Some of the peripheral tert-butyl and methyl-sulfanyl groups are disordered over two positions. A region of disordered electron density, occupying voids of ca 700 Å(3) for an electron count of 124, was treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. PMID:24046595

  12. Renal involvement in behcet's disease

    International Nuclear Information System (INIS)

    There are conflicting reports about the renal involvement in Behcet's disease (BD). In this study we aimed to study the frequency and type of renal involvement in a group of patients with BD in Azerbaijan province that is one of the prevalent areas of BD in Iran. All cases of BD were prospectively followed between June 2004 and January 2007, and evaluated for renal dys-function (serum creatinine > 1.7 mg/dL), glomerular hematuria and proteinuria. Those patients with proteinuria > 500 mg/day and serum creatinine level > 2 mg/dL, underwent renal biopsy. From a total number of 100 patients, six patients (6%) had obvious renal involvements. Four patients had glomerular hematuria and proteinuria. Renal biopsy in two of them revealed measangial proliferative glumerulonephritis with IgA deposit in one of them and membranoproliferative glumerolonephritis in another one. Two remaining patients had serum creatinine > 2 mg/dL without any hematuria or proteinuria. Serologic study for viral agents and collagen vascular disease were negative in all patients with renal involvements. In conclusion, renal involvement in BD is not infrequent, although in most cases it is mild in nature and may be missed. (author)

  13. Amino acids separation with the tetracarboxylic derived of the para-ter-butylcalix[4]arene by means of solid-liquid extraction assisted with lanthanides

    International Nuclear Information System (INIS)

    The tetracarboxylic derived of the para-ter-butylcalix[4]arene (B4ACEbL4) does not exist commercially for what was synthesized and characterized at laboratory level. The separation of the L-tyrosine amino acid was studied by means of a solid-liquid extraction system with the B4ACEbL4 as solid phase, in function of ph (2.5-7.5) and contact time (5 and 15 hours) to temperature of 15-17 grades C. Resulted that the ph and the contact time were decisive in the extraction percentage of water tyrosine. The lowest percentage was 49% to ph 4 and the highest percentage was 61% to ph 7.5 with 15 hours of contact. In a contact time of 5 hours the extraction was inferior to 32% (ph 4) and of 47% to ph 6.5. The europium effect (Eu (III)) was studied to ph acid in the tyrosine separation and was found that the tyrosine extraction is not increased neither decomposes in europium presence, this is simultaneously extracted by the calixarene but it does not enter in competition for the calixarene with the amino acid. The separate solid phases: calixarene-tyrosine was analyzed by Far infrared radiation (Fir), Mid-Infrared (Mir) spectroscopy and luminescence to check the tyrosine presence in the separate solids as well as the nature of the connection calixarene-tyrosine. In this way was possible to check the tyrosine presence and to propose the formed molecular species tyrosine-calixarene, those which interact mainly by means of hydrogen connections and Van der Waals forces. The liquid phases before and after the extraction were analyzed by UV-Vis spectrophotometry and luminescence. The Neutron activation analysis was used to determine the europium content in the solid and liquid phases of extractions in europium presence. The tyrosine degradation also shows dependence with the ph, obtaining 88% degradation to the 24 hours to ph 7.5, while to ph 3 is degraded the 54% of tyrosine present in the sample. The europium presence does not affect the tyrosine extraction but if its photo

  14. Conjugation of a Ru(II) arene complex to neomycin or to guanidinoneomycin leads to compounds with differential cytotoxicities and accumulation between cancer and normal cells.

    Science.gov (United States)

    Grau-Campistany, Ariadna; Massaguer, Anna; Carrion-Salip, Dolors; Barragán, Flavia; Artigas, Gerard; López-Senín, Paula; Moreno, Virtudes; Marchán, Vicente

    2013-05-01

    with the guanidinylated conjugate, since its cytotoxicity in the normal cell line (IC50 = 12.75 μM for 3) was similar or even lower than that found in MCF-7 and DU-145 cancer cell lines, respectively. Cell uptake studies performed by ICP-MS with conjugates 2 and 3 revealed that guanidinylation of the neomycin moiety had a positive effect on accumulation (about 3-fold higher in DU-145 and 4-fold higher in HEK293), which correlates well with the higher antiproliferative activity of 3. Interestingly, despite the slightly higher accumulation in the normal cell than in the cancer cell line (about 1.4-fold), guanidinoneomycin-ruthenium conjugate (3) was more cytotoxic to cancer cells (about 1.8-fold), whereas the opposite tendency applied for neomycin-ruthenium conjugate (2). Such differences in cytotoxic activity and cellular accumulation between cancer and normal cells open the way to the creation of more selective, less toxic anticancer metallodrugs by conjugating cytotoxic metal-based complexes such as ruthenium(II) arene derivatives to guanidinoglycosides.

  15. Strategy Innovation with Employee Involvement

    DEFF Research Database (Denmark)

    Friis, Ole Uhrskov; Koch, Christian

    2015-01-01

    if the managers still dominate, some processes of direct involvement of employees occur, in particular when employees are asked to supplement overall strategic goals and when they directly shape several sub-strategies. Strategy practices found include strategy planning, an open space workshop and organised......The purpose of this article is to investigate how employees can be involved in strategy innovation processes and how new strategy practices (new tools and procedures) are used to change strategy praxis in order to sustain value creation. In the strategizing actions, we found that even...... strategy projects. Especially the latter two are important in facilitating the employee involvement. The case, however, also exhibits enterprise-situated praxises related to unplanned events, like the mitigation of taboos....

  16. [Heart involvement in Friedreich's ataxia].

    Science.gov (United States)

    Weidemann, F; Scholz, F; Florescu, C; Liu, D; Hu, K; Herrmann, S; Ertl, G; Störk, S

    2015-03-01

    Friedreich's ataxia is a rare hereditary disease and although the gene defect has already been identified as a deficiency of the mitochondrial protein frataxin, the pathophysiology is still unknown. Although a multisystem disorder organ involvement is predominantly neurological. Besides the characteristic features of spinocerebellar ataxia the heart is frequently also affected. Cardiac involvement typically manifests as hypertrophic cardiomyopathy, which can progress to heart failure and death. So far most research has focused on the neurological aspects and cardiac involvement in Friedreich's ataxia has not been systematically investigated. Thus, a better understanding of the progression of the cardiomyopathy, cardiac complications and long-term cardiac outcome is warranted. Although no specific treatment is available general cardiac therapeutic options for cardiomyopathy should be considered. The current review focuses on clinical and diagnostic features of cardiomyopathy and discusses potential therapeutic developments for Friedreich's ataxia. PMID:24848865

  17. Vertebral osteomyelitis without disc involvement

    Energy Technology Data Exchange (ETDEWEB)

    Kamani, I.; Syed, I.; Saifuddin, A. E-mail: asaifuddin@aol.com; Green, R.; MacSweeney, F

    2004-10-01

    Vertebral osteomyelitis is most commonly due to pyogenic or granulomatous infection and typically results in the combined involvement of the intervertebral disc and adjacent vertebral bodies. Non-infective causes include the related conditions of chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. Occasionally, these conditions may present purely within the vertebral body, resulting in various combinations of vertebral marrow oedema and sclerosis, destructive lesions of the vertebral body and pathological vertebral collapse, thus mimicking neoplastic disease. This review illustrates the imaging features of vertebral osteomyelitis without disc involvement, with emphasis on magnetic resonance imaging (MRI) findings.

  18. Guidance on accidents involving radioactivity

    International Nuclear Information System (INIS)

    This annex contains advice to Health Authorities on their response to accidents involving radioactivity. The guidance is in six parts:-(1) planning the response required to nuclear accidents overseas, (2) planning the response required to UK nuclear accidents a) emergency plans for nuclear installations b) nuclear powered satellites, (3) the handling of casualties contaminated with radioactive substances, (4) background information for dealing with queries from the public in the event of an accident, (5) the national arrangements for incident involving radioactivity (NAIR), (6) administrative arrangements. (author)

  19. Musculoskeletal involvement in systemic sclerosis.

    Science.gov (United States)

    Lóránd, Veronika; Czirják, László; Minier, Tünde

    2014-10-01

    Musculoskeletal (MSK) involvement is a very frequent manifestation of patients with systemic sclerosis (SSc). There are several reports about clinical trials assessing musculoskeletal involvement in SSc. However, only few controlled studies have been conducted. The prevalence of musculoskeletal symptoms, clinical and radiographic findings has been assessed. The most important articular (arthralgia, synovitis, contractures), tendon (tendon friction rubs, tenosynovitis) and muscular manifestations (myalgia, muscle weakness, myositis) should be carefully evaluated during the assessment of SSc patients, because these are not only common, but substantially influence the quality of life and some of them also have predictive value concerning disease activity and severity. PMID:25179276

  20. Multisystem involvement in neuromyelitis optica

    Directory of Open Access Journals (Sweden)

    Megan M Langille

    2015-01-01

    Full Text Available We describe a case of pediatric neuromyelitis optica (NMO with muscle and lung involvement in addition to central nervous system disease. Our patient initially presented with features of area postrema syndrome, then subsequently with optic neuritis. The patient also had recurrent hyperCKemia that responded to corticosteroids. Finally, axillary and hilar adenopathy with pulmonary consolidation were noted as well and responded to immunomodulation. Our case highlights multisystem involvement in NMO including non-infectious pulmonary findings which have not been described in the pediatric population previously.

  1. Words Aren't Cheap

    Science.gov (United States)

    Rockwell, Mark

    2011-01-01

    Textbooks are a crushingly substantial portion of students' costs every semester, and they're getting more expensive every year. With the cost of some individual textbooks surpassing a monthly cable television bill, students are moving to relieve that economic pressure by renting textbooks instead of buying them new or used. The idea of renting…

  2. QUALITY ASSURANCE: THROUGH STUDENT'S INVOLVEMENT

    OpenAIRE

    Vandana Jadhav- Nalawade

    2014-01-01

    The quality of education is determined by quality of teaching & quality of the teaching in term is determined by the desired behavioural change in the students. So far enhancing quality of teaching and learning students’involvement is the major aspect.

  3. Some integrals involving Bessel functions

    OpenAIRE

    Glasser, M. Lawrence; Montaldi, Emilio

    1993-01-01

    A number of new definite integrals involving Bessel functions are presented. These have been derived by finding new integral representations for the product of two Bessel functions of different order and argument in terms of the generalized hypergeometric function with subsequent reduction to special cases. Connection is made with Weber's second exponential integral and Laplace transforms of products of three Bessel functions.

  4. Managing Parent Involvement during Crisis

    Science.gov (United States)

    Merriman, Lynette S.

    2008-01-01

    In the wake of 9/11, Hurricane Katrina, and the Virginia Tech shooting tragedy, it is no surprise that concern for students' safety is the primary reason attributed to parents' increased involvement. Parents and university administrators share in their commitment to student safety. However, college and university staff who assume responsibility…

  5. Involving Employees in Strategy innovation

    DEFF Research Database (Denmark)

    Friis, Ole Uhrskov; Koch, Christian

    2011-01-01

    Strategy as a practice and continuous innovation approaches are combined to conceptualise dilemmas of short versus long term and to analyse a case of employee participation as a particular example of strategy innovation. The case is a medium size textile company developing its strategy involving...

  6. Putaminal involvement in Rasmussen encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Rajesh, Bhagavatheeswaran; Ashalatha, Radhakrishnan [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Neurology, Trivandrum, Kerala (India); Kesavadas, Chandrasekharan; Thomas, Bejoy [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Imaging Sciences and Interventional Radiology, Trivandrum, Kerala (India)

    2006-08-15

    Rasmussen encephalitis (RE) is a rare devastating disease of childhood causing progressive neurological deficits and intractable seizures, typically affecting one hemisphere. Characteristic MRI features include progressive unihemispheric focal cortical atrophy and grey- or white-matter high-signal changes and basal ganglion involvement, particularly of the caudate nucleus. To analyse the pattern of involvement of different brain structures in a series of patients with RE and to attempt clinical correlation. We reviewed the medical records and neuroimaging data of 12 patients diagnosed with RE satisfying the European Consensus Statement diagnostic criteria. The disease manifested as seizures in all patients and was refractory; epilepsia partialis continua was a notable feature (nine patients). Hemiparesis of varying grades was noted in all but one patient; none had extrapyramidal signs. Neuroimaging showed cortical involvement in the insular/periinsular regions in 11 patients. Caudate atrophy was noted in ten patients. Putaminal atrophy was seen in nine patients, six of whom had additional hyperintense signal changes. Our study highlights frequent putaminal atrophy and signal changes in RE, which suggests a more extensive basal ganglion involvement than emphasized previously. Recognition of putaminal changes may be a useful additional tool in the radiological diagnosis of RE. (orig.)

  7. Systemic involvement in mycosis fungoides.

    Science.gov (United States)

    Burg, Günter

    2015-01-01

    Mycosis fungoides (MF) represents almost 50% of all primary cutaneous lymphomas and more than 70% of cutaneous T-cell lymphomas (CTCL). Arising from preferentially skin-homing lymphocytes with genetic instability, MF evolves through stages (IA-IVB), producing inconspicuous inflammatory features in the beginning and finally resulting in a proliferation of cytomorphologic, phenotypic, and genotypic abnormal tumor cells. Over the past 200 years, there has been much confusion in the classification of lymphomas due to semantic disagreements (MF, CTCL, parapsoriasis, lymphosarcoma, reticulum cell sarcoma, and many other terms), lack of diagnostic standard criteria, and new molecular diagnostic methods. Studies on extracutaneous involvement in early stages (IA-IIA) are almost completely lacking. In advanced stages of MF (IIB-IVB), discovery of extracutaneous involvement is dependent on the methods used (physical examination, technology, molecular diagnostics, autopsy, and laparoscopy) and reveals a wide range of results. Due to the inflammation-simulating features in the beginning of the disease, early diagnosis is very difficult to assess. Extracutaneous involvement has previously been documented in more than 70% of autopsies. More recent studies give much lower figures. Like all lymphomas, MF is a systemic disease from the very beginning, with distinct homing preferences in tumor cells. Organs most commonly involved during the lengthy course of the disease are, in descending frequency, lymph node/peripheral blood, liver, spleen, lung, bone marrow, GI tract, pancreas, and kidney. PMID:26321404

  8. Community Involvement in TB Research

    NARCIS (Netherlands)

    M. van der Werf (Marloes); S.G. Heumann (Silke); E.M.H. Mitchell

    2011-01-01

    textabstractWhile communities at risk have been both drivers and partners in HIV research, their important role in TB research is yet to be fully realized. Involvement of communities in tuberculosis care and prevention is currently on the international agenda. This creates opportunities and indicate

  9. Parental Involvement in Norwegian Schools

    Science.gov (United States)

    Paulsen, Jan Merok

    2012-01-01

    This article examines findings on key challenges of school-parent relations in Norway. The review is based on recent large-scale studies on several issues, including formalized school-parent cooperation, parental involvement in the pedagogical discourse, and teacher perspectives on the parents' role in the school community. Findings suggest a…

  10. Lupus panniculitis involving the breast

    Energy Technology Data Exchange (ETDEWEB)

    Sabate, Josep M.; Gomez, Antonio; Torrubia, Sofia; Salinas, Teresa; Clotet, Montse [Universitat Autonoma de Barcelona, Unity of Breast Imaging, Department of Diagnostic Radiology, Hospital de Sant Pau, Barcelona (Spain); Lerma, Enrique [Universitat Autonoma de Barcelona, Department of Pathology, Hospital de Sant Pau, Barcelona (Spain)

    2006-01-01

    Lupus panniculitis is an unusual immunological disease that characteristically affects the subcutaneous fat and occurs in 2% of patients with systemic lupus erythematosus. We report a case of lupus panniculitis involving the breast, which represents a very uncommon location. Mammographically, it presented as a suspicious irregular mass involving the subcutaneous fat pad with skin thickening. High echogenicity constituted the most relevant sonographic finding. To the best of our knowledge, the magnetic resonance (MR) features have not been previously described. High signal intensity was found on both T1- and T2-weighted precontrast MR images. A dynamic contrast-enhanced study revealed a suspicious focal mass with irregular margins and rim enhancement, with a type 3 time-signal intensity curve. Differential diagnosis with carcinoma and fat necrosis and the value of core biopsy are discussed. (orig.)

  11. Liver involvement in systemic infection

    Institute of Scientific and Technical Information of China (English)

    Masami; Minemura; Kazuto; Tajiri; Yukihiro; Shimizu

    2014-01-01

    The liver is often involved in systemic infections,resulting in various types of abnormal liver function test results.In particular,hyperbilirubinemia in the range of 2-10 mg/dL is often seen in patients with sepsis,and several mechanisms for this phenomenon have been proposed.In this review,we summarize how the liver is involved in various systemic infections that are not considered to be primarily hepatotropic.In most patients with systemic infections,treatment for the invading microbes is enough to normalize the liver function tests.However,some patients may show severe liver injury or fulminant hepatic failure,requiring intensive treatment of the liver.

  12. Audiovestibular involvement in systemic sclerosis.

    Science.gov (United States)

    Berrettini, S; Ferri, C; Pitaro, N; Bruschini, P; Latorraca, A; Sellari-Franceschini, S; Segnini, G

    1994-01-01

    In order to evaluate the nature and association of audiovestibular disturbances and systemic sclerosis (SSC), 37 unselected SSC patients were studied with a detailed audiological and vestibular examination since November, 1987. Pure-tone audiometry, speech audiometry, impedance audiometry, brainstem response audiometry and vestibular function using electronystagmographic recording were performed. We found a rather frequent audiovestibular involvement (41%). A hearing loss was found in 14 SSC patients; hearing loss was sensorineural in 10 cases and mixed in 4 cases. The latter revealed a finding similar to tympanosclerosis. Four patients showed altered vestibular test values and only one of these had normal hearing. Sensorineural deafness was the more frequent pathological finding and in all cases the site of lesion was cochlear. SSC appears to be directly responsible for audiovestibular damage, since in 12 out of 15 patients with such involvement, no other apparent cause could be revealed. SSC may be included among the autoimmune diseases which may cause audiovestibular disturbances. PMID:8078672

  13. Lupus panniculitis involving the breast

    International Nuclear Information System (INIS)

    Lupus panniculitis is an unusual immunological disease that characteristically affects the subcutaneous fat and occurs in 2% of patients with systemic lupus erythematosus. We report a case of lupus panniculitis involving the breast, which represents a very uncommon location. Mammographically, it presented as a suspicious irregular mass involving the subcutaneous fat pad with skin thickening. High echogenicity constituted the most relevant sonographic finding. To the best of our knowledge, the magnetic resonance (MR) features have not been previously described. High signal intensity was found on both T1- and T2-weighted precontrast MR images. A dynamic contrast-enhanced study revealed a suspicious focal mass with irregular margins and rim enhancement, with a type 3 time-signal intensity curve. Differential diagnosis with carcinoma and fat necrosis and the value of core biopsy are discussed. (orig.)

  14. Hodgkin's lymphoma with cutaneous involvement

    OpenAIRE

    Dhull, Anil Kumar; Soni, Abhishek; Kaushal, Vivek

    2012-01-01

    We report a case of a 22-year-old previously healthy woman with Hodgkin's lymphoma who presented initially with multiple lymphadenopathy and later, with a solitary cutaneous ulcer. Unlike Non-Hodgkin's lymphoma subtypes, skin involvement of Hodgkin's lymphoma is extremely rare. The prognosis of Hodgkin's lymphoma with skin infiltration is felt to be extremely poor. Contrary to other reports, this case demonstrates that a good response with standard therapy is possible.

  15. Palmar involvement in lichen planus

    OpenAIRE

    Müzeyyen Gönül; Gökçe Işıl Kurmuş; Filiz Canpolat; Aysun Gökçe

    2014-01-01

    Lichen planus (LP), which is clinically characterized by plan, pruritic, violaceous, polygonal papules, is a chronic inflammatory dermatosis with unknown etiology. According to the site of involvement, LP has mucosal (oral, genital, conjunctival), nail, scalp, inverse, palmoplantar subtypes. Palmoplantar lichen planus is a rare, localized variant of LP and does not show the typical clinical features of the disease. Unlike other types of LP, palmoplantar variant is more common in men and usual...

  16. Employee involvement in Ukrainian companies

    OpenAIRE

    Croucher, Richard

    2010-01-01

    This paper examines the hypothesis that the introduction of Western quality standards has brought some development of employee involvement in Ukrainian manufacturing and service companies and analyses the consequences for managements' use of the institutions of employee representation. The subject is pursued through eight case studies, four in a test and four in a control group. Quality developments were driven by top managers and not by human resource (HR) practitioners. In the test companie...

  17. Subcutaneous sarcoidosis without systemic involvement

    OpenAIRE

    O'Neill, Jenna L; Moustafa, Farah; Teague, Daniel; Huang, William W

    2014-01-01

    Subcutaneous sarcoidosis is a rare variant of cutaneous sarcoidosis, which typically presents as single or multiple, indurated, ill-defined plaques, typically on the upper extremities. Granulomas consisting of macrophages with multinucleated giant cells and sparse lymphocytic inflammation are confined to the subcutaneous tissue, rather than to their usual location within the dermis in typical lesions of cutaneous sarcoidosis. An association between subcutaneous sarcoidosis and systemic involv...

  18. Hydrogen Bonds Involving Metal Centers

    OpenAIRE

    Pavlović, G.; Raos, N.

    2006-01-01

    Hydrogen bonds involving metal center as a hydrogen donor or hydrogen acceptor are only a specific type of metal-hydrogen interactions; it is therefore not easy to differentiate hydrogen bond from other metal-hydrogen interactions, especially agostic ones. The first part of the review is therefore devoted to the results of structural chemistry and molecular spectroscopy (NMR, IR), as a tool for differentiating hydrogen bondings from other hydrogen interactions. The classical examples of Pt···...

  19. Cardiac involvement in tuberous sclerosis.

    OpenAIRE

    Mühler, E G; Turniski-Harder, V; Engelhardt, W.; von Bernuth, G

    1994-01-01

    OBJECTIVE--To assess the incidence, importance, and history of cardiac involvement in infants and children with tuberous sclerosis. DESIGN--Prospective study; clinical examination, sector and Doppler echocardiography, standard and ambulatory electrocardiography. SETTING--A tertiary referral centre. PATIENTS--21 patients with tuberous sclerosis aged 1 day to 16 years (mean 6.3 years); follow up investigations were available in 14 cases (10 retrospective, 4 prospective; mean follow up 4.3 years...

  20. Cardiac involvement in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    V. De Gennaro Colonna

    2011-06-01

    Full Text Available Rheumatoid arthritis (RA is a systemic disease of unknown etiology characterized by a chronic inflammatory process mainly leading to destruction of synovial membrane of small and major diarthrodial joints. The prevalence of RA within the general adult population is about 1% and female subjects in fertile age result mostly involved. It’s an invalidating disease, associated with changes in life quality and a reduced life expectancy. Moreover, we can observe an increased mortality rate in this population early after the onset of the disease. The mortality excess can be partially due to infective, gastrointestinal, renal or pulmonary complications and malignancy (mainly lung cancer and non- Hodgkin lymphoma. Among extra-articular complications, cardiovascular (CV involvement represents one of the leading causes of morbidity and mortality. Every cardiac structure can be affected by different pathogenic pathways: heart valves, conduction system, myocardium, endocardium, pericardium and coronary arteries. Consequently, different clinical manifestations can be detected, including: pericarditis, myocarditis, myocardial fibrosis, arrhythmias, alterations of conduction system, coronaropathies and ischemic cardiopathy, valvular disease, pulmonary hypertension and heart failure. Considering that early cardiac involvement negatively affects the prognosis, it is mandatory to identify high CV risk RA patients to better define long-term management of this population.

  1. 25,27-二(α,γ-二酮苯丁氧基)-26,28-二羟基杯[4]芳烃的合成%Synthesis of 25,27-di(α,γ-diketophenylbutoxy)-26,28-dihydroxy calix[4]arene

    Institute of Scientific and Technical Information of China (English)

    罗再刚; 马超; 徐雪梅; 张晓梅

    2013-01-01

      以对叔丁基杯[4]芳烃为原料脱除叔丁基得到杯[4]芳烃,再经醚化、缩合两步反应首次合成25,27-二(α,γ-二酮苯丁氧基)-26,28-二羟基杯[4]芳烃,其结构经1 H NMR、13 C NMR、MS及元素分析表征。研究表明,目标化合物中的α,γ-二酮结构存在酮醇异构现象,在溶液中其酮醇异构体比例近似为1∶2。%25,27-Di(α,γ-diketophenylbutoxy)-26,28-dihydroxy calix[4]arene was synthesized by a two-step reaction of etherifica-tion and condensation from calix [4] arene,which was prepared by p-tert-butylcalyx [4] arene as the raw material via dealkyla-tion.The structure of title compound was characterized by 1 H NMR,13 C NMR,MS and elemental analysis.The results also indicated that keto-enol tautomerism of the α,γ-diketo motif of the title compound was observed and the ratio of the keto-enol isomer approxi-mately was 1:2.

  2. DHA involvement in neurotransmission process

    Directory of Open Access Journals (Sweden)

    Vancassel Sylvie

    2007-05-01

    Full Text Available The very high enrichment of the nervous system in the polyunsaturated fatty acids, arachidonic (AA, 20: 4n-6 and docosahexaenoic acids (DHA, 22: 6n-3, is dependant of the dietary availability of their respective precursors, linoleic (18: 2n-6 and_-linolenic acids (18: 3n-3. Inadequate amounts of DHA in brain membranes have been linked to a wide variety of abnormalities ranging from visual acuity and learning irregularities, to psychopathologies. However, the molecular mechanisms involved remain unknown. Several years ago, we hypothesized that a modification of DHA contents of neuronal membranes by dietary modulation could change the neurotransmission function and then underlie inappropriate behavioural response. We showed that, in parallel to a severe loss of brain DHA concomitant to a compensatory substitution by 22:5n-6, the dietary lack of α-linolenic acid during development induced important changes in the release of neurotransmitters (dopamine, serotonin, acetylcholine in cerebral areas specifically involved in learning, memory and reward processes. Data suggested alteration of presynaptic storage process and dysregulations of reciprocal functional interactions between monoaminergic and cholinergic pathways. Moreover, we showed that recovery of these neurochemical changes was possible when the deficient diet was switched to a diet balanced in n-3 and n-6 PUFA before weaning. The next step is to understand the mechanism involved. Particularly, we focus on the study of the metabolic cooperation between the endothelial cell, the astrocyte and the neuron which regulate synaptic transmission.These works could contribute to the understanding of the link between some neuropsychiatric disorders and the metabolism of n-3 PUFA, through their action on neurotransmission.

  3. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H;

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...... of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal...

  4. Skeletal muscle involvement in cardiomyopathies.

    Science.gov (United States)

    Limongelli, Giuseppe; D'Alessandro, Raffaella; Maddaloni, Valeria; Rea, Alessandra; Sarkozy, Anna; McKenna, William J

    2013-12-01

    The link between heart and skeletal muscle disorders is based on similar molecular, anatomical and clinical features, which are shared by the 'primary' cardiomyopathies and 'primary' neuromuscular disorders. There are, however, some peculiarities that are typical of cardiac and skeletal muscle disorders. Skeletal muscle weakness presenting at any age may indicate a primary neuromuscular disorder (associated with creatine kinase elevation as in dystrophinopathies), a mitochondrial disease (particularly if encephalopathy, ocular myopathy, retinitis, neurosensorineural deafness, lactic acidosis are present), a storage disorder (progressive exercise intolerance, cognitive impairment and retinitis pigmentosa, as in Danon disease), or metabolic disorders (hypoglycaemia, metabolic acidosis, hyperammonaemia or other specific biochemical abnormalities). In such patients, skeletal muscle weakness usually precedes the cardiomyopathy and dominates the clinical picture. Nevertheless, skeletal involvement may be subtle, and the first clinical manifestation of a neuromuscular disorder may be the occurrence of heart failure, conduction disorders or ventricular arrhythmias due to cardiomyopathy. ECG and echocardiogram, and eventually, a more detailed cardiovascular evaluation may be required to identify early cardiac involvement. Paediatric and adult cardiologists should be proactive in screening for neuromuscular and related disorders to enable diagnosis in probands and evaluation of families with a focus on the identification of those at risk of cardiac arrhythmia and emboli who may require specific prophylactic treatments, for example, pacemaker, implantable cardioverter-defibrillator and anticoagulation. PMID:24149064

  5. Subfascial involvement in glomuvenous malformation

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, Raja; Alomari, Ahmad I.; Chaudry, Gulraiz [Boston Children' s Hospital, Division of Interventional Radiology, Boston, MA (United States); Mulliken, John B. [Boston Children' s Hospital, Division of Plastic Surgery, Boston, MA (United States); Fishman, Steven J. [Boston Children' s Hospital, Department of Surgery, Boston, MA (United States); Kozakewich, Harry P.W. [Boston Children' s Hospital, Department of Pathology, Boston, MA (United States)

    2014-07-15

    Glomuvenous malformation (GVM) is an inherited autosomal dominant trait. The lesions, which appear as bluish nodules or plaque-like cutaneous elevations, are usually tender and more firm than sporadic venous malformations. Conventionally, the lesions are thought to be limited to the cutaneous and subcutaneous tissue planes. The objective was to characterize the depth of involvement of GVM lesions. Magnetic resonance imaging (MRI) findings in GVM were retrospectively evaluated by two radiologists. The signal characteristics, tissue distribution, pattern of contrast enhancement of the lesions in GVM were documented. Thirty patients (19 female) aged 1-35 years (mean 18 years) were diagnosed with GVM based on clinical features (n = 20) and/or histopathological findings (n = 10). The lesions were present in the lower extremity (n = 15), upper extremity (n = 6), cervico-facial region (n = 6), pelvis (n = 2), and chest wall (n = 1). All patients had skin and subcutaneous lesions. Fifty percent of the patients (n = 15) demonstrated subfascial intramuscular (n = 15), intra-osseous (n = 1), and intra-articular involvement (n = 1). Contrary to the conventional belief that GVMs are generally limited to the skin and subcutaneous tissue, deep subfascial extension of the lesions is common. (orig.)

  6. 香豆素杯[4]芳烃的合成及其锌(Ⅱ)配合物的光谱%Synthesis of Coumarin- Calix[ 4 ] arene Derivative and Spectral Properties of Its Zn(Ⅱ) Complex

    Institute of Scientific and Technical Information of China (English)

    王飞; 张晓梅; 徐国财

    2011-01-01

    为探寻对过渡金属离子具有配合作用的新型超分子配体,将杯[4]芳烃经醚化、氨解得到的中间体3与香豆素-3-甲酰氯反应,合成了新的合香豆素片段的杯[4]芳烃配体H2L,用1 HNMR、13CNMR、IR、MS( Maldi - Tof)表征其结构.H2L与醋酸锌反应,获得了相应锌(Ⅱ)配合物(LZn),元素分析及MS( ESI)分析结果表明,LZn的化学组成为L(ZnAc)2·2H2O.研究了锌(Ⅱ)配合物的UV和IR吸收光谱性质,还测定了它的荧光强度.结果表明,与H2L相比,锌(Ⅱ)配合物分子中共轭体系增大且平面刚性增加.%In order to seek a new supramolecular ligand with the capacity for coordination to transition metal I-ons, a new calix[4]arene derivative H2L with coumarin sections was synthesized by the reaction of coumarin -3 -formyl chloride with intermediater 3 prepared by etherification firstly and then ammonolysis of calix[4]arene, and its structure was characterized by 1HNMR, 13C NMR, IR and MS (Maldi -Tof). Reacting H2L with zinc acetate could produce a Zn(II) complex (LZn) , and the chemical composition of LZn was L(ZnAc)2 · 2H2O determined by elementary analysis and MS (ESI). Using IR and UV, the absorption spectra of LZn were studied, and the fluorescence intensity was examined also. Results showed that conjugation system in LZn was enlarged and plane rigidity increased by comparison with those in H2L.

  7. Impacto en la salud ambiental por efecto de emisiones de dióxido de azufre del Volcán Arenal, en la población de la Fortuna de San Carlos

    Directory of Open Access Journals (Sweden)

    Xinia Alvarado Zeledón

    2006-12-01

    Full Text Available Introducción: Las emisiones de dióxido de azufre (SO2del volcán Arenal representan un riesgo para la salud ambiental en La Fortuna. Se realizó un análisis teórico de las diferentes variaciones en las concentraciones de SO2 del volcán, con posible impacto a la salud de sus pobladores. Estudios teóricos sobre emisión y dispersión de gases volcánicos, así como su impacto potencial a la salud en el país, han sido realizados en 1999 por Morales &Liao (1. Material y métodos: Basados en datos de máxima emisión de SO2 del Arenal (1, se presumen escenarios de diferentes volúmenes de emisión de SO2, a diferentes velocidades de salida, y aplicados a las diferentes clases de condiciones atmosféricas. Para determinar el mecanismo de dispersión del SO2 y sus concentraciones en La Fortuna, se utilizó el modelo Gaussiano con cálculo de penacho y dispersión horizontal a nivel de piso. Resultados: Emisiones de SO2 con caudales inferiores a 190 ton/día no representan riesgo para la salud humana en La Fortuna. Emisiones superiores a 800 ton/día, con velocidades de salida superiores a 40 km/h provocan concentraciones de SO2 cercanas a los 365 µg/m³, (máxima concentración para un período de 24 horas de exposición, para atmósferas tipo A y B. Emisiones de SO2 mayores a 12.000 ton/día, en atmósferas tipos A y B, alcanzan concentraciones entre 1.417 µg/m³ y 4.869 µg/m³. Discusión y conclusiones: Emisiones de SO2 superiores a 800 ton/día, implican un riesgo a la salud de los pobladores de La Fortuna, incluyendo características fatales. Se recomienda implementar monitoreos constantes de las emisiones de SO2, para tomar medidas de protección en La Fortuna en caso de emisiones iguales o mayores a 800 ton/día.

  8. Hirayama Disease with Proximal Involvement.

    Science.gov (United States)

    Kim, Jinil; Kim, Yuntae; Kim, Sooa; Oh, Kiyoung

    2016-10-01

    Hirayama disease is a slowly progressing benign motor neuron disease that affects the distal upper limb. A 29-year-old man visited the hospital with a 1-year history of weakened left proximal upper limb. He was diagnosed with Hirayama disease 9 years ago, while there was no further progression of the muscle weakness afterward. Atrophy and weakness was detected in proximal upper limb muscles. Magnetic resonance imaging and somatosensory evoked potentials were normal. Needle electromyography showed abnormal findings in proximal upper limb muscles. Our patient had Hirayama disease involving the proximal portion through secondary progression. Clinical manifestation and accurate electromyography may be useful for diagnosis. Rare cases with progression patterns as described here are helpful and have clinical meaning for clinicians. PMID:27550499

  9. CHANGE AT CERN - BE INVOLVED

    CERN Multimedia

    2002-01-01

    The encouragement of individual members of staff to contribute to the work of the task forces by making suggestions via the form on the Users'page of the web has been successful. Therefore, as announced by the Director General in his talk to the Staff in April, the management would like staff to continue to be involved in the change process by making further suggestions. Suggestions received will be distributed to the Director(s)/Division Leader(s) concerned, for reply and action where appropriate. The Director General has set up a small Panel that will ensure the proper processing of the ideas and will present a regular overview to the Director General. Members of the Panel are: Jan van der Boon, Vincent Hatton, Karl-Heinz Kissler, Thomas Pettersson, Florian Sonnemann, and Horst Wenninger.

  10. Cutaneous Plasmacytosis with Perineural Involvement

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Brezinski

    2014-01-01

    Full Text Available Importance. Cutaneous and systemic plasmacytosis are rare conditions of unknown etiology with characteristic red-brown skin lesions and a mature polyclonal plasma cell infiltrate within the dermis. Perineural plasma cell infiltrates may be a histologic clue to the diagnosis of cutaneous plasmacytosis. Observations. Our patient had a five-year history of persistent reddish-brown plaques on the neck and trunk without systemic symptoms. Histologic examination showed dermal perivascular and perineural plasma cells with excess lambda light chain expression. Due to decreased quality of life caused by his skin lesions, he was placed on a chemotherapeutic regimen with bortezomib. Conclusions and Relevance. The patient was diagnosed with cutaneous plasmacytosis based on classic histopathology results with a recently characterized pattern of perineural involvement. Bortezomib therapy was initiated to manage his skin eruption, which has not been previously described as a treatment for this chronic condition.

  11. Metronidazole neurotoxicity: Sequential neuroaxis involvement

    Directory of Open Access Journals (Sweden)

    Kyung-Il Park

    2011-01-01

    Full Text Available Neurological manifestation of metronidazole toxicity include neuropathy and encephalopathy. We report a 67-year-old man with progressive painful paresthesias involving all the four limbs of 3 weeks′ duration before admission. He had been treated with metronidazole and cephalosporin for 10 weeks for a hepatic abscess. Five weeks after the symptom onset, he complained of dysarthria and limb ataxia. Magnetic resonance imaging revealed signal abnormalities in the splenium of the corpus callosum and bilateral dentate nuclei. A few hours after brain imaging, the patient exhibited excessive diaphoresis and fluctuation in blood pressure, which resolved within several hours after discontinuation of metronidazole. Whereas his speech returned to near normal within approximately 1 week, a burning sensation was not completely relieved, even 6 months after discharge.

  12. Measuring Purchase‐decision involvement ,

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2014-08-01

    Full Text Available Nowadays, increasing competition is forcing businesses to pay more attention on customer satisfaction providing strong customer services. Increased competition has also increased marketing activities. This paper presents an empirical investigation to determine important factors influencing purchase decision involvement in food industry in city of Tehran, Iran. The study designs a questionnaire in Likert scale, distributes it among 270 experts in food industry and, using principle component (PCA analysis, extracts important group of factors. The questionnaire consists of 27 questions, which is reduced to 23 questions because of sensitivity of the PCA to Skewness of data. Cronbach alpha is calculated as 0.81, which is well above the minimum acceptable level. The results indicate that there were four factors including individual differences, product validation, triggers and dependent behavior influencing purchasing decisions.

  13. Kidney involvement in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    P. Lazzarini

    2011-09-01

    Full Text Available Rheumatoid Arthritis (RA is a widespread disease and its renal involvement, relatively common, is clinically significant because worsens course and mortality of the primary disease. There is still no agreement on the prevalence of renal disorders in RA: data analysis originates from different sources, as death certificates, autopsies, clinical and laboratory findings and kidney biopsies, each with its limitations. Histoimmunological studies on bioptical specimens of patients with RA and kidney damage, led to clarify prevalent pathologies. In order of frequency: glomerulonephritis and amyloidosis (60-65% and 20-30% respectively, followed by acute or chronic interstitial nephritis. Kidney injury during RA includes secondary renal amyloidosis, nephrotoxic effects of antirheumatic drugs and nephropathies as extra-articular manifestations (rheumatoid nephropathy. Amyloidosis affects survival, increases morbidity and is the main cause of end stage renal disease in patients with RA and nephropathy. Strong association between RA activity and amyloidosis needs the use of immunosuppressive and combined therapies, to prevent this complication and reduce risk of dialysis. Long-lasting and combined RA pharmacotherapy involves various renal side effects. In this review we describe NSAIDs and DMARDs (Disease-Modifying Antirheumatic Drugs nephrotoxicity, particularly by gold compounds, D-penicillamine, cyclosporine A and methotrexate. Rare cases of IgA glomerulonephritis during immunomodulating therapy with leflunomide and TNF blocking receptor (etanercept are reported; real clinical significance of this drug-related nephropathy will be established by development of RA treatment. In RA nephropathies, mesangial glomerulonephritis is the most frequent histological lesion (35-60 % out of biopsies from patients with urinary abnormalities and/or kidney impairment, followed by minimal change glomerulopathy (3-14% and p-ANCA positive necrotizing crescentic

  14. Drug hypersensitivity reactions involving skin.

    Science.gov (United States)

    Hausmann, Oliver; Schnyder, Benno; Pichler, Werner J

    2010-01-01

    Immune reactions to drugs can cause a variety of diseases involving the skin, liver, kidney, lungs, and other organs. Beside immediate, IgE-mediated reactions of varying degrees (urticaria to anaphylactic shock), many drug hypersensitivity reactions appear delayed, namely hours to days after starting drug treatment, showing a variety of clinical manifestations from solely skin involvement to fulminant systemic diseases which may be fatal. Immunohistochemical and functional studies of drug-specific T cells in patients with delayed reactions confirmed a predominant role for T cells in the onset and maintenance of immune-mediated delayed drug hypersensitivity reactions (type IV reactions). In these reactions, drug-specific CD4+ and CD8+ T cells are stimulated by drugs through their T cell receptors (TCR). Drugs can stimulate T cells in two ways: they can act as haptens and bind covalently to larger protein structures (hapten-carrier model), inducing a specific immune response. In addition, they may accidentally bind in a labile, noncovalent way to a particular TCR of the whole TCR repertoire and possibly also major histocompatibility complex (MHC)-molecules - similar to their pharmacologic action. This seems to be sufficient to reactivate certain, probably in vivo preactivated T cells, if an additional interaction of the drug-stimulated TCR with MHC molecules occurs. The mechanism was named pharmacological interaction of a drug with (immune) receptor and thus termed the p-i concept. This new concept may explain the frequent skin symptoms in drug hypersensitivity to oral or parenteral drugs. Furthermore, the various clinical manifestations of T cell-mediated drug hypersensitivity may be explained by distinct T cell functions leading to different clinical phenotypes. These data allowed a subclassification of the delayed hypersensitivity reactions (type IV) into T cell reactions which, by releasing certain cytokines and chemokines, preferentially activate and recruit

  15. PULMONARY INVOLVEMENT IN RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    D. V. Bestaev

    2014-01-01

    Full Text Available Rheumatoid arthritis (RA is an autoimmune disease with erosive and destructive polyarthritis and systemic manifestations. Pulmonary involvement (PI is common in RA. With high-resolution computed tomography, the detection rate of PI in RA is as high as 50%. PI is a direct cause of death in 10–20% of patients with RA. Autoimmune mechanisms play a leading part in the development of PI in RA. Under the hypothesis advanced by M. Selman et al., that impaired alveolocyte regeneration processes after injury rather inflammation underlie the pathogenesis of pulmonary fibrosis. The pathological process is triggered by damaged alveolocytes and characterized by the migration and proliferation of fibroblasts and myofibroblasts, the suppressed apoptosis of the latter, and the enhanced activity of pneumofibrosis-stimulating cytokines. This gives rise to remodeling of the extracellular matrix, including destruction of the basement membrane, angiogenesis, and fibrosis. The paper considers the types of lung injury in RA and main methods for diagnosis and therapy.

  16. Palmar involvement in lichen planus

    Directory of Open Access Journals (Sweden)

    Müzeyyen Gönül

    2014-12-01

    Full Text Available Lichen planus (LP, which is clinically characterized by plan, pruritic, violaceous, polygonal papules, is a chronic inflammatory dermatosis with unknown etiology. According to the site of involvement, LP has mucosal (oral, genital, conjunctival, nail, scalp, inverse, palmoplantar subtypes. Palmoplantar lichen planus is a rare, localized variant of LP and does not show the typical clinical features of the disease. Unlike other types of LP, palmoplantar variant is more common in men and usually seen between third and fifth decades of life. Palmoplantar LP has been reported in the literature with several morphological patterns which were characterized by erythematous scaly papules and plaques (most common, punctate keratosis-like, diffuse keratoderma, erosive, hyperkeratotic, ulcerative, petechia and vesicle-like lesions. Because of having variety of clinical appearance, palmoplantar LP may cause difficulty in diagnosis when the only findings are isolated lesions which are seen solely in the palmoplantar regions. Palmoplantar LP shows classic histopathological characteristics of LP and the treatment is similar. Herein, we report a 65-year-old man with hyperkeratotic, erythematous scaly lesions on both palms, especially in the hypotenar and tenar area. Histopathological examination of his lesions revealed typical features of LP.

  17. Flow-injection potentiometry by poly(vinyl chloride)-membrane electrodes with diphosphoryl-dicarboxylicacid-p-tert-butylcalix[4]arene ionophore for the determination of Th(IV) ions.

    Science.gov (United States)

    Mizani, Farhang; Shamsipur, Mojtaba; Yaftian, Mohammad R; Matt, Dominique

    2013-01-01

    A new coated ion-selective electrode for the determination of trace thorium ions by flow-injection potentiometry (FIP) has been developed. A poly(vinyl chloride) (PVC)-based membrane was coated on a graphite electrode. The optimum membrane contained 5 wt% diphosphoryl-dicarboxylicacid-p-tert-butylcalix[4]arene (L) as the ionophore, 59 wt% dioctyl phthalate (DOP), 33 wt% PVC and 3 wt% additive sodium tetraphenylborate. The response was linear from 2.0 × 10(-7) to 1.0 × 10(-2) M with a slope of 13.9 mV decade(-1) and a limit of detection of 9.0 × 10(-8) M. The pH-independent region ranged from 3.15 to 6.5, and the lifetime was longer than 8 weeks when used in the flow injection analysis (FIA) system. Selectivity coefficients for several ions were obtained by the separate solutions method. Results showed that, for all cations used, the selectivity coefficients were in the order of 10(-3), or smaller. The flow cell is simple to construct and free from memory effect problems over long periods of use. The proposed sensor was successfully applied to the direct determination of thorium in both real and synthetic samples.

  18. 杯芳烃衍生物与环糊精空腔间的超分子相互作用%Supramolecular Interaction between the Calix[n]arene Derivatives and the Cavity of Cyclodextrin

    Institute of Scientific and Technical Information of China (English)

    张华承; 郝爱友; 申健

    2008-01-01

      The study of the supramolecular interaction between calix[n]arene derivatives and cavity of cyclodextrin is the base for understanding the host-guest interaction in self-assembling monolayers (SAMs) and is the main subject of molecular printboard. On the other hand, this kind of supramolecular interaction can be applied tof nanotech and is one of the preconditions of the nanofabrications.%  针对杯芳烃衍生物与环糊精空腔间的超分子相互作用的研究是理解自组装单分子层(SAMs)主客体作用的基础,也是“分子印刷板”(molecular printboard)研究的主要内容。另外,这种类型的超分子相互作用可以被应用于纳米技术领域,是研究纳米构建技术的前提之一。

  19. Synthesis and properties of semicarbazide-bridged calix[4]arene derivative%氨基脲桥联杯[4]芳烃衍生物的合成及性能研究

    Institute of Scientific and Technical Information of China (English)

    郑林禄; 杨发福; 刘朝晖

    2013-01-01

      设计并合成了下沿含缩氨脲基和席夫碱基的新型桥联杯[4]芳烃衍生物,经1H NMR、MS和元素分析等表征确证其结构;测定了新型桥联杯[4]芳烃衍生物对金属阳离子和氨基酸分子的两相萃取性能,结果表明新型主体分子通过多官能团的协同作用具有较好的配位性能。%A new bridged calix[4]arene derivative containing semicarbazone groups and Schiff-base groups was designed and synthesized and its structure was confirmed by 1H NMR,MS and element analysis. Their binding properties for metal ions and amino acid were investigated. Experimental results showed that it possessed good extraction capabilities for cations and amino acid based on multifunctional complexation.

  20. Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides: Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

    Directory of Open Access Journals (Sweden)

    Teruo Umemoto

    2012-03-01

    Full Text Available Various arylsulfur pentafluorides, ArSF5, have long been desired in both academic and industrial areas, and ArSF5 compounds have attracted considerable interest in many areas such as medicines, agrochemicals, and other new materials, since the highly stable SF5 group is considered a “super-trifluoromethyl group” due to its significantly higher electronegativity and lipophilicity. This article describes the first practical method for the production of various arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides, from the corresponding diaryl disulfides or aryl thiols. The method consists of two steps: (Step 1 treatment of a diaryl disulfide or an aryl thiol with chlorine in the presence of an alkali metal fluoride, and (step 2 treatment of the resulting arylsulfur chlorotetrafluoride with a fluoride source, such as ZnF2, HF, and Sb(III/V fluorides. The intermediate arylsulfur chlorotetrafluorides were isolated by distillation or recrystallization and characterized. The aspects of these new reactions are revealed and reaction mechanisms are discussed. As the method offers considerable improvement over previous methods in cost, yield, practicality, applicability, and large-scale production, the new processes described here can be employed as the first practical methods for the economical production of various arylsulfur pentafluorides and their higher homologues, which could then open up a new era of “super-trifluoromethyl” arene chemistry and its applications in many areas.

  1. Evaluating Parent Involvement. Issue Paper No. 1.

    Science.gov (United States)

    Safran, Daniel

    This paper poses a series of questions to assist programs in deciding what it is about parent involvement that they wish to evaluate. The questions focus on the nature of parent involvement, why parent involvement is needed, and what evaluation of parent involvement should include. A conceptual framework for research on the impact of parent…

  2. Cardiovascular involvement in psoriatic arthritis

    Directory of Open Access Journals (Sweden)

    V. De Gennaro Colonna

    2011-11-01

    Full Text Available Psoriasis is a chronic, genetically determined and immunomediated inflammatory skin disease that affects 2-3% of the Caucasian population. A considerable proportion of these patients develop a form of inflammatory arthritis known as psoriatic arthritis (PsA, although the prevalence of this has not been well defined. Patients with PsA have a higher mortality rate than the general population and the risk of mortality is related to disease severity at the time of presentation. Endothelial dysfunction and early atherosclerosis have been found in patients with PsA without any cardiovascular disease (CVD risk factors, and experts believe that CVD is one of the leading causes of death, as it is in patients with rheumatoid arthritis (RA. Various disease-related mechanisms may be involved in the development of premature vascular damage in both cases, including an increased synthesis of proinflammatory mediators (such as cytokines, chemokines and adhesion molecules, autoantibodies against endothelial cell components, perturbations in T-cell subsets, genetic polymorphisms, hyperhomocysteinemia, oxidative stress, abnormal vascular repair, and iatrogenic factors. In a recent study of 22 patients with PsA without any signs of CVD, we found that the plasma concentration of asymmetric dimethylarginine (ADMA levels were significantly high and coronary flow reserve (CFR was significantly reduced. Moreover, there was a significant correlation between CFR and plasma ADMA levels in the PsA group. The significant correlation between the reduced CRF and increased ADMA levels suggests that, like patients with early RA, PsA patients suffer from endothelial dysfunction and impaired coronary microcirculation. Active PsA is a risk factor for CVD, and so PsA patients should be screened for subclinical forms of the disease and its risk factors, and an early treatment approach should be adopted.

  3. Temporal relationships between the variations of diffuse gaseous emanations and the explosive activity of some active volcanoes of Costa-Rica, examples at the Arenal, Irazu and at the Rincon de la Vieja; Relations temporelles entre les variations des emanations gazeuses diffuses et l`activite explosive de quelques volcans actifs du Costa-Rica, exemples a l`Arenal, l`Irazu et au Rincon de la Vieja

    Energy Technology Data Exchange (ETDEWEB)

    Baubron, J.C. [BRGM, 45 - Orleans (France); Allard, P. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Direction des Sciences de la Matiere; Fernandez, E. [Obviscori, Heridia (Costa Rica); Hammouya, G. [Observatoire de la Soufriere, IPG-P, le Houelmont, 97 - Gourgeyre (France); Soto, G.J. [ICE, San Jose (Costa Rica)

    1996-12-31

    The surveillance of the temporal evolution of radon and helium concentrations in the carbon dioxide of crater fumaroles and gaseous emanations is performed since 1992 on the Irazu, Arenal, Poas and Rincon de la Vieja volcanoes in Costa-Rica. The {sup 3}He/{sup 4}He ratio is used as an indicator of the deep origin of the volcanic gas while radon is an indicator of the CO{sub 2} flux. Radon measurements performed on the Irazu show a continuous decay of radon concentration in the intra-crater fumaroles with an important increase of the gaseous flux since 1992. On the contrary, the external fumaroles on the NW flank were characterized by an important increase in radon concentration in 1994 with a stable flux. The radon surveillance performed in soils around the volcano has shown an intense increase of the diffuse gaseous flows probably linked to the micro-seismic activity of the volcano. Similar observations are reported for the Rincon de la Vieja volcano and correlated with its eruptive history and its phreatic and phreato-magmatic activity. Short paper. (J.S.).

  4. Quality assurance - how to involve the employees

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    1996-01-01

    An overview of strategies for involvement of employees in quality assurance developement and implementation.......An overview of strategies for involvement of employees in quality assurance developement and implementation....

  5. Levels of Audience Involvement in Participation Theatre.

    Science.gov (United States)

    Jones, Claire

    1982-01-01

    Analyzes levels of audience involvement in participation theater: (1) instruction, (2) direct contact, (3) independent creative, (4) contribution of ideas, (5) representative involvement, (6) decision making, (7) story control, and (8) spontaneous involvement. Contends that participation plays help a child develop into a responsive adult audience…

  6. 36 CFR 1010.12 - Public involvement.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Public involvement. 1010.12 Section 1010.12 Parks, Forests, and Public Property PRESIDIO TRUST ENVIRONMENTAL QUALITY § 1010.12 Public involvement. The Trust will make public involvement an essential part of its environmental review...

  7. 7-Amino-5-methyl-2-phenyl-6-(phenyl­diazenyl)pyrazolo[1,5-a]pyrimidine crystallizes with Z′ = 2: pseudosymmetry and the formation of complex sheets built from N—H⋯N and C—H⋯π(arene) hydrogen bonds

    OpenAIRE

    Portilla, Jaime; Estupiñan, Diego; Cobo, Justo; Glidewell, Christopher

    2010-01-01

    The title compound, C19H16N6, crystallizes with Z′ = 2 in the space group P21/n. The two mol­ecules in the selected asym­metric unit are approximate mirror images of one another; most corresponding pairs of atoms are related by an approximate half-cell translation along [100]. Each mol­ecule contains an intra­molecular N—H⋯N hydrogen bond and the mol­ecules are linked into complex sheets by a combination of two inter­molecular N—H⋯N and four C—H⋯π(arene) hydrogen bonds. Comparisons are made w...

  8. 杯[4]芳烃磺酸钠催化合成乙酸正丁酯%Synthesis of n-Butyl Acetate Using Calix[4]arene Sulfonic Acid Sodium as a Catalyst

    Institute of Scientific and Technical Information of China (English)

    刘丽梅; 张岱良; 陈平

    2014-01-01

    以杯[4]芳烃磺酸钠为催化剂,以乙酸与正丁醇为原料,通过酯化反应合成乙酸正丁酯,考察了催化剂用量、原料配比和反应时间对酯化反应的影响,产品进行折光指数检测。结果表明,杯[4]芳烃磺酸钠作为催化剂,乙酸物质的量为0.1 mol,醇酸物质的量比为1.2,催化剂质量为1 g,反应时间为4 h时,酯化率可达81.41%,杯[4]芳烃磺酸钠可以重复使用多次。%Calix[4]arene Sulfonic Acid Sodium was used as a non homogenous catalyst for synthesis of n-Butyl acetate using acetic acid and n-butyl alcohol as raw materials.The effects of reaction conditions,such as the quantity of catalyst,the ratio of the reactants and reaction time were discussed respectively.The product was characterized by index of refraction.The suitable conditions for the reaction were as follows:acetic acid 0.1 mol,molar ratio of n-butyl alcohol to acetic acid 1.2,catalyst amout 1 g,reaction time 4 h,the yield of n-butyl acetate can reach 81.41%.The catalyst could be used repeatedly keeping its initial activity.

  9. Synthesis and Performances of a New Ag+-selective Fluorescent Sensor Based on Calix[4] arene%基于杯[4]芳烃的银离子荧光探针的合成及性能

    Institute of Scientific and Technical Information of China (English)

    王炜; 何松; 陆燕; 曾宪顺

    2012-01-01

    合成了25,27-二羟基-26,28-二{ 3-[N-(2-萘基)-2-硫代乙酰胺]丙氧基}-5,11,17,23-四叔丁基杯[4]芳烃(2),并利用荧光光谱考察了其在乙醇-水混合溶液中对Ag+的光谱选择性.结果表明,含有S2O2结合位点的探针分子2对Ag+具有良好的选择性.通过荧光光谱连续滴定测得探针分子2-Ag+体系的猝灭常数为3.39×103 L/mol,探针分子对Ag+的检出限可达2.34×10-7 mol/L.在实际的Ag+检测中,探针分子2具有一定的应用前景.%A new calix[4]arene derivative 2 with naphthalene fluorophores at the lower rim was synthesized. The chemosensing behavior of the host compound 2 for metal ions was investigated by fluorescence spectra. The results revealed that chemosensor 2 containing S2O2 atoms as soft donors had a good selectivity towards Ag+ ion. It exhibits high sensitivity toward Ag+ over a wide range of metal ions in C2H5OH/H2O(3 : 2, volume ratio). The fluorescence quenching behavior was observed under binding of the Ag+ with a detection limit of 2. 34 ×10-7 mol/L.

  10. Brainstem involvement in subacute sclerosing panencephalitis

    Directory of Open Access Journals (Sweden)

    Pawan Sharma

    2011-01-01

    Full Text Available The parieto-occipital region of the brain is most frequently and severely affected in subacute sclerosing panencephalitis (SSPE. The basal ganglia, cerebellum and corpus callosum are less commonly involved. Brainstem involvement is rarely described in SSPE, and usually there is involvement of other regions of the brain. We describe a patient with subacute sclerosing panencephalitis with brain magnetic resonance imaging showing extensive brainstem involvement without significant involvement of other cortical structures. Though rarely described in SSPE, one should be aware of such brainstem and cerebellum involvement, and SSPE should be kept in mind when brainstem signal changes are seen in brain MRI with or without involvement of other regions of brain to avoid erroneous reporting.

  11. Patient involvement in Danish health care

    DEFF Research Database (Denmark)

    Vrangbaek, Karsten

    2015-01-01

    for analysis of patient involvement in health care. This framework is used to analyze key governance features of patient involvement in Denmark based on previous research papers and reports describing patient involvement in Danish health care. FINDINGS: Patient involvement is important in Denmark...... be identified when pursuing the strategies at the same time. RESEARCH LIMITATIONS/IMPLICATIONS: Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed framework further. PRACTICAL IMPLICATIONS: The paper includes...... implications for the development of patient involvement in health care. ORIGINALITY/VALUE: This paper fulfills a need to study different types of patient involvement and to develop a theoretical framework for characterizing and analyzing such involvement strategies....

  12. Half-sandwich (6-arene)ruthenium(II) chiral Schiff base complexes: Analysis of the diastereomeric mixtures in solution by 2D-NMR spectroscopy

    Indian Academy of Sciences (India)

    Rakesh K Rath; G A Nagana Gowda; Akhil R Chakravarty

    2002-10-01

    2D NMR spectroscopy has been used to determine the metal configuration in solution of three complexes, viz. [($\\eta^6$--cymene)Ru(L∗)Cl] (1) and [(6--cymene)Ru(L∗)(L')] (ClO4) (L' = H2O, 2; PPh3, 3), where L∗ is the anion of ()-(1-phenylethyl)salicylaldimine. The complexes exist in two diastereomeric forms in solution. Both the (Ru, C)- and (Ru, C)-diastereomers display the presence of attractive CH/ interaction involving the phenyl group attached to the chiral carbon and the cymene ring hydrogens. This interaction restricts the rotation of the C∗-N single bond and, as a result, two structural types with either the hydrogen atom attached to the chiral carbon (C∗) or the methyl group attached to C∗ in close proximity of the cymene ring protons get stabilized. Using 2D NMR spectroscopy as a tool, the spatial interaction involving these protons are studied in order to obtain the metal configuration(s) of the diastereomeric complexes in solution. This technique has enabled us to determine the metal configuration as (Ru, C) for the major isomers of 1-3 in solution.

  13. Top Management Involvement in New Product Development

    DEFF Research Database (Denmark)

    Felekoglu, Burcu; Maier, Anja; Moultrie, James

    2010-01-01

    antecedents, realisation and consequences of top management involvement in NPD. It is argued that top management has different involvement at different NPD levels: organisation level and project level. Resulting from this literature review, a tentative framework for top management involvement in NPD......Involvement of top managers in new product development (NPD) is a critical factor affecting NPD performance and frequently considered to be the participation of top management to certain activities in NPD or their NPD related behaviours. However, “Top management involvement in NPD” occupies...... a broader conceptual space than this participation. This paper reviews the literature on top management involvement in new product development (NPD) and discusses relevance of different theoretical perspectives from other disciplines such as management, organisational behaviour and communication to analyse...

  14. Nail involvement in mycosis fungoides: brief report

    OpenAIRE

    Amir Houshang Ehsani; Fatemeh Gholamali; Mahboubeh Sadat Hosseini; Mojgan Nouri; Pedram Noormohammadpour

    2014-01-01

    Background: Mycosis fungoides (MF) is the commonest T-Cell lymphoma (CTCL) involving skin and its appendages to variable degrees. Nail involvement is one of multiple dermatologic manifestation of this disorder and could have negative impact on psychological status of patients and producing therapeutic challenge to physician. We aimed to evaluate prevalence and subtypes of nail involvement in MF patients attending dermatology clinic, Razi Hospital in Tehran, Iran. Methods: All patients havi...

  15. The Gaming Involvement and Informal Learning Framework

    OpenAIRE

    Iacovides, Ioanna; McAndrew, Patrick; Scanlon, Eileen; Aczel, James

    2014-01-01

    Aim. This article presents a model of how gaming involvement and informal learning come together in practice. Method. Based on a series of interviews, case studies, and a wider survey, the Gaming Involvement and Informal Learning (GIIL) framework indicates how involvement with a variety of gaming practices can lead to a range of different learning experiences. Results. The framework is able to account for both how and what people learn from gaming while also highlighting the inf...

  16. Disseminated cysticercosis with pulmonary and cardiac involvement

    OpenAIRE

    Jain Bharat; Sankhe Shilpa; Agrawal Mukta; Naphade Prashant

    2010-01-01

    Pulmonary and cardiac involvement by cysticercosis is extremely rare, and is usually asymptomatic. We report the case of a 19-year-old boy who presented with a history of headache and vomiting and was found to have disseminated cysticercosis with pulmonary and cardiac involvement; the emphasis is on the rare occurrence of pulmonary, cardiac, pancreatic, intraocular, and extradural spinal canal involvement in the same patient. This case demonstrates the extent to which cysticercosis can be dis...

  17. Dual Headquarters Involvement in Subsidiary Innovation

    DEFF Research Database (Denmark)

    Dellestrand, Henrik; Kappen, Philip; Nell, Phillip Christopher

    2014-01-01

    innovation importance, i.e., an innovation that is important for the division and the corporate level, drives dual headquarters involvement in innovation development. Contrary to expectations, no significant effect of dual embeddedness on dual headquarters involvement is found. The network size......The strategy and international business literature has identified the overall potential for headquarters to add value by allocating resources to subsidiary activities, but little is known about the extent to which multiple headquarters simultaneously involves itself in subsidiary operations...

  18. Liver involvement in Langerhans cell histiocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Adelaine; Ortiz-Neira, Clara L.; Abou Reslan, Walid; Kaura, Deepak [Alberta Children' s Hospital, Department of Diagnostic Imaging, Calgary, Alberta (Canada); Sharon, Raphael; Anderson, Ronald [Alberta Children' s Hospital, Department of Oncology, Calgary, AB (Canada); Pinto-Rojas, Alfredo [Alberta Children' s Hospital, Department of Pathology, Calgary, AB (Canada)

    2006-10-15

    Liver involvement in Langerhans cell histiocytosis (LCH) typically presents with hepatomegaly and other signs of liver dysfunction. We present an 11-month-old child having only minimally elevated liver enzymes as an indication of liver involvement. Using sonography as the initial diagnostic tool followed by MRI, LCH of the liver was revealed. A review of sonographic, CT, MRI and MR cholangiopancreatography findings in liver LCH is presented. We recommend that physicians consider sonography and MRI screening for liver involvement in patients with newly diagnosed LCH, as periportal involvement may be present with little or no liver function abnormality present, as in this patient. (orig.)

  19. Liver involvement in Langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Liver involvement in Langerhans cell histiocytosis (LCH) typically presents with hepatomegaly and other signs of liver dysfunction. We present an 11-month-old child having only minimally elevated liver enzymes as an indication of liver involvement. Using sonography as the initial diagnostic tool followed by MRI, LCH of the liver was revealed. A review of sonographic, CT, MRI and MR cholangiopancreatography findings in liver LCH is presented. We recommend that physicians consider sonography and MRI screening for liver involvement in patients with newly diagnosed LCH, as periportal involvement may be present with little or no liver function abnormality present, as in this patient. (orig.)

  20. Nail Involvement in Frontal Fibrosing Alopecia

    OpenAIRE

    Macpherson, Melanie; Hohendorf-Ansari, Parinaz; Trüeb, Ralph Michel

    2015-01-01

    A case of frontal fibrosing alopecia with nail involvement is presented. Nail involvement provides evidence for underlying lichen planus, and that the disease represents a rather generalized than localized process. Favorable response of the scalp condition to oral dutasteride points to an inflammatory reaction on the background of androgenetic alopecia.

  1. Bullying Prevention and the Parent Involvement Model

    Science.gov (United States)

    Kolbert, Jered B.; Schultz, Danielle; Crothers, Laura M.

    2014-01-01

    A recent meta-analysis of bullying prevention programs provides support for social-ecological theory, in which parent involvement addressing child bullying behaviors is seen as important in preventing school-based bullying. The purpose of this manuscript is to suggest how Epstein and colleagues' parent involvement model can be used as a…

  2. Strategic Management: Managing Change by Employee Involvement

    Directory of Open Access Journals (Sweden)

    Dr. Fareeha Zafar

    2014-05-01

    Full Text Available Strategic management attempts to link strategic planning with decision making and these decisions implementation. The role of involvement -who should be involved and how that involvement should be managed is essential for effectual decision making. This paper scrutinizes the significance of involvement in decision making generally and demonstrate how involvement management principles apply to the strategic management process explicitly. Strategic management composed of three important steps: creation of a documented plan, making strategic planning an effectual part of the management systems, and appropriately manage involvement in the planning process. It requires that an organization's managers must be involved in a process of objectives identification, strategies development and implementation plans to accomplish those objectives, and sporadically evaluate the decisions implementation of decisions. Decision making, implementation, feedback, and evaluation; is a continuous process. Basically, effective decision making and implementation means congregating the right mix of people, convincing them that what they are doing is significant to the senior executive, and effectively managing their involvement in the decision making process. This paper provides some proven techniques that add value to many organizations.

  3. Involving Migrant Families in Education. ERIC Digest.

    Science.gov (United States)

    Martinez, Yolanda G.; Velazquez, Jose A.

    This digest describes parent involvement in their children's education from the perspective of migrant parents and educators and offers strategies to enhance the experience of schooling for migrant students and their families. Teachers often perceive parent involvement as preparing children for school, attending school events, and fulfilling…

  4. Peer Involvement in Adolescent Dating Violence

    Science.gov (United States)

    Stephenson, Pam S.; Martsolf, Donna; Draucker, Claire Burke

    2013-01-01

    This study investigated the ways in which peers are involved in adolescent dating violence. Eighty-eight young adults aged 18-21 were interviewed and asked to reflect on aggressive dating relationships they experienced as teens. The researchers used grounded theory to analyze the data. Findings showed that male and female peers were involved in…

  5. Defining stakeholder involvement in participatory design processes

    NARCIS (Netherlands)

    Vink, P.; Imada, A.S.; Zink, K.J.

    2008-01-01

    A participatory approach could be used to implement work place or organizational improvements. However, the question is which participants should be involved and how. In this paper the theoretical involvement in different steps of a linear stepwise approach is described and compared with the latest

  6. Involving fathers in psychology services for children

    OpenAIRE

    Carr, Alan

    2006-01-01

    This paper is a commentary on five papers in a special series on father-involvement in child psychology services. The following themes are addressed: the effects of fathers on child development; benefits of father-involvement in child psychology services; obstacles to fatherinvolvement ; engaging fathers; specific interventions for fathers; and implications for service development, training and research.

  7. Citizen Involvement in Local Security Networks

    NARCIS (Netherlands)

    Terpstra, J.B.

    2009-01-01

    This paper deals with the involvement of citizens (and local businesspersons) in the prevention and control of crime and disorder. Four models of citizen involvement in local security networks are distinguished. In each of these models the role of citizens concentrates on different functions: (1) p

  8. Macrodystrophia lipomatosa of foot involving great toe.

    Science.gov (United States)

    Gaur, A K; Mhambre, A S; Popalwar, H; Sharma, R

    2014-06-01

    Macrodystrophia lipomatosa is a rare form of congenital disorder in which there is localized gigantism characterized by progressive overgrowth of all mesenchymal elements with a disproportionate increase in the fibroadipose tissues. The adipose tissue infiltration involves subcutaneous tissue, periosteum, nerves and bone marrow. Most of the cases reported have hand or foot involvement. Patient seeks medical help for improving cosmesis or to get the size of the involved part reduced in order to reduce mechanical problems. We report a case of macrodystrophia lipomatosa involving medial side of foot with significant enlargement of great toe causing concern for cosmesis and inconvenience due to mechanical problems. The X-rays showed increased soft tissue with more of adipose tissue and increased size of involved digits with widening of ends. Since the patient's mother did not want any surgical intervention he was educated about foot care and proper footwear design was suggested.

  9. Supporting Active User Involvment in Prototyping

    DEFF Research Database (Denmark)

    Grønbæk, Kaj

    1990-01-01

    development of prototypes to early evaluation of prototypes in envisioned use situations. Having users involved in such activities creates new requirements for tool support. Tools that support direct manipulation of prototypes and simulation of behaviour have shown promise for cooperative prototyping......The term prototyping has in recent years become a buzzword in both research and practice of system design due to a number of claimed advantages of prototyping techniques over traditional specification techniques. In particular it is often stated that prototyping facilitates the users' involvement...... in the development process. But prototyping does not automatically imply active user involvement! Thus a cooperative prototyping approach aiming at involving users actively and creatively in system design is proposed in this paper. The key point of the approach is to involve users in activities that closely couple...

  10. Macrodystrophia lipomatosa of foot involving great toe.

    Science.gov (United States)

    Gaur, A K; Mhambre, A S; Popalwar, H; Sharma, R

    2014-06-01

    Macrodystrophia lipomatosa is a rare form of congenital disorder in which there is localized gigantism characterized by progressive overgrowth of all mesenchymal elements with a disproportionate increase in the fibroadipose tissues. The adipose tissue infiltration involves subcutaneous tissue, periosteum, nerves and bone marrow. Most of the cases reported have hand or foot involvement. Patient seeks medical help for improving cosmesis or to get the size of the involved part reduced in order to reduce mechanical problems. We report a case of macrodystrophia lipomatosa involving medial side of foot with significant enlargement of great toe causing concern for cosmesis and inconvenience due to mechanical problems. The X-rays showed increased soft tissue with more of adipose tissue and increased size of involved digits with widening of ends. Since the patient's mother did not want any surgical intervention he was educated about foot care and proper footwear design was suggested. PMID:24703060

  11. Hydrogenation of arenes and N-heteroaromatic compounds over ruthenium nanoparticles on poly(4-vinylpyridine): a versatile catalyst operating by a substrate-dependent dual site mechanism.

    Science.gov (United States)

    Fang, Minfeng; Machalaba, Nataliya; Sánchez-Delgado, Roberto A

    2011-10-28

    A nanostructured catalyst composed of Ru nanoparticles immobilized on poly(4-vinylpyridine) (PVPy) has been synthesized by NaBH(4) reduction of RuCl(3)·3H(2)O in the presence of the polymer in methanol at room temperature. TEM measurements show well-dispersed Ru nanoparticles with an average diameter of 3.1 nm. Both powder XRD patterns and XPS data indicate that the Ru particles are predominantly in the zerovalent state. The new catalyst is efficient for the hydrogenation of a wide variety of aromatic hydrocarbons and N-heteroaromatic compounds representative of components of petroleum-derived fuels. The experimental data indicate the existence of two distinct active sites in the nanostructure that lead to two parallel hydrogenation pathways, one for simple aromatics involving conventional homolytic hydrogen splitting on Ru and a second one for N-heteroaromatics taking place via a novel heterolytic hydrogen activation on the catalyst surface, assisted by the basic pyridine groups of the support. PMID:21850360

  12. 以杯[4]芳烃为母体的新型电子传输材料及其OPC的特性%A Novel Electron Transport Material Based on Calix[4]arene and Its Properties as OPC

    Institute of Scientific and Technical Information of China (English)

    吴倜; 王文广; 张伟民; 蒲嘉陵

    2004-01-01

    It designed and prepared a series of new electron transport molecules, i.e., a ring-structured diphenoquione based on calix[ 4 ] arene(termed as, hereinafter, ring-structured ETM). And, molecular structure was confirmed by using CTL, IR, NMR, MS and so on. Single-layered multi-component OPC devices were made by incorporating the ring-structured ETM with properly chosen HTM and CGM, and their xerographic performances were systematically investigated. Experimental results indicated that molecules with two diphenoquione units, isopropyl group and p-propyl ether group were of good solubility in common organic solvents, excellent compatibility with polymers, such as PC and Vylon200(a polyester) and enabled doping at high concentrations,say, over 40wt%. In addition, the new ring-structured ETM showed improved performances over TNF and was characterized of better xerographic properties at relatively low concentrations.%设计并合成制备了一系列环化结构的新型电子传输材料:杯[4]芳烃类环化联苯醌化合物(环化结构ETM),并通过CTL、IR、核磁、质谱等手段确认了分子结构.用环化结构ETM与空穴传输材料和电荷产生材料配合,制作了多组分单层结构有机光导体,并对其静电照相性能进行了全面考察.实验结果表明,分子结构中带有两个联苯醌单元、取代基为异丙基以及环对位丙醚化的环化结构ETM在常规有机溶剂中具有良好的溶解度,与树脂PC和Vylon200(一种聚酯)的相容性良好,均可以实现40wt%及以上的高浓度掺杂.并且,这种新型的环化结构ETM的整体性能优于TNF,而且可以在较低掺杂浓度下,实现良好的静电照相性能.

  13. Comparing Methods for Involving Users in Ideation

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Scupola, Ada; Sørensen, Flemming

    2015-01-01

    In this paper we discuss how users may be involved in the ideation phase of innovation. The study compares the use of a blog and three future workshops (students, employees and a mix of the two) in a library. Our study shows that the blog is efficient in giving the users voice whereas the mixed...... workshop method (involving users and employees) is especially good at qualifying and further developing ideas. The findings suggest that methods for involving users in ideation should be carefully selected and combined to achieve optimum benefits and avoid potential disadvantages....

  14. Comparing Methods for Involving Users in Ideation

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Scupola, Ada; Sørensen, Flemming

    2015-01-01

    In this paper we discuss how users may be involved in the ideation phase of innovation. The study compares the use of a blog and three future workshops (students, employees and a mix of the two) in a library. Our study shows that the blog is efficient in giving the users voice whereas the mixed w...... workshop method (involving users and employees) is especially good at qualifying and further developing ideas. The findings suggest that methods for involving users in ideation should be carefully selected and combined to achieve optimum benefits and avoid potential disadvantages....

  15. Pediatric Neurocutaneous Syndromes with Cerebellar Involvement.

    Science.gov (United States)

    Bosemani, Thangamadhan; Huisman, Thierry A G M; Poretti, Andrea

    2016-08-01

    Neurocutaneous syndromes encompasses a broad group of genetic disorders with different clinical, genetic, and pathologic features that share developmental lesions of the skin as well as central and peripheral nervous system. Cerebellar involvement has been shown in numerous types of neurocutaneous syndrome. It may help or be needed for the diagnosis and to explain the cognitive and behavioral phenotype of affected children. This article describes various types of neurocutaneous syndrome with cerebellar involvement. For each neurocutaneous disease or syndrome, clinical features, genetic, neuroimaging findings, and the potential role of the cerebellar involvement is discussed. PMID:27423801

  16. Dual Headquarters Involvement in Subsidiary Innovation

    DEFF Research Database (Denmark)

    Nell, Phillip Christopher; Kappen, Philip; Dellestrand, Henrik

    . The current paper takes on this neglected question by empirically investigating corporate and divisional headquarters direct involvement in innovation development projects at the subsidiary level. Analyses that draw upon 85 innovation development projects in 23 multinational enterprises reveal that dual...... innovation importance, i.e., an innovation that is important for the division and the corporate level, drives dual headquarters involvement in innovation development. Contrary to expectations, no significant effect of dual embeddedness on dual headquarters involvement is found. The network size...... on headquarters. It appears that multiple headquarters do get involved in specific subsidiary activities and that the theoretical advancements on headquarters should be discussed in the context of their complexity to reflect the nature of the contemporary multinational enterprise....

  17. Actinomycosis involving the chest wall: CT findings

    International Nuclear Information System (INIS)

    Two cases of pulmonary actinomycosis with extension to involve the chest wall that were evaluated using computerized tomography are reported. In both cases, the relation of pulmonary and chest wall disease was best shown using CT

  18. Nurses' political involvement: responsibility versus privilege.

    Science.gov (United States)

    Boswell, Carol; Cannon, Sharon; Miller, Joyce

    2005-01-01

    Nursing apathy toward participation in the political process is pandemic. Never more so than today has the profession needed a strong united stand within the political arena. Political involvement encompasses being knowledgeable about issues, laws, and health policy. Barriers to political activism are thought to encompass several spectra including heavy workloads, feelings of powerlessness, time constraints, sex issues, and lack of understanding of a complex political process. The implementation of a political role for a nurse is based on three levels of commitment including survival, success, and significance. Survival includes individual involvement within communities. Success accepts challenges in addressing injustices especially within the health-care arena. Significant involvement uses visionary nurses toward the betterment of the nurse profession. Strategies for involvement include political awareness, incorporation of course/program expectations on both undergraduate and graduate levels and teamwork. As patient advocates, nurses cannot continue to be spectators in the political arena.

  19. Fires and Burns Involving Home Medical Oxygen

    Science.gov (United States)

    ... nfpa.org Fires and Burns Involving Home Medical Oxygen The air is normally 21% oxygen. Oxygen is not flammable, but fire needs it to burn. ¾ When more oxygen is present, any fire that starts will burn ...

  20. The ethics of medical involvement in torture.

    OpenAIRE

    Downie, R S

    1993-01-01

    The difficulties of establishing a definition of torture are discussed, and a definition is suggested. It is then argued that, irrespective of general ethical questions, doctors in particular should never be involved because of their social role.

  1. EXPLORE SIGNIFICANT FACTORS TO AFFECT CUSTOMER INVOLVEMENT

    Directory of Open Access Journals (Sweden)

    Yu-Jia Hu

    2012-01-01

    Full Text Available Although literature review supported the concept that customer loyalty, brand equity and perceived risk are significant factors to affect customer involvement, very limited studies have extensively examined the relationship among those variables. This research applied quantitative study to comprehensively explore the relationship between customer loyalty, brand equity, perceived risk and customer involvement for consumers. The population for this research was identified as consumers having the shopping experience for digital camera. The findings supported the hypothesis that customer loyalty, brand equity and perceived risk have significant and positive relationship to customer involvement. The findings identified the predictors of customer loyalty, brand equity and perceived risk on the customer involvement and generated the recommendations for corporate operations and future scholar studies.

  2. Fatal incidents involving pickup trucks in Alabama.

    Science.gov (United States)

    Hamar, G B; King, W; Bolton, A; Fine, P R

    1991-03-01

    Death or injury resulting from crashes involving light trucks (ie, pickup trucks) is a significant problem. Data show that fatal crashes and occupant fatalities involving light trucks have steadily increased since 1983. This project describes vehicle crashes involving passengers riding in the beds of pickup trucks. Actual crashes were identified through the Fatal Accident Reporting System (FARS) of the National Highway Traffic Safety Administration. The 40 incidents studied involved 204 pickup truck passengers. Of these, 45 were killed, 107 sustained visible injuries or were carried from the scene, 6 had bruises and abrasions, and 2 had no visible injury but were briefly unconscious or had a documented complaint of pain. The risk of death among pickup truck passengers who were fully ejected from the vehicle was nearly six times that of passengers not fully ejected. Correspondingly, the risk of ejection from the truck was 26.7 times greater among occupants riding in the bed than occupants riding in the cab. PMID:2000522

  3. [Unusual muscular involvement in ankylosing spondylitis].

    Science.gov (United States)

    Wattiaux, M J; Rondier, J; Bletry, O; Godeau, P; Cayla, J

    1985-03-01

    Muscle involvement in ankylosing spondylitis has been little studied. The authors report two cases with marked muscular atrophy and functional impotence, which had directed the diagnosis towards a myopathy over a period of several years in the first case, and a suspected primary muscular disease associated with ankylosing spondylitis in the second. Muscle biopsies eliminated the diagnosis of myopathy in both cases, with rapid functional recovery with proper treatment. Following a review of the literature, two hypotheses can be considered to explain the muscular involvement in ankylosing spondylitis: one mechanism which appears well-established is a radiculitis with involvement of the paravertebral muscles: other authors suggest that there is nonspecific, generalized muscular involvement in this disorder.

  4. Intradural Involvement of Multicentric Myxoid Liposarcoma

    OpenAIRE

    Cho, Su-Hee; Rhim, Seung-Chul; Hyun, Seung-Jae; Bae, Chae Wan; Khang, Shin-Kwang

    2010-01-01

    Liposarcomas are malignant tumors of the soft tissue, with myxoid liposarcoma being the second most common subtype, tending to occur in the limbs, particularly in the thighs. Myxoid liposarcomas have an intermediate prognosis between well-differentiated and pleomorphic tumors. Spinal metastasis is usual but intradural involvement is extremely rare. We present an unusual case of a multicentric myxoid liposarcoma with intradural involvement. A 41-year-old woman complained of tingling sensation ...

  5. EXPLORE SIGNIFICANT FACTORS TO AFFECT CUSTOMER INVOLVEMENT

    OpenAIRE

    Yu-Jia Hu

    2012-01-01

    Although literature review supported the concept that customer loyalty, brand equity and perceived risk are significant factors to affect customer involvement, very limited studies have extensively examined the relationship among those variables. This research applied quantitative study to comprehensively explore the relationship between customer loyalty, brand equity, perceived risk and customer involvement for consumers. The population for this research was identified as consumers having th...

  6. Consultation on Personal and Public Involvement strategy

    OpenAIRE

    Public Health Agency

    2011-01-01

    Personal and Public Involvement (PPI) is an integral element of effective commissioning and is underpinned by a core set of values and principles - involving and listening to people in order to help us make services better.It brings about a number of recognised benefits if fully embraced into our culture and practice, these include:Use of service user knowledge and expertise;Better priority setting and decision making;More responsive, appropriate, efficient and tailored services;Transformatio...

  7. Spin versus helicity in processes involving transversity

    OpenAIRE

    Mekhfi, Mustapha

    2011-01-01

    We construct the spin formalism in order to deal in a direct and natural way with processes involving transversity which are now of increasing popularity. The helicity formalism which is more appropriate for collision processes of definite helicity has been so far used also to manage processes with transversity, but at the price of computing numerous helicity amplitudes generally involving unnecessary kinematical variables.In a second step we work out the correspondence between both formalism...

  8. Stakeholder involvement in Swedish nuclear waste management

    Energy Technology Data Exchange (ETDEWEB)

    Elam, Mark; Sundqvist, Goeran [Goeteborg Univ. (Sweden). Section for Science and Technology Studies

    2006-09-15

    This report concerning Swedish nuclear waste management has been produced as part of a cross national research project: CARL - A Social Science Research Project into the Effects of Stakeholder involvement on Decision-Making in Radioactive Waste Management. Besides Sweden, the participating countries are Belgium, Canada, Finland, Slovenia and United Kingdom. A social science research team, working for three years, is in the first phase conducting research in their own countries in order to produce 6 country reports. During the next years the focus will shift to comparisons of stakeholder involvement practices in the participating countries. The report addresses current practices of Swedish nuclear waste management and their historical development. The main focus is on past, current and emerging patterns of stakeholder involvement in the siting of a deep repository for the final disposal of Sweden's spent nuclear fuel. The general questions attended to in the report are: Who are the main stakeholders, and how have they emerged and gained recognition as such? What are the issues currently subject to stakeholder involvement and how have these been decided upon? How is stakeholder involvement organized locally and nationally and how has this changed over time? How has stakeholder involvement gained acceptance as an activity of value in the siting of major waste facilities? The report have attempted to show the development of stakeholder involvement in the siting of a final repository for Sweden's spent nuclear fuel as resembling something other than a straightforward linear process of improvement and refinement. Stakeholder involvement has developed, over the past 15 years or so, into something more like a patchwork of different shapes and forms. Some of the forces that may well contribute to the further elaboration of the patchwork of stakeholder involvement have been pointed out, contingently modifying once more its overall colour and orientation. Questions

  9. Stakeholder involvement in Swedish nuclear waste management

    International Nuclear Information System (INIS)

    This report concerning Swedish nuclear waste management has been produced as part of a cross national research project: CARL - A Social Science Research Project into the Effects of Stakeholder involvement on Decision-Making in Radioactive Waste Management. Besides Sweden, the participating countries are Belgium, Canada, Finland, Slovenia and United Kingdom. A social science research team, working for three years, is in the first phase conducting research in their own countries in order to produce 6 country reports. During the next years the focus will shift to comparisons of stakeholder involvement practices in the participating countries. The report addresses current practices of Swedish nuclear waste management and their historical development. The main focus is on past, current and emerging patterns of stakeholder involvement in the siting of a deep repository for the final disposal of Sweden's spent nuclear fuel. The general questions attended to in the report are: Who are the main stakeholders, and how have they emerged and gained recognition as such? What are the issues currently subject to stakeholder involvement and how have these been decided upon? How is stakeholder involvement organized locally and nationally and how has this changed over time? How has stakeholder involvement gained acceptance as an activity of value in the siting of major waste facilities? The report have attempted to show the development of stakeholder involvement in the siting of a final repository for Sweden's spent nuclear fuel as resembling something other than a straightforward linear process of improvement and refinement. Stakeholder involvement has developed, over the past 15 years or so, into something more like a patchwork of different shapes and forms. Some of the forces that may well contribute to the further elaboration of the patchwork of stakeholder involvement have been pointed out, contingently modifying once more its overall colour and orientation. Questions have been

  10. Construction contractors involvement in disaster management planning

    Directory of Open Access Journals (Sweden)

    Peter Stringfellow

    2014-06-01

    Full Text Available Disasters, both natural and man-made, cause major damage and loss of life. Because of this, governments around the world are looking at building resilience to ensure communities can recover quickly and have minimal impact from a disaster. Part of building resilience is to plan for disaster management and recovery. Literature reveals that construction contractors can play a critical role within this process as they have control of resource supply chains and key knowledge and skills they are well suited to assist in disaster planning. However, as literature also reveals there is currently little involvement of construction contractors in the disaster planning process. This gap between what should be done and what is currently done is investigated. Representatives from industry bodies are interviewed to determine their understanding of the industry’s involvement in disaster planning and what capacity the industry might have to be involved. The interviewee’s responses agree with current literature that there is currently little or no involvement with disaster planning however there is interest in being involved with disaster management planning if there was a forum for this to occur. Based on the responses the researcher has proposed a model to engage construction contractors within state government disaster management planning.

  11. Peer Effects and Academics’ Industry Involvement

    DEFF Research Database (Denmark)

    Aschhoff, Birgit; Grimpe, Christoph

    of the scientist. We suggest that both localized and personal peer effects drive industry involvement but that the effects from such imprinting are more pronounced for younger researchers, suggesting that professional imprinting takes place in the early stages of a scientist’s academic career. Based on a sample...... of 330 German academics in the field of biotechnology and publication data from the Science Citation Index Expanded (SCIE), we find that scientists with industry-oriented co-authors are more likely to be involved with industry (personal peer effect). Moreover, we find that the scientist’s involvement...... increases with the orientation of the scientist’s department towards industry (localized peer effect). Only the latter effect turns out to be moderated by scientist’s age. While personal peer effects are independent of the scientist’s age, localized peer effects emerge for younger researchers....

  12. Pulmonary Involvement in Rheumatic Diseases: HRCT Findings

    Directory of Open Access Journals (Sweden)

    Serhat Avcu

    2011-05-01

    Full Text Available Aim: Systemic rheumatic disease (SRD may affect all the components of the pulmonary system. This study was designed to investigate the frequency and pattern of pulmonary involvement of systemic collagen tissue diseases. Material and Methods: A total of 128 patients -44 with rheumatoid arthritis (RA, 8 with giant cell arteritis, 14 with systemic lupus erythematosus (SLE, 8 with juvenile chronic arthritis, 24 with ankylosing spondylitis (AS, 6 with scleroderma, 12 with Behcet’s disease, 4 with mixed connective tissue disease (MCTD, 4 with polymyositis and 4 with dermatomyositis- who had presented to the Department of Physical Medicine and Rehabilitation/Rheumatology between January 2007 and December 2008 were included in the study. All the ptients were informed about the study in detail and all gave written consent before enrollment. HRCT was performed in all patients. Results: Pulmonary involvement was detected in 21 patients with RA (48%, in 8 patients withcSLE (57%, in 16 patients with AS (67%, in 4 patients with scleroderma (67%, and in 4 patients with MCTD (50%. No pulmonary involvement was observed in patients with Behçet’s disease, polymyositis and dermatomyositis. Conclusions: Our results suggest that patients with SRD may present with pulmonary involvement in varying degrees. Pulmonary symptoms may be underdiagnosed due to limited capacity of exercise secondary to musculoskeletal involvement. Therefore, a routine pulmonary X-ray should be performed in the process of the diagnosis and prior to treatment, even in the lack of complaints suggesting pulmonary involvement. Further investigations including HRCT should be performed if needed. 

  13. Justification of novel practices involving radiation exposure

    International Nuclear Information System (INIS)

    The concept of 'justification' of practices has been one of the three basic principles of radiation protection for many decades. The principle is simple in essence - that any practice involving radiation exposure should do more good than harm. There is no doubt that the many uses of radiation in the medical field and in industry generally satisfy this principle, yielding benefits that could not be achieved using other techniques; examples include CT scanning and industrial radiography. However, even in the early period after the introduction of the justification principle, there were practices for which the decision on justification was not clear and for which different decisions were made by the authorities in different countries. Many of these involved consumer products such as luminous clocks and watches, telephone dials, smoke detectors, lightning preventers and gas mantles. In most cases, these practices were relatively small scale and did not involve large exposures of either individual workers or members of the public. Decisions on justification were therefore often made by the regulator without extensive national debate. Over recent years, several practices have been proposed and undertaken that involve exposure to radiation for purposes that were generally not envisaged when the current system of radiation protection was created. Some of these practices were reviewed during a recent symposium held in Dublin, Ireland and involve, for example, the x-raying of people for theft detection purposes, for detection of weapons or contraband, for the prediction of physical development of young athletes or dancers, for age determination, for insurance purposes and in cases of suspected child abuse. It is particularly in the context of such novel practices that the need has emerged for clearer international guidance on the application of the justification principle. This paper reviews recent activities of the IAEA with respect to these issues, including the

  14. Isolated lingual involvement in Wilson's disease.

    Science.gov (United States)

    Choudhary, Neera; Joshi, Laxmikant; Duggal, Ashish; Puri, Vinod; Khwaja, Geeta Anjum

    2015-01-01

    Lingual involvement can occur in a variety of neurological disorders including pyramidal, extrapyramidal and lower motor neuron disorders. It can be seen in the form of tremor, bradykinesia, dystonia, atrophy and weakness of tongue movements and can clinically present as difficulty in swallowing and dysarthria which can be a source of great discomfort to the patient. We describe a patient who presented with isolated lingual involvement and was diagnosed to have Wilsons's disease. This case emphasizes the clinical variability in presentation of Wilson's disease and importance of early clinical diagnosis.

  15. Langerhans Cell Histiocytosis Involving Maxilla and Mandible

    Directory of Open Access Journals (Sweden)

    M. Guna Shekhar

    2009-06-01

    Full Text Available Langerhans cell histiocytosis is a relatively rare unique disease process characterized by an abnormal proliferation of immature dendritic cells usually affecting children and young adults. Jaws are involved in less than 10% of children with the disease while mandibular involvement in young children is uncommon and bilateral affection is very rare. The purpose of this report is to describe a unique and very rare case of simultaneous and bilateral occurrence of Langerhans cell histiocytosis in both the jaws of a four-year-old boy.

  16. Learning from adverse incidents involving medical devices.

    Science.gov (United States)

    Amoore, John; Ingram, Paula

    While an adverse event involving a medical device is often ascribed to either user error or device failure, the causes are typically multifactorial. A number of incidents involving medical devices are explored using this approach to investigate the various causes of the incident and the protective barriers that minimised or prevented adverse consequences. User factors, including mistakes, omissions and lack of training, conspired with background factors--device controls and device design, storage conditions, hidden device damage and physical layout of equipment when in use--to cause the adverse events. Protective barriers that prevented or minimised the consequences included staff vigilance, operating procedures and alarms. PMID:12715578

  17. Meningeal involvement in Behcet's disease: MRI

    International Nuclear Information System (INIS)

    Behcet's disease is a multisystem disease that involves the central nervous system up to half of cases. Presentation with neurologic symptoms occurs in 5 % of cases and cerebral venous thrombosis is one of its major manifestations. A feature not previously reported is progressive meningeal thickening with involvement of both optic nerves. We report a patient with cerebral venous thrombosis, meningeal thickening and contrast enhancement on MRI. This patient had two other unusual features: positive antineutrophil cytoplasmic antibodies and later development of central diabetes insipidus. (orig.)

  18. Involving Customer Relations in Contextual Design

    DEFF Research Database (Denmark)

    Simonsen, Jesper

    1996-01-01

    This paper presents a case study in the form of a contextual design project, the aim of which was to design a system for a particular organization. The starting point in the case was a need in the organization for a specific system. The case involved an analysis of the organizations customer...... point of the design project, how the project was conducted, and which results it ended up with. This is followed by a discussion of the effects of, and lessons learned by, involving customer relations in contextual design....

  19. Autophagy and proteins involved in vesicular trafficking.

    Science.gov (United States)

    Amaya, Celina; Fader, Claudio Marcelo; Colombo, María Isabel

    2015-11-14

    Autophagy is an intracellular degradation system that, as a basic mechanism it delivers cytoplasmic components to the lysosomes in order to maintain adequate energy levels and cellular homeostasis. This complex cellular process is activated by low cellular nutrient levels and other stress situations such as low ATP levels, the accumulation of damaged proteins or organelles, or pathogen invasion. Autophagy as a multistep process involves vesicular transport events leading to tethering and fusion of autophagic vesicles with several intracellular compartments. This review summarizes our current understanding of the autophagic pathway with emphasis in the trafficking machinery (i.e. Rabs GTPases and SNAP receptors (SNAREs)) involved in specific steps of the pathway.

  20. Opinions on Career Involvement of Married Women

    Science.gov (United States)

    McMillin, Marvin R.; And Others

    1971-01-01

    The results of the study show that a potential area of conflict exists for young adults regarding the career involvement of the wife. College women preferred a career and marriage rather than either alone, while college men preferred that their wives not work after the birth of children. (BY)