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.


    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. Negative ion gas-phase chemistry of arenes. (United States)

    Danikiewicz, Witold; Zimnicka, Magdalena


    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

  3. 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


    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.

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

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


    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.

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

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


    Transition-metal-arene complexes such as bis(benzene)chromium Cr(η6-C6H6)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 UX3 (X = aryloxide, amide) spontaneously disproportionate, transferring an electron and X-ligand, allowing the resulting UX2 to bind and reduce arenes, forming inverse sandwich molecules [X2U(µ-η6:η6-arene)UX2] and a UX4 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 UX3 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.

  6. Lice Aren't So Nice (United States)

    ... dientes Video: Getting an X-ray Lice Aren't So Nice KidsHealth > For Kids > Lice Aren't So Nice Print A A A What's in ... are yellow, tan, or brown, the lice haven't hatched yet. If the eggs are white or ...

  7. Triazole-linked-thiophene conjugate of calix[4]arene: its selective recognition of Zn2+ and as biomimetic model in supporting the events of the metal detoxification and oxidative stress involving metallothionein. (United States)

    Pathak, Rakesh Kumar; Hinge, Vijaya Kumar; Mondal, Milon; Rao, Chebrolu Pulla


    Supramolecular calix[4]arene conjugate (L) has been developed as a sensitive and selective sensor for Zn(2+) in HEPES buffer among the 12 metal ion by using fluorescence, absorption and ESI MS and also by visual fluorescent color. The structural, electronic, and emission properties of the calix[4]arene conjugates L and its zinc complex, [ZnL], have been demonstrated using ab initio density functional theory (DFT) combined with time-dependent density functional theory (TDDFT) calculations. The TDDFT calculations reveal the switch on fluorescence behavior of L is mainly due to the utilization of the lone pair of electrons on imine moiety by the Zn(2+). The resultant fluorescent complex, [ZnL], has been used as a secondary sensing chemo-ensemble for the detection of -SH containing molecules by removing Zn(2+) from [ZnL] and forming {Cys/DTT·Zn} adducts as equivalent to those present in metallothioneins. The displacement followed by the release of the coordinated zinc from its Cys/DTT complex by heavy metal ion (viz. Cd(2+) and Hg(2+)), as in the metal detoxification process or by ROS (such as H(2)O(2)) as in the oxidative stress, has been well demonstrated using the conjugate L through the fluorescence intensity retrieval wherein the fluorescence intensity is the same as that observed with [ZnL], which in turn mimics the zinc sensing element (MTF) in biology.

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

    Institute of Scientific and Technical Information of China (English)


    <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. Preparation of phenols by phthaloyl peroxide-mediated oxidation of arenes. (United States)

    Yuan, Changxia; Eliasen, Anders M; Camelio, Andrew M; Siegel, Dionicio


    This protocol describes an approach to installing hydroxyls into arenes through the direct replacement of C-H bonds with C-O bonds. This direct oxidation avoids the need to prefunctionalize the substrate, use precious metals, introduce directing groups, or use strong Brønsted or Lewis acids. Phthaloyl peroxide, the sole reagent used for this transformation, can be prepared readily from the commodity chemicals phthaloyl chloride and sodium percarbonate. Phthaloyl peroxide oxidizes a diverse range of arenes, and the reactions that involve its use are characterized by high functional group compatibility, which enables the hydroxylation of simple arenes, advanced synthetic intermediates, natural products and other drug-like molecules forming the corresponding phenolic compounds. Notably, the reaction is operationally straightforward and has no special requirements for the exclusion of oxygen and water. The synthesis of phthaloyl peroxide takes 4  h and the subsequent hydroxylation of mesitylene takes 21  h.

  10. Medicinal organometallic chemistry: designing metal arene complexes as anticancer agents. (United States)

    Peacock, Anna F A; Sadler, Peter J


    The field of medicinal inorganic chemistry is rapidly advancing. In particular organometallic complexes have much potential as therapeutic and diagnostic agents. The carbon-bound and other ligands allow the thermodynamic and kinetic reactivity of the metal ion to be controlled and also provide a scaffold for functionalization. The establishment of structure-activity relationships and elucidation of the speciation of complexes under conditions relevant to drug testing and formulation are crucial for the further development of promising medicinal applications of organometallic complexes. Specific examples involving the design of ruthenium and osmium arene complexes as anticancer agents are discussed.


    Directory of Open Access Journals (Sweden)

    Nur Afni Evalia


    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


    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)


    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.


    Directory of Open Access Journals (Sweden)

    Mody Lempang


    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. Lewis acid/Brönsted acid mediated benz-annulation of thiophenes and electron-rich arenes. (United States)

    Rafiq, Settu Muhamad; Sivasakthikumaran, Ramakrishnan; Mohanakrishnan, Arasambattu K


    A facile preparation of benz-annulated heterocycles were achieved at rt involving a Lewis acid/Brönsted acid mediated annulation of heterocycles using 2,5-dimethoxytetrahydrofuran as a four-carbon synthon. The benz-/naphth-annulation was found to be successful with electron-rich arenes as well.

  16. Calix[4]arene methylenebisphosphonic acids as inhibitors of fibrin polymerization.

    NARCIS (Netherlands)

    Lugovskoy, E.V.; Gritsenko, P.; Koshel, T.A.; Koliesnik, I.O.; Cherenok, S.O.; Kalchenko, O.I.; Kalchenko, V.I.; Komisarenko, S.V.


    Calix[4]arenes bearing two or four methylenebisphosphonic acid groups at the macrocyclic upper rim have been studied with respect to their effects on fibrin polymerization. The most potent inhibitor proved to be calix[4]arene tetrakis-methylene-bis-phosphonic acid (C-192), in which case the maximum

  17. What Indiana's Education Schools Aren't Teaching About Reading (United States)

    National Council on Teacher Quality, 2009


    In May 2006 the National Council on Teacher Quality (NCTQ) released a groundbreaking study, "What Education Schools Aren't Teaching About Reading - and "What Elementary Teachers Aren't Learning." The primary findings were disheartening: in a representative sampling of education schools in 35 states, only 15 percent of schools…

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

    Institute of Scientific and Technical Information of China (English)


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

    Institute of Scientific and Technical Information of China (English)


    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.

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

    Directory of Open Access Journals (Sweden)

    Kevin Cottet


    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.

  1. Annelation of furan rings to arenes (United States)

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


    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.

  2. Field reconnaissance of the effects of the earthquake of April 13, 1973, near Laguna de Arenal, Costa Rica (United States)

    Plafker, George


    At about 3:34 a.m. on April 13, 1973, a moderate-sized, but widely-felt, earthquake caused extensive damage with loss of 23 lives in a rural area of about 150 km2 centered just south of Laguna de Arenal in northwestern Costa Rica (fig. 1). This report summarizes the results of the writer's reconnaissance investigation of the area that was affected by the earthquake of April 13, 1973. A 4-day field study of the meizoseismal area was carried out during the period from April 28 through May 1 under the auspices of the U.S. Geological Survey. The primary objective of this study was to evaluate geologic factors that contributed to the damage and loss of life. The earthquake was also of special interest because of the possibility that it was accompanied by surface faulting comparable to that which occurred at Managua, Nicaragua, during the disastrous earthquake of December 23, 1972 (Brown, Ward, and Plafker, 1973). Such earthquake-related surface faulting can provide scientifically valuable information on active tectonic processes at shallow depths within the Middle America arc. Also, identification of active faults in this area is of considerable practical importance because of the planned construction of a major hydroelectrical facility within the meizoseismal area by the Instituto Costarricense de Electricidad (I.C.E.). The project would involve creation of a storage reservoir within the Laguna de Arenal basin and part of the Río Arenal valley with a 75 m-high earthfill dam across Río Arenal at a point about 10 km east of the outlet of Laguna de Arenal.

  3. Head-to-head linked double calix[4]arenes: convenient synthesis and complexation properties

    NARCIS (Netherlands)

    Struck, Oliver; Chrisstoffels, Lysander A.J.; Lugtenberg, Ronny J.W.; Verboom, Willem; Hummel, van Gerrit J.; Harkema, Sybolt; Reinhoudt, David N.


    Combination of calix[4]arenes functionalized at the upper rim at the 5- and 17-positions with amino and formyl groups, respectively, gives a new series of "head-to-head" linked double calix[4]arenes in nearly quantitative yield. The X-ray structure of a modified double calix[4]arene is reported. The

  4. Aminolysis reaction of calix [ 4 ] arene esters and crystal structures and conformational behaviors of calix[4]arene amides

    Institute of Scientific and Technical Information of China (English)

    WU, Yong; LIU, Hui-Biao; HU, Jun; DUAN, Chun-Ying; XU, Zheng


    We first make use of aminolysis of calix[4]arene esters to synthesize calix[4]arene amides. When the two ethyl esters of the calix[4]arene esters are aminolysized, the 1, 3-amide derivative is formed selectively. The crystal structures of the calix[4]arene with two butyl amide (3b) and four butyl amide moieties (4b) were determined. The intermolecular hydrogen bonds make 4b form two-dimensional net work insolid state.The 1H NMR spectra prove that 3b is of a pinched cone conformation, while 4b and tetraheptylamide-calix[4]arene (6b)take fast interconversion between two C2v isomers in solution and appear an apparent cone conformation at room temperature. As decreasing temperature, the interconversion rate decreases gradually and, finally, the interconversion process is frozen at Tc= - 10℃, which makes both conformations of 4b and 6b the pinched cone structures. The hydrogen bond improves the interconversion barrier, and the large different values of the potential barrier between 6b and 4b (or 6b) may be of forming different hydrogen bonds.

  5. Spatially Directional Resorcin[4]arene Cavitand Glycoconjugates for Organic Catalysis. (United States)

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


    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.

  6. Synthesis and assembly of self-complementary calix[4]arenes. (United States)

    Shimizu, K D; Rebek, J


    A calix[4]arene was designed to reversibly dimerize and form an egg-shaped enclosure. Adhesive interactions in the assembly were provided by four self-associating ureas, which form a cyclic array containing 16 hydrogen bonds. The synthesis was completed in four steps from the previously described O,O',O",O"'-tetrabenzylcalix[4]arene. Evidence for dimerization of the calixarene tetraurea was provided by H NMR, mass spectrometry, and the observation of encapsulated molecules. The resulting cavity was of sufficient size to capture guests such as ethyl benzene and p-xylene. Images Fig. 1 Fig. 2 Fig. 6 PMID:8618910

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

    Index Scriptorium Estoniae

    Jagodin, Karen, 1982-


    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

  8. Chemoselective hydrogenation of arenes by PVP supported Rh nanoparticles

    DEFF Research Database (Denmark)

    Ibrahim, Mahmoud; Poreddy, Raju; Philippot, Karine


    Polyvinylpyrrolidone-stabilized Rh nanoparticles (RhNPs/PVP) of ca. 2.2 nm in size were prepared by the hydrogenation of the organometallic complex [Rh(η3-C3H5)3] in the presence of PVP and evaluated as a catalyst in the hydrogenation of a series of arene substrates as well as levulinic acid...

  9. 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


    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.

  10. Protein-calixarene interactions: complexation of Bovine Serum Albumin by sulfonatocalix[n]arenes. (United States)

    Memmi, L; Lazar, A; Brioude, A; Ball, V; Coleman, A W


    The complexation of Bovine Serum Albumin with sulfonatocalix[n]arenes has been demonstrated by means of electrospray mass spectrometry, dynamic light scattering and atomic force microscopy; with sulfonatocalix[4]arene one strong and two weaker binding sites are detected; the effects on the structure of thin films formed by surface deposition of BSA show that the sulfonatocalix[n]arenes act to reticulate the films and produce essentially planar systems.

  11. Comparative Study of Tributyltin Adsorption onto Mesoporous Silica Functionalized with Calix[4]arene, p-tert-Butylcalix[4]arene and p-Sulfonatocalix[4]arene

    Directory of Open Access Journals (Sweden)

    Sana Alahmadi


    Full Text Available The adsorption of tributyltin (TBT, onto three mesoporous silica adsorbents functionalized with calix[4]arene, p-tert-butylcalix[4]arene and p-sulfonatocalix[4]arene (MCM-TDI-C4, MCM-TDI-PC4 and MCM-TDI-C4S, respectively has been compared. Batch adsorption experiments were carried out and the effect of contact time, initial TBT concentration, pH and temperature were studied. The Koble–Corrigan isotherm was the most suitable for data fitting. Based on a Langmuir isotherm model, the maximum adsorption capacities were 12.1212, 16.4204 and 7.5757 mg/g for MCM-TDI-C4, MCM-TDI-PC4 and MCM-TDI-C4S, respectively. The larger uptake and stronger affinity of MCM-TDI-PC4 than MCM-TDI-C4 and MCM-TDI-C4S probably results from van der Waals interactions and the pore size distribution of MCM-TDI-PC4. Gibbs free energies for the three adsorption processes of TBT presented a negative value, reflecting that TBT/surface interactions are thermodynamic favorable and spontaneous. The interaction processes were accompanied by an increase of entropy value for MCM-TDI-C4 and MCM-TDI-C4S (43.7192 and 120.7609 J/mol K, respectively and a decrease for MCM-TDI-PC4 (−37.4704 J/mol K. It is obviously observed that MCM-TDI-PC4 spontaneously adsorbs TBT driven mainly by enthalpy change, while MCM-TDI-C4 and MCM-TDI-C4S do so driven mainly by entropy changes.

  12. Alkali-metalated forms of thiacalix[4]arenes. (United States)

    Zeller, Jürgen; Radius, Udo


    The alkali metal salts [TCALi4] (1), [TCANa4] (2), and [TCALK4] (3) of fully deprotonated p-tert-butyltetrathiacalix[4]arene (H(4)TCA) are readily available from the reactions of thiacalix[4]arene and n-BuLi, NaH, or KH as deprotonating reagents. Crystals of the sodium salts 2 and the potassium salt 3 suitable for X-ray diffraction were obtained in the form of the pyridine solvates [(TCA)2Na8.8py] (2.8py) and [(TCA)2K(8).8py] (3.8py). These molecules are dimers in the solid state but are structurally not related. In addition, the reaction of H(4)TCA and lithium hydroxide afforded the structurally characterized complex [(TCA)Li5(OH).4THF] (4). The molecular structure of 4 as well as the structures of 2.8py and 3.8py reveal a close relationship to the corresponding alkali metal salts of the calix[4]arenes.

  13. 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


    @@ 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.

  14. 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


    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)

  15. 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.


    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

  16. 2-(4-Bromobenzyl-5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxycalix[4]arene

    Directory of Open Access Journals (Sweden)

    Conrad Fischer


    Full Text Available In the title compound, C55H69BrO4, the calixarene molecule displays a `partial cone' conformation bearing the lateral substituent in a sterically favorable equatorial arrangement between two syn-orientated arene units. The crystal packing is stabilized by weak C—H...π contacts, involving one tert-butyl group, and π–stacking interactions of the lateral bromobenzene units [centroid–centroid distance = 3.706 (1 Å].

  17. 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


    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

  18. Photodissociation dynamics of the iodine-arene charge-transfer complex

    NARCIS (Netherlands)

    Lenderink, Egbert; Duppen, Koos; Everdij, Frank P.X.; Mavri, Janez; Torre, Renato; Wiersma, Douwe A.


    The photodissociation reaction of the molecular iodine:arene charge-transfer (CT) complex into an iodine atom and an iodine atom-arene fragment has been investigated using femtosecond pump-probe, resonance Raman, and molecular dynamics simulations. In the condensed phase the reaction proceeds on a t

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

    Directory of Open Access Journals (Sweden)


    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.

  20. An Inherent Chiral Calix[4]arene Bearing Chiral Groups without Forming Sub-ring

    Institute of Scientific and Technical Information of China (English)

    Xian Xian LIU; Yan Song ZHENG; Wan Ling MO


    The NMR spectra revealed that the calixarene frame of 1, 3-disubstituted calix[4]arenes bearing optically active groups is asymmetric, even without the formation of a sub-ring. This inherent chirality arises from the interaction of the two chiral groups, which hinder the substituents' free rotation. Thus, these chiral calix[4]arenes display good chiral recognition ability.

  1. Improved Catalytic Activity of Ruthenium–Arene Complexes in the Reduction of NAD+

    NARCIS (Netherlands)

    Soldevila-Barreda, J.J.; Bruijnincx, P.C.A.; Habtemariam, A.; Clarkson, G.J.; Deeth, R.J.; Sadler, Peter J.


    A series of neutral RuII half-sandwich complexes of the type [(η6-arene)Ru(N,N′)Cl] where the arene is para-cymene (p-cym), hexamethylbenzene (hmb), biphenyl (bip), or benzene (bn) and N,N′ is N-(2-aminoethyl)-4-(trifluoromethyl)benzenesulfonamide (TfEn), N-(2-aminoethyl)-4-toluenesulfonamide (TsEn)

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

    Institute of Scientific and Technical Information of China (English)


    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.

  3. 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.


    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.

  4. 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


    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.

  5. Solution structures of nanoassemblies based on pyrogallol[4]arenes. (United States)

    Kumari, Harshita; Deakyne, Carol A; Atwood, Jerry L


    Nanoassemblies of hydrogen-bonded and metal-seamed pyrogallol[4]arenes have been shown to possess novel solution-phase geometries. Further, we have demonstrated that both guest encapsulation and structural rearrangements may be studied by solution-phase techniques such as small-angle neutron scattering (SANS) and diffusion NMR. Application of these techniques to pyrogallol[4]arene-based nanoassemblies has allowed (1) differentiation among spherical, ellipsoidal, toroidal, and tubular structures in solution, (2) determination of factors that control the preferred geometrical shape and size of the nanoassemblies, and (3) detection of small variations in metric dimensions distinguishing similarly and differently shaped nanoassemblies in a given solution. Indeed, we have shown that the solution-phase structure of such nanoassemblies is often quite different from what one would predict based on solid-state studies, a result in disagreement with the frequently made assumption that these assemblies have similar structures in the two phases. We instead have predicted solid-state architectures from solution-phase structures by combining the solution-phase analysis with solid-state magnetic and elemental analyses. Specifically, the iron-seamed C-methylpyrogallol[4]arene nanoassembly was found to be tubular in solution and predicted to be tubular in the solid state, but it was found to undergo a rearrangement from a tubular to spherical geometry in solution as a function of base concentration. The absence of metal within a tubular framework affects its stability in both solution and the solid state; however, this instability is not necessarily characteristic of hydrogen-bonded capsular entities. Even metal seaming of the capsules does not guarantee similar solid-state and solution-phase architectures. The rugby ball-shaped gallium-seamed C-butylpyrogallol[4]arene hexamer becomes toroidal on dissolution, as does the spherically shaped gallium/zinc-seamed C-butylpyrogallol[4

  6. Molecular Design of Calixarene 5. Syntheses and Cation Selectivities of Novel Schiff' s Base p-tert-Butylcalix[4]arenes

    Institute of Scientific and Technical Information of China (English)

    刘育; 赵邦屯; 王浩; 陈企发; 张衡益


    Five novel Schiff's bases p-tert-butylcalix[4]arenes have ben synthesized in high yields by the reaction of 1,3-distally disubstituted p-tert-butyicalix[4]arene amine(1) with the corresponding aromatic aldehydes,and their cation binding abilities and selectivities with alkali and heavy metal ions have been evaluated by solvent extraction of aqueous metal picrates to show the highet Ag+ extractability for Schiff' s base p-tertbutylcalix[4]arene (6) and the best Na+/Li+ and Ag+/Tl+selectivities for Schiff's base p-tert-butylcalix[4]arene (4 and 2) over any other caltx[4]arene derivatives, respectively.

  7. Calix[4]arene methylenebisphosphonic acids as inhibitors of fibrin polymerization. (United States)

    Lugovskoy, Eduard V; Gritsenko, Pavel G; Koshel, Tatyana A; Koliesnik, Ievgen O; Cherenok, Serhey O; Kalchenko, Olga I; Kalchenko, Vitaliy I; Komisarenko, Serhey V


    Calix[4]arenes bearing two or four methylenebisphosphonic acid groups at the macrocyclic upper rim have been studied with respect to their effects on fibrin polymerization. The most potent inhibitor proved to be calix[4]arene tetrakis-methylene-bis-phosphonic acid (C-192), in which case the maximum rate of fibrin polymerization in the fibrinogen + thrombin reaction decreased by 50% at concentrations of 0.52 × 10(-6) M (IC(50)). At this concentration, the molar ratio of the compound to fibrinogen was 1.7 : 1. For the case of desAABB fibrin polymerization, the IC(50) was 1.26 × 10(-6) M at a molar ratio of C-192 to fibrin monomer of 4 : 1. Dipropoxycalix[4]arene bis-methylene-bis-phosphonic acid (C-98) inhibited fibrin desAABB polymerization with an IC(50) = 1.31 × 10(-4) M. We hypothesized that C-192 blocks fibrin formation by combining with polymerization site 'A' (Aα17-19), which ordinarily initiates protofibril formation in a 'knob-hole' manner. This suggestion was confirmed by an HPLC assay, which showed a host-guest inclusion complex of C-192 with the synthetic peptide Gly-Pro-Arg-Pro, an analogue of site 'A'. Further confirmation that the inhibitor was acting at the initial step of the reaction was obtained by electron microscopy, with no evidence of protofibril formation being evident. Calixarene C-192 also doubled both the prothrombin time and the activated partial thromboplastin time in normal human blood plasma at concentrations of 7.13 × 10(-5) M and 1.10 × 10(-5) M, respectively. These experiments demonstrate that C-192 is a specific inhibitor of fibrin polymerization and blood coagulation and can be used for the design of a new class of antithrombotic agents.

  8. Local and 2-Local derivations on noncommutative Arens algebras

    CERN Document Server

    Ayupov, Sh A; Nurjanov, B O; Alauatdinov, A K


    The paper is devoted to so-called local and 2-local derivations on the noncommutative Arens algebra $L^\\omega(M, \\tau)$ associated with a von Neumann algebra $M$ and a faithful normal semi-finite trace $\\tau.$ We prove that every 2-local derivation on $L^\\omega(M, \\tau)$ is a spatial derivation, and if $M$ is a finite von Neumann algebra, then each local derivation on $L^\\omega(M, \\tau)$ is also a spatial derivation and every 2-local derivation on $M$ is in fact an inner derivation.

  9. 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


    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.

  10. Solution superstructures: truncated cubeoctahedron structures of pyrogallol[4]arene nanoassemblies. (United States)

    Kumari, Harshita; Kline, Steven R; Fowler, Drew A; Mossine, Andrew V; Deakyne, Carol A; Atwood, Jerry L


    Giant nanocapsules: the solution-phase structures of PgC1Ho and PgC3Ho have been investigated using in situ neutron scattering measurements. The SANS results show the presence of spherical nanoassemblies of radius 18.2 Å, which are larger than the previously reported metal-seamed PgC3 hexamers (radius = 10 Å). The spherical architectures conform to a truncated cubeoctahedron geometry, indicating formation of the first metal-containing pyrogallol[4]arene-based dodecameric nanoassemblies in solution.

  11. 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: [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)


    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.

  12. Host-Guest Complexes of Carboxylated Pillar[n]arenes With Drugs. (United States)

    Wheate, Nial J; Dickson, Kristie-Ann; Kim, Ryung Rae; Nematollahi, Alireza; Macquart, René B; Kayser, Veysel; Yu, Guocan; Church, W Bret; Marsh, Deborah J


    Pillar[n]arenes are a new family of nanocapsules that have shown application in a number of areas, but because of their poor water solubility their biomedical applications are limited. Recently, a method of synthesizing water-soluble pillar[n]arenes was developed. In this study, carboxylated pillar[n]arenes (WP[n], n = 6 or 7) have been examined for their ability to form host-guest complexes with compounds relevant to drug delivery and biodiagnostic applications. Both pillar[n]arenes form host-guest complexes with memantine, chlorhexidine hydrochloride, and proflavine by (1)H nuclear magnetic resonance and modeling. Binding is stabilized by hydrophobic effects within the cavities, and hydrogen bonding and electrostatic interactions at the portals. Encapsulation within WP[6] results in the complete and efficient quenching of proflavine fluorescence, giving rise to "on" and "off" states that have potential in biodiagnostics. The toxicity of the pillar[n]arenes was examined using in vitro growth assays with the OVCAR-3 and HEK293 cell lines. The pillar[n]arenes are relatively nontoxic to cells except at high doses and after prolonged continuous exposure. Overall, the results show that there could be a potentially large range of medical applications for carboxylated pillar[n]arene nanocapsules.

  13. Los peligros volcánicos del Arenal

    Directory of Open Access Journals (Sweden)

    Sjöbohm Castillo, Linda Marie


    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

  14. Immobilization of [60]fullerene on silicon surfaces through a calix[8]arene layer

    Energy Technology Data Exchange (ETDEWEB)

    Busolo, Filippo; Silvestrini, Simone; Maggini, Michele [Department of Chemical Sciences, ITM-CNR University of Padova, Via F. Marzolo 1, 35131 Padova (Italy); Armelao, Lidia [Department of Chemical Sciences, IENI-CNR and INSTM, University of Padova, Via F. Marzolo 1, 35131 Padova (Italy)


    In this work, we report the functionalization of flat Si(100) surfaces with a calix[8]arene derivative through a thermal hydrosilylation process, followed by docking with [60]fullerene. Chemical grafting of calix[8]arene on silicon substrates was evaluated by X-ray photoelectron spectroscopy, whereas host-guest immobilization of fullerene was demonstrated by atomic force microscopy and sessile drop water contact angle measurements. Surface topographical variations, modelled on the basis of calix[8]arene and [60]fullerene geometrical parameters, are consistent with the observed morphological features relative to surface functionalization and to non-covalent immobilization of [60]fullerene.

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

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


    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.

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


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


    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 ...

  17. Functionalized O6-Corona[6]arenes: Synthesis, Structure, and Fullerene Complexation Property. (United States)

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


    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).

  18. Studies on Properties of p—Nitrophenylazo Calix[4]arene Derivatives

    Institute of Scientific and Technical Information of China (English)

    金传明; 归敏芝; 陆国元; 郭勋; 张宏; 游效曾


    The p-nitrophenylazo calix[4] arene derivatives la-ld with nonlinear optical(NLO)properties were prepared by the diazo-coupling reaction of calix[4]arene with p-nitrophenyl diazonium.The diazotization reaction of p-nltroaniline was caried out with isoamyl nitrite as a source of nitrous acid in EtONa/EtOH under refluxing conditon.X-Ray crystallographic analysis and 1H NMR sptectra reveal that they exist as cone conformation in crystal state or in soution.HRS measurements at 1064 nm in THF indicate that p-nitrophenylazo calix[4]arenes have higher hyperpolarizability βz values than the corresponding reference compound 4-(4-nitrophenylazo)-2,6-dimethyl-phenol,without red shift of the charge transfer band.The tetrakis p-nitropheylazo calix[4]arene(2)with longer alkyl chains can form monolayer aht the air/water interface.

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

    Energy Technology Data Exchange (ETDEWEB)

    Echabaane, M., E-mail: [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)


    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)

  20. Microwave Assisted Efficient Synthesis and Crystal Structures of O-Hexadecalkylated Pyrogallol[4]arenes

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiao; CHEN Weifeng; YAN Chaoguo


    Under microwave irradiation alkylation reactions of sixteen phenolic hydroxyl groups in tetrap-hydroxyphenylpyrogallol[4]arene with alkylating reagents such as n-butyl iodide,benzyl chloride,and ethyl a-chloroacetate were finished quickly in one step to give the fully O-alkylated products.The X-ray single crystal diffraction showed that the three peralkylated pyrogallol[4]arenes existed in rcttcis-trans-transconfiguration.

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


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


    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...

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

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    Lele Wang


    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.

  3. Calix-arene silver nanoparticles interactions with surfactants are charge, size and critical micellar concentration dependent. (United States)

    Tauran, Yannick; Brioude, Arnaud; Shahgaldian, Patrick; Cumbo, Alessandro; Kim, Beomjoon; Perret, Florent; Coleman, Anthony W; Montasser, Imed


    The interactions of silver nanoparticles capped by various calix[n]arenes bearing sulphonate groups at the para and/or phenolic faces with cationic, neutral and anionic surfactants have been studied. Changes in the plasmonic absorption show that only the calix[4]arene derivatives sulphonated at the para-position interact and then only with cationic surfactants. The interactions follow the CMC values of the surfactants either as simple molecules or mixed micelles.


    Directory of Open Access Journals (Sweden)

    V. O. Chernyshenko


    Full Text Available The aim of the research was to study a potential antithrombotic sodium salt of calix[4]arene-methylene-bis-phosphonic acid (С-145 — on activation and aggregation of platelets in vivo, as well as on proliferation and apoptosis of endothelial cells in the cell culture. Effects of calix[4]arene С-145 estimated in vitro after addition to the platelet rich plasma, and in vivo after intravenous injection into rabbit bloodstream in equivalent amounts (46 μM. Aggregation of platelets was induced by adenosine diphosphate and detected using aggregometer Solar AP2110. Platelet shape and cytoplasmic granularity were monitored on COULTER EPICS XL Flow Cytometer. The level of tissuetype plasminogen activator — tPA — was estimated using enzyme-linked immunosorbent assay ELISA. Effects of calix[4]arene C-145 on culture of endotelial cells cells was studied using 3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyltetrazolium Bromide — MTT-test. The population of proliferative pool of cells (G2/M+S was determined using flow cytometry. Aggregometry and flow cytometry showed that calix[4]arene C-145 did not activate platelets nor affect their aggregation in vitro. However intravenous injection of calix[4]arene C-145 into the bloodstream of healthy rabbits leads to strong inhibition of platelet aggregation and changes of shape and granularity of most of the platelets after 2 hours of administration. Any additional appearance of endothelial cells activation marker tPA in vivo and any inhibition of calix[4]arene C-145 on proliferation of endothelial cells in cell culture did not observe. So calix[4]arene C-145 had strong anti-platelet effect in vivo that was not a result of their direct action on platelets or endothelial cells in vitro. This allowed to assume the possibility of calix[4]arene C-145 use as an effective antithrombotic agent.

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

    Directory of Open Access Journals (Sweden)

    Sana M. Alahmadi


    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.

  6. Synthesis and characterization of mesoporous silica functionalized with calix[4]arene derivatives. (United States)

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


    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. Chemoselective hydrogenation of arenes by PVP supported Rh nanoparticles. (United States)

    Ibrahim, Mahmoud; Poreddy, Raju; Philippot, Karine; Riisager, Anders; Garcia-Suarez, Eduardo J


    Polyvinylpyrrolidone-stabilized Rh nanoparticles (RhNPs/PVP) of ca. 2.2 nm in size were prepared by the hydrogenation of the organometallic complex [Rh(η(3)-C3H5)3] in the presence of PVP and evaluated as a catalyst in the hydrogenation of a series of arene substrates as well as levulinic acid and methyl levulinate. The catalyst showed excellent activity and selectivity towards aromatic ring hydrogenation compared to other reported transition metal-based catalysts under mild reaction conditions (room temperature and 1 bar H2). Furthermore, it was shown to be a highly promising catalyst for the hydrogenation of levulinic acid and methyl levulinate in water leading to quantitative formation of the fuel additive γ-valerolactone under moderate reaction conditions compared to previously reported catalytic systems.

  8. Homodiselenacalix[4]arenes: Molecules with Unique Channelled Crystal Structures. (United States)

    Thomas, Joice; Dobrzańska, Liliana; Van Meervelt, Luc; Quevedo, Mario Alfredo; Woźniak, Krzysztof; Stachowicz, Marcin; Smet, Mario; Maes, Wouter; Dehaen, Wim


    A synthetic route towards homodiselenacalix[4]arene macrocycles is presented, based on the dynamic covalent chemistry of diselenides. The calixarene inner rim is decorated with either alkoxy or tert-butyl ester groups. Single-crystal X-ray analysis of two THF solvates with methoxy and ethoxy substituents reveals the high similarity of their molecular structures and alterations on the supramolecular level. In both crystal structures, solvent channels are present and differ in both shape and capacity. Furthermore, the methoxy-substituted macrocycle undergoes a single-crystal-to-single-crystal transformation during which the molecular structure changes its conformation from 1,3-alternate (loaded with THF/water) to 1,2-alternate (apohost form). Molecular modelling techniques were applied to explore the conformational and energetic behaviour of the macrocycles.

  9. Modulating the Anticancer Activity of Ruthenium(II)-Arene Complexes. (United States)

    Clavel, Catherine M; Păunescu, Emilia; Nowak-Sliwinska, Patrycja; Griffioen, Arjan W; Scopelliti, Rosario; Dyson, Paul J


    Following the identification of [Ru(η(6)-p-cymene)Cl2(1H,1H,2H,2H-perfluorodecyl-3-(pyridin-3-yl)propanoate)], a ruthenium(II)-arene complex with a perfluoroalkyl-modified ligand that displays remarkable in vitro cancer cell selectivity, a series of structurally related compounds were designed. In the new derivatives, the p-cymene ring and/or the chloride ligands are substituted by other ligands to modulate the steric bulk or aquation kinetics. The new compounds were evaluated in both in vitro (cytotoxicity and migration assays) and in vivo (chicken chorioallantoic membrane) models and were found to exhibit potent antivascular effects.

  10. Activation of C-H bonds of arenes: selectivity and reactivity in bis(pyridyl) platinum(II) complexes. (United States)

    Zhang, Fenbao; Kirby, Christopher W; Hairsine, Douglas W; Jennings, Michael C; Puddephatt, Richard J


    The reaction of [PtMe2(NN)] and B(C6F5)3/H2O in CF3CH2OH with arenes Ar-H gives [PtAr{HOB(C6F5)3}(LL)] if the bis(pyridyl) ligand NN forms a six-membered, but not five-membered, chelate ring; methyl-substituted arenes give selectivity for metalation of meta > para > ortho, but methoxy-substituted arenes give ortho > meta, para.

  11. NMR Evidence for a Planar Arene Intermediate in the Electron-Transfer Induced Eta 6 to Eta 4 Hapticity Change of a Rhodium Arene Complex (United States)


    complex. Elschenbroich and co-workers2 8 observed large differences in coupling constants for the protons of the bent benzene ring in the ESR spectrum...characterization by Elschenbroich , et al., of the bent arene 19-electron complex [(n4-C6H6 )Cr(C 6H6 )3- 28, it rust be considered that bent arene structures...Koelle, U.; Fuss, B.; Rajasekharan, M.V.; Ramakrishna, B.L. Ammeter, J.H.; Boehm, M.C. J. Amer. Chem. Soc., 1984, 206, 4152. 28. Elschenbroich , Ch

  12. Discriminatory antibacterial effects of calix[n]arene capped silver nanoparticles with regard to gram positive and gram negative bacteria. (United States)

    Boudebbouze, Samira; Coleman, Anthony W; Tauran, Yannick; Mkaouar, Hela; Perret, Florent; Garnier, Alexandrine; Brioude, Arnaud; Kim, Beomjoon; Maguin, Emmanuelle; Rhimi, Moez


    Silver nanoparticles capped with nine different sulphonated calix[n]arenes were tested for their anti-bacterial effects against B. subtilis and E. coli at an apparent concentration of 100 nM in calix[n]arene. The results show the para-sulphonato-calix[n]arenes are active against Gram positive bacteria and the derivatives having sulphonate groups at both para and alkyl terminal positions are active against Gram negative bacteria. The calix[6]arene derivative with only O-alkyl sulphonate groups shows bactericidal activity.

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

    Index Scriptorium Estoniae

    Hint, Gitte


    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


    Directory of Open Access Journals (Sweden)



    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.

  15. Cobalt bis(dicarbollides)(1-) covalently attached to the calyx[4]arene platform: the first combination of organic bowl-shaped matrices and inorganic metallaborane cluster anions

    NARCIS (Netherlands)

    Grüner, Bohumír; Mikulasek, Libor; Baca, Jirí; Cisarova, Ivana; Böhmer, Volker; Danila, Crenguta; Reinoso-Garcia, Marta M.; Verboom, Willem; Reinhoudt, David N.; Casnati, Alessandro; Ungaro, Rocco


    Various calix[4]arene and resorc[4]arene ionic compounds substituted by cobalt bis(dicarbollide) anions (1) have been prepared for the first time. From tBu-calix[4]arene (A) the complete series of mono-, di-, tri- and tetrasubstituted derivatives bearing one to four cluster anions on the lower rim (

  16. Evaluation of Complexation Behavior of Calix[4]arene Derivative

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    Mansoor Ahmed Qazi


    Full Text Available In this article we have explored the solvatochromic behavior including solvent selection, time study and complexation ability of 5,11,17,23-Tetrakis(N-piperidinomethyl-25,26,27,28-tetrahydroxycalix[4]arene (3. The complexation behavior of 3 toward the selected transition metals has been explored through FT-IR, UV-visible and fluorescence spectroscopic techniques. It has been found that the ligand 3 has remarkable complexation ability for all selected transition metal (Cd2+, Cu2+, Ni2+, Co2+, Pb2+, Hg2+ ions used in the experiment with exceptionally high affinity for Hg2+ ions. Besides this, by applying method of continuous variation, i.e. Job’s method; the stoichiometric ratio for the complexation between 3 and Hg2+ ion in acetonitrile has been determined, which indicates that 3 forms a 1:1 metal:ligand complex. The strong complexation behavior of 3 for Hg2+ ions was also confirmed by FT-IR and fluorescence spectroscopy. Consequently, it has been deduced that 3 is a versatile compound and can be used in diverse fields such as analytical/environmental chemistry and sensor technology.

  17. A1/A2-Diamino-Substituted Pillar[5]arene-Based Acid-Base-Responsive Host-Guest System. (United States)

    Hu, Wei-Bo; Hu, Wen-Jing; Zhao, Xiao-Li; Liu, Yahu A; Li, Jiu-Sheng; Jiang, Biao; Wen, Ke


    An acid-base-responsive supramolecular host-guest system based on a planarly chiral A1/A2-diamino-substituted pillar[5]arene (1)/imidazolium ion recognition motif was created. The pillar[4]arene[1]diaminobenzene 1 can bring an electron-deficient imidazolium cation into its cylindrically shaped cavity under neutral or basic conditions and release it under acidic conditions.

  18. Direct access to pyrazolo(benzo)thienoquinolines. Highly effective palladium catalysts for the intramolecular C-H heteroarylation of arenes. (United States)

    Churruca, Fátima; Hernández, Susana; Perea, María; SanMartin, Raul; Domínguez, Esther


    A short and atom-efficient strategy to obtain a series of pyrazolo(benzo)thienoquinolines is developed. Alternative catalytic systems for the key intramolecular direct heteroarylation of arenes are presented and include the first example of C-H (hetero)arylation of (hetero)arenes catalyzed by very low catalyst loadings of a palladium source.

  19. Non-covalent synthesis of calix[4]arene-capped porphyrins in polar solvents via ionic interactions

    NARCIS (Netherlands)

    Fiammengo, Roberto; Timmerman, Peter; Huskens, Jurriaan; Versluis, Kees; Heck, Albert J.R.; Reinhoudt, David N.


    Non-covalent synthesis of calix[4]arene capped porphyrins can be achieved in polar solvents (up to 45% molar fraction of water) via ionic interaction. Thus tetracationic meso-tetrakis(N-alkylpyridinium-3-yl) porphyrins 1a–d and tetra anionic 25,26,27,28-tetrakis(2-ethoxyethoxy)-calix[4]arene tetrasu

  20. Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

    Directory of Open Access Journals (Sweden)

    Silvia Bernardi


    Full Text Available Four novel calix[4]arene-based glycoclusters were synthesized by conjugating the saccharide units to the macrocyclic scaffold using the CuAAC reaction and using long and hydrophilic ethylene glycol spacers. Initially, two galactosylcalix[4]arenes were prepared starting from saccharide units and calixarene cores which differ in the relative dispositions of the alkyne and azido groups. Once the most convenient synthetic pathway was selected, two further lactosylcalix[4]arenes were obtained, one in the cone, the other one in the 1,3-alternate structure. Preliminary studies of the interactions of these novel glycocalixarenes with galectin-3 were carried out by using a lectin-functionalized chip and surface plasmon resonance. These studies indicate a higher affinity of lactosyl- over galactosylcalixarenes. Furthermore, we confirmed that in case of this specific lectin binding the presentation of lactose units on a cone calixarene is highly preferred with respect to its isomeric form in the 1,3-alternate structure.

  1. 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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Meenakshi, C., E-mail: [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)


    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.

  3. High water contents in basaltic melt inclusions from Arenal volcano, Costa Rica (United States)

    Wade, J. A.; Plank, T.; Hauri, E. H.; Melson, W. G.; Soto, G. J.


    Despite the importance of water to arc magma genesis, fractionation and eruption, few quantitative constraints exist on the water content of Arenal magmas. Early estimates, by electron microprobe sum deficit, suggested up to 4 wt% H2O in olivine-hosted basaltic andesite melt inclusions (MI) from pre-historic ET-6 tephra (Melson, 1982), and up to 7 wt% H2O in plagioclase and orthopyroxene-hosted dacitic MI from 1968 lapilli (Anderson, 1979). These high water contents are consistent with abundant hornblende phenocrysts in Arenal volcanics, but inconsistent with geochemical tracers such as 10Be and Ba/La that suggest a low flux of recycled material (and presumably water) from the subduction zone. In order to test these ideas, and provide the first direct measurements of water in mafic Arenal magmas, we have studied olivine-hosted MI from the prehistoric (900 yBP; Soto et al., 1998) ET3 tephra layer. MI range from andesitic (> 58% SiO2) to basaltic compositions ( 4 wt%) found here for Arenal basaltic MI support the semi-quantitative data from earlier studies, but are somewhat unexpected given predictions from slab tracers. Arenal water contents (4%) approach those of the 1995 eruption of Cerro Negro in Nicaragua (4-5 wt% in basaltic MI; Roggensack et al., 1997), despite the fact that the latter has Ba/La of > 100, while Arenal has Ba/La Boletin de Volcanologia; Roggensack et al. (1997) Science; Soto et al. (1998) OSIVAM; Williams-Jones et al. (2001) Journal of Volc. and Geoth. Res.

  4. La mirada social en la prensa: Concepción Arenal

    Directory of Open Access Journals (Sweden)

    Simón Palmer, María del Carmen


    Full Text Available In La Voz de la Caridad Concepción Arenal set out her views on a series of social problems that remain current even today, although though they have not received as much attention as those relating to women, prisoners, or poverty.Concepción Arenal dejó en La Voz de la Caridad, sus opiniones sobre una serie de problemas sociales que, aún hoy, siguen de plena actualidad aunque no han merecido tanta atención como los referentes a la mujer, los presos o la pobreza.

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

    Crochet, Pascale; Cadierno, Victorio


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


    Saeed Taghvaee Ganjali; Karim Akbari Dilmaghani; Behrouz Shaabani; Abdol Ali Alemi


    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 lig...

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

    Directory of Open Access Journals (Sweden)

    Saeed Taghvaee Ganjali


    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.

  8. 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


    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.

  9. Removal of uranyl ions by p-hexasulfonated calyx[6]arene acid (United States)

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


    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.


    Directory of Open Access Journals (Sweden)

    Rosidah R Radam


    Full Text Available Gula aren salah satu pemanis yang telah diproduksi oleh bangsa Indonesia sejak lama. Gula aren sebagai alternatif bahan pemanis makanan dan merupakan mata pencaharian sampingan bagi kebanyakan masyarakat di Desa Banua Hanyar. Tujuan penelitian ini untuk mengetahui produktivitas dan kontribusi terhadap pendapatan masyarakat. Objek penelitian ini adalah pembuat gula aren. Data yang dikumpulkan terdiri dari  karakteristik responden, proses pembuatan gula aren, perhitungan produktivitas dan kontribusinya terhadap pendapatan masyarakat. Produktivitas gula aren (Arenga pinnata Merr berkisar antara 0,465 Kg/hari hingga 1,137 kg/hari. Kontribusi dari pengolahan gula aren sebesar 60,48% dari pendapatan masyarakat. Tingkat kesejahteraan masyarakat termasuk dalam golongan termiskin dengan pendapatan tahunan per kapita Rp.962 919,- atau setara dengan 148 kg beras. Disarankan perlu pembentukan kelompok tani dengan tujuan keseragaman dalam harga pasar gula aren. Peningkatan kualitas dengan peningkatan bentuk cetakan, kemasan dan aneka  rasa. Sehingga produk gula aren dapat dijual di pasar modern. Palm sugar is a sweetener that has been produced by the nation of Indonesia since long ago.  Palm sugar as an alternative sweetener foodstuffs as well as an second job for most people in the Banua Hanyar village.  The purpose of this research to know the productivity and contribution to community income. The object of this research is the maker of palm sugar. Data collected as data characteristics, the process of making palm sugar, calculation of productivity and its contribution to household income. Productivity sugar palm (Arenga pinnata Merr ranged from 0.465 Kg / day up to 1,137 kg / day. Contributions from processing palm sugar by 60.48% of household income. The level of welfare including in the poorest of the poor with annual income  per capita of IDR 962 919, - or the equivalent of 148 kg of rice.  Need formation of farmer groups with the goal of

  11. Mechanized silica nanoparticles based on pillar[5]arenes for on-command cargo release. (United States)

    Sun, Yu-Long; Yang, Ying-Wei; Chen, Dai-Xiong; Wang, Guan; Zhou, Yue; Wang, Chun-Yu; Stoddart, J Fraser


    Mechanized silica nanoparticles, equipped with pillar[5]arene-[2]pseudorotaxane nanovalves, operate in biological media to trap cargos within their nanopores, but release them when the pH is lowered or a competitive binding agent is added. Although cargo size plays an important role in cargo loading, cargo charge-type does not appear to have any significant influence on the amount of cargo loading or its release. These findings open up the possibility of using pillar[n]arene and its derivatives for the formation of robust and dynamic nanosystems that are capable of performing useful functions.

  12. 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: [“Al.I. Cuza” University of Iasi, The Faculty of Chemistry, Bd. Carol-I No. 11, Iasi 700506 (Romania)


    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.

  13. Antioxidant and DPPH (1,1-diphenyl-2-picrylhydrazyl Free Radical Scavenging Activities of Boniger Acid and Calix[4]arene Derivative

    Directory of Open Access Journals (Sweden)

    E. ERDEM


    Full Text Available Diazonium derivative of calix[4]arene has been synthesized using three different synthetic steps. Initially p-tert-butylcalix[4]arene was synthesized with the condensation reaction of p-tert-butylphenol and formaldehyde in basic conditions. Calix[4]arene was obtained after the debutylation reaction of p-tert-butylcalix[4]arene with AlCl3. Calix[4]arene reacted with diazonium salt of Böniger acid to yield the 5,17-[(Bis(azo-bis(5-hydroxy-2,7-naphthalenedisulfonicacid]-25,26,27,28-tetrahydroxy calix[4]arene which has eight free phenolic hydroxyl group. Reaction steps were shown in Fig.1.2,7-naphthalenedisulfonicacid]-25,26,27,28-tetrahydroxy calix[4]arene The antioxidant activity of the Böniger acid and calix[4]aren derivative were determined using β-karotene-linoleic acid system. Moreover, the free radical scavenging activity values were tested with DPPH free radical. The two compounds showed strong antioxidant activity. Total antioxidant activity of Böniger acid and calix[4]aren derivative was determined using β–carotenelinoleic acid model system and was found the antioxidant activity of 84.00% and 85.60 % respectively. The free radical scavenging activities were determined as 83.05% and 84.69 %. Results show that, two compounds has the antioxidant activity. The calix[4]aren derivaties has more higher activity then Boniger acid because of calix[4]aren derivative has much hydroxl groups.

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

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


    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

  15. 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: [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)


    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.

  16. Why Aren't Philosophers and Educators Speaking to Each Other? Some Reasons for Hope. (United States)

    Ellett, Frederick S., Jr.


    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…

  17. A Pyrenyl-Appended Triazole-Based Calix arene as a Fluorescent Sensor for Iodide Ion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seung; Park, Sun Young; Kim, Sang Hoon [Korea University, Seoul (Korea, Republic of); Thuery, Pierre [CEA, IRAMIS, SCM, LCCEf, Yvette (France); Matthews, Susan E. [University of East Anglia, Norwich (United Kingdom); Souane, Rachid; Vicens, Jacques [IPHC-UdS-ECPM-CNRS, Cedex (France)


    The synthesis and evaluation of a novel calix arene-based fluorescent chemosensor 1 for the detection of I. is described. The fluorescent changes observed upon addition of various anions show that 1 is selective for I. over other anions. Addition of I. results in ratiometric measurements with 1 : 1 complex ratio.

  18. Review of "Incomplete: How Middle Class Schools Aren't Making the Grade". Think Tank Review (United States)

    Baker, Bruce D.


    "Incomplete: How Middle Class Schools Aren't Making the Grade" is a new report from Third Way, a Washington, D.C.-based policy think tank. The report aims to convince parents, taxpayers and policymakers that they should be as concerned about middle-class schools not making the grade as they are about the failures of the nation's large, poor, urban…

  19. Thermal decomposition mechanism of p-tert-butyl-calix[n]arenes

    Energy Technology Data Exchange (ETDEWEB)

    Chennakesavulu, K., E-mail: [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India); Department of Chemistry, Sathyabama University, Jeppiaar Nagar, Chennai 600 119 (India); Sreedevi, P.; Raviathul Basaria, M. [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India); Ramanjaneya Reddy, G. [Department of Inorganic Chemistry, Guindy Campus, University of Madras, Chennai 600 025 (India); Sasipraba, T. [International Research Centre, Sathyabama University, Jeppiaar Nagar, Chennai 600 119 (India); Bhaskar Raju, G.; Prabhakar, S. [National Metallurgical Laboratory Madras Centre, CSIR Madras Complex, Taramani, Chennai 600 113 (India)


    Highlights: • Systematic thermal decomposition, structural elucidation of intermediates at various quenched temperatures. • At solid state the phenolic free radical was quenched and was evidenced by recording stable EPR. • Since the lower decomposition energy these p-tert-butyl-calix[n]arenes can be used as a antioxidants for thermal stabilization of polyolefins. • Solid state NMR CP-MAS studies show the breakage of calixarene at bridged methylene. • Kinetic triplets of p-tert-butyl-calixarenes were determined by model free methods. - Abstract: Thermal decomposition of p-tert-butyl-calix[n]arene was studied using thermo gravimetry (TG) and differential thermo gram (DTG) methods. Non-isothermal TG was done under static air atmosphere with 1, 2.5, 5.0 and 10.0 K/min. Model-free methods such as Friedman and Flynn Wall Ozawa (FWO) were used to evaluate the kinetic parameters such as activation energy and exponential factors. The probable thermal decomposition mechanism was proposed by analyzing the quenched intermediate p-tert-butyl-calix[n]arene samples with FTIR, mass, {sup 1}H NMR, {sup 13}C NMR cross polarization magic angle spectrometry (CP-MAS), EPR spectroscopy and elemental analysis. The thermal stability of the polyolefins was checked with p-tert-butyl-calix[n]arene as an antioxidant additive.

  20. Synthesis of phosphorylated calix[4]arene derivatives for the design of solid phases immobilizing uranyl cations

    Energy Technology Data Exchange (ETDEWEB)

    Maroun, E.B.; Hagege, A.; Asfari, Z. [Laboratoire de Chimie Analytique et Minerale, UMR 7178 ULP/CNRS/IN2P3 LC4, ECPM, Strasbourg Cedex (France); Basset, CH.; Quemeneur, E.; Vidaud, C. [CEA IBEB, SBTN, Centre de Marcoule, Bagnols-sur-Ceze (France)


    With the aim of developing supports for uranyl cations immobilisation, new 1, 3-alternate calix[4]arenes bearing both phosphonic acid functions as chelating sites and N-succinimide-4-oxa-butyrate as the anchoring arm were synthesised in good yields. The coupling of such calixarenes to a gel was performed and a successful immobilisation of uranyl cations was obtained. (authors)

  1. 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;


    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....

  2. Research on Synthesis of New Azo Calix[4]arene and its Dyeing Properties

    Directory of Open Access Journals (Sweden)

    Tang Jun


    Full Text Available With the raw materials of calix[4]arene, benzocaine, tricaine and procaine hydrochloride, three new azo calix[4]arene derivatives—6a, 6b and 6c are synthesized by diazotization–coupling reaction of an aromatic amine, with its yield of 83%, 81% and 83% respectively. The structural characterization is in a way of IR, 1H NMR and elemental analysis. This paper investigates the spectral properties of azo calix[4]arene derivatives under different solution pH conditions through the UV–visible spectroscopy, and researches the dyeing properties through the dyeing curve, color yield test and fastness test. The results show that, with the increase of pH value, the azo calix[4]arene derivatives—6a, 6b and 6c form azo–hydrazone tautomeric isomers with the maximum absorption peak redshift; the dyeing effect of the compound is good, of which the dye–uptake rate of the compound 6a is as high as 78%; the surface depth of color yield is 2.798, and the dry and wet rubbing fastness and the soaping fastness are respectively 4, which is a better disperse dye.

  3. 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;


    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 de...

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

    Institute of Scientific and Technical Information of China (English)


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

    Directory of Open Access Journals (Sweden)

    Robert A. Cazar


    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.

  6. Transition metal cations extraction by ester and ketone derivatives of chromogenic azocalix[4]arenes. (United States)

    Ak, Metin; Taban, Deniz; Deligöz, Hasalettin


    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+.

  7. Ni-B/TiO2 Amorphous Catalyst Used in Heavy Arenes of Petrochemicals Hydrogenation

    Institute of Scientific and Technical Information of China (English)


    A supported Ni-B/TiO2 amorphous catalyst was prepared by impregnation and reduction. It was characterized by XRD, SAED, DSC, XPS, etc.. The catalytic activity of catalyst was measured through the hydrogenation of heavy arenes in petrochemicals for the first time.

  8. Palladium-catalyzed regioselective decarboxylative alkylation of arenes and heteroarenes with aliphatic carboxylic acids. (United States)

    Premi, Chanchal; Dixit, Ankit; Jain, Nidhi


    An unprecedented Pd(OAc)2-catalyzed decarboxylative alkylation of unactivated arenes, with aliphatic carboxylic acids as inexpensive alkyl sources, is reported. The alkylation, controlled by the directing group, is regioselective, shows high functional group tolerance, and provides mild access to alkylated indolines, 2-phenylpyridines, and azobenzenes under solvent-free conditions in moderate to high yields.

  9. 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.


    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

  10. Oxatub[4]arene: a molecular "transformer" capable of hosting a wide range of organic cations. (United States)

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


    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.

  11. New Calix[4]arene dibenzocrown ethers for selective sensing of cesium ion in aqueous environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seung; Kim, Jong Kuk [Konyang University, Nonsan (Korea, Republic of); Choi, Wang Kyu; Lee, Kune Woo; Oh, Won Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)


    1,3-dialkoxycalix[4]arene dibenzocrown ethers (6-9) were successfully synthesized in the fixed 1,3-alternate conformation with over 90% yields by the reaction of corresponding 1,3dialkoxycalix[4]arenes 2-5 with dibenzodimesylate 13 in acetonitrile as a solvent in the presence of cesium carbonate as a base. In view of cyclization yield, the use of dimesylate is found to be better than that of dibenzoditosylate. With an unusual AB pattern in {sup 1}H NMR spectrum for compound 9, it is suggested that conformational structure of 1,3-diallyloxycalix[4]arene dibenzocrown ether be less flexible than that of usual 1,3-alternate calixcrown ether, probably due to steric effects of two ally1 group. Complexation of the corresponding calix[4]arene 6-9 toward alkali metal ions using single flux method through bulk liquid membrane system was found to give a high cesium selectivity. 28 refs., 1 tab., 1 fig.

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

    KAUST Repository

    Reiner, Thomas


    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.

  13. Cytochrome P450-catalysed arene-epoxidation of the bioactive tea tree oil ingredient p-cymene: indication for the formation of a reactive allergenic intermediate? (United States)

    Meesters, R J W; Duisken, M; Hollender, J


    1. The cytochrome P450-mediated metabolism of the tea tree oil ingredient p-cymene (p-isopropyltoluene) was studied by the application of in vitro enzymatic assays using different recombinant human cytochrome P450 enzymes. 2. In total, four enzymatic products were identified by gas chromatography-mass spectrometry. The enzymatic products identified were: thymol (2-isopropyl-5-methylphenol), p-isopropylbenzyl alcohol, p,alpha,alpha-trimethylbenzyl alcohol, and p-isopropylbenzaldehyde. 3. The enzymatic products of p-cymene resulted from catalysed enzymatic arene-epoxidation and hydroxylation reactions by the studied cytochrome P450 enzymes. 4. An in vivo study could only confirm the formation of one enzymatic product, namely thymol. Thymol was identified after enzymatic hydrolysis of glucuronide and sulphate conjugates in collected blood and urine samples. 5. The obtained results may help to increase the understanding of cases where skin sensitization and irritation by tea tree oil-containing products that are involved with allergic reactions of users of these products. The results also indicate that skin sensitization and irritation reactions not only can be explained by the frequently in literature reported auto-oxidation of tea tree resulting in bioactive oxidized products, but also now by the formation of epoxide intermediates resulting from catalysed arene-epoxidation reactions by selected human cytochrome P450 enzymes which are also located in different organs in humans.

  14. Distinct rat hepatic microsomal epoxide hydrolases catalyze the hydration of cholesterol 5,6 alpha-oxide and certain xenobiotic alkene and arene oxides. (United States)

    Levin, W; Michaud, D P; Thomas, P E; Jerina, D M


    Metabolism of cholesterol 5,6 alpha-oxide to the 5,6-glycol is catalyzed by a rat liver microsomal epoxide hydrolase that is distinct from the microsomal epoxide hydrolase that metabolizes a wide range of xenobiotic alkene and arene oxides. The two enzymes are antigenically distinct, and the purified microsomal epoxide hydrolase that metabolizes xenobiotic oxides does not catalyze the hydration of cholesterol 5,6 alpha-oxide. In vivo treatment of rats with inducers of microsomal epoxide hydrolase does not enhance the activity of cholesterol 5,6 alpha-oxide hydrolase and, in some cases, actually depresses enzyme activity in the resultant microsomal preparations. Octene 1,2-oxide and benz[a]anthracene 5,6-oxide, both good substrates for xenobiotic epoxide hydrolase, are not competitive inhibitors of cholesterol oxide hydration by rat liver microsomes. The above results establish the existence of a liver microsomal epoxide hydrolase that is under different regulatory control and that appears to have a different substrate specificity than the well-characterized microsomal epoxide hydrolase involved in the metabolism of a widely diverse group of alkene and arene oxides.

  15. 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


    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+.

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


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


    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...

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

    Directory of Open Access Journals (Sweden)

    Geoffroy Guillemot


    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.

  18. 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


    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.

  19. Electrochemical Studies for Cation Recognition with Diazo-Coupled Calix[4]arenes

    Directory of Open Access Journals (Sweden)

    Bongsu Kim


    Full Text Available The electrochemical properties of diazophenylcalix[4]arenes bearing ortho-carboxyl group (o-CAC and ortho-ester group (o-EAC, respectively, in the presence of various metal ions were investigated by voltammetry in CH3CN. o-CAC and o-EAC showed voltammetric changes toward divalent metal ions and no significant changes with monovalent alkali metal ions. However, o-CAC preferentially binds with alkaline earth and transition metal ions, whereas no significant changes in voltammetric signals are observed in o-EAC with alkaline earth metal ions. o-EAC only binds with other transition metal ions. This can be explained on metal ion complexation-induced release of proton from the azophenol to the quinone-hydrazone tautomer followed by internal complexation of the metal ion with aid of nitrogen atoms and ortho-carbonyl groups in the diazophenylazocalix[4]arenes.

  20. Bis-tert-Alcohol-Functionalized Crown-6-Calix[4]arene: An Organic Promoter for Nucleophilic Fluorination. (United States)

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


    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.

  1. Studies on Properties of Tetra-p-nitro-tetra-O-alkyl-calix [4] arenes

    Institute of Scientific and Technical Information of China (English)

    LU,Guo-Yuan; SONG,Wei; LIU,Min-Hua; LIU,Fang; JIN,Chuan-Min


    This paper reports the properties of the novel tetra- p-nitro- te tra-O-alkyl-calix[4]arenes (alkyl= n-C4H9, 1; n-C8H17, 2; n-C12H25, 3; n-C16H33, 4). X-ray crystallographic analysis and 1H NMR revealed that they exist as pinched-cone confor mation in crystal or cone conformation in soiution. EFISH ex periments at 1064 nm in CHCl3 indicated that tetra-p-nitro-te- tra-O-butyl-calix[4]arene (1) has higher hyperpolarizability βz values than the corresponding reference compound p-nitro phenyl butyl ether, without red shift of the charge transfer band. Compounds 2, 3 and 4 with longer alkyl chains can form monolayer at the air/water.

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

  3. Synthesis and anion recognition of neutral receptors based on multiamide calix[4]arene

    Institute of Scientific and Technical Information of China (English)

    LIU; Shunying; WANG; Fajun; WEI; Lanhua; XIAO; Wang; MENG


    Two multiamide calix[4]arenes (5, 6) were synthesized and characterized by IR, 1H NMR, MS and elemental analysis. The binding properties of receptors with some anions (p-O2NPhOPO2-3, p-O2NPhO-, H2PO-4, Ac-, Cl-, Br- and I-) were studied by UV-Vis spectra. The results indicate that the tetraamide calix[4]arenes (5, 6) have a good selectivity to the anions containing aromatic ring (p-O2NPhOPO32 , p-O2NPhO-). The 1 : 1 complexes between host and guest were formed through multiple hydrogen bonding and π-π interactions. The hosts 5 and 6also show a definite binding ability for the anions (H2 PO-4, Ac-, Cl-) that have no ultraviolet absorption, which provides a simple method of spectrum detection for these anions.

  4. Picomolar inhibition of cholera toxin by a pentavalent ganglioside GM1os-calix[5]arene. (United States)

    Garcia-Hartjes, Jaime; Bernardi, Silvia; Weijers, Carel A G M; Wennekes, Tom; Gilbert, Michel; Sansone, Francesco; Casnati, Alessandro; Zuilhof, Han


    Cholera toxin (CT), the causative agent of cholera, displays a pentavalent binding domain that targets the oligosaccharide of ganglioside GM1 (GM1os) on the periphery of human abdominal epithelial cells. Here, we report the first GM1os-based CT inhibitor that matches the valency of the CT binding domain (CTB). This pentavalent inhibitor contains five GM1os moieties linked to a calix[5]arene scaffold. When evaluated by an inhibition assay, it achieved a picomolar inhibition potency (IC50 = 450 pM) for CTB. This represents a significant multivalency effect, with a relative inhibitory potency of 100,000 compared to a monovalent GM1os derivative, making GM1os-calix[5]arene one of the most potent known CTB inhibitors.

  5. Theoretical study of a novel imino bridged pillar[5]arene derivative (United States)

    Xie, Ju; Zuo, Tongfei; Huang, Zhiling; Huan, Long; Gu, Qixin; Gao, Chenxi; Shao, Jingjing


    In this paper, we report a novel imino bridged pillar[5]arene derivative (P5N) for the first time. Four conformers (P5N0, P5N1, P5N12, and P5N13, arising due to the different orientation of Nsbnd H bond of imino bridging group) are obtained by quantum chemical calculations at the CAM-B3LYP/6-31+G(d, p) level of theory. The geometries, energies, electronic structures, and absorption spectra of P5N conformers as well as pillar[5]arene (P5) are discussed in detail. The inclusion complexes of paraquat (Pq) with P5N and P5, respectively, are also obtained at the same level of theory. Compared to P5, P5N exhibits better performance in inclusion complexation toward Pq.

  6. Synthesis and self-assembly of thio derivatives of calix[4]arene on noble metal surfaces. (United States)

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


    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.

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

    KAUST Repository

    Fathalla, Maher


    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.

  8. 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


    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+.

  9. A protocol to generate phthaloyl peroxide in flow for the hydroxylation of arenes. (United States)

    Eliasen, Anders M; Thedford, Randal P; Claussen, Karin R; Yuan, Changxia; Siegel, Dionicio


    A flow protocol for the generation of phthaloyl peroxide has been developed. This process directly yields phthaloyl peroxide in high purity (>95%) and can be used to bypass the need to isolate and recrystallize phthaloyl peroxide, improving upon earlier batch procedures. The flow protocol for the formation of phthaloyl peroxide can be combined with arene hydroxylation reactions and provides a method for the consumption of peroxide as it is generated to minimize the accumulation of large quantities of peroxide.

  10. Arene control over thiolate to sulfinate oxidation in albumin by organometallic ruthenium anticancer complexes. (United States)

    Hu, Wenbing; Luo, Qun; Ma, Xiaoyan; Wu, Kui; Liu, Jianan; Chen, Yi; Xiong, Shaoxiang; Wang, Jianping; Sadler, Peter J; Wang, Fuyi


    Interactions of organometallic ruthenium anticancer complexes [Ru(eta6-arene)Cl(en)][PF6] (arene=p-cymene (1) or biphenyl (2), en=ethylenediamine) with human serum albumin were investigated by means of mass spectrometry combined with trypsin digestion, specific sidechain modifications and computational modelling. Both complexes were shown to bind to surface histidine (His128, His247, His510) and methionine (Met298) residues in human albumin, but only the p-cymene complex can gain entry to the crevice containing the free cysteine thiolate (Cys34) and induce oxidation to sulfinate. The two complexes exhibit a similar coordination preference for histidine and methionine residues on the protein surface. His128 binding is favoured both kinetically and thermodynamically. At 310 K, six days of incubation of recombinant human albumin (rHA) with complex 1 (rHA:Ru 50:250 microM) led to about 18 % ruthenation of His128 in the protein. However, the extent of ruthenation of albumin by complex 2 was less than that by 1, due to the steric hindrance from the biphenyl ligand. These results imply that the arene ligand in the organometallic ruthenium anticancer complexes plays a crucial role in interactions with proteins.

  11. Antiseptic properties of two calix[4]arenes derivatives on the human coronavirus 229E. (United States)

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


    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.

  12. Experimental study into the petrogenesis of crystal-rich basaltic to andesitic magmas at Arenal volcano (United States)

    Parat, F.; Streck, M. J.; Holtz, F.; Almeev, R.


    Arenal volcano is nearly unique among arc volcanoes with its 42 year long (1968-2010) continuous, small-scale activity erupting compositionally monotonous basaltic andesites that also dominate the entire, ~7000 year long, eruptive history. Only mineral zoning records reveal that basaltic andesites are the result of complex, open-system processes deriving minerals from a variety of crystallization environments and including the episodic injections of basalt. The condition of the mafic input as well as the generation of crystal-rich basaltic andesites of the recent, 1968-2010, and earlier eruptions were addressed by an experimental study at 200 MPa, 900-1,050 °C, oxidizing and fluid-saturated conditions with various fluid compositions [H2O/(H2O + CO2) = 0.3-1]. Phase equilibria were determined using a phenocryst-poor (~3 vol%) Arenal-like basalt (50.5-wt% SiO2) from a nearby scoria cone containing olivine (Fo92), plagioclase (An86), clinopyroxene (Mg# = 82) and magnetite (Xulvö = 0.13). Experimental melts generally reproduce observed compositional trends among Arenal samples. Small differences between experimental melts and natural rocks can be explained by open-system processes. At low pressure (200 MPa), the mineral assemblage as well as the mineral compositions of the natural basalt were reproduced at 1,000 °C and high water activity. The residual melt at these conditions is basaltic andesitic (55 wt% SiO2) with 5 wt% H2O. The evolution to more evolved magmas observed at Arenal occurred under fluid-saturated conditions but variable fluid compositions. At 1,000 °C and 200 MPa, a decrease of water content by approximately 1 wt% induces significant changes of the mineral assemblage from olivine + clinopyroxene + plagioclase (5 wt% H2O in the melt) to clinopyroxene + plagioclase + orthopyroxene (4 wt% H2O in the melt). Both assemblages are observed in crystal-rich basalt (15 vol%) and basaltic andesites. Experimental data indicate that the lack of orthopyroxene

  13. Interaction between Langmuir and Langmuir-Blodgett films of two calix[4]arenes with aqueous copper and lithium ions. (United States)

    Supian, Faridah L; Richardson, Tim H; Deasy, Mary; Kelleher, Fintan; Ward, James P; McKee, Vickie


    The binding interactions between aqueous copper (Cu(2+)) and lithium (Li(+)) ions and Langmuir monolayers and Langmuir-Blodgett (LB) multilayers have been investigated by studying surface pressure-area (Pi-A) isotherms and surface potential-area (DeltaV-A) behavior in order to find the effective dipole moment, mu(perpendicular), of the calixarene molecules in the uncomplexed and complexed states. The orientation of both calix[4]arenes, namely, 5,11,17,23-tetra-tert-butyl-25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene and 5,17-(9H-fluoren-2-yl)methyleneamino)-11,23-di-tert-butyl-25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene, is such that the plane of the calix ring is parallel with the plane of the water surface regardless of the ion content of the subphase. The Gibbs equation was used to interpret the adsorption of ions with both calix[4]arenes as a function of the concentration. Effective dipole moments have been calculated from surface potential values using the Helmholtz equation. In this work, new LB films have been prepared employing two novel amphiphilic calix[4]arene derivatives bearing different upper rim substituents. Thus, the effect of modifiying the upper rim has been observed. The results have shown that these calixarenes may be useful components of ion sensors.

  14. Analisis Pendapatan Usaha Pengrajin Gula Aren Di Desa Tulo’a Kecamatan Bulango Utara Kabupaten Bone Bolango

    Directory of Open Access Journals (Sweden)

    Yanti Saleh


    Full Text Available Penelitian ini bertujuan untuk menganalisis besarnya pendapatan pengrajin gula aren di Desa Tulo’a dan untuk menganalisis besarnya keuntungan pengrajin gula aren di Desa Tulo’a. Penelitian ini dilaksanakan pada bulan mei sampai bulan juli 2013. Metode yang digunakan dalam penelitian ini adalah metode survey yang terdiri dari data primer yang diperoleh melalui wawancara dengan pengrajin gula aren dengan menggunakan kuisioner/daftar pertanyaan dan data sekunder diperoleh dari Kantor Desa Tulo’a serta Dinas Perindustrian dan Perdagangan Kabupaten Bone Bolango. Teknik pengambilan sampel dilakukan dengan menggunakan metode sampling jenuh atau sensus dimana semua anggota populasi responden dijadikan sampel. Analisis data yang digunakan yaitu biaya tetap, biaya variabel, total biaya, penerimaan, pendapatan, dan analisis R/C Ratio. Hasil penelitian menunjukkan bahwa rata-rata pendapatan bersih/keuntungan yang diperoleh pengrajin gula aren di Desa Tulo’a yaitu sebesar Rp. 1.395.684/bulan atau Rp. 16.748.208/tahun. Dengan nilai R/C Ratio sebesar 2,12. Berdasarkan kriteria nilai R/C Ratio lebih dari satu berarti dapat dikatakan usaha pengrajin gula aren di Desa Tulo’a menguntungkan dan layak untuk diusahakan

  15. Impact of the Solvent on the Conformational Isomerism of Calix[4]arenes:  A Study Based on Continuum Solvation Models

    NARCIS (Netherlands)

    Aleman, Carlos; Otter, den W.K.; Tolpekina, T.V.; Briels, W.J.


    The influence of solvation on the conformational isomerism of calix[4]arene and p-tert-butylcalix[4]arene has been investigated by using the continuum model reported by Miertus, Scrocco, and Tomasi (MST). The quantum mechanical (QM) and semiclassical (SC) formalisms of the MST model have been consid

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

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


    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.

  17. Synthesis, Structure and Fluorescence Properties of 5,17-Distyryl-25,26,27,28-tetraproproxycalix[4]arenes in the Cone Conformation

    DEFF Research Database (Denmark)

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


    The HWE (Horner-Wadsworth-Emmons) reaction performed on the easily obtainable 5,17-diformyl- calix[4]arenes (cone) with arylmethyl phosphorus ylides yielded 5,17-distyryl-25,26,27, 28-tetrapropoxycalix[4]arenes (cone) in high yield and purely in the E/E configuration. Compounds 2-5 were prepared...

  18. Porous Carbon Fibers Containing Pores with Sizes Controlled at the Ångstrom Level by the Cavity Size of Pillar[6]arene. (United States)

    Ogoshi, Tomoki; Yoshikoshi, Kumiko; Sueto, Ryuta; Nishihara, Hirotomo; Yamagishi, Tada-Aki


    We report a new synthesis method of fibrous carbon material with pores sizes that are precisely controlled at the Ångstrom level, by carbonization of two dimensional (2D) porous sheets of pillar[6]arenes. The 2D porous sheets were prepared by 2D supramolecular polymerization induced by oxidation of hydroquinone units of pillar[6]arenes. Owing to the hexagonal structure of pillar[6]arene, the assembly induced by 2D supramolecular polymerization gave hexagonal 2D porous sheets, and the highly ordered structure of the 2D porous sheets formed regular fibrous structures. Then, carbonization of the 2D porous sheets afforded fibrous carbon materials with micropores. The micropore size of the fibrous porous carbon prepared from pillar[6]arene was the same size as that of the starting material pillar[6]arene assembly.

  19. 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


    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.

  20. 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)


    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-.

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

    Directory of Open Access Journals (Sweden)

    Muhammad eHanif


    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.

  2. Characteristics of a novel calix[8]arene modified with carbon nanotubes thin films for metal cations detection (United States)

    Supian, Faridah Lisa; Bakar, Suriani Abu; Azahari, Noor Azyyati; Richardson, Tim H.


    This study focuses on the properties of a novel calix[8]arene that have been modified with carbon nanotubes (CNT) as ion sensor application. Calix[8]arene modified with carbon nanotubes were done by mixing CNT (Calix8A-CNT) with a novel calix[8]arene in a long ultrasonication process. This study is interesting due to the process on the attaching of the functionalization of the calixarene on the carbon nanotubes outer wall. Morphological and spectroscopic studies of Calix8A-CNT were done using Π-A isotherm, Surface Potential Probe (S-Pot), Field mission scanning electron microscopy (FE-SEM) and Raman spectroscopy in order to understand the behavior in the molecular level. This water-soluble supramolecular hybrid materials have potential as metal cations detection and nanoelectronics applications, yet the CNT provide the thermal stability to the polymers.

  3. Electroanalytical studies on cadmium(II) selective potentiometric sensors based on t-butyl thiacalix[4]arene and thiacalix[4]arene in poly(vinyl chloride)

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinod K. [Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal (India)], E-mail:; Jain, Ajay K. [Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal (India); Ludwig, Rainer [Institute for Inorganic and Analytical Chemistry, Freie Universitaet, Berlin 14195 (Germany); Maheshwari, Gaurav [Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal (India)


    Cd{sup 2+}-selective sensors have been fabricated from poly(vinyl chloride) (PVC) matrix membranes containing t-butyl thiacalix[4]arene (I) and thiacalix[4]arene (II) as electroactive materials. The addition of sodium tetraphenylborate and the plasticizer 2-nitrophenyl octyl ether has been found to improve the performance of the sensors substantially. The membranes of various compositions of the two thiacalixarenes have been investigated and it was found that the best performance was obtained for the membrane of composition II:PVC:NaTPB:NPOE in the ratio 5:120:3:150. The sensor shows a linear potential response for Cd{sup 2+} over a wide activity range 3.2 x 10{sup -6} to 1.0 x 10{sup -1} M with Nernstian compliance (29.5 mV decade{sup -1} of activity) in pH range 4.5-6.5 and a fast response time of {approx}8 s. The potentiometric selectivity coefficient values determined by matched potential method indicate excellent selectivity for Cd{sup 2+} ions over mono-, di- and trivalent interfering cations. The sensor exhibits adequate shelf life ({approx}3 months) with good reproducibility (S.D. {+-}0.2 mV) and can also be used in partially non-aqueous media having up to 20% (v/v) methanol, ethanol or acetone content with no significant change in the value of slope or working activity range. The sensor has been used in the potentiometric titration of Cd{sup 2+} with EDTA. The sensor could be successfully used for the quantification of cadmium in river water samples.

  4. Synthesis of calix[4]arene-grafted magnetite nanoparticles and Evaluation of their arsenate as well as dichromate removal efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sayin, Serkan; Ozcan, Fatih; Yilmaz, Mustafa; Cengeloglu, Yunus [Department of Chemistry, Selcuk University, Konya (Turkey); Tor, Ali [Department of Environmental Engineering, Selcuk University, Konya (Turkey); Memon, Shahabuddin [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro (Pakistan)


    In this study, 5,17-bis-[(4-benzylpiperidine)methyl]-25,26,27,28-tetrahydroxy-calix[4]arene (3) has been prepared by the treatment of calix[4]arene with a secondary amine (4-benzylpiperidine) and formaldehyde by means of Mannich reaction. The prepared Mannich base (3) has been grafted onto [3-(2,3-epoxypropoxy)-propyl]-trimethoxysilane-modified Fe{sub 3}O{sub 4} magnetite nanoparticles (EPPTMS-MN) in order to obtain 5,17-bis-[(4-benzylpiperidine)methyl]-25,26,27,28-tetrahydroxy calix[4]arene-grafted EPPTMS-MN (BP-calix[4]arene-grafted Fe{sub 3}O{sub 4}). All new compounds were characterized by a combination of FTIR and {sup 1}H-NMR analyses. The morphology of the magnetic nanoparticles was examined by transmission electron microscopy. Moreover, the studies regarding the removal of arsenate and dichromate ions from the aqueous solutions were also carried out by using 5,17-bis-[(4-benzylpiperidine)methyl]-25,26,27,28-tetrahydroxy-calix[4]arene in liquid-liquid extraction and BP-calix[4]arene-grafted Fe{sub 3}O{sub 4} (4) in solid-liquid extraction experiments. The extraction results indicated that 3 is protonated at proton-switchable binding sites in acidic conditions. Hence, facilitating binding of arsenate and dichromate is resulted from both electrostatic interactions and hydrogen bonding. To understand the selectivity of 3, the retention of dichromate anions in the presence of Cl{sup -}, NO{sub 3}{sup -}, and SO{sub 4}{sup 2-} anions at pH 1.5 was also examined. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. The extraction of thorium by calix[6]arene columns for urine analysis. (United States)

    Mekki, S; Bouvier-Capely, C; Jalouali, R; Rebière, F


    Thorium is a natural alpha-emitting element occurring in various ores and has numerous industrial applications. Routine monitoring of potentially exposed workers is generally achieved through radiobioassay (urine and faeces). The procedures currently used for analysing actinides such as thorium in urine require lengthy chemical separation associated with long counting times by alpha-spectrometry due to low activity levels. Thus, their main drawback is that they are time-consuming, which limits the frequency and flexibility of individual monitoring. In this context, this study developed new radiochemical procedures based on the use of tertbutylcalix[6]arenes bearing three carboxylic acid groups or three hydroxamic acid groups. These previous works demonstrated that these macrocyclic molecules immobilised on an inert solid support are excellent extractants for uranium, plutonium and americium. In this study, the authors investigated the thorium extraction by calix[6]arene columns. Experiments were performed on synthetic solutions and on real urine samples. The influence of various parameters, such as the thorium solution pH and the column flow rate on thorium extraction, was studied. The results showed that both calix[6]arenes are efficient to extract thorium. Thorium extraction is quantitative from pH = 2 for synthetic solution and from pH = 3 for real urine samples. This study has demonstrated that the column flow rate is a crucial parameter since its value must not be too high to achieve the steady-state complexation equilibrium. Finally, these results will be compared with those obtained for other actinides (U, Pu and Am) and the conditions of actinides' separation will be discussed.

  6. 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


    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.

  7. The synthesis of new amphiphilic p-tert-butylthiacalix[4]arenes containing peptide fragments and their interaction with DNA. (United States)

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


    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.

  8. 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)

    WANG; Hao; LI; Zhe; LIU; Yu


    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+.

  9. Detection and differentiation of neutral organic compounds by 19F NMR with a tungsten calix[4]arene imido complex. (United States)

    Zhao, Yanchuan; Swager, Timothy M


    Fluorinated tungsten calix[4]arene imido complexes were synthesized and used as receptors to detect and differentiate neutral organic compounds. It was found that the binding of specific neutral organic molecules to the tungsten centers induces an upfield shift of the fluorine atom appended on the arylimido group, the extent of which is highly dependent on electronic and steric properties. We demonstrate that the specific bonding and size-selectivity of calix[4]arene tungsten-imido complex combined with (19)F NMR spectroscopy is a powerful new method for the analysis of complex mixtures.

  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


    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. Opciones para la prevención: el caso del Volcán Arenal

    Directory of Open Access Journals (Sweden)

    Esquivel Valverde, Lidier


    Full Text Available El presente artículo analiza una serie de aspectos relacionados con la actividad del volcán Arenal y su repercusión la zona. Como tema principal, explica ampliamente la propuesta Uso de suelos en los alrededores del volcán, creada por el Comité Asesor Técnico en Vulcanología, integrada por el Observatorio Vulcanológico y Sismológico de Costa Rica de la Universidad Nacional (OVSICORI, la Red Sismológica Nacional de la Universidad de Costa Rica (RSN y el Área de Amenaza y Auscultación Sísmica y Volcánica del Instituto Costarricense de Electricidad (ICE, la cual estipula las zonas de restricción para el uso de suelo, dividida en dos niveles de restricción y cuatro sub áreas. El artículo incluye un Mapa de restricciones de uso del suelo, tránsito de personas y ubicación de los proyectos de desarrollo más importantes en los alrededores del volcán Arenal. Las conclusiones exponen los motivos que propiciaron la creación de la propuesta y su aplicación, así como algunos puntos deficitarios con respecto a la participación de otros actores This article analyses a series of aspects related to the activity of the Arenal Volcano and its repercussion in the zone. The main topic broadly explains the proposal about soil use around the Volcano, created by the Technical Advisor Committee in Volcanology, composed by the Volcanological and Seismological Observatory of the Costa Rica, National University (Observatorio Vulcanológico y Sismológico de Costa Rica de la Universidad Nacional - OVSICORI, the National Seismic Network of the University of Costa Rica (Red Sismológica Nacional de la Universidad de Costa Rica - RSN and the Threat Area and Seismic Auscultation of the Costa Rican Electricity Institute (Área de Amenaza y Auscultación Sísmica y Volcánica del Instituto Costarricense de Electricidad - ICE that includes the restricted zones for soil use, divided in two levels of restriction and four sub areas. The article includes a

  12. Protein surface recognition of the novel tetra-carboxylphenyl calix[4]arene to cytochrome c

    Institute of Scientific and Technical Information of China (English)

    Wen Ting An; Yong Jiao; Xiao Hua Sun; Chuan Dong; Shao Min Shuang; Ping Fang Xia; Man Shing Wong


    The interaction of the novel tetra-carboxylphenyl calix[4]arene (TCPC) with the bovine heart cytochrome c (Cc) was first investigated by fluorescence spectroscopy and molecular modeling methods.The formation of a stable 1:1complex was monitored by fluorescence titration,and its binding constant is 1.916 ×10 7 L mol- 1.Molecular modeling reveals the recognition mechanism of TCPC to the Cc surface,that is,the electrostatic interaction drives TCPC to the Cc surface,and the van der Waals interaction orientates TCPC parallel to the cleft of Cc.

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

  14. Silver-catalyzed arylation of (hetero)arenes by oxidative decarboxylation of aromatic carboxylic acids. (United States)

    Kan, Jian; Huang, Shijun; Lin, Jin; Zhang, Min; Su, Weiping


    A long-standing challenge in Minisci reactions is achieving the arylation of heteroarenes by oxidative decarboxylation of aromatic carboxylic acids. To address this challenge, the silver-catalyzed intermolecular Minisci reaction of aromatic carboxylic acids was developed. With an inexpensive silver salt as a catalyst, this new reaction enables a variety of aromatic carboxylic acids to undergo decarboxylative coupling with electron-deficient arenes or heteroarenes regardless of the position of the substituents on the aromatic carboxylic acid, thus eliminating the need for ortho-substituted aromatic carboxylic acids, which were a limitation of previously reported methods.

  15. 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)


    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.

  16. 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


    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-).

  17. Understanding the self-assembly process and behavior of metal-seamed pyrogallol[4]arene nanocapsules (United States)

    Mossine, Andrew V.

    C-alkylpyrogallol[4]arenes (PgCs) are bowl-shaped compounds that are commonly used as supramolecular building blocks in the construction of larger entities such as capsules, nanotubes, and layered networks. Many of these assemblies are constructed using non-covalent means and, as such, are inherently unstable in polar media. Although metal coordination with the hydroxyl-rich PgC upper rim can be exploited to synthesize assemblies with enhanced stability, few reports of this can be found in the literature. Thus, a thorough investigation of these metal-seamed assemblies and their manipulation is of importance. Prior work in the Atwood lab has produced three examples of metal-organic nanocapsules (MONCs) based on PgCs. These include two hexameric MONCs (based on Cu2+ and Ga3+) as well as a single example of a dimeric MONC (based on Zn2+). As it was unknown whether other metal cations could lead to the formation of similar entities, PgC complexation experiments were conducted with other first series transition metal cations, notably Ni2+, Co2+ and Mn2+. All of these led to nanocapsular materials, which were identified and studied using single crystal X-ray diffraction (scXRD). Once the foundational studies were complete, syntheses were also performed under varied conditions, specifically with Ni2+ and Cu2+. This led to the characterization of both dimeric and hexameric MONCs with these two metals, as well as the characterization of many other capsular materials. The information collected from these experiments also led to an intriguing question: which specific conditions lead to the formation of dimeric vs. hexameric MONCs? To answer this question, solid-state analysis using scXRD was coupled to in situ analysis utilizing small angle neutron scattering (SANS). This work showed that the formation of the dimer is typically favored at higher temperatures while the formation of the hexamer is favored at lower temperatures for both of the metals tested. Studies that varied

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

    Energy Technology Data Exchange (ETDEWEB)

    Echabaane, M., E-mail: [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)


    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.

  19. Synthesis and structures of O-anthrylmethyl-substituted hexahomotrioxacalix[3]arenes (United States)

    Jiang, Xue-Kai; Ikejiri, Yusuke; Ni, Xi-Long; Zeng, Xi; Redshaw, Carl; Yamato, Takehiko


    O-Alkylation of 7,15,23-tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix[3]arene (1H3) with 9-chloromethylanthracene 5 was carried out under different reaction conditions. Variation of the number of anthrylmethyl group introduced at the phenolic rim of hexahomotrioxacalix[3]arene 1H3 was achieved through selective O-alkylation using stoichiometric amounts of 9-chloromethylanthracene 5 in acetone to afford the mono-O-alkylated product 2H2An, the di-O-alkylated product 3HAn2 and the tri-O-alkylated product partial-cone-4An3, respectively. Interestingly, by using an acetone/benzene (1:1 v/v) mixed solvent system, the cone-4An3 was successfully synthesized. These results suggest that the solvent can also control the conformation of the O-alkylation products. The possible reaction routes of the cone-4An3 and partial-cone-4An3 are also discussed.

  20. Size Switchable Supramolecular Nanoparticle Based on Azobenzene Derivative within Anionic Pillar[5]arene (United States)

    Zhang, Cai-Cai; Li, Sheng-Hua; Zhang, Cui-Fang; Liu, Yu


    A photo/thermal-switchable supramolecular nanoparticles assembly has been constructed based on an inclusion complex between anionic pillar[5]arene 2C-WP5A and azobenzene derivative Azo-py-OMe (G). The novel anionic pillar[5]arene-based host-guest inclusion complexation was investigated by the 1H NMR titration, 2D ROESY and isothermal titration microcalorimetry (ITC) showing high association constant (Ka) of (2.60 ± 0.06) × 104 M‑1 with 1:1 binding stoichiometry. Furthermore, the supramolecular nanoparticles assembly can be conveniently obtained from G and a small amount of 2C-WP5A in aqueous solution, which was so-called “host induced aggregating (HIA)”. The size and morphology of the supramolecular nanoparticles assembly were characterized by TEM and DLS. As a result of the photo/thermal-isomerization of G included in the cavity of 2C-WP5A, the size of these nanoparticles could reversibly change from ~800 nm to ~250 nm, which could switch the solution of this assembly from turbid to clear.

  1. 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


    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.

  2. Binding of DNA by a dinitro-diester calix[4]arene: denaturation and condensation of DNA. (United States)

    Ostos, F J; Lebron, J A; Moyá, M L; Deasy, M; López-Cornejo, P


    A study of a dinitro-diester calix[4]arene (5,17-(3-nitrobenzylideneamino)-11,23-di-tert-butyl-25,27-diethoxycarbonyl methyleneoxy-26,28-dihydroxycalix[4]arene) interaction with calf-thymus DNA was carried out using several techniques. The measurements were done at various molar ratios X=[calixarene]/[DNA]. Results show diverse changes in the DNA conformation depending on the X value. Thus, at low macrocycle concentrations, the calixarene binds to the polynucleotide. This interaction, mainly in groove mode, weakens the hydrogen bonds between base pairs of the helix inducing denaturation of the double strands, as well as condensation of the macromolecule, from an extended coil state to a globular state. An opposite effect is observed at X molar ratios higher than 0.07. The de-condensation of DNA happens, that is, the transition from a compact state to a more extended conformation, probably due to the stacking of calixarene molecules in the solution. Results also show the importance of making a proper choice of the system under consideration.

  3. Why aren't we curious about nannies? (United States)

    Scheftel, Susan


    This paper is an exploration of a topic whose specific intrapsychic significance has remained relatively unformulated in the psychoanalytic literature. Though nannies (that is, caregivers whose job it is to care for children at home in their parents' absence) have had a ubiquitous presence among professional working women and are frequently involved in the lives of patients seen in private practice, their psychological significance for both employers and charges has rarely been considered. The paper attempts to demonstrate how the nanny's literal position is at risk for engendering ambivalence in parents and children alike, since she is necessarily there when the parents are not. It is postulated that the actual, reality-based power of the nanny as placeholder for parents in their absence may be instrumental in the tendency of our patients to scotomatize this relationship. In the first part of the paper, clinical examples are used to underscore the complexity of the nanny's role, while the second half of the paper draws upon the text of the children's classic Mary Poppins, to further explore the subject.

  4. Synthesis of novel redox calix[4]arene derivative with 1,3-substituted large conjugated ferrocene bridge

    Institute of Scientific and Technical Information of China (English)

    Bi Qiong Hong; Fa Fu Yang; Hong Yu Guo; Yan Hua Wang; Xian Feng Chai


    A novel redox calix[4]arene derivative with 1,3-substituted large conjugated ferrocene bridge was designed and synthesized in high yield.Its structure was characterized by element analysis,IR,ESI-MS,NMR spectrum,etc.The primary study of cyclic voltammetry showed it possessed excellent reversible electrochemistry response property.

  5. Calix[4]arene-triacids as receptors for lanthanides; synthesis and luminescence of neutral Eu3+ and Tb3+ complexes

    NARCIS (Netherlands)

    Rudkevich, Dmitry M.; Verboom, Willem; Tol, van der Erik B.; Staveren, van Catharina J.; Kaspersen, Frans M.; Verhoeven, Jan W.; Reinhoudt, David N.


    Calix[4]arene triacids (3a–d) have been prepared that are able to form neutral complexes with lanthanides. Complexes of 3a–d with Eu3+ and Tb3+ have been studied with respect to their luminescent properties in a protic solvent (methanol). In all cases it was found that the luminescent lifetime of th

  6. 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)


    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.

  7. Synthesis, Structure, and Anticancer Activity of Arene-Ruthenium(II) Complexes with Acylpyrazolones Bearing Aliphatic Groups in the Acyl Moiety. (United States)

    Palmucci, Jessica; Marchetti, Fabio; Pettinari, Riccardo; Pettinari, Claudio; Scopelliti, Rosario; Riedel, Tina; Therrien, Bruno; Galindo, Agustin; Dyson, Paul J


    A series of neutral ruthenium(II) arene complexes [(arene)Ru(Q(R))Cl] (arene = p-cymene (cym) or hexamethylbenzene (hmb)) containing 4-acyl-5-pyrazolonate Q(R) ligands with different electronic and steric substituents (R = 4-cyclohexyl, 4-stearoyl, or 4-adamantyl) and related ionic complexes [(arene)Ru(Q(R))(PTA)][PF6] (PTA = 1,3,5-triaza-7-phosphaadamantane) were synthesized and characterized by spectroscopy (IR, UV-vis, ESI-MS, and (1)H and (13)C NMR), elemental analysis, X-ray crystallography, and density functional theory studies. The cytotoxicity of the proligands and metal complexes was evaluated in vitro against human ovarian carcinoma cells (A2780 and A2780cisR), as well as against nontumorous human embryonic kidney (HEK293) cells. In general the cationic PTA-containing complexes are more cytotoxic than their neutral precursors with a chloride ligand in place of the PTA. Moreover, the complexes do not show cross-resistance and are essentially equally cytotoxic to both the A2780 and A2780cisR cell lines, although they only show limited selectivity toward the cancer cell lines.

  8. Self-assembled arene-ruthenium-based rectangles for the selective sensing of multi-carboxylate anions. (United States)

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


    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.

  9. Self-assembly of amphiphilic anionic calix[4]arenes and encapsulation of poorly soluble naproxen and flurbiprofen. (United States)

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


    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.

  10. Colourimetric and spectroscopic discrimination between nucleotides and nucleosides using para-sulfonato-calix[4]arene capped silver nanoparticles. (United States)

    Tauran, Yannick; Grosso, Marie; Brioude, Arnaud; Kassab, Rima; Coleman, Anthony W


    The complexation of nucleosides and nucleotides by hybrid nanoparticles capped by para-sulfonato-calix[4]arene shows clear discrimination between purine and pyrimidine based molecules. For the pyrimidine nucleotides there is appearance of a new absorption band around 550 nm, and a colour change from yellow to orange red and pink.

  11. Understanding the complexation of Eu3+ with three diglycolamide-functionalized calix{4]arenes: spectroscopic and DFT studies

    NARCIS (Netherlands)

    Ansari, S.A.; Mohapatra, P.K.; Ali, S.M.; Sengupta, A; Bhattacharyya, A.; Verboom, W.


    Complexation of Eu3+ with three diglycolamide-functionalized calix[4]arene (C4DGA) ligands was investigated by UV-Vis and luminescence spectroscopy measurements in acetonitrile medium. The complexation thermodynamics was studied by micro-calorimetry while structural information was obtained from DFT

  12. Eco-friendly Oxidative Iodination of Various Arenes with Sodium Percarbonate as the Oxidantâ€

    Directory of Open Access Journals (Sweden)

    Lech Skulski


    Full Text Available Six easy laboratory procedures are presented for the oxidative iodination ofvarious aromatics, mostly arenes, with either molecular iodine or potassium iodide (usedas the sources of iodinating species, I or I3 , in the presence of sodium percarbonate(SPC, a stable, cheap, easy to handle, and eco-friendly commercial oxidant.

  13. 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


    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.

  14. Computational and Experimental Studies of Phthaloyl Peroxide-Mediated Hydroxylation of Arenes Yield a More Reactive Derivative, 4,5-Dichlorophthaloyl Peroxide. (United States)

    Camelio, Andrew M; Liang, Yong; Eliasen, Anders M; Johnson, Trevor C; Yuan, Changxia; Schuppe, Alex W; Houk, K N; Siegel, Dionicio


    The oxidation of arenes by the reagent phthaloyl peroxide provides a new method for the synthesis of phenols. A new, more reactive arene oxidizing reagent, 4,5-dichlorophthaloyl peroxide, computationally predicted and experimentally determined to possess enhanced reactivity, has expanded the scope of the reaction while maintaining a high level of tolerance for diverse functional groups. The reaction proceeds through a novel "reverse-rebound" mechanism with diradical intermediates. Mechanistic insight was achieved through isolation and characterization of minor byproducts, determination of linear free energy correlations, and computational analysis of substituent effects of arenes, each of which provided additional support for the reaction proceeding through the diradical pathway.

  15. Complex behavior and source model of the tremor at Arenal volcano, Costa Rica (United States)

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


    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

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

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


    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.

  17. Preparation and Antibacterial Activity of Inclusion Complex Sulfonatocalix[4]arene-Xanthone against Escherichia Coli (United States)

    Kusumaningsih, T.; Firdaus, M.; Suparjo, H. F.


    The preparation of inclusion complex sulfonatocalix[4]arene (SC[4]A) with xanthone and measurement of antibacterial activity against Escherichia coli have been performed. Analysis of the structure of inclusion complex between SC[4]A and xanthone was investigated by using Fourier Transform Infrared Spectroscopy (FT-IR) and H Nuclear Magnetic Resonance (H-NMR). The solubility of the product in water was examined. Surface area and porous determination were analyzed by Surface Area Analyzer (SAA). Antibacterial activity test was performed for 0, 3, 6, 9, 12, and 24 hours. The results showed that antibacterial activity of the complex of xanthone SC[4]An against Escherichia coli was higher than that of xanthone it self.

  18. Discovery of a highly tumor-selective organometallic ruthenium(II)-arene complex. (United States)

    Clavel, Catherine M; Păunescu, Emilia; Nowak-Sliwinska, Patrycja; Griffioen, Arjan W; Scopelliti, Rosario; Dyson, Paul J


    A ruthenium(II)-arene complex with a perfluoroalkyl-ligand was found to display remarkable selectivity toward cancer cells. IC50 values on several cancer cell lines are in the range of 25-45 μM, and no cytotoxic effect was observed on nontumorigenic (HEK-293) cells at concentrations up to 500 μM (the maximum concentration tested). Consequently, this complex was used as the basis for the development of a number of related derivatives, which were screened in cancerous and noncancerous cell lines. The lead compound was then evaluated in vivo for antiangiogenic activity in the CAM model and in a xenografted ovarian carcinoma tumor (A2780) grown on the CAM. A 90% reduction in the tumor growth was observed.

  19. Calix[4]arene-Based Enantioselective Fluorescent Sensors for the Recognition of N-Acetyl-aspartate

    Institute of Scientific and Technical Information of China (English)

    QING Guang-Yan; CHEN Zhi-Hong; WANG Feng; YANG Xi; MENG Ling-Zhi; HE Yong-Bing


    Two-armed chiral anion receptors (1 and 2), calix[4]arenes bearing dansyl fluorophore and (1R,2R)- or(1S,2S)-1,2-diphenylethylenediamine binding sites, were prepared and examined for their chiral amino acid anion binding abilities by the fluorescence spectra in dimethylsulfoxide (DMSO). The results of non-linear curve fitting indicate that 1 or 2 forms a 1 : 1 stoichiometry complex with N-acetyl-L-or D-aspartate by multiple hydrogen bonding interactions, exhibiting good enantioselective fluorescent recognition for the enantiomers of N-acetyl-as-partate, [receptor 1: Kass(D)/Kass(L)=6.74; receptor 2: Kass(L)/Kass(D)=6.48]. The clear fluorescent response difference indicates that receptors 1 and 2 could be used as a fluorescent chemosensor for N-Acetyl-aspartate.

  20. Arene- and quinoline-sulfonamides as novel 5-HT7 receptor ligands. (United States)

    Zajdel, Paweł; Marciniec, Krzysztof; Maślankiewicz, Andrzej; Paluchowska, Maria H; Satała, Grzegorz; Partyka, Anna; Jastrzębska-Więsek, Magdalena; Wróbel, Dagmara; Wesołowska, Anna; Duszyńska, Beata; Bojarski, Andrzej J; Pawłowski, Maciej


    Novel arene- and quinolinesulfonamides were synthesized using different solutions and a solid-support methodology, and were evaluated for their affinity for 5-HT(1A), 5-HT(2A), 5-HT(6), and 5-HT(7) receptors. Compound 54 (N-Ethyl-N-[4-(1,2,3,4,4a,5,6,7,8,8a-decahydroisoquinolin-2-yl)butyl]-8-quinolinesulfonamide) was identified as potent 5-HT(7) antagonist (K(i)=13 nM, K(B)=140 nM) with good selectivity over 5-HT(1A), 5-HT(2A), 5-HT(6) receptors. In the FST in mice, it reduced immobility in a manner similar to the selective 5-HT(7) antagonist SB-269970.

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

  2. Adsorption behavior of Am with gamma irradiated Thiacalix[4]arene impregnated silica adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Takahiro [Institute of Research and Innovation (IRI), 1201 Takada, Kashiwa, Chiba 277-0861 (Japan)]. E-mail:; Suzuki, Kazunori [Institute of Research and Innovation (IRI), 1201 Takada, Kashiwa, Chiba 277-0861 (Japan)


    Thiacalix[4]arene impregnated silica adsorbent which is called CAPS-SO{sub 2}-adsorbent in this paper shows the excellent separative performance of trivalent actinoids, such as Am from the high-level radioactive liquid waste (HLLW) in weak-acid solution. The chemical stability of the adsorbent was investigated under strong irradiation conditions. The amount of dissolved CAPS-SO{sub 2} was only 1% by gamma-ray irradiation at a total dose of 1 MGy. The value of distribution coefficient of Am (Kd{sub Am}) at pH 4 by the adsorbent was constant even the high irradiation dose. Moreover, the separation factor of Am to lanthanoids is kept a high value. It was also found that the value of Kd{sub Am} by the irradiated CAPS-SO{sub 2}-adsorbent increases at pH 2.

  3. Study on the inclusion behavior of p-sulfonatocalix[6]arene with propranolol by spectrofluorometry (United States)

    Li, Hui; Song, Jin-Ping; Chao, Jian-Bin; Shuang, Shao-Min; Dong, Chuan


    The inclusion interaction between propranolol (PPL) and p-sulfonatocalix[6]arene (SCX6) was investigated by fluorescence and 1H NMR spectroscopy. Influences of pH, temperature, ionic strength and the concentration of SCX6 were examined in detail. In phosphate buffer solution with pH 7.5, the fluorescence of PPL dramatically quenched upon addition of SCX6 revealing the formation of inclusion complexes between PPL and SCX6. The stoichiometric ratio was verified to be 1:1 by the continuous variation method. The inclusion constant of PPL-SCX6 complexes was calculated as 2.2 × 104 L/mol by the nonlinear curve fitting method. 1H NMR titration spectra testified that the aliphatic chain of PPL may be partially penetrated into the hydrophobic cavity of SCX6. This was confirmed by molecular dynamics calculations.

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

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


    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.

  5. 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


    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.

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

    Directory of Open Access Journals (Sweden)

    Imdadullah Qureshi


    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.

  7. Supramolecular Drug Delivery Systems Based on Water-Soluble Pillar[n]arenes. (United States)

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


    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.

  8. 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


    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.

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

    Institute of Scientific and Technical Information of China (English)

    Li Xiu-juan; Xiao Rui-min; Li Hai-bing; Zeng Zhao-rui


    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.

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

    Directory of Open Access Journals (Sweden)



    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.

  11. Hydrogen ion-selective poly(vinyl chloride) membrane electrode based on a calix[4]arene. (United States)

    Kuruoğlu, Demet; Canel, Esin; Memon, Shahabuddin; Yilmaz, Mustafa; Kiliç, Esma


    A hydrogen ion-selective poly(vinyl chloride) membrane electrode was constructed using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanomethoxycalix[4]arene as a neutral carrier. The electrode showed an apparent Nernstian response in the 2-11.5 pH range with a slope of 54.0 +/- 0.2 mV/pH at 20 +/- degrees C. This electrode showed a rapid response of the emf to changes in the pH, high ion selectivity with respect to lithium, sodium and potassium, and characteristics similar to those reported for the conventional pH glass membrane electrode. It can be used as a potentiometric indicator electrode in hydrofluoric acid solutions. The effects of iodide, thiocyanate, perchlorate and bromide on the characteristics of the electrode were also considered.

  12. Guest exchange in dimeric capsules formed by tetra-urea calix[4]arenes. (United States)

    Vatsouro, Ivan; Alt, Ellen; Vysotsky, Myroslav; Böhmer, Volker


    Ten tetra-urea calix[4]arene derivatives with different ether residues (methyl, pentyl, benzyl, all combinations of methyl and pentyl, 1,3-dibenzyl-2,4-dipentyl), including also the tetrahydroxy compound and the 1,3-dipentyl ether, were synthesised. Their urea groups were substituted with a lipophilic residue to ensure sufficient solubility in cyclohexane. Thus, kinetics for the exchange of the included guest (benzene) against the solvent (cyclohexane) could be followed by 1H NMR spectroscopy. The apparent first order rate constants decrease with increasing size of the ether residues from methyl to benzyl by more than three orders of magnitude. This can be understood by a decreasing flexibility/mobility of the calixarene skeleton. In line with this explanation is the rather slow exchange for the tetrahydroxy compound, where the cone conformation is stabilised by a cyclic array of intramolecular OH...OH hydrogen bonds.

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

    Directory of Open Access Journals (Sweden)

    M. Kumar


    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.

  14. Pengembangan dan Implementasi Aplikasi Pengawasan Ternak Berbasis Android di Peternakan Bukit Aren Farm Majalengka

    Directory of Open Access Journals (Sweden)

    Faraj Faraj


    Full Text Available Bukit Aren Farm located in Majalengka, West Java is a company specialized in the broiler of the agriculture industry, farming broiler performed in different places and every breeding cattle carried monitored by the supervisory staff. Every day, staf record information manually about the animal in the cage that data will be used as a performance evaluation of animal production. The livestock management personnel encountered problems when running calculations of the evaluation product and efficiency livestock because the calculation process can be done if the existing data stored carefully and systematically, in particular the data recorded cattle in significant quantities, it would require much time for staff supervision to determine the level of production performance. Application developed using waterfall method. The waterfall model is composed of: requirements, design, implementation, verification, maintenance. To begin the design steps required observations or interviews to determine the needs of the system under design. Applications developed using CodeIgniter framework, angularjs and ionic based architecture. Results of the project is the application mobile livestock monitoring data storage that can serve the number of deaths, data on the number quarantine of chicken, and the amount of data that then feed use these data will generate a data value prices and feed consumption levels of livestock mortality information for the evaluation process in the livestock in line with the business processes of Bukit Aren Farm. The application has been tested by using black box method and the results of these tests indicate that all functions in the system has been well running on the Android operating system from version 4.1.

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

    Energy Technology Data Exchange (ETDEWEB)

    Leontie, Liviu, E-mail: [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)


    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.

  16. 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


    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.

  17. 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


    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)

  18. 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


    Ikuhide Fujisawa; Katsuyuki Aoki


    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-e...

  19. The (Calix[4]arene)chloromolybdate(IV) anion [MoCl(Calix)](-): a convenient entry into molybdenum Calix[4]arene chemistry. (United States)

    Radius, Udo; Attner, J


    The complex (HNEt(3))[MoCl(NCMe)(Calix)] (1), prepared from the reaction of [MoCl(4)(NCMe)(2)] with p-tert-butylcalix[4]arene, H(4)Calix, in the presence of triethylamine, has been used as a source of the d(2)-[Mo(NCMe)(Calix)] fragment. Complex 1 is readily oxidized with PhICl(2) to afford the molybdenum(VI) dichloro complex [MoCl(2)(Calix)] (2). Both complexes are a convenient entry point into molybdenum(VI) and molybdenum(IV) calixarene chemistry. The reaction of 1 with trimethylphosphine and pyridine in the presence of catalytic amounts [Ag(OTf)] led to the formation of neutral d(2) complexes [Mo(PMe(3))(NCMe)(Calix)] (3) and [Mo(NC(5)H(5))(NCMe)(Calix)] (4). The role of the silver salt in the reaction mixture is presumably the oxidation of the chloromolybdate anion of 1 to give a reactive molybdenum(V) species. The same reactions can also be initiated with ferrocenium cations such as [Cp(2)Fe](BF(4)). Without the presence of coordinating ligands, the dimeric complex [[Mo(NCMe)(Calix)](2)] (5) was isolated. The reaction of 1 with Ph(2)CN(2) led to the formation of a metallahydrazone complex [Mo(N(2)CPh(2))(NCMe)(Calix)] (6), in which the diphenyldiazomethane has been formally reduced by two electrons. Molybdenum(VI) complexes were also obtained from reaction of 1 with azobenzene and sodium azide in the presence of catalytic amounts of silver salt. The reaction with azobenzene led under cleavage of the nitrogen nitrogen bond to an imido complex [Mo(NPh)(NCMe)(Calix)] (7), whereas the reaction with sodium azide afforded the mononuclear molybdenum(VI) nitrido complex (HNEt(3))[MoN(Calix)] (8).

  20. 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 (United States)

    Chen, Zi; Wu, Yan; Wei, Yuezhou


    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.

  1. Langmuir monolayers and thin films of amphifilic thiacalix[4]arenes. Properties and matrix for the immobilization of cytochrome c. (United States)

    Solovieva, Svetlana E; Safiullin, Roman A; Kochetkov, Evgeni N; Melnikova, Nina B; Kadirov, Marsil K; Popova, Elena V; Antipin, Igor S; Konovalov, Alexander I


    Formation and properties of Langmuir films of thiacalix[4]arene (TCA) derivatives containing N-donor groups on the lower rim (Y═O(CH2)3CN; OCH2CN; NH2; OCH2ArCN-p) in 1,3-alternate conformation on aqueous subphase and solid substrates have been studied. Only tetra-cyanopropoxy-p-tert-butylthiacalix[4]arene 1 forms a typical monomolecular layer with perpendicular orientation of the macrocycle relative to the water-air interface that is able to immobilize cytochrome c in the entire range of the surface pressure. Obtained monolayers were transferred by Langmuir-Schaefer technique onto quartz, indium-tin oxide (ITO), and silicon. It was demonstrated that protein activity is retained after immobilization on the substrate.

  2. Thiacalix[4]arene functionalized gold nano-assembly for recognition of isoleucine in aqueous solution and its antioxidant study (United States)

    Darjee, Savan M.; Bhatt, Keyur; Kongor, Anita; Panchal, Manthan K.; Jain, Vinod K.


    Thiacalix[4]arenes comes under heteracalixarene class which has notable utility in the area of nanoscience. This stimulation has led to the synthesis of water-dispersible gold nanoparticles (AuNps) using thiacalix[4]arene tetrahydrazide (TCTH) as both reducing as well as stabilizing agent. The synthesized nanoparticles (TCTH-AuNps) were characterized by SPR, TEM and EDX. TCTH-AuNps were found to be selective and sensitive for isoleucine. The concentration of isoleucine was detected in the limit of 1 nM to 1.2 μM based on fluorescence enhancement. TCTH-AuNps were also used to measure antioxidant capacity against the standard ascorbic acid.

  3. 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


    @@ 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.

  4. 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


    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.

  5. Sulfinylcalix[4]arene-impregnated amberlite XAD-7 resin for the separation of niobium(V) from tantalum(V). (United States)

    Matsumiya, Hiroaki; Yasuno, Shizu; Iki, Nobuhiko; Miyano, Sotaro


    Amberlite XAD-7 resin was impregnated with p-tert-butylsulfinylcalix[4]arene. Niobium(V) was collected on the impregnated resin in yields of more than 90% around pH 5.4, whereas tantalum(V) was negligibly collected. The collected niobium(V) was desorbed with 9 M sulfuric acid nearly quantitatively, hence the separation of niobium(V) from tantalum(V) was successfully achieved.

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

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


    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.

  7. 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


    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.

  8. Detoxification of VX and Other V‐Type Nerve Agents in Water at 37 °C and pH 7.4 by Substituted Sulfonatocalix[4]arenes (United States)

    Schneider, Christian; Bierwisch, Anne; Koller, Marianne; Worek, Franz


    Abstract Sulfonatocalix[4]arenes with an appended hydroxamic acid residue can detoxify VX and related V‐type neurotoxic organophosphonates with half‐lives down to 3 min in aqueous buffer at 37 °C and pH 7.4. The detoxification activity is attributed to the millimolar affinity of the calixarene moiety for the positively charged organophosphonates in combination with the correct arrangement of the hydroxamic acid group. The reaction involves phosphonylation of the hydroxamic acid followed by a Lossen rearrangement, thus rendering the mode of action stoichiometric rather than catalytic. Nevertheless, these calixarenes are currently the most efficient low‐molecular‐weight compounds for detoxifying persistent V‐type nerve agents under mild conditions. They thus represent lead structures for novel antidotes that allow treatment of poisonings by these highly toxic chemicals. PMID:27627873

  9. Theoretical study on interactions of fluorinated organomercurials with arene and gold fragments. (United States)

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


    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.

  10. Hybrid liposomal PEGylated calix[4]arene systems as drug delivery platforms for curcumin. (United States)

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


    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.

  11. Supramolecular gels with high strength by tuning of calix[4]arene-derived networks (United States)

    Lee, Ji Ha; Park, Jaehyeon; Park, Jin-Woo; Ahn, Hyo-Jun; Jaworski, Justyn; Jung, Jong Hwa


    Supramolecular gels comprised of low-molecular-weight gelators are generally regarded as mechanically weak and unable to support formation of free-standing structures, hence, their practical use with applied loads has been limited. Here, we reveal a technique for in situ generation of high tensile strength supramolecular hydrogels derived from low-molecular-weight gelators. By controlling the concentration of hydrochloric acid during hydrazone formation between calix-[4]arene-based gelator precursors, we tune the mechanical and ductile properties of the resulting gel. Organogels formed without hydrochloric acid exhibit impressive tensile strengths, higher than 40 MPa, which is the strongest among self-assembled gels. Hydrogels, prepared by solvent exchange of organogels in water, show 7,000- to 10,000-fold enhanced mechanical properties because of further hydrazone formation. This method of molding also allows the gels to retain shape after processing, and furthermore, we find organogels when prepared as gel electrolytes for lithium battery applications to have good ionic conductivity. PMID:25799459

  12. Mirror-image organometallic osmium arene iminopyridine halido complexes exhibit similar potent anticancer activity. (United States)

    Fu, Ying; Soni, Rina; Romero, María J; Pizarro, Ana M; Salassa, Luca; Clarkson, Guy J; Hearn, Jessica M; Habtemariam, Abraha; Wills, Martin; Sadler, Peter J


    Four chiral Os(II) arene anticancer complexes have been isolated by fractional crystallization. The two iodido complexes, (S(Os),S(C))-[Os(η(6)-p-cym)(ImpyMe)I]PF6 (complex 2, (S)-ImpyMe: N-(2-pyridylmethylene)-(S)-1-phenylethylamine) and (R(Os),R(C))-[Os(η(6)-p-cym)(ImpyMe)I]PF6 (complex 4, (R)-ImpyMe: N-(2-pyridylmethylene)-(R)-1-phenylethylamine), showed higher anticancer activity (lower IC50 values) towards A2780 human ovarian cancer cells than cisplatin and were more active than the two chlorido derivatives, (S(Os),S(C))-[Os(η(6)-p-cym)(ImpyMe)Cl]PF6, 1, and (R(Os),R(C))-[Os(η(6)-p-cym)(ImpyMe)Cl]PF6, 3. The two iodido complexes were evaluated in the National Cancer Institute 60-cell-line screen, by using the COMPARE algorithm. This showed that the two potent iodido complexes, 2 (NSC: D-758116/1) and 4 (NSC: D-758118/1), share surprisingly similar cancer cell selectivity patterns with the anti-microtubule drug, vinblastine sulfate. However, no direct effect on tubulin polymerization was found for 2 and 4, an observation that appears to indicate a novel mechanism of action. In addition, complexes 2 and 4 demonstrated potential as transfer-hydrogenation catalysts for imine reduction.

  13. Photorelease of Pyridyl Esters in Organometallic Ru(II Arene Complexes

    Directory of Open Access Journals (Sweden)

    Abraha Habtemariam


    Full Text Available New Ru(II arene complexes of formula [(η6-p-cymRu(N-N(X]2+ (where p-cym = para-cymene, N-N = 2,2'-bipyrimidine (bpm or 2,2'-bipyridine (bpy and X = m/p-COOMe-Py, 1–4 were synthesised and characterized, including the molecular structure of complexes [(η6-p-cymRu(bpy(m-COOMe-Py]2+ (3 and [(η6-p-cymRu(bpy (p-COOMe-Py]2+ (4 by single-crystal X-ray diffraction. Complexes 1–4 are stable in the dark in aqueous solution over 48 h and photolysis studies indicate that they can photodissociate the monodentate m/p-COOMe-Py ligands selectively with yields lower than 1%. DFT and TD-DFT calculations (B3LYP/LanL2DZ/6-31G** performed on singlet and triplet states pinpoint a low-energy triplet state as the reactive state responsible for the selective dissociation of the monodentate pyridyl ligands.

  14. Highly selective and sensitive fluorescent sensor: Thiacalix[4]arene-1-naphthalene carboxylate for Zn2+ ions (United States)

    Darjee, Savan M.; Modi, Krunal M.; Panchal, Urvi; Patel, Chirag; Jain, Vinod K.


    Thiacalix[4]arene based fluorescent sensor bearing two naphthoyl groups, thiacalix-1-naphthalene carboxylate (TCNC) has been synthesized and characterized by 1H NMR, 13C NMR, FTIR, ESI-MS spectroscopic techniques. The interaction behavior of TCNC with various metal ions like Fe3+, Hg2+, Co2+, Ni2+, Cu2+, Cd2+, Pb2+, Mg2+, K+, Na+, and Zn2+ was studied by UV-visible and emission spectrophotometry. It was observed that TCNC recognizes Zn2+ ions with high selectivity and sensitivity. The enhancement of fluorescence intensity due to presence of Zn2+ ions was not perturbed in the presence of high concentration of other associated metal ions. The 1:1 stoichiometry of TCNC:Zn2+ complex was confirmed by job's plot, ESI-MS study and 1H NMR titration. The binding constant and quantum yield were also calculated by using spectrofluorimetric titration data. Linear detection range of zinc ions was found to be 1 nM-740 nM. Furthermore, molecular docking study was performed to evaluate the binding affinity and possible interactions between TCNC and Zn2+ depicting that TCNC interact with Zn2+ via weak intramolecular forces. In addition to that molecular dynamics has also been performed to evaluate the conformational changes and it's structural stability in the particular environment.

  15. Calix[4]arene based dipodal receptor nanohybrids for selective determination of chloride ions in aqueous media. (United States)

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


    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.

  16. 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


    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.

  17. Evaluation of Factors Affecting Cesium Extraction Performance by Calix[4]Arene Derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Rumppe, J.L.; Delmau, L.


    Novel aza-crown derivatives of dioctyloxy-calix[4]arene crown-6 were examined for their cesium extraction performance at different pH levels. These studies are of interest in addressing high-level waste tank remediation and the removal of 137Cs, a major contributor to heat and radiation generation. Preliminary studies were done to assess the performance of these calixarene compounds under varying conditions. Results showed an increase of cesium extraction with pH as well as expected trends in diluent effects and anion selectivity. Poor extraction performance of some aza-crown derivatives raised questions regarding the possibility of intramolecular hydrogen-bonding. A novel methylated derivative was used to address these questions. Additional experiments were conducted to determine the extraction effect on pH. Results indicate an increase in cesium extraction with pH, as shown in preliminary studies. Mono-aza derivatives were shown to exhibit better cesium extraction performance than their di-aza counterparts. The methylated derivative showed poorer extraction performance than the non-methylated derivative, indicating that completely removing the possibility of intramolecular hydrogen-bonding has negative effects on extraction performance. This suggests that the hydrogen-bonding facilitates anion co-extraction, which would lead to better overall extraction. Mono-aza derivatives were shown to cause unexpected changes in pH. This could possibly be attributed to protonation of the calix crown.


    Directory of Open Access Journals (Sweden)



    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

  19. Biosensor for dopamine based on stabilized lipid films with incorporated resorcin[4]arene receptor. (United States)

    Nikolelis, Dimitrios P; Theoharis, George


    This work reports a technique for the stabilization after storage in air of a lipid film with incorporated resorcin[4]arene receptor based biosensor for dopamine. Microporous filters composed of glass fibers (nominal pore sizes, 0.7 and 1.0 microm) were used as supports for the formation and stabilization of these devices and the lipid film is formed on the filter by polymerization prior its use. Methacrylic acid was the functional monomer, ethylene glycol dimethacrylate was the crosslinker and 2,2'-azobis-(2-methylpropionitrile) was the initiator. The stability of the lipid films by incorporation of a receptor for the preparation of stabilized lipid film biosensor is studied throughout this work. The response towards dopamine of the present stabilized for repetitive uses lipid membrane biosensor composed of dipalmitoyl phosphatidylcholine and dipalmitoyl phosphatidic acid was compared with planar freely suspended bilayer lipid membranes (BLMs). The stabilized lipid membranes provided similar artificial ion gating events as BLMs in the form of transient signals and can function for repetitive uses after storage in air. However, the response of the stabilized lipid films was slower than that of the freely suspended BLMs. This will allow the practical use of the techniques for chemical sensing based on lipid films and commercialization of these devices, because it is now possible to prepare stabilized lipid film based biosensors and store them in the air.

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

    Directory of Open Access Journals (Sweden)

    Hongxia Chen


    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.

  1. Efficient catalytic phosphate diester cleavage by the synergetic action of two Cu(II) centers in a dinuclear cis-diaqua Cu(II) calix[4]arene enzyme model

    NARCIS (Netherlands)

    Molenveld, Peter; Engbersen, Johan F.J.; Kooijman, Huub; Spek, Anthony L.; Reinhoudt, David N.


    A calix[4]arene derivative 2-[Cu(II)]2 functionalized with two cis-diaqua Cu(II) centers at the distal positions of the upper rim was synthesized and investigated as a model for dinuclear metalloenzymes that catalyze chemical transformations of phosphate esters. The flexible dinuclear calix[4]arene

  2. Parental Involvement


    Ezra S Simon


    This study was conducted in Ghana to investigate, (1) factors that predict parental involvement, (2) the relationship between parental home and school involvement and the educational achievement of adolescents, (3) the relationship between parental authoritativeness and the educational achievement of adolescent students, (4) parental involvement serving as a mediator between their authoritativeness and the educational achievement of the students, and (5) whether parental involvement decreases...

  3. Thermo gravimetric analysis of supramolecular complexes of p-tert-butylcalix[6]arene and ammonium cations: crystal structure of diethylammonium complex

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarotto, Marcio [Departamento de Quimica Organica, UFRGS, Av. Bento Goncalves 9500, CEP 91501 970, C.P. 15003, Porto Alegre, Rio Grande do Sul (Brazil)]. E-mail:; Nachtigall, Francine Furtado [Departamento de Quimica Organica, UFRGS, Av. Bento Goncalves 9500, CEP 91501 970, C.P. 15003, Porto Alegre, Rio Grande do Sul (Brazil); Schnitzler, Egon [Departamento de Quimica, Universidade Estadual de Ponta Grossa, Campus de Uvaranas, Av. General Carlos Cavalcanti 4748, CEP 84030 900 Ponta Grossa, Parana, Brazil. (Brazil); Castellano, Eduardo Ernesto [Departamento de Fisica, Universidade de Sao Paulo, Sao Carlos, Av. Trabalhador Saocarlense 400, Centro, CEP 13566-590, Sao Carlos, SP (Brazil)


    Thermo gravimetric analysis of ammonium-p-tert-butylcalix[6]arene salts were carried out to determine the stoichiometry of the inclusion compounds and the temperature of leaving of the ammonium cation, as amine, from the solid phase by a reverse proton transfer reaction to calixarene. The chain length of the amine molecules and their relative basicity order are the main factors which determine the decomplexation temperatures for the ammonium salts of piperidinium, diethylammonium, ethylenediammonium, morpholinium, s-butylammonium, butylammonium, hexylammonium and triethylammonium salts of p-tert-butylcalix[6]arene anion. The solid state structure of bis-diethylammonium-p-tert-butylcalix[6]arene dianion is reported. The calix moiety adopts a 1,2,3 alternate conformation, with one ammonium as exo-calix and other as endo-calix, with an intricate array of hydrogen bonds between phenol, phenolate and ammonium cations.

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

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


    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.

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

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


    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.

  6. 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.


    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

  7. Shaping the cavity of the macrocyclic ligand in metallocalix[4]arenes: the role of the ligand sphere. (United States)

    Radius, U


    The coordination form of calix[4]arene ligands and therefore the cavity of the macrocyclic ligand can be controlled by other ligands in transition metal calix[4]arene complexes, if strong directing coligands such as oxo groups are used. This paper describes the synthesis and characterization of the d(0) transition metal complexes [Cax(OMe)(2)O(2)TiCl(2)] 1 (monoclinic, space group P2(1)/c, lattice constants a = 21.639(4), b = 20.152(3), c = 12.750(3) A, beta = 95.68(3), V = 5532.6(19) A(3)) and [Cax(OMe)(2)O(2)MoO(2)] 2 (monoclinic, space group P2/c, lattice constants a = 12.433(3), b = 16.348(3), c = 24.774(5) A, beta = 99.15(3), V = 4971.6(17) A(3)). Whereas in 1 the calix[4]arene ligand adopts an elliptically distorted cone conformation, the macrocyclic ligand binds in a paco-like conformation to the metal center of 2, in the solid state and in solution. This was predicted by density functional theory calculations on models of different isomers of 1 and 2: cis,cone-1',2', trans,cone-1',2', and cis,paco-1',2'. According to these calculations, the energetic difference of 72.9 kJ/mol between both cis-dioxomolybdenum compounds is quite pronounced in favor of the cis,paco isomer, and 28.0 kJ/mol for the titanium compounds in favor of the cis,cone isomer.

  8. 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


    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.

  9. 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


    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.

  10. Enantioselective Fluorescent Sensor Based on Calix[4]arene and S-Binol for the Recognition of N-Boc-glutamate

    Institute of Scientific and Technical Information of China (English)

    HU Chenguang; HUANG Xiaohuan; CHEN Zhihong; HE Yongbing


    A new chiral macrocyclic receptor 4 based on calix[4]arene and S-binol units was synthesized. The binding properties for anions were examined by fluorescence and 、1H NMR spectra. The results of non-linear curve fitting indicated that the receptor 4 formed a 1 : 1 stoichiometry complex with N-Boc-L- or D-glutamate by multiple hy-drogen bonding interactions, exhibiting a good enantioselective fluorescent recognition for the enantiomers of N-Boc-glutamate. The enantioselectivity: Kass(L)/Kass(D)=4.65. The different fluorescent response indicates that the receptor 4 could be used as a fluorescent chemosensor for N-Boc-glutamate.

  11. Development of ultrafast photochromic organometallics and photoinduced linkage isomerization of arene chromium carbonyl derivatives. (United States)

    To, Tung T; Heilweil, Edwin J; Duke, Charles B; Ruddick, Kristie R; Webster, Charles Edwin; Burkey, Theodore J


    We review recent studies of processes relevant to photoinduced linkage isomerization of organometallic systems with the goal of preparing organometallics with an efficient and ultrafast photochromic response. The organometallic system thus corresponds to two linkage isomers with different electronic environments that are responsible for different optical properties. Much of this work has focused on examining processes following irradiation of cyclopentadienyl manganese tricarbonyl derivatives (compounds 3-21) including solvent coordination, thermal relaxation, solvent displacement by tethered functional groups (chelation), dissociation of tethered functional groups, and linkage isomerization. A new platform is investigated for obtaining a photochromic response in new experiments with arene chromium dicarbonyl complexes. A photochromic response is observed for arene chromium dicarbonyl complexes with tethered pyridine and olefin functional groups based on light-driven linkage isomerization on the nanosecond time scale. Irradiation at 532 nm of 23 ([Cr{eta(6)-C(6)H(5)CH(2-Py-kappaN)CH(2)CH=CH(2)}(CO)(2)]) (Py = pyridine) results in the isomerization to 22 ([Cr{eta(6)-C(6)H(5)CH(2-Py)CH(2)-eta(2)-CH=CH(2)}(CO)(2)]), and 355 nm irradiation isomerizes 22 to 23. The ultrafast linkage isomerization has been investigated at room temperature in n-heptane solution on the picosecond to microsecond time scale with UV- or visible-pump and IR-probe transient absorption spectroscopy by comparing the dynamics with model compounds containing only a tethered pyridine. Irradiation of 24 ([Cr{eta(6)-C(6)H(5)(CH(2))(3)(2-Py)}(CO)(3)]) and 25 ([Cr{eta(6)-C(6)H(5)(CH(2))(2)(2-Py)}(CO)(3)]) at 289 nm induces CO loss to immediately yield a Cr-heptane solvent coordinated intermediate of the unsaturated Cr fragment, which then converts to the kappaN(1)-pyridine chelate within 200 and 100 ns, respectively. Irradiation of 26 ([Cr{eta(6)-C(6)H(5)CH(2)(2-Py)}(CO)(3)]) also induces CO loss to

  12. [Study on the inclusion behavior of p-sulphonatocalix[4]arene with acridine by spectrofluorometric titrations]. (United States)

    Zhou, Yun-You; Lu, Qin; Liu, Chun; She, Shi-Ke; Yang, Xu-Lai; Wang, Lun


    p-sulphonatocalix[4] arene (1) was prepared according to the literature, and spectrofluorometric titrations were performed to investigate the inclusion behavior of (1) and acridine in citrate buffer solution (pH 5.92, 0.1 mol x L(-1)) at different temperatures. It was found that in definite concentration range, the emission peak of acridine exhibited a slight red shift and th fluorescence intensity decreased when (1) was added. They form stable host-guest complex, and the stoichiometry of the inclusion complex is 1 : 1. The stability constants of the inclusion complex at 15.0 degrees C, 20.0, 25.0 and 30.0 degrees C were determined as 3.08 x 10(5), 4.45 x 10(4), 2.58 x 10(4) and 8.90 x 10(3), respectively. The thermodynamic parameters of inclusion process, deltaG, deltaH and deltaS, were determined. The experimental results indicated that the inclusion process was an exothermic and enthalpy-driven process. It was found that the stability constants descended when temperature rose. The most probable pattern of the inclusion complex between (1) and acridine was proposed as: acridine partially goes into the cavity of (1), and the protonated N atom and the negatively charged sulphonyl group bond firmly owing to strong electrostatic interaction. With the main contribution of electrostatic interaction and the assistance of Van de Waals and hydrophobic interaction, the host and the guest molecules form 1 : 1 supramolecular complex.

  13. 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. (United States)

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


    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.

  14. 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)


    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.

  15. A simple and rapid creatinine sensing via DLS selectivity, using calix[4]arene thiol functionalized gold nanoparticles. (United States)

    Sutariya, Pinkesh G; Pandya, Alok; Lodha, Anand; Menon, Shobhana K


    A new, simple, ultra-sensitive and selective approach has been reported for the "on spot" colorimetric detection of creatinine based on calix[4]arene functionalized gold nanoparticles (AuNPs) with excellent discrimination in the presence of other biomolecules. The lower detection limit of the method is 2.16nM. The gold nanoparticles and p-tert-butylcalix[4]arene were synthesized by microwave assisted method. Specifically, in our study, we used dynamic light scattering (DLS) which is a powerful method for the determination of small changes in particle size, improved selectivity and sensitivity of the creatinine detection system over colorimetric method. The nanoassembly is characterized by Transmission electron microscopy (TEM), DLS, UV-vis and ESI-MS spectroscopy, which demonstrates the binding affinity due its ability of hydrogen bonding and electrostatic interaction between -NH group of creatinine and pSDSC4. It exhibits fast response time (creatinine and has long shelf-life (>5 weeks). The developed pSDSC4-AuNPs based creatinine biosensor will be established as simple, reliable and accurate tool for the determination of creatinine in human urine samples.

  16. Photodissociation of a ruthenium(II) arene complex and its subsequent interactions with biomolecules: a density functional theory study. (United States)

    Wang, Hanlu; DeYonker, Nathan J; Zhang, Xiting; Zhao, Cunyuan; Ji, Liangnian; Mao, Zong-Wan


    The piano-stool Ru(II) arene complex [(η⁶-benz)Ru(bpm)(py)]²⁺ (benz = benzene, bpm = 2,2'-bipyrimidine, and py = pyridine), which is conventionally nonlabile (on a timescale and under conditions relevant for biological reactivity), can be activated by visible light to selectively photodissociate the monodentate ligand (py). In the present study, the aquation and binding of the photocontrolled ruthenium(II) arene complex [(η⁶-benz)Ru(bpm)(py)]²⁺ to various biomolecules are studied by density functional theory (DFT) and time-dependent DFT (TDDFT). Potential energy curves (PECs) calculated for the Ru-N (py) bonds in [(η⁶-benz)Ru(bpm)(py)]²⁺ in the singlet and triplet state give useful insights into the photodissociation mechanism of py. The binding energies of the various biomolecules are calculated, which allows the order of binding affinities among the considered nuleic-acid- or protein-binding sites to be discerned. The kinetics for the replacement of water in the aqua complex with biomolecules is also considered, and the results demonstrate that guanine is superior to other biomolecules in terms of coordinating with the Ru(II) aqua adduct, which is in reasonable agreement with experimental observations.

  17. A new ligand system based on a bipyridine-functionalized calix[4]arene backbone leading to mono- and bimetallic complexes. (United States)

    Dorta, Reto; Shimon, Linda J W; Rozenberg, Haim; Ben-David, Yehoshoa; Milstein, David


    The synthesis of a new ligand system for mono- and bimetallic complexes based on a calixarene is described. Ligand BBPC (3, bis(bipyridine)-calix[4]arene) is obtained in three steps in 40% overall yield by first brominating one of the methyl groups of the 4,4'-dimethyl-2,2'-bipyridine in two steps and subsequently reacting it with p-tert-butylcalix[4]arene under basic conditions. Reaction of BBPC (3) with 2 equiv of [Rh(NBD)(2)]BF(4) or [Rh(NBD)(CH(3)CN)(2)]BF(4) (NBD = norbornadiene) produces the bimetallic compound BBPC[Rh(NBD)BF(4)](2) (4). Treatment of the ligand with PdCl(2)(CH(3)CN)(2) leads to the isolation of the bimetallic complex BBPC[PdCl(2)](2) (5). When the nickel precursor NiBr(2)(DME) (DME = dimethoxyethane) is reacted with BBPC, the bimetallic complex BBPC[NiBr(2)](2) (6) is isolated which, upon crystallization from methanol, gives the mononuclear bis(bipyridine) complex BBPC[NiBr(OMe)] (7). Full characterization includes X-ray structural studies of complexes 4, 5, and 7. The bimetallic compounds 4 and 5 show metal to metal distances of 4.334 A (for 4) and 3.224 A (for 5). For all three complexes, unique molecular packing arrangements were found, based on hydrophobic/hydrophilic interactions.

  18. Benzocaine complexation with p-sulfonic acid calix[n]arene: experimental ((1) H-NMR) and theoretical approaches. (United States)

    Arantes, Lucas M; Varejão, Eduardo V V; Pelizzaro-Rocha, Karin J; Cereda, Cíntia M S; de Paula, Eneida; Lourenço, Maicon P; Duarte, Hélio A; Fernandes, Sergio A


    The aim of this work was to study the interaction between the local anesthetic benzocaine and p-sulfonic acid calix[n]arenes using NMR and theoretical calculations and to assess the effects of complexation on cytotoxicity of benzocaine. The architectures of the complexes were proposed according to (1) H NMR data (Job plot, binding constants, and ROESY) indicating details on the insertion of benzocaine in the cavity of the calix[n]arenes. The proposed inclusion compounds were optimized using the PM3 semiempirical method, and the electronic plus nuclear repulsion energy contributions were performed at the DFT level using the PBE exchange/correlation functional and the 6-311G(d) basis set. The remarkable agreement between experimental and theoretical approaches adds support to their use in the structural characterization of the inclusion complexes. In vitro cytotoxic tests showed that complexation intensifies the intrinsic toxicity of benzocaine, possibly by increasing the water solubility of the anesthetic and favoring its partitioning inside of biomembranes.

  19. Efficient anodic and direct phenol-arene C,C cross-coupling: the benign role of water or methanol. (United States)

    Kirste, Axel; Elsler, Bernd; Schnakenburg, Gregor; Waldvogel, Siegfried R


    C,C cross-coupling reactions for the synthesis of nonsymmetrical biaryls represent one of the most significant transformations in contemporary organic chemistry. A variety of useful synthetic methods have been developed in recent decades, since nonsymmetrical biaryls play an evident role in natural product synthesis, as ligand systems in homogeneous catalysis and materials science. Transformation of simple arenes by direct C,H activation belongs to the cutting-edge strategies for creating biaryls; in particular the 2-fold C,H activation is of significant interest. However, in most examples very costly noble metal catalysts, ligand systems, and significant amount of waste-producing oxidants are required. Electrochemical procedures are considered as inherently "green" methods, because only electrons are required and therefore, no reagent waste is produced. Here, we report a metal-free electrochemical method for cross-coupling between phenols and arenes using boron-doped diamond (BDD) anodes in fluorinated media. Our sustainable approach requires no leaving functionalities. Employing water or methanol as mediator represents the key improvement for achieving nonsymmetrical biaryls with superb selectivity and synthetic attractive yields.

  20. The effect of alcohol structures on the interaction mode with the hexameric capsule of resorcin[4]arene. (United States)

    Slovak, Sarit; Cohen, Yoram


    After more than a century of research on resorcin[4]arenes (1) it is clear that such systems form spontaneously [1(6)(H(2)O)(8)]-type hexameric capsules in wet, non-polar, organic solvents. However, the interactions of these hexameric capsules with alcohols are far from being solved. Here we provide the results of an extensive study on the interaction of different alcohols with the hexameric capsules of resorcin[4]arene 1a by focusing on the exchange of magnetization manifested in diffusion NMR measurements of such capsular systems. We found that some alcohols such as 2-octyl-1-dodecanol and 1-octadecanol do not interact with the hexamers of 1a, whereas other alcohols such as 3-ethyl-3-pentanol, 2-ethyl-1-butanol and more act as simple guests and are simply encapsulated in the hexamers. Others alcohols such as 3-pentanol, 2-methyl-1-butanol and others, are part of the hexameric structure where they can exchange magnetization with alcohols in the bulk. The bulkier alcohols, due to an increase of the chain length or in branching, have a higher tendency to be encapsulated rather than being part of the hexameric capsule superstructure. This study demonstrate the unique information that diffusion NMR spectroscopy can provide on supramolecular systems in solution and on the precaution that should be exercised when analyzing diffusion NMR data of such dynamic supramolecular capsules.

  1. 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.


    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

  2. 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.


    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

  3. 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.


    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

  4. QCM Coated with Self-assembled Cystine-bearing 1,3-Bridged Calix[4]arenes for Recognizing Gas-phase Butylamines

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-Yuan; YIN Hong-Zong; HE Xi-Wen; CHEN Lang-Xing; ZHANG Guo-Zhu; HE Jia-Qi


    Two cystine-bearing 1,3-bridged calix[4]arenes were used as the coatings of the quartz crystal microbalance (QCM) with gold electrodes. The two calix[4]arene derivatives were self-assembled onto the gold electrode surface by the covalent attachment between the di-sulfur and gold. The compound of cystine-bearing bi-phenylalanine 1,3-bridged calix[4]arene (CPC) with longer alkyl chain had better self-assembled capacity onto the fresh surfaces of gold electrode than that of cystine-bearing 1,3-bridged calix[4]arene (CC) with comparably shorter alkyl chain.The modified QCM sensors were used to recognize the butylamine isomers in gas. The results showed that the QCM coated with both compounds had preferential affinity to n-butylamine, then i-butylamine, t-butylamine in the range of low concentrations, indicating that in the recognition process, the steric hindrance effect played an important role when forming complex with guest molecules. When the concentrations of the analytes were increased, the polarity and the magnetism of the butylamine became determinative factors. The reversibility was improved greatly and the equilibrium time was much shorter on the self-assembled film than on the film obtained by dropping coating.

  5. 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


    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.

  6. Antioxidant and DPPH (1,1-diphenyl-2-picrylhydrazyl Free Radical Scavenging Activities of New the Calix[4]arene-bodipy Derivative

    Directory of Open Access Journals (Sweden)

    E. ERDEM


    Full Text Available p-tert-butylcalix[4]arene was synthesized with the condesation reaction of p-tert-butylphenol and formaldehyde in basic conditions and then has derivatized from the both of two hydroxyl position with chloride which is containing donor oxygen atoms. BODIPY compound (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene was synthesized with appropriate pyrrole and aldehyde compounds and then was bonded p-tert-butylcalix[4]arene derivative via lower rim hydroxyl groups.The antioxidant activity of the calix[4]arene-BODIPY compound were determined using β-karotene-linoleic acid system. Moreover, the free radical scavenging activity values were tested with DPPH free radical. The compound showed strong antioxidant activity.Total antioxidant activity of the compound was determined using β–carotenelinoleic acid model system and was found the antioxidant activity of 72,50%. The free radical scavenging activities were determined as 75.19%. Results show that, calix[4]arene-BODIPY compound has the antioxidant activity. 

  7. Monofunctionalization of Calix[4]arene Tetracarboxylic Acid at the Upper Rim with Isothiocyanate Group: First Bifunctional Chelating Agent for Alpha-Emitter Ac-225. (United States)

    Chen, Xiaoyuan; Ji, Min; Fisher, Darrell R; Wai, Chien M


    A procedure is reported for synthesizing a novel, water-soluble bifunctional chelating agent derived from calix[4]arene. This chelate features tetracarboxylic acid groups at the lower rim as an actinium-225 ionophore, and an isothiocyanate functional group at the upper rim for labeling of the N-terminus of monoclonal antibodies through thiourea linkage.

  8. 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:


    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.

  9. Synthesis and reactivity of calix[4]arene-supported group 4 imido complexes. (United States)

    Dubberley, Stuart R; Friedrich, Andreas; Willman, David A; Mountford, Philip; Radius, Udo


    New mononuclear titanium and zirconium imido complexes [M(NR)(R'(2)calix)] [M=Ti, R'=Me, R=tBu (1), R=2,6-C(6)H(3)Me(2) (2), R=2,6-C(6)H(3)iPr(2) (3), R=2,4,6-C(6)H(2)Me(3) (4); M=Ti, R'=Bz, R=tBu (5), R=2,6-C(6)H(3)Me(2) (6), R=2,6-C(6)H(3)iPr(2) (7); M=Zr, R'=Me, R=2,6-C(6)H(3)iPr(2) (8)] supported by 1,3-diorganyl ether p-tert-butylcalix[4]arenes (R'(2)calix) were prepared in good yield from the readily available complexes [MCl(2)(Me(2)calix)], [Ti(NR)Cl(2)(py)(3)], and [Ti(NR)Cl(2)(NHMe(2))(2)]. The crystallographically characterised complex [Ti(NtBu)(Me(2)calix)] (1) reacts readily with CO(2), CS(2), and p-tolyl-isocyanate to give the isolated complexes [Ti[N(tBu)C(O)O](Me(2)calix)] (10), [[Ti(mu-O)(Me(2)calix)](2)] (11), [[Ti(mu-S)(Me(2)calix)](2)] (12), and [Ti[N(tBu)C(O)N(-4-C(6)H(4)Me)](Me(2)calix)] (13). In the case of CO(2) and CS(2), the addition of the heterocumulene to the Ti-N multiple bond is followed by a cycloreversion reaction to give the dinuclear complexes 11 and 12. The X-ray structure of 13.4(C(7)H(8)) clearly establishes the N,N'-coordination mode of the ureate ligand in this compound. Complex 1 undergoes tert-butyl/arylamine exchange reactions to form 2, 3, [Ti(N-4-C(6)H(4)Me)(Me(2)calix)] (14), [Ti(N-4-C(6)H(4)Fc)(Me(2)calix)] (15) [Fc=Fe(eta(5)-C(5)H(5))(eta(5)-C(5)H(4))], and [[Ti(Me(2)calix)](2)[mu-(N-4-C(6)H(4))(2)CH(2)

  10. Community involvement

    Directory of Open Access Journals (Sweden)

    Editorial Office


    Full Text Available Community involvement is the main theme of Health Year. Governments have a responsibility for the health of their people, and in this country under the present 3-tier system of government, the responsibility for the rendering of health services is divided between central, provincial and local government. However, under our democratic system, all people have the right to, and it is indeed their duty, to participate individually and collectively in the planning and implementation of services to meet their health needs. Ultimately, through involvement of individuals, families and communities, greater self-reliance is achieved leading to greater responsibility being assumed by people for their own health.

  11. 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 (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Adebayo A. Adeniyi


    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.

  13. Diagnóstico del Refugio Nacional de Vida Silvestre Caño Negro, Arenal - Huetar Norte, Costa Rica


    Caño Negro (Grup de recerca)


    Se ha elaborado un diagnóstico a partir de un exhaustivo análisis del Refugio Nacional de Vida Silvestre Caño Negro. Esta zona pertenece al Área de Conservación Arenal Huetar Norte, situado al norte de Costa Rica. El refugio forma parte de la cuenca de río Frío y consiste en un sistema de humedales continentales. El diagnóstico contiene la descripción de los aspectos biofísicos, socioeconómicos y administrativo-institucionales del área. La metodología utilizada se basa en un estudio de la bib...

  14. 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


    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.

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

    Schulz, J; Roucoux, A; Patin, H


    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.

  16. Domino Oxidative [Pd]-Catalysis: One-Pot Synthesis of Fluorenones Starting from Simple Benzylamines and Iodo Arenes. (United States)

    Ravi Kumar, Devarapalli; Satyanarayana, Gedu


    A domino [Pd]-catalysis for the efficient synthesis of fluorenones is presented. The overall reaction proceeds through the formation of a five membered Pd(II)-cycle via a highly regioselective ortho C(sp(2))-H activation(s) of simple benzylamine that combines with external iodo arenes to give ortho arylated products. Significantly, the reaction further activates the C(sp(3))-H and C(sp(2))-H (intramolecular oxidative Heck coupling) bonds to give tricyclic imine systems. Then the usual water workup affords the fused tricyclic ketones (fluorenones). Remarkably, this one-pot operation enabled the effective construction of two C-C to three C-C bonds.

  17. 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)



    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.

  18. Iniciativas para el desarrollo sostenible del Área de Conservación Arenal- Huetar Norte, Costa Rica


    MALEKU (Grup de recerca)


    El presente proyecto tiene como zona de estudio el Área de Conservación Arenal- Huetar Norte (ACA-HN), concretamente los cantones de Upala, Los Chiles y Guatuso. El propósito del proyecto es promover el desarrollo sostenible de la zona mediante los pilares de la educación y la economía. Para ello se elabora un manual de educación ambiental de la cuenca de río Frío y así poder solventar algunas de las carencias en educación que tienen los docentes de las escuelas de la cuenca hidrográfica. Por...

  19. Determination of safranine T in food samples by CTAB sensitised fluorescence quenching method of the derivatives of calix[4]arene. (United States)

    Wang, Wenjun; Zhu, Xiashi; Yan, Chaoguo


    In this paper, the interaction of safranine T (ST) and calix[4]arene (4,10,16,22-tetramethoxylresorcinarene carboxylic acid derivatives (TRCA)) was investigated with fluorescence spectroscopy. The results was shown that the fluorescence intensity of TRCA could be quenched by ST, and the fluorescence quenching (ΔF=FTRCA-FST-TRCA) was sensitised in cetyltrimethyl ammonium bromide (CTAB). Under the optimal conditions, the linear range of calibration curve for the determination of ST was 0.10-4.00 μg/mL. The detection limit and RSD was 0.034 μg/mL, 2.30% (n=3). The quantum yield (Yu) of ST was approximately 2.0 times higher in the presence of CTAB than that in the absence of CTAB. The method has been applied for the determination of ST in food samples with satisfactory results.

  20. Host-guest inclusion system of ferulic acid with p-Sulfonatocalix[n]arenes: Preparation, characterization and antioxidant activity (United States)

    Chao, Jianbin; Wang, Huijuan; Song, Kailun; Wang, Yongzhao; Zuo, Ying; Zhang, Liwei; Zhang, Bingtai


    The inclusion complexes of ferulic acid (FA) with p-Sulfonatocalix[n]arenes (SCXn, n = 4, 6, 8) were prepared and characterized both in the solid state and in solution using fluorescence spectroscopy, 1H nuclear magnetic resonance (1H NMR), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). The results show that FA is able to form inclusion complexes with SCXn in a molar ratio of 1:1, causing a significant decrease in the fluorescence intensity of FA. The association constant of the inclusion complexes was calculated from the fluorescence titration data. 1H NMR spectroscopy analysis demonstrates that the aromatic ring and methoxy group of FA are partially covered by SCXn.

  1. Anthracene-tethered ruthenium(II) arene complexes as tools to visualize the cellular localization of putative organometallic anticancer compounds. (United States)

    Nazarov, Alexey A; Risse, Julie; Ang, Wee Han; Schmitt, Frederic; Zava, Olivier; Ruggi, Albert; Groessl, Michael; Scopelitti, Rosario; Juillerat-Jeanneret, Lucienne; Hartinger, Christian G; Dyson, Paul J


    Anthracene derivatives of ruthenium(II) arene compounds with 1,3,5-triaza-7-phosphatricyclo[]decane (pta) or a sugar phosphite ligand, viz., 3,5,6-bicyclophosphite-1,2-O-isopropylidene-α-d-glucofuranoside, were prepared in order to evaluate their anticancer properties compared to the parent compounds and to use them as models for intracellular visualization by fluorescence microscopy. Similar IC(50) values were obtained in cell proliferation assays, and similar levels of uptake and accumulation were also established. The X-ray structure of [{Ru(η(6)-C(6)H(5)CH(2)NHCO-anthracene)Cl(2)(pta)] is also reported.

  2. Solvent Extraction of Thorium Using 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl(azophenyl]calix[4]arene

    Directory of Open Access Journals (Sweden)

    Quang Hieu Tran


    Full Text Available A rapid, sensitive, and selective method for determination of thorium based on the complex with ortho-ester tetra-azophenylcalix[4]arene (TEAC was described. In the presence of pH of 4–6, TEAC-Th(IV complex is extracted from an acidic aqueous solution into chloroform layer. The absorbance intensity of complex was measured by UV-Vis spectrometer at 525 nm and the molar absorptivity was found to be 2.4 × 104. Beer’s law was obeyed in the range of 1.0 to 25 × 10−5 M thorium(IV. The effects of pH, TEAC concentration, and shaking time were also studied. The tolerance limits for several metal ions were calculated. The proposed method was applied to the determination of thorium in synthetic solution and in the monazite sand samples with good results.

  3. Hexameric Capsules Studied by Magic Angle Spinning Solid-State NMR Spectroscopy: Identifying Solvent Molecules in Pyrogallol[4]arene Capsules. (United States)

    Avram, Liat; Goldbourt, Amir; Cohen, Yoram


    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.

  4. 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)


    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.

  5. 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


    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

  6. 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


    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

  7. 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


    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).

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

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


    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).

  9. Qualitative Analysis of the Helical Electronic Energy of Inherently Chiral Calix[4]arenes: An Approach to Effectively Assign Their Absolute Configuration

    Directory of Open Access Journals (Sweden)

    Shuang Zheng


    Full Text Available For all microhelices on aromatic rings of inherently chiral calix[4]arene, an expression was derived from one approximation and one hypothesis on the basis of the electron-on-a-helix model of Tinoco and Woody as follows: 1/E = μ (H − K Δα2 , where μ = 1 for the right-handed microhelix and μ = −1 for the left-handed microhelix; and H and K are constant and greater than zero. The expression correlates microhelical electronic energy (E with the atom polarizability difference (Δα on both microhelix ends, which intuitively and clearly shows the impact of helical substituent polarizability on helical electronic energy. The case analysis almost entirely proves that the qualitative analysis of the helical electronic energy of inherently chiral calix[4]arenes with the expression is scientific and can be used to effectively assign their absolute configuration

  10. 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)


    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).

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

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


    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.

  12. DNA Binding and Recognition of a CC Mismatch in a DNA Duplex by Water-Soluble Peptidocalix[4]arenes: Synthesis and Applications. (United States)

    Alavijeh, Nahid S; Zadmard, Reza; Balalaie, Saeed; Alavijeh, Mohammad S; Soltani, Nima


    Water-soluble peptidocalix[4]arenes were synthesized by the introduction of arginine-rich narrow groove-binding residues at lower rims through solid-phase synthesis. The study of binding of these water-soluble bidentate ligands to well-matched and mismatched DNA duplexes by fluorescent titrations, ethidium bromide (EB) displacement assays, DNA-melting experiments, and circular dichroism (CD) analysis revealed a sequence-dependent groove-binding mechanism.

  13. 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


    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+).

  14. 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


    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.

  15. Enantiopure inherently chiral calix[4]arene derivatives containing quinolin-2-yl-methanol moiety:Synthesis and application in the catalytic asymmetric addition of diethylzinc to benzaldehyde

    Institute of Scientific and Technical Information of China (English)


    A series of novel N,O-type chiral ligands derived from enantiopure inherently chiral calix[4]arenes containing quinolin-2-yl-methanol moiety in the cone or partialcone conformation have been synthe-sized and characterized. Moreover,they have been applied to the catalytic asymmetric addition of diethylzinc to benzaldehyde,which represents the first example that the inherently chiral calixarene can be used as the chiral ligands for the catalytic asymmetric synthesis.

  16. Microwave-assisted synthesis of arene ruthenium(II) complexes that induce S-phase arrest in cancer cells by DNA damage-mediated p53 phosphorylation. (United States)

    Wu, Qiong; Fan, Cundong; Chen, Tianfeng; Liu, Chaoran; Mei, Wenjie; Chen, Sidong; Wang, Baoguo; Chen, Yunyun; Zheng, Wenjie


    A series of arene ruthenium(II) complexes coordinated by phenanthroimidazole derivates, [(C6H6)Ru(L)Cl]Cl·2H2O (1b L = IP, 2b L = p-NMe2PIP, 3b L = p-MeOPIP, 4b L = p-HOPIP, 5b L = p-COOHPIP, 6b L = p-CF3PIP, 7b L = p-BrPIP) have been synthesized in yields of 89-92% under microwave irradiation in 30 min, and the crystal structure of 1b by XRD gives a typical "piano stool" conformation. The antitumor activity of these complexes against various tumor cells have been evaluated by MTT assay, and the results show that this type of arene Ru(II) complexes exhibit acceptable inhibitory effect against all of these tumor cells, especially osteosarcoma MG-63 cells, but with low toxicity toward HK-2 human normal cells. Studies on the mechanism revealed that cell cycle arrest at S-phase in MG-63 cells induced by the arene Ru(II) complex 2b, which was confirmed by the increase in the percentage of cells at S-phase and down-regulator of cyclin A. The further studies by Comet assay at single cell level indicated that DNA damage in MG-63 cells was triggered by 2b, following with the up-regulation of phosphorylated p53 and histone. The studies by spectroscopy in vitro also indicate that 2b bind to DNA molecule by intercalative mode to disturb the bio-function of tumor cells. In conclusion, the synthetic arene Ru(II) complexes could serve as novel p53 activator with potential application in cancer chemotherapy.

  17. 1-(2-biphenyl)-3-methyltriazenide-N-oxide as a template for intramolecular copper(II)⋯arene-π interactions (United States)

    Paraginski, Gustavo Luiz; Hörner, Manfredo; Back, Davi Fernando; Wohlmuth Alves dos Santos, Aline Joana Rolina; Beck, Johannes


    Deprotonated triazene N-oxides are able to chelate metal ions resulting in five-membered rings without carbon atoms. A new ligand 1-(2-biphenyl)-3-methyltriazenide-N-oxide (1) and its mononuclear Cu(II) complex (2) were synthesized to verify the capability of this ligand to promote Cu(II)⋯arene-π interactions. Ligand 1 and complex 2 have been characterized by elemental analysis, mass spectrometry (ESI(+)-TOF), IR, and UV-Vis spectroscopy. In addition, ligand 1 was characterized by 1H and 13C NMR and complex 2 by X-ray diffraction on single crystal. The crystal structure of complex 2 reveals a distorted tetrahedral geometry of Cu(II) in the first coordination sphere, which expands to a distorted octahedral environment by two symmetrically independent intramolecular metal⋯arene-π interactions. These interactions are provided by ortho-phenyl rings of both triazene N-oxide ligands 1. The aim of this work was to contribute to the architecture of new Cu(II)⋯arene-π complexes based on the synthesis of appropriated ligand for intramolecular interactions

  18. β-Cyclodextrin and calix[4]arene-25,26,27,28-tetrol capped carbon dots for selective and sensitive detection of fluoride. (United States)

    Baruah, Upama; Gogoi, Neelam; Majumdar, Gitanjali; Chowdhury, Devasish


    In this work we have designed a novel system based on carbon dots prepared from chitosan gel capped with β-cyclodextrin and calix[4]arene-25,26,27,28-tetrol for sensitive and selective detection of fluoride ions in aqueous media. Fluorescent carbon dots prepared from chitosan gel when capped with β-cyclodextrin and calix[4]arene-25,26,27,28-tetrol results in quenching of its fluorescence intensity. Introduction of F(-) ions to carbon dots capped with β-cyclodextrin and calix[4]arene-25,26,27,28-tetrol system results in enhancement and restoration of fluorescence intensity leading to detection of F(-) ion. Minimum detection limit was determined to be ∼6.6 μM. The detection is selective as with other halide ions i.e. Cl(-), Br(-) and I(-) and hydroxyl ion (OH(-)), there is observed decrease of fluorescence intensity. A possible mechanism to justify the observation is also discussed in the paper.

  19. Calix[4]arene-linked bisporphyrin hosts for fullerenes: binding strength, solvation effects, and porphyrin-fullerene charge transfer bands. (United States)

    Hosseini, Ali; Taylor, Steven; Accorsi, Gianluca; Armaroli, Nicola; Reed, Christopher A; Boyd, Peter D W


    A calix[4]arene scaffolding has been used to construct bisporphyrin ("jaws" porphyrin) hosts for supramolecular binding of fullerene guests. Fullerene affinities were optimized by varying the nature of the covalent linkage of the porphyrins to the calixarenes. Binding constants for C60 and C70 in toluene were explored as a function of substituents at the periphery of the porphyrin, and 3,5-di-tert-butylphenyl groups gave rise to the highest fullerene affinities (26,000 M(-1) for C60). The origin of this high fullerene affinity has been traced to differential solvation effects rather than to electronic effects. Studies of binding constants as a function of solvent (toluene solubility, indicating that desolvation of the fullerene is a major factor determining the magnitude of binding constants. The energetics of fullerene binding have been determined in terms of DelatH and DeltaS and are consistent with an enthalpy-driven, solvation-dependent process. A direct relationship between supramolecular binding of a fullerene guest to a bisporphyrin host and the appearance of a broad NIR absorption band have been established. The energy of this band moves in a predictable manner as a function of the electronic structure of the porphyrin, thereby establishing its origin in porphyrin-to-fullerene charge transfer.

  20. A new arene-Ru based supramolecular coordination complex for efficient binding and selective sensing of green fluorescent protein. (United States)

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


    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.

  1. Interaction of bolaform surfactants with p-sulfonatocalix[4]arene: the role of two positive charges in the binding. (United States)

    Francisco, Vitor; Garcia-Rio, Luis


    The inclusion binding manners of bolaform surfactants of type C(n)R6(2+) 2Br(-) with different spacer lengths (n = 6, 12) and terminal headgroup volumes (R = methyl, ethyl) by p-sulfonatocalix[4]arene were studied. The combination of ITC parameters (binding constants and complexation enthalpy and entropy) and NMR chemical shifts and NOE cross-peaks obtained upon complexation allows us to propose different binding modes. The results point out that the spacer length has an influence on the binding stoichiometry. The bolaforms with larger spacer lengths between polar head groups enable the formation of 2:1 complexes in addition to 1:1, while with the shorter spacer they form only 1:1 complexes. On the other hand, the formation of 1:1 complexes is not affected by the headgroup volume or the spacer length of the bolaform. Unexpectedly, a complex binding mode was observed where both positive charged terminal groups of the bolaform are accommodated in the cavity of the calixarene. The inclusion of both terminal groups of the guests can be related to its own structure but also evidence the high flexibility of the calixarene.

  2. Cycloalkane and alicyclic heterocycle complexation by new switchable resorcin[4]arene-based container molecules: NMR and ITC binding studies. (United States)

    Hornung, Jens; Fankhauser, Daniel; Shirtcliff, Laura D; Praetorius, Antonia; Schweizer, W Bernd; Diederich, François


    The synthesis and structural characterization of novel, "molecular basket"-type bridged cavitands is reported. The resorcin[4]arene-based container molecules feature well-defined cavities that bind a wide variety of cycloalkanes and alicyclic heterocycles. Association constants (K(a)) of the 1:1 inclusion complexes were determined by both (1)H NMR and isothermal titration calorimetry (ITC). The obtained K(a) values in mesitylene ranged from 1.7×10(2) M(-1) for cycloheptane up to 1.7×10(7) M(-1) for morpholine. Host-guest complexation by the molecular baskets is generally driven by dispersion interactions, C-H···π interactions of the guests with the aromatic walls of the cavity, and optimal cavity filling. Correlations between NMR-based structural data and binding affinities support that the complexed heterocyclic guests undergo additional polar C-O···C=O, N-H···π, and S···π interactions. The first crystal structure of a cavitand-based molecular basket is reported, providing precise information on the geometry and volume of the inner cavity in the solid state. Molecular dynamic (MD) simulations provided information on the size and conformational preorganization of the cavity in the presence of encapsulated guests. The strongest binding of heterocyclic guests, engaging in polar interactions with the host, was observed at a cavity filling volume of 63 ± 9%.

  3. Determination of dopamine hydrochloride by host-guest interaction based on water-soluble pillar[5]arene (United States)

    Xiao, Xue-Dong; Shi, Lin; Guo, Li-Hui; Wang, Jun-Wen; Zhang, Xiang


    The supramolecular interaction between the water-soluble pillar[5]arene (WP[5]) as host and dopamine hydrochloride (DH) as guest was studied by spectrofluorometry. The fluorescence intensity of DH gradually decreased with increasing WP[5] concentration, and the possible interaction mechanism between WP[5] and DH was confirmed by 1H NMR, 2D NOESY, and molecular modelling. Based on significant DH fluorescence, a highly sensitive and selective method for DH determination was developed for the first time. The fluorescence intensity was measured at 312 nm, with excitation at 285 nm. The effects of pH, temperature, and reaction time on the fluorescence spectra of the WP[5]-DH complex were investigated. A linear relationship between fluorescence intensity and DH concentration in the range of 0.07-6.2 μg mL- 1 was obtained. The corresponding linear regression equation is ΔF = 25.76 C + 13.56 (where C denotes the concentration in μg mL- 1), with the limit of detection equal to 0.03 μg mL- 1 and the correlation coefficient equal to 0.9996. This method can be used for the determination of dopamine in injection and urine samples. In addition, the WP[5]-DH complex has potential applications in fluorescent sensing and pharmacokinetics studies of DH.

  4. Site-Specific Description of the Enhanced Recognition Between Electrogenerated Nitrobenzene Anions and Dihomooxacalix[4]arene Bidentate Ureas. (United States)

    Martínez-González, Eduardo; Armendáriz-Vidales, Georgina; Ascenso, José R; Marcos, Paula M; Frontana, Carlos


    Electron transfer controlled hydrogen bonding was studied for a series of nitrobenzene derivative radical anions, working as large guest anions, and substituted ureas, including dihomooxacalix[4]arene bidentate urea derivatives, in order to estimate binding constants (Kb) for the hydrogen-bonding process. Results showed enhanced Kb values for the interaction with phenyl-substituted bidentate urea, which is significantly larger than for the remaining compounds, e.g., in the case of 4-methoxynitrobenzene a 28-fold larger Kb value was obtained for the urea bearing a phenyl (Kb ∼ 6888) vs tert-butyl (Kb ∼ 247) moieties. The respective nucleophilic and electrophilic characters of the participant anion radical and urea hosts were parametrized with global and local electrodonating (ω(-)) and electroaccepting (ω(+)) powers, derived from DFT calculations. ω(-) data were useful for describing trends in structure–activity relationships when comparing nitrobenzene radical anions. However, ω(+) for the host urea structures lead to unreliable explanations of the experimental data. For the latter case, local descriptors ωk(+)(r) were estimated for the atoms within the urea region in the hosts [∑kωk(+)(r)]. By compiling all the theoretical and experimental data, a Kb-predictive contour plot was built considering ω(-) for the studied anion radicals and ∑kωk(+)(r) which affords good estimations.

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

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Sowrirajan


    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.

  6. Method development and validation of arene substituted regioisomers in a pharmaceutical candidate by high temperature GC-FID. (United States)

    Salisbury, John J; Do, Nga M; Ragan, John A


    This paper describes the development and validation of a high temperature gas chromatography flame ionization detection (HTGC-FID) method for the purity evaluation of arene substituted regioisomers in a key starting material of a pharmaceutical candidate in Phase 3 studies. The chromatographic conditions of the method employ a (5%-phenyl)-methylpolysiloxane packed column (30m×0.25mm) at a constant flow of 1.0mLmin(-1) with a gradient temperature program from 150°C to 400°C with injector and detector temperatures of 300°C and 340°C, respectively. The calibration curve for the desired product (r=0.9999) was assessed for five points in the range from approximately 1.0μgmL(-1) to 40μgmL(-1). The precision (% RSD) of the method was calculated for six replicate injections and found to be 0.81%. The limits of detection and quantitation were determined to be 0.06 and 0.20μgmL(-1), respectively.

  7. Photo-driven redox-neutral decarboxylative carbon-hydrogen trifluoromethylation of (hetero)arenes with trifluoroacetic acid (United States)

    Lin, Jin; Li, Zhi; Kan, Jian; Huang, Shijun; Su, Weiping; Li, Yadong


    Catalytic oxidative C–H bond functionalization reactions that proceed without requiring stoichiometric amounts of external oxidants or pre-functionalized oxidizing reagents could maximize the atom- and step-economy in chemical syntheses. However, such a transformation remains elusive. Here, we report that a photo-driven catalytic process enables decarboxylative C–H trifluoromethylation of (hetero)arenes with trifluoroacetic acid as a trifluoromethyl source in good yields in the presence of an external oxidant in far lower than stoichiometric amounts (for example, 0.2 equivalents of Na2S2O8) using Rh-modified TiO2 nanoparticles as a photocatalyst, in which H2 release is an important driving force for the reaction. Our findings not only provide an approach to accessing valuable decarboxylative C–H trifluoromethylations via activation of abundant but inert trifluoroacetic acid towards oxidative decarboxylation and trifluoromethyl radical formation, but also demonstrate that a photo-driven catalytic process is a promising way to achieve external oxidant-free C–H functionalization reactions. PMID:28165474

  8. 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


    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.

  9. Effect of para-substituents on alkaline earth metal ion extraction by proton di-ionizable calix[4]arene-crown-6 ligands in cone, partial-cone and 1,3-alternate conformations. (United States)

    Zhou, Hui; Liu, Dazhan; Gega, Jerzy; Surowiec, Kazimierz; Purkiss, David W; Bartsch, Richard A


    Two carboxylic acid or N-(X)sulfonyl carboxamide groups were incorporated into calix[4]arene-crown-6 compounds to afford di-ionizable ligands for use in divalent metal ion separations. Acidities of the N-(X)sulfonyl carboxamide groups were tuned by variation of the electron-withdrawing properties of X. Cone, partial-cone and 1,3-alternate conformations were obtained by different synthetic strategies and their structures verified by NMR spectroscopy. Competitive solvent extractions of alkaline earth metal cations from aqueous solutions into chloroform were performed and the results compared with those reported previously for di-ionizable p-tert-butylcalix[4]arene-crown-6 analogues to probe the influence of the para-substituent on the calix[4]arene scaffold on extraction selectivity and efficiency.

  10. Palladium(II)-catalyzed direct alkoxylation of arenes: evidence for solvent-assisted concerted metalation deprotonation. (United States)

    Anand, Megha; Sunoj, Raghavan B


    Density functional theory investigations on the mechanism of palladium acetate catalyzed direct alkoxylation of N-methoxybenzamide in methanol reveal that the key steps involve solvent-assisted N-H as well as C-H bond activations. The transition state for the critical palladium-carbon bond formation through a concerted metalation deprotonation (CMD) process leading to a palladacycle intermediate has been found to be more stable in the methanol-assisted pathway as compared to an unassisted route.

  11. 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: [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)


    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.

  12. 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


    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.

  13. A Zn2+ specific triazole based calix[4]arene conjugate (L) as a fluorescence sensor for histidine and cysteine in HEPES buffer milieu. (United States)

    Pathak, Rakesh Kumar; Tabbasum, Khatija; Rai, Ankit; Panda, Dulal; Rao, Chebrolu Pulla


    A highly fluorescent Zn(2+) complex of the triazole linked salicyl-imino-thiophenyl conjugate of calix[4]arene, [ZnL] has been demonstrated to be a chemo-sensing ensemble for the recognition of His and Cys among the naturally occurring amino acids in HEPES buffer milieu. The recognition behaviour of the [ZnL] towards these amino acids has been shown on the basis of fluorescence, absorption and visual fluorescent colour changes. The species of recognition were shown by ESI MS titrations, AFM & TEM microscopy and cell studies.

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

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


    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.

  15. Calix[4]arene decorated with four Tn antigen glycomimetic units and P3CS immunoadjuvant: synthesis, characterization, and anticancer immunological evaluation. (United States)

    Geraci, Corrada; Consoli, Grazia M L; Galante, Eva; Bousquet, Ennio; Pappalardo, Maria; Spadaro, Angelo


    A novel anticancer vaccine candidate built on a nonpeptidic scaffold has been synthesized. Four S-Tn tumor-associated glycomimetic antigens have been clustered onto a calix[4]arene scaffold bearing an immunoadjuvant moiety (P3CS). The immunogenicity of the synthetic construct has been investigated by immunization of mice in vivo. ELISA assay has evidenced that the tetravalent construct stimulates a higher production of anti-Tn antigen IgG antibodies when compared to an analogous monovalent compound. This result is ascribable to an antigen cluster effect and makes the reported vaccine candidate a good mimic of the natural motifs present on the mucine surface.

  16. Solvent extraction of Li+, H3O+ and NH4+ into nitrobenzene by using sodium dicarbollylcobaltate and calix[4]arene-bis(t-octylbenzo-18-crown-6)

    Energy Technology Data Exchange (ETDEWEB)

    Makrlik, Emanuel [Czech University of Life Sciences, Prague, Kamy´cká; Selucky, P. [Nuclear Research Institute, Rez, Czech Republic; Vanura, Petr [Institute of Chemical Technology, Prague, Czech Republic; Moyer, Bruce A [ORNL


    From extraction experiments and c-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+ (aq) + NaL+ (nb) , ML+ (nb) + Na+ (aq) taking place in the two-phase water nitrobenzene system (M+ = Li+, H3O+, NH+4; L = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML+ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: zH3O+ < Li+ < NH+4.

  17. The transfection efficiency of calix[4]arene-based lipids: the role of the alkyl chain length. (United States)

    Mochizuki, Shinichi; Nishina, Koichi; Fujii, Shota; Sakurai, Kazuo


    The size, surface charge, and microstructure of lipoplexes comprising cationic lipids and nucleic acids are important factors for transfection efficiency. As these properties are largely determined by the cationic lipids used, a number of studies on the relationship between cationic lipids and the transfection efficiency have been reported. Among the many cationic lipids, lipids with multivalent cationic head groups are expected to be potent transfection reagents. Here, we prepared calix[4]arene-based lipids with different alkyl chain lengths from C3 to C15 and evaluated the relationship between the alkyl chain length and the transfection efficiency. C6 lipoplexes exhibited the highest transfection efficiency among all lipoplexes. The gene expression with C9 and C12 lipoplexes was slightly lower than that with C6 lipoplexes. C3 lipoplexes hardly induced gene expression, while C15 lipoplexes exhibited no complexation with plasmid DNA. Although all lipoplexes exhibited nearly identical characteristics, they exhibited different behaviours in terms of the interactions between the lipoplexes and anionic micelles comprising phosphatidylserine, a model of endosomal vehicle. After mixing with phosphatidylserine micelles, C6 lipoplexes released the bound plasmid DNA at pH 5 but not at pH 7, indicating that they can interact with the late endosomal membrane after being incorporated into cells. No plasmid DNA was released from C9 or C12 lipoplexes at either pH values. Thus, the alkyl chain length of cationic lipids is related to their interaction with the endosomal compartment and can provide a basis for the design of novel transfection reagents.

  18. Dioxygen activation at a mononuclear Cu(I) center embedded in the calix[6]arene-tren core. (United States)

    Izzet, Guillaume; Zeitouny, Joceline; Akdas-Killig, Huriye; Frapart, Yves; Ménage, Stéphane; Douziech, Bénédicte; Jabin, Ivan; Le Mest, Yves; Reinaud, Olivia


    The reaction of a cuprous center coordinated to a calix[6]arene-based aza-cryptand with dioxygen has been studied. In this system, Cu(I) is bound to a tren unit that caps the calixarene core at the level of the small rim. As a result, although protected from the reaction medium by the macrocycle, the metal center presents a labile site accessible to small guest ligands. Indeed, in the presence of O2, it reacts in a very fast and irreversible redox process, leading, ultimately, to Cu(II) species. In the coordinating solvent MeCN, a one electron exchange occurs, yielding the corresponding [CalixtrenCu-MeCN](2+) complex with concomitant release of superoxide in the reaction medium. In a noncoordinating solvent such as CH2Cl2, the dioxygen reaction leads to oxygen insertions into the ligand itself. Both reactions are proposed to proceed through the formation of a superoxide-Cu(II) intermediate that is unstable in the Calixtren environment due to second sphere effects. The transiently formed superoxide ligand either undergoes fast substitution for a guest ligand (in MeCN) or intramolecular redox evolutions toward oxygenation of Calixtren. Interestingly, the latter process was shown to occur twice on the same ligand, thus demonstrating a possible catalytic activation of O2 at a single cuprous center. Altogether, this study illustrates the oxidizing power of a [CuO2](+) adduct and substantiates a mechanism by which copper mono-oxygenases such as DbetaH and PHM activate O2 at the Cu(M) center to produce such an intermediate capable of C-H breaking before the electron input provided by the noncoupled Cu(H) center.

  19. Recognition of bio-relevant dicarboxylate anions by an azacalix[2]arene[2]triazine derivative decorated with urea moieties. (United States)

    Santos, Miguel M; Marques, Igor; Carvalho, Sílvia; Moiteiro, Cristina; Félix, Vítor


    A new dichloroazacalix[2]arene[2]triazine receptor (1) with two chiral urea binding moieties is reported. The binding affinity of this macrocycle was evaluated by (1)H NMR titrations in CDCl3 for the dicarboxylate anions oxalate (ox(2-)), malonate (mal(2-)), succinate (suc(2-)), glutarate (glu(2-)), diglycolate (dg(2-)), fumarate (fum(2-)), maleate (male(2-)), and (R,R)- and (S,S)-tartarate (tart(2-)) enantiomers. Among the first five linear anions, the higher association constants were calculated for the larger anions glu(2-) and dg(2-) and for the smallest anion ox(2-), with Kass values following the sequence dg(2-) > glu(2-) > ox(2-) > suc(2-) > mal(2-). Despite the high binding affinity 1 of for both tart(2-) enantiomers, no enantioselectivity was observed. By contrast, Kass for fum(2-) is ca. 8.9 times greater than that for male(2-), showing the selectivity of 1 for the trans isomer. These binding preferences were further elucidated by theoretical methods. Molecular dynamics simulations showed that the linear anions are lodged between both pendant arms and that each anion can assume two distinct binding poses, with one or two carboxylate groups establishing intermittent hydrogen bonds with both urea binding units. On the other hand, the recognition of male(2-) ensues in an alternative scenario, characterised by the interaction between a carboxylate group and a single urea binding unit, mirroring the lower experimental binding affinity relatively to fum(2-). A linear increase of the receptor's Nurea···Nurea and the anions' (-)O2C···CO2(-) distances versus experimental Kass was established for mal(2-), suc(2-), glu(2-) and dg(2-) associations, indicating that the match between these two distances determines the anion binding strength. The affinity for ox(2-) was associated with the most negative values of electrostatic potential positioned near carboxylate groups.

  20. 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


    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.

  1. Arene guest selectivity and pore flexibility in a metal-organic framework with semi-fluorinated channel walls (United States)

    Smith, Rebecca; Vitórica-Yrezábal, Iñigo J.; Hill, Adrian; Brammer, Lee


    A metal-organic framework (MOF) with one-dimensional channels of approximately hexagonal cross-section [Ag2(O2CCF2CF2CO2)(TMP)] 1 (TMP =2,3,5,6-tetramethylpyrazine) has been synthesized with MeOH filling the channels in its as-synthesized form as [Ag2(O2CCF2CF2CO2)(TMP)]·n(MeOH) 1-MeOH (n = 1.625 by X-ray crystallography). The two types of ligand connect columns of Ag(I) centres in an alternating manner, both around the channels and along their length, leading to an alternating arrangement of hydrocarbon (C-H) and fluorocarbon (C-F) groups lining the channel walls, with the former groups projecting further into the channel than the latter. MeOH solvent in the channels can be exchanged for a variety of arene guests, ranging from xylenes to tetrafluorobenzene, as confirmed by gas chromatography, 1H nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis and 13C cross-polarization magic angle spinning NMR spectroscopy. Alkane and perfluoroalkane guests, however, do not enter the channels. Although exhibiting some stability under a nitrogen atmosphere, sufficient to enable crystal structure determination, the evacuated MOF 1 is unstable for periods of more than minutes under ambient conditions or upon heating, whereupon it undergoes an irreversible solid-state transformation to a non-porous polymorph 2, which comprises Ag2(O2CCF2CF2CO2) coordination layers that are pillared by TMP ligands. This transformation has been followed in situ by powder X-ray diffraction and shown to proceed via a crystalline intermediate. This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  2. Arene guest selectivity and pore flexibility in a metal–organic framework with semi-fluorinated channel walls (United States)

    Smith, Rebecca; Vitórica-Yrezábal, Iñigo J.; Hill, Adrian


    A metal–organic framework (MOF) with one-dimensional channels of approximately hexagonal cross-section [Ag2(O2CCF2CF2CO2)(TMP)] 1 (TMP =2,3,5,6-tetramethylpyrazine) has been synthesized with MeOH filling the channels in its as-synthesized form as [Ag2(O2CCF2CF2CO2)(TMP)]·n(MeOH) 1-MeOH (n = 1.625 by X-ray crystallography). The two types of ligand connect columns of Ag(I) centres in an alternating manner, both around the channels and along their length, leading to an alternating arrangement of hydrocarbon (C–H) and fluorocarbon (C–F) groups lining the channel walls, with the former groups projecting further into the channel than the latter. MeOH solvent in the channels can be exchanged for a variety of arene guests, ranging from xylenes to tetrafluorobenzene, as confirmed by gas chromatography, 1H nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis and 13C cross-polarization magic angle spinning NMR spectroscopy. Alkane and perfluoroalkane guests, however, do not enter the channels. Although exhibiting some stability under a nitrogen atmosphere, sufficient to enable crystal structure determination, the evacuated MOF 1 is unstable for periods of more than minutes under ambient conditions or upon heating, whereupon it undergoes an irreversible solid-state transformation to a non-porous polymorph 2, which comprises Ag2(O2CCF2CF2CO2) coordination layers that are pillared by TMP ligands. This transformation has been followed in situ by powder X-ray diffraction and shown to proceed via a crystalline intermediate. This article is part of the themed issue ‘Coordination polymers and metal–organic frameworks: materials by design’. PMID:27895259

  3. 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


    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.

  4. 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.


    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.

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

    Nemati, Mohammad; Zadmard, Reza; Mohadjerani, Maryam


    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

  6. 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


    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...

  7. 6,12,18,24-Tetra-meth-oxy-4,10,16,22-tetra-kis-[(meth-oxy-carbon-yl)meth-oxy]-2,8,14,20-tetra-kis-(2-phenyl-eth-yl)resorcin[4]arene. (United States)

    Pansuriya, Pramod B; Friedrich, Holger B; Maguire, Glenn E M


    The title compound, C(76)H(80)O(16), is a macrocyclic structure. This novel resorcin[4]arene derivative has (meth-oxy-carbon-yl)meth-oxy 'head' groups on the upper rim. The compound has a C(2v) 'boat' geometry and there are a range of C-H⋯O contacts in the crystal structure.

  8. Polyvinyl chloride-based 18-crown-6, dibenzo18-crown-6 and calix-[6]-arene zinc(II-potentiometric sensors

    Directory of Open Access Journals (Sweden)

    Magda A. Akl


    Full Text Available Polyvinyl chloride (PVC based membranes of 18-crown-6 (18C6, dibenzo 18-crowen-6 (DB18C6 and calix[6]arene (CAX, as ionophores, with dioctylphenylphosphonate (DOPP, bis(ethylhexylsebacate (DOS dioctyl phthalate (DOP, 2-nitrophenyloctylether (o-NPOE and didecylphthalate (DDP as plasticizing solvent mediators are prepared and constructed for the determination of Zn(II. Of the 15 membranes constructed, only the PVC based membranes of DB18C6 and 18C6 ionophores with DOPP, as plasticizer, in the ratio (w/w PVC:ionophore:DOPP (60:2:120 give the best results in terms of working concentration range (1.0 × 10−5–1.0 × 10−1 M with a Nernstian slope of 29.0 mV/decade of activity for membrane composed of DOPP + DB18C6(1a and (1.0 × 10−5–1.0 × 10−1 M with a Nernstian slope of 30.0 mV/decade of activity for membrane composed of DOPP + 18C6(1b. The usable pH range of the sensors is 3.0–8.0, beyond which a drift in potential is observed. The response time of the sensors is ⩽15 s with a lifetime of 2 months during which they can be used without any measurable divergence. The selectivity coefficient values indicate that the electrode is highly selective for Zn2+ over a number of other cations except Pb2+ and Ag+. The electrodes have successfully been used to determine Zn(II in real alloys and standard samples with a precision as relative standard deviation (RSD <2% for each of the cited electrodes. The results obtained by the proposed ISEs are in good agreement with the results obtained by direct flame AAS method.

  9. Who and What Does Involvement Involve?

    DEFF Research Database (Denmark)

    Hansen, Jeppe Oute; Petersen, Anders; Huniche, Lotte


    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...

  10. Structures and Nonlinear Optical Properties of Alkali Metal-Doped t-Bu-calix[4]arene Molecules%碱金属掺杂叔丁基杯[4]芳烃体系的结构及非线性光学性质

    Institute of Scientific and Technical Information of China (English)

    侯娜; 李莹; 吴迪; 李志儒


    采用密度泛函理论B3LYP方法得到了M@t-Bu-calix[4]arene和(M@t-Bu-calix[4]arene)Li′(M=Li, Na, K)体系的几何结构.其中(M@t-Bu-calix[4]arene)Li′(M=Li, Na, K)三个体系各有5个稳定异构体,在前三个异构体中,碱金属与t-Bu-calix[4]arene分子间具有很强的相互作用能,说明了体系的稳定性.在部分(M@t-Bu-calix[4]arene)Li异构体中Li′原子以阴离子形式存在,整个体系表现出碱金属化物的特性.此外,使用CAM-B3LYP方法计算了t-Bu-calix[4]arene及碱金属掺杂后体系的非线性光学性质.结果表明, t-Bu-calix[4]arene内部掺杂一个碱金属原子M后,体系的一阶超极化率(β0)有较大提高,而在配体外部又掺杂一个Li原子后,体系具有更大的β0值.其中(M@t-Bu-calix[4]arene)Li′体系的MLi′-4异构体表现出最高的β0值(41827-114354 a.u.),并且随着M原子序数的增加而逐渐增大.可见,碱金属掺杂是提高t-Bu-calix[4]arene非线性光学响应的一种有效策略.%Using density functional theory with the B3LYP functional, the optimized geometrical structures of the M@t-Bu-calix[4]arene and (M@t-Bu-calix[4]arene)Li′(M=Li, Na, K) compounds were obtained. Five stable isomers were identified for each bi-alkali-metal-doped (M@t-Bu-calix[4]arene)Li′species. The first three low-lying isomers have considerable intramolecular interaction energies between alkali metal atoms and the t-Bu-calix[4]arene molecule, indicating their stabilities. According to natural bond orbital analyses, the outside Li′atom is negatively charged in some (M@t-Bu-calix[4]arene)Li′structures, indicating the alkalide characteristics of these isomers. In addition, the nonlinear optical (NLO) properties of isolated and alkali-metal-doped t-Bu-calix [4]arene molecules were calculated using the CAM-B3LYP method. The results indicate that the single-doped effect of alkali metal M greatly enhances the first hyperpolarizability (β0) of the t-Bu-calix[4]arene molecule. In

  11. Extraction and separation of thorium and rare earths with 5,11,17,23-tetra (diethoxyphosphoryl)-25,26,27,28-tetraacetoxycalix [4] arene

    Institute of Scientific and Technical Information of China (English)

    LI Yanling; LU Youcai; BAI Yan; LIAO Wuping


    A calixarene derivative,5,11,17,23-tetra(diethoxyphosphoryl)-25,26,27,28-tetraacetoxycalix[4]arene (L),was studied for the extraction and separation of thorium and rare earths in nitrate medium.Thorium was extracted into the organic phase by a complex of Th(NO3)4·L with the logarithm of the equilibrium constant of 2.77.Thermodynamic functions,△H,△G and △S were calculated to be -2.49,-15.55 kJ/mol and 44.53 J/(mol·K),respectively.The results indicated that this calixarene derivative might be used to separate thorium from rare earths and the separation factors were larger than 26.However,the salting-out agents affected the separation.

  12. A new method for predicting the heats of combustion of polynitro arene, polynitro heteroarene, acyclic and cyclic nitramine, nitrate ester and nitroaliphatic compounds. (United States)

    Keshavarz, Mohammad Hossein; Saatluo, Bahman Ebrahimi; Hassanzadeh, Ali


    A new method is presented for estimating the gross and net heats of combustion of important classes of energetic compounds including polynitro arene, polynitro heteroarene, acyclic and cyclic nitramine, nitrate ester and nitroaliphatic compounds. Elemental compositions as well as the presence of some specific polar groups and molecular fragments are important parameters in the new model. The novel method can be easily used for any complex organic compounds with at least one nitro, nitramine or nitrate functional groups by which the predictions of their heats of combustion by the available methods are inaccurate or difficult. The predicted results show that this method gives reliable predictions of heats of combustion with respect to group additivity method and computed values based on atom-type electrotopological state indices for several energetic compounds where the models can be applied.

  13. Continuous-Flow Electrophilic Amination of Arenes and Schmidt Reaction of Carboxylic Acids Utilizing the Superacidic Trimethylsilyl Azide/Triflic Acid Reagent System. (United States)

    Chen, Yuesu; Gutmann, Bernhard; Kappe, C Oliver


    A continuous flow protocol for the direct stoichiometric electrophilic amination of aromatic hydrocarbons and the Schmidt reaction of aromatic carboxylic acids using the superacidic trimethylsilyl azide/triflic acid system is described. Optimization of reagent stoichiometry, solvent, reaction time, and temperature led to an intensified protocol at elevated temperatures that allows the direct amination of arenes to be completed within 3 min at 90 °C. In order to improve the selectivity and scope of this direct amination protocol, aromatic carboxylic acids were additionally chosen as substrates. Selected carboxylic acids could be converted to their corresponding amine counterparts in good to excellent yields (11 examples, 55-83%) via a Schmidt reaction employing similar flow reaction conditions (acid intermediate, the corrosive nature of triflic acid, and the exothermic quenching were addressed by designing a suitable continuous flow reaction setup for both types of transformations.

  14. Unusual mode of protein binding by a cytotoxic π-arene ruthenium(ii) piano-stool compound containing an O,S-chelating ligand. (United States)

    Hildebrandt, Jana; Görls, Helmar; Häfner, Norman; Ferraro, Giarita; Dürst, Matthias; Runnebaum, Ingo B; Weigand, Wolfgang; Merlino, Antonello


    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.

  15. Supramolecular complexation of biological phosphates with an acyclic triazolium-linked anthracenyl-1,3-diconjugate of calix[4]arene: synthesis, characterization, spectroscopy, microscopy, and computational studies. (United States)

    Sreenivasu Mummidivarapu, V V; Kumar Hinge, Vijaya; Samanta, Kushal; Yarramala, Deepthi S; Pulla Rao, Chebrolu


    A triazolium-anthracenyl calix[4]arene conjugate (L) was synthesized by methylating the precursor triazole derivative and then characterized. The potential of the cationic L to differentiate nucleoside triphosphates (NTPs) from their mono- and diphosphates was demonstrated. Due to its unique combination of arms with the calix-platform, a fluorescence enhancement was observed for L with all the NTPs, whereas there is no report with such enhancement being exhibited in case of all the NTPs. This has been supported by the aggregation of L observed from microscopy. Selectivity of L towards NTPs over other phosphates was a result of specific weak interactions, namely, ion-ion, hydrogen bonding and π⋅⋅⋅π, present in the 1:2 complex of L and NTPs (based on ESI MS), which were absent in their congener-phosphates as delineated by NMR and computational studies. Thus, L stands as a unique receptor for NTPs.

  16. 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)


    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.

  17. Comparison of hydration reactions for "piano-stool" RAPTA-B and [Ru(η6- arene)(en)Cl]+ complexes: Density functional theory computational study (United States)

    Chval, Zdeněk; Futera, Zdeněk; Burda, Jaroslav V.


    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.

  18. EVALUASI MUTU KIMIA, FISIKA DAN MIKROBIOLOGI NIRA AREN (Arenga pinnata SELAMA PENYIMPANAN Chemical, Physical, Microbiology Property Evaluation of Neera (Arenga pinnata during Storage

    Directory of Open Access Journals (Sweden)

    Ira Mulyawanti


    Full Text Available The study was conducted to evaluate the changes of quality of neera during storage after process improvement withfiltration and pasteurization. Research conducted using completely randomized design with factorial pattern. Factor treatment were filtering (coarse sieve, sieve 40 mesh, and without filtering, pasteurization (pasteurization and without pasteurization, and storage at room temperature (0, 3, 6, 9, 12 , and 15 hours and performed as many as 3 replication. Observations were carried out for the quality of chemical, physical and microbiological. The results showed that the handling of juice with coarse filtration using filter and pasteurization can maintain the stability of palm juice for 15 hours in storage at room temperature, with a sucrose content was 14.48 %, TSS was 16.4 ° Briks, alcohol was 1,39 % , total acid was 0.182 %, pH was 6.82, viscosity was 14.53 cp, bias index was 1.355 nd, and the total growth of bacteria, yeasts and molds which slowed. ABSTRAK Penelitian dilakukan untuk mengevaluasi perubahan mutu nira aren selama penyimpanan setelah diberikan perbaikanproses penanganan segarnya yaitu dengan penyaringan dan pasteurisasi. Penelitian dilakukan dengan menggunakan rancangan acak lengkap pola faktorial dengan faktor perlakuan yaitu penyaringan (saringan kasar, saringan 40 mesh, dan tanpa penyaringan, pasteurisasi (pasteurisasi dan tanpa pasteurisasi, dan penyimpanan pada suhu ruang (0, 3,6, 9, 12, dan 15 jam serta dilakukan sebanyak 3 kali ulangan. Pengamatan dilakukan terhadap mutu kimia, fisik dan mikrobiologi. Hasil penelitian menunjukkan bahwa penanganan nira dengan penyaringan menggunakan saringan kasar dan pasteurisasi dapat mempertahankan kestabilan nira aren selama 15 jam dalam penyimpanan di suhu ruang, dengan kandungan sukrosa 14,48 %, TSS 16,4 °Briks, total alkohol 1,39 %, total asam 0,182 %, pH 6,82, viskositas 14,53 cp, indeks bias 1,355 nd, dan pertumbuhan total bakteri, khamir dan kapang yang diperlambat.

  19. 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


    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.

  20. Synthesis and alkaline earth metal cation extraction by proton di-ionizable p-tert-butylcalix[4]arene-crown-5 compounds in cone, partial-cone and 1,3-alternate conformations. (United States)

    Zhou, Hui; Surowiec, Kazimierz; Purkiss, David W; Bartsch, Richard A


    Synthetic strategies for novel, proton di-ionizable p-tert-butylcalix[4]arene-crown-5 compounds in cone, partial-cone and 1,3-alternate conformations are reported. Selective linkage of the two diametrical phenolic oxygens in p-tert-butylcalix[4]arene with tetraethylene glycol ditosylate gave 1,3-bridged p-tert-butylcalix[4]arene-crown-5. The two remaining phenolic units were alkylated using NaH and KH as the bases to give the cone and partial-cone conformers, respectively. Preparation of the 1,3-alternate conformers utilized a different sequence in which O-alkylation was followed by crown ether ring formation. Structures of these new ligands were elucidated by (1)H and (13)C NMR spectroscopy. These proton-ionizable ligands were tested for their solvent extraction properties toward alkaline earth metal cations. Surprising differences in their extraction behaviors are noted compared to those reported previously for di-ionizable p-tert-butylcalix[4]arenecrown-6 analogues.

  1. C-F activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: selectivity and mechanistic investigations. (United States)

    Schaub, Thomas; Fischer, Peter; Steffen, Andreas; Braun, Thomas; Radius, Udo; Mix, Andreas


    The reaction of [Ni2((i)Pr2Im)4(COD)] 1a or [Ni((i)Pr2Im)2(eta(2)-C2H4)] 1b with different fluorinated arenes is reported. These reactions occur with a high chemo- and regioselectivity. In the case of polyfluorinated aromatics of the type C6F5X such as hexafluorobenzene (X = F) octafluorotoluene (X = CF3), trimethyl(pentafluorophenyl)silane (X = SiMe3), or decafluorobiphenyl (X = C6F5) the C-F activation regioselectively takes place at the C-F bond in the para position to the X group to afford the complexes trans-[Ni((i)Pr2Im)2(F)(C6F5)]2, trans-[Ni((i)Pr2Im)2(F)(4-(CF3)C6F4)] 3, trans-[Ni((i)Pr2Im)2(F)(4-(C6F5)C6F4)] 4, and trans-[Ni((i)Pr2Im)2(F)(4-(SiMe3)C6F4)] 5. Complex 5 was structurally characterized by X-ray diffraction. The reaction of 1a with partially fluorinated aromatic substrates C6H(x)F(y) leads to the products of a C-F activation trans-[Ni((i)Pr2Im)2(F)(2-C6FH4)] 7, trans-[Ni((i)Pr2Im)2(F)(3,5-C6F2H3)] 8, trans-[Ni((i)Pr2Im)2(F)(2,3-C6F2H3)] 9a and trans-[Ni((i)Pr2Im)2(F)(2,6-C6F2H3)] 9b, trans-[Ni((i)Pr2Im)2(F)(2,5-C6F2H3)] 10, and trans-[Ni((i)Pr2Im)2(F)(2,3,5,6-C6F4H)] 11. The reaction of 1a with octafluoronaphthalene yields exclusively trans-[Ni((i)Pr2Im)2(F)(1,3,4,5,6,7,8-C10F7)] 6a, the product of an insertion into the C-F bond in the 2-position, whereas for the reaction of 1b with octafluoronaphthalene the two isomers trans-[Ni((i)Pr2Im)2(F)(1,3,4,5,6,7,8-C10F7)] 6a and trans-[Ni((i)Pr2Im)2(F)(2,3,4,5,6,7,8-C10F7)] 6b are formed in a ratio of 11:1. The reaction of 1a or of 1b with pentafluoropyridine at low temperatures affords trans-[Ni((i)Pr2Im)2(F)(4-C5NF4)] 12a as the sole product, whereas the reaction of 1b performed at room temperature leads to the generation of trans-[Ni((i)Pr2Im)2(F)(4-C5NF4)] 12a and trans-[Ni((i)Pr2Im)2(F)(2-C5NF4)] 12b in a ratio of approximately 1:2. The detection of intermediates as well as kinetic studies gives some insight into the mechanistic details for the activation of an aromatic carbon-fluorine bond at

  2. Improving the Flash Flood Frequency Analysis using dendrogeomorphological evidences in the Arenal River crossing Arenas de San Pedro Village (Spanish Central System) (United States)

    Ruiz-Villanueva, V.; Ballesteros, J. A.; Díez-Herrero, A.; Bodoque, J. M.


    The flash flood frequency analysis in mountainous catchments presents specific scientific challenges. One of the challenges is the relevant gradient in precipitation intensity with altitude. Another challenge is the lack of information from rainfall or discharge gauge stations or from documentary sources. Dendrogeomorphology studies the response in the wood growth pattern and the botanical signs on the trees affected by geomorphological processes. With regard to the flood frequency, the dendrogeomorphological evidences bring forward valuable infomation about single past events (with annual or even seasonal precision) and their occurrence periodicity. The main macro-evidence that we can find in the tree trunk is a stem scar originated by a wound in the bark of the tree. When the tree grows, this wound remains reflected in the tree ring sequence. The best way to analyze the tree ring sequence is by using a complete section of the trunk, this couldn't be possible unless the tree is cut down. Due to the unfeasibility of cutting down the trees, in Dendrogeomorphology is enough to obtain an increment core, using a Pressler borer. Nevertheless, this study has been based on complete stem sections analysis facilitated for the felling works in the riverine vegetation in the Arenal River, carried out by the Tagus River Water Authority. These felling works have allowed us to obtain sections and to analyze the stump of the tree in situ. On this way, 100 samples of Alnus glutinosa and Fraxinus angustifolia located by the river along the Arenal River crossing Arenas de San Pedro Village (Ávila, northern slopes of the Gredos Mountain Range in the Spanish Central System) have been analyzed. This village is known for its historical problems of flood during extreme events. A meticulous fieldwork has been carried out. Every sample was analyzed locating its geomorphological position, the distance to the riverbed and the height of the stump in which the evidences were observed. Using a

  3. Removal of diclofenac on calyx [4] arene based Amberlite XAD-4 resin from aqueous solutions.%杯[4]芳烃修饰Amberlite XAD-4树脂去除水中双氯芬酸

    Institute of Scientific and Technical Information of China (English)

    王月; 熊振湖; 周建国


    The calyx [4] arene was synthesized and connected to Amberlite XAD-4 resin covalently through a diazotization bound. The structure of Amberlite XAD-4 resin base on calyx [4] arene was characterized using FT-IR, SEM and TG/DTA. The sorption results showed that Amberlite XAD-4 resin base on calyx [4] arene had much better removal to the diclofenac in aqueous solutions than Amberlite XAD-4 resin and calyx [4] arene which were presence alone in aqueous solutions. The removal rate of diclofenac increased rapidly with the calyx [4] arene modified Amberlite XAD-4 resin dosage. In the condition of DCF concentration was 20mg/L, when the Amberlite XAD-4 resin base on calyx [4] arene dosage came up to 80mg/L, the removal rate of diclofenac was 92.8% and reached equilibrium, the corresponding amount adsorbed was 34.02mg/g. Kinetic analyses were conducted using pseudo first-order and second-order models. The linear correlation coefficients and standard deviations of Langmuir and Freundlich isotherms were determined, and the results revealed that Langmuir and Freundlich isotherm were fitted the experimental data well. The thermodynamic parameters calculated indicated, AH and AG were negative, which predicated adsorption process of diclofenac on f Amberlite XAD-4 resin base on calyx [4] arene resin was exothermic and spontaneous.%通过偶氮化反应将合成的去叔丁基杯[4]芳烃连接到Amberlite XAD-4树脂上,并且采用FTIR、SEM和TG/DTA法表征了杯[4]芳烃修饰Amberlite XAD-4树脂的结构.结果表明,水溶液中杯[4]芳烃修饰Amberlite XAD-4树脂对双氯芬酸的去除率远大于单独AmberliteXAD-4树脂和杯[4]芳烃.双氯芬酸的浓度为20mg/L时,随着杯[4]芳烃修饰AmberliteXAD-4树脂投加量的增加,双氯芬酸的去除率增加很快.当吸附剂量增加到80mg/L时,双氯芬酸的去除率为92.8%,并且达到吸附平衡,吸附的双氯芬酸量为34.02mg/g.Langmuir和Freundlich等温线与实验数据均有很好的拟合度.

  4. Doctors' involvement in torture

    DEFF Research Database (Denmark)

    Sonntag, Jesper


    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...

  5. 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


    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.

  6. Pyrophosphate sensing by a fluorescent Zn2+ bound triazole linked imino-thiophenyl conjugate of calix[4]arene in HEPES buffer medium: spectroscopy, microscopy, and cellular studies. (United States)

    Pathak, Rakesh K; Tabbasum, Khatija; Rai, Ankit; Panda, Dulal; Rao, Chebrolu P


    An in situ prepared Zn(2+) complex of triazole linked imino-thiophenyl conjugate of calix[4]arene, [ZnL], was demonstrated to be highly fluorescent in HEPES buffer solution. [ZnL] has been used as a chemo-sensing ensemble for the recognition of phosphates in general and pyrophosphates in particular among the eighteen different anions studied. The chemo-sensing behavior of the [ZnL] has been demonstrated through fluorescence, absorption, visual fluorescent color changes, ESI MS, and (1)H NMR titrations. Variations in the microstructural features of L, its zinc complex and the complex upon addition of PPi have been demonstrated through atomic force microscopy and transmission electron microscopy. Such studies have been extended to see the permeability of the conjugate into the HeLa cells by fluorescence microscopy. In accession, a reversible "write-read-erase-read" logic gate property of L has been demonstrated through a feedback loop in the presence of Zn(2+) and PPi.

  7. Versatile, Reversible, and Reusable Gel of a Monocholesteryl Conjugated Calix[4]arene as Functional Material to Store and Release Dyes and Drugs Including Doxorubicin, Curcumin, and Tocopherol. (United States)

    Bandela, Anil Kumar; Hinge, Vijaya Kumar; Yarramala, Deepthi S; Rao, Chebrolu Pulla


    Gels are interesting soft materials owing to their functional properties leading to potential applications. This paper deals with the synthesis of monocholesteryl derivatized calix[4]arene (G) and its instantaneous gelation at a minimum gelator concentration of 0.6% in 1:1 v/v THF/acetonitrile. The gel shows remarkable thermoreversibility by exhibiting Tgel→sol at ∼48 °C and is demonstrated for several cycles. The gel shows an organized network of nanobundles, while that of the sol shows spherical nanoaggregates in microscopy. A bundle with ∼12 nm diameter possessing hydrophobic pockets in itself is obtained from computationally modeled gel, and hence the gel is suitable for storage and release applications. The guest-entrapped gels exhibit the same microstructures as that observed with simple gels, while fluorescence spectra and molecular mechanics suggests that the drug molecules occupy the hydrophobic pockets. All the entrapped drug molecules are released into water, suggesting a complete recovery of the trapped species. The reusability of the gel for the storage and release of the drug into water is demonstrated for four consecutive cycles, and hence the gel formed from G acts as a functional material that finds application in drug delivery.

  8. Investigation on Al(III) and Zn(II) complexes containing a calix[4]arene bearing two 8-oxyquinoline pendant arms used as emitting materials for OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Bagatin, Izilda A. [Instituto de Quimica, Universidade de Sao Paulo, Cx. P.: 26077, CEP 05513-970, Sao Paulo, SP (Brazil)], E-mail:; Legnani, Cristiano [Divisao de Metrologia em Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, CEP 25250-020, Duque de Caxias, RJ (Brazil); Cremona, Marco [Divisao de Metrologia em Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, CEP 25250-020, Duque de Caxias, RJ (Brazil); Pontificia Universidade Catolica do Rio de Janeiro, Depto de Fisica, C.P.38071, Rio de Janeiro (Brazil)


    A comparison between [Al{center_dot}1]{sup 3+} and [Zn{center_dot}1]{sup 2+} complexes (1 = 5,11,17,23-tetra-tert-butyl-25,27-bis[(quinoline-8-oxy)propyloxy]-26, 28-dihydroxy-calix[4]arene) has been made using electrochemical techniques and the experimental results obtained in the fabrication of organic light emitting devices (OLEDs). The electrochemically determined values of the ionization potential I{sub p} and electron affinity E{sub a} parameters for the [Al{center_dot}1]{sup 3+} (I{sub p} = 5.82eV, E{sub a} = 2.80eV) and [Zn{center_dot}1]{sup 2+} (I{sub p} = 5.67eV, E{sub a} = 2.32eV) evidenced that the [Al{center_dot}1]{sup 3+} complex is a better electron transporting layer with respect to the Zn complex one. The fabricated OLEDs based on these supramolecular complexes show a superior quality with the [Al{center_dot}1]{sup 3+} systems expected from the energy level diagrams.

  9. Molecular tectonics: p-H-thiacalix[4]arene pyridyl appended positional isomers as tectons for the formation of 1D and 2D mercury coordination networks. (United States)

    Ovsyannikov, A; Ferlay, S; Solovieva, S E; Antipin, I S; Konovalov, A I; Kyritsakas, N; Hosseini, M W


    Three p-H-thiacalix[4]arene pyridyl appended coordinating tectons (2-4) in a 1,3-alternate conformation have been prepared and structurally characterised in the solid state. These compounds are positional isomers differing only by the position of the nitrogen atom on the pyridyl ring. Their combinations with HgCl2 lead to the formation of 1- and 2-D neutral mercury coordination networks. Whereas for tecton 2 (ortho isomer) a 2D architecture resulting from the bridging of consecutive tectons by the mononuclear HgCl2 unit is obtained, for tecton 3 (meta isomer) again a 2D network is formed. However, in that case, the interconnection of consecutive organic tectons 3 takes place through a binuclear Hg2Cl4 species. Finally, in the case of tecton 4 (para position), a 1D ribbon type double chain arrangement resulting from the bridging of consecutive tectons by trinuclear Hg3Cl6 units followed by the interconnection of two chains through the fusion of the trinuclear centres into a hexanuclear node is observed.

  10. Spectrofluorimetric study on the inclusion interaction between vitamin K 3 with p-( p-sulfonated benzeneazo)calix[6]arene and determination of VK 3 (United States)

    Zhou, Yunyou; Xu, Hongwei; Wu, Lian; Liu, Chun; Lu, Qin; Wang, Lun


    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.

  11. 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


    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.

  12. 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


    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.

  13. Temperature effects on the retention of n-alkanes and arenes in helium-squalane gas-liquid chromatography. Experiment and molecular simulation. (United States)

    Wick, Collin D; Siepman, J Ilja; Klotz, Wendy L; Schure, Mark R


    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.

  14. Lateral assembly of oxidized graphene flakes into large-scale transparent conductive thin films with a three-dimensional surfactant 4-sulfocalix[4]arene (United States)

    Sundramoorthy, Ashok K.; Wang, Yilei; Wang, Jing; Che, Jianfei; Thong, Ya Xuan; Lu, Albert Chee W.; Chan-Park, Mary B.


    Graphene is a promising candidate material for transparent conductive films because of its excellent conductivity and one-carbon-atom thickness. Graphene oxide flakes prepared by Hummers method are typically several microns in size and must be pieced together in order to create macroscopic films. We report a macro-scale thin film fabrication method which employs a three-dimensional (3-D) surfactant, 4-sulfocalix[4]arene (SCX), as a lateral aggregating agent. After electrochemical exfoliation, the partially oxidized graphene (oGr) flakes are dispersed with SCX. The SCX forms micelles, which adsorb on the oGr flakes to enhance their dispersion, also promote aggregation into large-scale thin films under vacuum filtration. A thin oGr/SCX film can be shaved off from the aggregated oGr/SCX cake by immersing the cake in water. The oGr/SCX thin-film floating on the water can be subsequently lifted from the water surface with a substrate. The reduced oGr (red-oGr) films can be as thin as 10−20 nm with a transparency of >90% and sheet resistance of 890 ± 47 kΩ/sq. This method of electrochemical exfoliation followed by SCX-assisted suspension and hydrazine reduction, avoids using large amounts of strong acid (unlike Hummers method), is relatively simple and can easily form a large scale conductive and transparent film from oGr/SCX suspension. PMID:26040436

  15. Spectrophotometric Determination of Cr(III and Pb(II Using Their Complexes with 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl(azophenyl]calix[4]arene

    Directory of Open Access Journals (Sweden)

    Le Van Tan


    Full Text Available New complexes of 5,11,17,23-tetra[(2-ethyl acetoethoxyphenyl(azophenyl]calix[4]arene (TEAC with Pb(II and Cr(III were prepared in basic solution with a mixture of MeOH and H2O as solvent. The ratio of TEAC and metal ion in complexes was found to be 1 : 1 under investigated condition. The complex formation constants (based on Benesi-Hildebrand method for TEAC-Pb(II and TEAC-Cr(III were 4.03 × 104 and 1.2 × 104, respectively. Additionally, the molar extinction coefficients were 5 × 104 and 1.42 × 104 for TEAC-Pb(II and TEAC-Cr(III, respectively. The H-Point Standard Addition Method (HPSAM has been applied for simultaneous determination of complexes formation of Cr(III/Pb(II and TEAC with concentration from 2 : 1 to 1 : 20 (w/w. The proposed method was successfully utilized to invest lead and chromium contents in plating wastewater samples. The results for several analyzed samples were found to be in satisfied agreement with those acquired by using the inductively coupled plasma mass spectrometry (ICP-MS technique.

  16. An experimental and theoretical study of the aggregate structure of calix[6]arenes in Langmuir films at the water/air interface. (United States)

    de Lara, Lucas S; Wrobel, Ellen C; Lazzarotto, Márcio; de Lázaro, Sérgio R; Camilo, Alexandre; Wohnrath, Karen


    In this paper, the aggregate formation of para-tert-butylcalix[6]arene molecules (Calix6) in dimeric structures was investigated at the water/air interface using experimental and theoretical studies. A specific orientation for such Calix6 molecules was observed with an average area of 133 Å(2), which corresponds to a flat-on orientation with the OH groups parallel to the interface. By varying the pressure on the Calix6 monolayer, the molecules tend to organize at the water/air interface and subsequently, at higher pressures, aggregates were formed atop the monolayer as cluster structures. Morphological characterization by the Brewster Angle Microscopy technique showed the formation of larger domains at lower pressures. Based on such experimental evidence, molecular dynamics (MD) simulations were performed to investigate possible dimeric structures for aggregated Calix6 molecules, which are localized at the water/air interface, where one molecule remains in the water phase and the other remains in the air phase. By increasing surface pressure, experimental and theoretical results corroborate the intermolecular interactions among Calix6 molecules. These results are relevant because a dimeric structure has a molecular cavity, which is a candidate for host-guest chemistry, an ion receptor or a drug-delivery system.

  17. A Bifunctional Thioether Linked Coumarin Appended Calix[4]arene Acquires Selectivity Toward Cu(2+) Sensing on Going from Solution to SAM on Gold. (United States)

    Samanta, Kushal; Rao, Chebrolu Pulla


    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.

  18. Consumer Involvement in Rehabilitation (United States)

    Daniels, Susan


    With the emphasis on consumer involvement in the Rehabilitation Act of 1973, changes in the counseling relationship must occur. This article discusses new interaction patterns for consumer and counselor. (Author)

  19. Clinical studies involving probiotics


    Degnan, Fred H


    Researchers from a diverse array of scientific disciplines have focused and continue to focus on opportunities and areas for responsible clinical research involving the possible beneficial health effects of “probiotics.” Investigators and researchers should be aware that not all clinical research involving probiotics reasonably falls within the requirements of the “investigational new drug” (IND) rubric administered and enforced by the US Food and Drug Administration. In determining whether a...

  20. Pancreatic Involvement in Melioidosis

    Directory of Open Access Journals (Sweden)

    Vui Heng Chong


    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

  1. [Pulmonary involvements of sarcoidosis]. (United States)

    Ohmichi, M; Hiraga, Y; Hirasawa, M


    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.

  2. Shrimp U-Pb age and Sr-Nd isotopes of the Morro do Baú mafic intrusion: implications for the evolution of the Arenópolis volcano-sedimentary sequence, Goiás Magmatic Arc

    Directory of Open Access Journals (Sweden)

    Márcio M. Pimentel


    Full Text Available The Arenópolis volcano-sedimentary sequence is located in the southern part of the Goiás Magmatic Arc and includes a ca. 900 Ma calc-alkaline arc sequence made of volcanic rocks ranging in composition from basalts to rhyolites, metamorphosed under greenschist to amphibolite facies. Small calc-alkaline gabbro to granite sub-volcanic bodies are also recognized. The Morro do Baú intrusion is the largest of these intrusions, and is made of gabbros and diorites. Zircon grains separated from one gabbro sample and analyzed by SHRIMP I yielded the mean 206Pb/238U age of 890 +/- 8 Ma, indicating that the intrusion is roughly coeval or only slightly younger than the Arenópolis volcanics. Contrary to the metavolcanics, which are juvenile, the Nd isotopic composition of the Morro do Baú gabbro indicates strong contamination with archean sialic material (T DM of 2.8 Ga and EpsilonNd(T of -9.7, represented in the area by an allochthonous sliver of archean/paleoproterozoic gneisses (Ribeirão gneiss which are the country-rocks for the gabbro/dioritic intrusion. The emplacement age of ca. 890 Ma represents a minimum age limit for the tectonic accretion of the gneiss sliver to the younger rocks of the Arenópolis sequence. The data suggest that this happened early in the evolution of the Goiás Magmatic Arc, between ca. 920 and 890 Ma.A seqüência vulcano-sedimentar de Arenópolis, localizada na porção sul do Arco Magmárico de Goiás, inclui uma associação de rochas vulcânicas calci-alcalinas de arco com ca. 900 Ma de idade, constituída de rochas variando em composição entre basaltos e riolitos, metamorfisados em fácies xisto verde a anfibolito. Pequenos corpos sub-vulcânicos de gabros a granitos calci-alcalinos são também reconhecidos. A intrusão do Morro do Baú é a maior dessas intrusões, compreendendo dioritos e gabros. Cristais de zircão separados de uma amostra de gabro e analisados no SHRIMP I indicaram a idade 206Pb/238U média de

  3. Involve physicians in marketing. (United States)

    Randolph, G T; Baker, K M; Laubach, C A


    Many everyday problems in medical group practice can be attacked by a marketing approach. To be successful, however, this kind of approach must have the full support of those involved, especially the physicians, since they are the principal providers of healthcare services. When marketing is presented in a broad context, including elements such as patient mix, population distribution, and research, physicians are more likely to be interested and supportive. The members of Geisinger Medical Center's Department of Cardiovascular Medicine addressed their patient appointment backlog problem with a marketing approach. Their method is chronicled here and serves as a fine example of how physician involvement in marketing can lead to a positive outcome.

  4. Microwave-assisted synthesis of arene ruthenium(II) complexes [(η⁶-RC₆H₅)Ru(m-MOPIP)Cl]Cl (R = -H and -CH₃) as groove binder to c-myc G4 DNA. (United States)

    Wu, Qiong; Chen, Tianfeng; Zhang, Zhao; Liao, Siyan; Wu, Xiaohui; Wu, Jian; Mei, Wenjie; Chen, Yanhua; Wu, Weili; Zeng, Lingli; Zheng, Wenjie


    Two arene Ru(II) complexes coordinated by 2-(3-methoxyphenyl)imidazole[4,5-f][1,10]phenanthroline, [(η(6)-RC6H5)Ru(m-MOPIP)Cl]Cl (R = H, ; R = CH3, 2), have been prepared under microwave irradiation; the crystal structure of 2 exhibits a typical "piano stool" conformation, with bond angles for N1-Ru1-Cl1 86.02 (14)° and N2-Ru1-Cl1 84.51 (14)°. The Ru-C distance for the Ru atom bound to the benzene ring is about 0.2178(8) nm, and the average Ru-N distance for Ru atom to the two chelating N atoms is about 0.2092(4) nm. The evaluation of in vitro anticancer activities revealed that these synthetic Ru(II) complexes selectively inhibited the growth of HepG2 hepatocellular carcinoma cells, with low cytotoxicity toward LO2 human normal liver cells. The results demonstrated that the complexes exhibited great selectivity between human cancer and normal cells by comparing with the ligand m-MOPIP. Furthermore, complexes 1 and 2 could bind to c-myc G4 DNA in groove binding mode in promising affinity, and the insertion of the methyl groups in the arene ligand contributed to strengthen the binding affinity. This was also confirmed by molecular docking calculation and (1)H NMR analysis which showed that both 1 and 2 can bind in the loop constructed by A6-G9 and G21-A25 base pairs in c-myc G4 DNA to block the replication of c-myc oligomer. Taken together, these results suggest that arene Ru(II) complexes display application potential as small molecule inhibitors of c-myc G4 DNA.

  5. 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


    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.

  6. La participación social como método de conservación. Estudio de caso en el área de conservación arenal Huetar norte de Costa Rica



    Nota: Aquest document conté originàriament altre material i/o programari només consultable a la Biblioteca de Ciència i Tecnologia. El presente estudio se realiza con la intención de contribuir a establecer las bases para una buena gestión del territorio en el Área de conservación arenal Huetar norte de Costa Rica mediante la participación social; garantizando la conservación del capital natural y el desarrollo económico, social y ambientalmente sostenible. Para ello, se ha colaborado en l...

  7. Reactions of N,3-diarylpropiolamides with arenes under superelectrophilic activation: synthesis of 4,4-diaryl-3,4-dihydroquinolin-2(1H)-ones and their derivatives (United States)

    Gurskaya, Larisa Yu; Belyanskaya, Diana S; Ryabukhin, Dmitry S; Nilov, Denis I; Boyarskaya, Irina A


    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

  8. Unprovability results involving braids

    CERN Document Server

    Carlucci, Lorenzo; Weiermann, Andreas


    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.

  9. 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: [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India)


    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.

  10. 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)


    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.)

  11. Preconcentration and determination of trace silver ion using benzothiazole calix[4]arene modified silica by flow injection flame atomic absorption spectrometry. (United States)

    Waluvanaruk, Jitwilai; Aeungmaitrepirom, Wanlapa; Tuntulani, Thawatchai; Ngamukot, Passapol


    The silica gel modified with benzothiazole calix[4]arene (APS-L1) via Schiff's base reaction was applied as a sorbent in an online system for preconcentration and determination of silver ion by flame atomic absorption spectrometry (FAAS). APS-L1 was used as an effective sorbent for solid phase extraction (SPE) of silver(I) ion in both batch and column methods. The optimum experimental parameters such as pH, eluent type, sample flow rate, eluent volume and eluent flow rate including the effect of interfering ions were investigated. Silver(I) ion was determined at pH 6-7. The capacity of APS-L1 sorbent was found to be 12.2 mg/g of sorbent. The high affinity was obtained without interference from the interfering ions. The optimum conditions of the online flow injection preconcentration coupled with the FAAS (FI-FAAS system) were evaluated. The sample flow rate was 3.0 mL min(-1) using sample volume of 5-10 mL. Elution was performed with 250 μL of 0.1 mol L(-1) thiosulfate at the flow rate of 1.5 mL min(-1). The analytical characteristics and performance of the FI-FAAS system were studied under optimum conditions using a solution spiked with standard silver(I) ion at 20 and 50 μg L(-1). The detection limit of 0.44 μg L(-1) was obtained. The accuracy of the proposed method was evaluated and percentages of recovery at 20 and 50 μg L(-1) were 100.2 and 99.5%, respectively. The percent relative standard deviations (%RSD) at 20 and 50 μg L(-1) were 6.1 and 3.3%, respectively. The developed method was successfully applied to determine trace silver(I) ion in drinking and tap water samples.

  12. 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.


    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.)

  13. Planar chiral (η6-arene)Cr(CO)3 containing carboxylic acid derivatives: synthesis and use in the preparation of organometallic analogues of the antibiotic platensimycin. (United States)

    Patra, Malay; Merz, Klaus; Metzler-Nolte, Nils


    With more and more organometallic compounds receiving attention for applications in medicinal organometallic chemistry, the need arises for stereoselective syntheses of more complicated structures containing organometallic moieties, for example as isosteric substitutes for organic drug candidates. Herein, the synthesis and characterization of both diastereomers of a planar chiral (η(6)-arene)Cr(CO)(3) containing carboxylic acid derivative, namely, 3-{η(6)-(1, 2, 3, 4-tetrahydro-1-endo/exo-methyl-2-oxonaphthalen-1-yl)-tricarbonylchromium(0)}propanoic acid (7 and 8) is reported. The molecular structures of both were confirmed by single crystal X-ray diffraction. The degree of diastereoselectivity in Cr(CO)(3) complexation with methyl/tert-butyl-3-(1,2,3,4-tetrahydro-1-methyl-2-oxonaphthalen-1-yl)propanoate (4a/4b) vs. the Michael addition of methyl/tert-butyl acrylate to (η(6)-1-methyl-2-tetralone)Cr(CO)(3) (9) was also examined. In the latter case the alkylation was found to be completely diastereoselective and gave methyl/tert-butyl-3-{η(6)-(1, 2, 3, 4-tetrahydro-1-endo-methyl-2-oxonaphthalen-1-yl)-tricarbonylchromium (0)}propanoate (5a and 5b) in excellent yield. Both the carboxylic acids 7 and 8 were coupled with the aminoresorcyclic acid core to achieve diastereomeric bioorganometallics 15a and 15b based on the naturally occurring antibiotic platensimycin lead structure (1a, see Fig. 1). The newly synthesized bioorganometallics were tested against various Gram-positive and Gram-negative bacterial strains but show no promising antibacterial activity.

  14. Insights into the binding properties of a cuprous ion embedded in the tren cap of a calix[6]arene and supramolecular trapping of an intermediate. (United States)

    Izzet, Guillaume; Rager, Marie-Noëlle; Reinaud, Olivia


    Coordination of Cu(I) to a tren unit that is covalently linked to a calix[6]arene has been explored. The resulting complex revealed itself very stable in solution under an inert atmosphere, but extremely sensitive to O2 in solution as well as in the solid state. Therefore, its binding properties towards non-redox ligands have been studied in detail. The electron-rich metal center displays moderate affinity for nitrilo ligands compared to the calix[6]tris-pyridine ligand. Indeed, the binding enthalpy with acetonitrile is only -30 kJ mol(-1), whereas it is -72 kJ mol(-1) with the tris-pyridine system. In contrast, CO binding is relatively strong due to important pi-back donation from the metal center, as evidenced by the CO stretch, which was found to be less energetic (2075 cm(-1)) than that measured for ligands based on aromatic donors such as imidazole or pyridine. The conformational and dynamic properties of this calix-system have also been studied in detail. With an empty cavity or with the very small CO guest-ligand, the calix-core undergoes partial self-inclusion leading to dissymmetrical conformations. In contrast, nitrilo ligands act as "shoe-trees" that maintain the calix-core in a C(3v) symmetrical cone conformation. Very interestingly, the variable T study relative to the ligand exchange process highlighted a two-step dissociative pathway, where Cu-N bond cleavage/formation is differentiated from the nitrilo guest expulsion/inclusion from/into the calixarene cavity.

  15. Involved Node Radiation Therapy

    DEFF Research Database (Denmark)

    Maraldo, Maja V; Aznar, Marianne C; Vogelius, Ivan R


    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...... to 36 Gy). Patients attended regular follow-up visits until 5 years after therapy. RESULTS: The 4-year freedom from disease progression was 96.4% (95% confidence interval: 92.4%-100.4%), median follow-up of 50 months (range: 4-71 months). Three relapses occurred: 2 within the previous radiation field......, and 1 in a previously uninvolved region. The 4-year overall survival was 94% (95% confidence interval: 88.8%-99.1%), median follow-up of 58 months (range: 4-91 months). Early radiation therapy toxicity was limited to grade 1 (23.4%) and grade 2 (13.8%). During follow-up, 8 patients died, none from HL, 7...

  16. Microorganisms involved in MIC

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, K. [Danish Technological Institute (Denmark)


    Microbiologically influenced corrosion (MIC) is a widespread problem that is difficult to detect and assess because of its complex mechanism. This paper presents the involvement of microorganisms in MIC. Some of the mechanisms that cause MIC include hydrogen consumption, production of acids, anode-cathode formation and electron shuttling. A classic bio-corrosive microorganism in the oil and gas industry is sulphate-reducing prokaryotes (SRP). Methanogens also increase corrosion rates in metals. Some of the phylogenetic orders detected while studying SRP and methanogens are archaeoglobales, clostridiales, methanosarcinales and methanothermococcus. There were some implications, such as growth of SRP not being correlated with growth of methanogens; methanogens were included in MIC risk assessment. A few examples are used to display how microorganisms are involved in topside corrosion and microbial community in producing wells. From the study, it can be concluded that, MIC risk assessment includes system data and empirical knowledge of the distribution and number of microorganisms in the system.

  17. Involvement Without Participation?

    DEFF Research Database (Denmark)

    Olsén, Peter


    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....

  18. Getting involved in research. (United States)

    Banner, Davina; Grant, Lyle G


    The need for quality nursing research to promote evidence-based practice and optimize patient care is well recognized. This is particularly pertinent in cardiovascular nursing, where cardiovascular disease continues to be the leading cause of morbidity and mortality worldwide (World Health Organization, 2007). Across the spectrum of academic, clinical, and health care administration nursing roles, research remains fundamental to bridging theory, practice, and education (LoBiondo-Wood, Haber, Cameron, & Singh, 2009). Despite recognition of the importance of nursing research, the gap between research and practice continues to be an ongoing issue (Funk, Tornquist, & Champagne, 1995; Pettengill, Gillies, & Clark, 1994; Rizzuto, Bostrom, Suterm, & Chenitz, 1994; Rolfe, 1998). Nurses are appropriately situated to contribute to research that improves clinical outcomes and health service delivery. However, the majority of nurses in clinical practice do not have a significant research component structured into their nursing role. In this research column, the authors outline the importance of nurses being engaged in research and present some different levels of involvement that nurses may assume. A continuum of nursing research involvement includes asking researchable questions, being a savvy consumer of research evidence, finding your own level of research involvement, and aspiring to lead.

  19. Zn-catalyzed enantio- and diastereoselective formal [4 + 2] cycloaddition involving two electron-deficient partners: asymmetric synthesis of piperidines from 1-azadienes and nitro-alkenes. (United States)

    Chu, John C K; Dalton, Derek M; Rovis, Tomislav


    We report a catalytic asymmetric synthesis of piperidines through [4 + 2] cycloaddition of 1-azadienes and nitro-alkenes. The reaction uses earth abundant Zn as catalyst and is highly diastereo- and regioselective. A novel BOPA ligand (F-BOPA) confers high reactivity and enantioselectivity in the process. The presence of ortho substitution on the arenes adjacent to the bis(oxazolines) was found to be particularly impactful, due to limiting the undesired coordination of 1-azadiene to the Lewis acid and thus allowing the reaction to be carried out at lower temperature. A series of secondary kinetic isotope effect studies using a range of ligands implicates a stepwise mechanism for the transformation, involving an initial Michael-type addition of the imine to the nitro-alkene followed by a cyclization event. The stepwise mechanism obviates the electronic requirement inherent to a concerted mechanism, explaining the successful cycloaddition between two electron-deficient partners.

  20. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetramethoxycalix[4]arene dichloromethane hemisolvate

    Directory of Open Access Journals (Sweden)

    Edwin Weber


    Full Text Available In the title compound, C48H64O4·0.5CH2Cl2, both crystallographically independent calixarene molecules display a partial cone conformation. Their crystal packing is stabilized by C—H...π contacts involving the methoxy groups. The solvent molecule is located interstitially between two calixarene units with C—H...Cl contacts to methoxy and tert-butyl groups. One tert-butyl residue of each calixarene molecule is disordered over two positions (occupancies 0.60/0.40 and 0.63/0.37, resulting in bond distances that deviate from ideal values. The tetramer calixarene molecules present models with approximate non-crystallographic Cs symmetry.

  1. 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


    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.

  2. 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 H{sub 2}O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Raoof, Jahan Bakhsh, E-mail: [Electroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, Mazandaran University, 3rd Kilometer of Air Force Road, 47416-95447 Babolsar (Iran, Islamic Republic of); Ojani, Reza; Hasheminejad, Ehteram [Electroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, Mazandaran University, 3rd Kilometer of Air Force Road, 47416-95447 Babolsar (Iran, Islamic Republic of); Rashid-Nadimi, Sahar [Department of Renewable Energy, Faculty of Advanced Science and Technology, University of Isfahan, 81746-73441 Isfahan (Iran, Islamic Republic of)


    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 (H{sub 2}O{sub 2}). The effects of p-isopropyl calix[6]arene concentration, applied potential for reduction of Ag{sup +}, 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 Multiplication-Sign 10{sup -5} to 6.5 Multiplication-Sign 10{sup -3} M and a detection limit 2.7 Multiplication-Sign 10{sup -5} M of H{sub 2}O{sub 2} (S/N = 3) using amperometric method.

  3. 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


    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].

  4. Involvement in Physical Activity

    Directory of Open Access Journals (Sweden)

    James Gavin


    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.

  5. Games are motivating, aren´t they? Disputing the arguments for digital game-based learning

    Directory of Open Access Journals (Sweden)

    Wim Westera


    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.

  6. Development of a V-shape bis(tetraoxacalix[2]arene[2]triazine) stationary phase for high performance liquid chromatography. (United States)

    Hu, Kai; Feng, Suxiang; Wu, Mingxia; Wang, Shuang; Zhao, Wenjie; Jiang, Qiong; Yu, Ajuan; Zhang, Shusheng


    A new stationary phase for high-performance liquid chromatography was prepared by covalently bonding a V-shape cage heteroatom-bridged calixarene onto silica gel using 3-aminopropyltriethoxysilane as coupling reagent. The structure of the new material was characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. Linear solvation energy relationship method was successfully employed to evaluate the new phase with a set of 34 solutes. The retention characteristic of the new phase shows significant similarities with ODS, as well as distinctive features. Multiple mechanisms including hydrophobic, hydrogen bonding, π-π and n-π interaction are involved. The chromatographic behavior of the phase was illustrated by using alkylbenzenes, aromatics positional isomers and flavonoids as probes. Moreover, inorganic anions were individually separated in anion-exchange mode by using the same column. Thus, multi-interaction mechanisms and mixed-mode separation of the new phase can very likely guarantee its excellent chromatographic performance for the analysis of complex samples. The column has been successfully employed for the analysis of clenbuterol in animal urine, and it is demonstrated to be suitable and a competitive alternative analytical method for the determination of clenbuterol.

  7. Between Involvement and Detachment

    DEFF Research Database (Denmark)

    Thomasen, Gry

    a traditional reading of de Gaulle’s policies, and feared that if Gaullist thinking spread among the European allies, it would merit to a return to traditional European power politics. The analysis shows that, by 1964 the administration believed, according to this study, that NATO’s principle of integration......Between Involvement and Detachment takes grasp with the Johnson administration’s (1963-1969) perceptions of and responses to the Western European realignments. Arguing that the Johnson administration set out to maintain the American unilateralist position in the transatlantic relation, not just......, essentially, were detached as America rejected the European reason of state. The Western European realignments were recorded in the Johnson administration with de Gaulle’s critique of US hegemony in Western Europe in the early 1960s. The thesis argues that the administration to a large extent had...

  8. Effectiveness of citizen involvement

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, L. [Prince William Sound Regional Citizen' s Advisory Council, Anchorage, AK (United States)


    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.

  9. Interaction of a dinuclear fluorescent Cd(II) complex of calix[4]arene conjugate with phosphates and its applicability in cell imaging. (United States)

    Sreenivasu Mummidivarapu, V V; Hinge, Vijaya Kumar; Rao, Chebrolu Pulla


    A triazole-linked hydroxyethylimino conjugate of calix[4]arene () and its cadmium complex have been synthesized and characterized, and their structures have been established. In the complex, both the Cd(2+) centers are bound by an N2O4 core, and one of it is a distorted octahedral, whereas the other is a trigonal anti-prism. The fluorescence intensity of the di-nuclear Cd(ii) complex is quenched only in the presence of phosphates and not with other anions studied owing to their binding affinities and the nature of the interaction of the phosphates with Cd(2+). These are evident even from their absorption spectra. Different phosphates exhibit changes in both their fluorescence as well as absorption spectra to varying extents, suggesting their differential interactions. Among the six phosphates, H2PO4(-) has higher fluorescence quenching even at low equivalents of this ion, whereas P2O7(4-) shows only 50% quenching even at 10 equivalents. The fluorescence quenching is considerable even at 20 ppb (0.2 μM) of H2PO4(-), whereas all other phosphates require a concentration of 50-580 ppb to exhibit the same effect on fluorescence spectra. Thus, the interaction of H2PO4(-) is more effective by ∼30 fold as compared to that of P2O7(4-). Fluorescence quenching by phosphate is due to the release of from its original cadmium complex via the formation of a ternary species followed by the capture of Cd(2+) by the phosphate, as delineated based on the combination of spectral techniques, such as absorption, emission, (1)H NMR and ESI MS. The relative interactive abilities of the six phosphates differ from each other. The removal of Cd(2+) is demonstrated to be reversible by the repeated addition of the phosphate followed by Cd(2+). The characteristics of the ternary species formed in each of these six phosphates have been computationally modeled using molecular mechanics. The computational study revealed that the coordination between cadmium and -CH2-CH2-OH breaks and new

  10. [Nail involvement in leprosy]. (United States)

    Belinchón Romero, I; Ramos Rincón, J M; Reyes Rabell, F


    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.

  11. Multidrug toxicity involving sumatriptan. (United States)

    Knittel, Jessica L; Vorce, Shawn P; Levine, Barry; Hughes, Rhome L; Bosy, Thomas Z


    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.

  12. 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. (United States)

    Acharya, Amitabha; Ramanujam, Balaji; Chinta, Jugun Prakash; Rao, Chebrolu P


    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

  13. Synthesis of p-tert-Butylcalix[4]arene and Ether Derivative%对叔丁基杯[4]芳烃及其醚类衍生物的合成

    Institute of Scientific and Technical Information of China (English)

    武秋朋; 赵群力; 陈平; 臧树良


    在碱催化下,由对叔丁基苯酚和甲醛反应合成对叔丁基杯[4]芳烃.加入适量的乙酸乙酯作为带水剂,同时溶剂二苯醚可以循环使用.考察了乙酸乙酯的加入量和二苯醚循环使用次数对产品收率的影响.结果表明,加入乙酸乙酯带水剂,可以提高产品收率,缩短脱水时间,反应易于控制;二苯醚的使用次数对收率也有显著的影响,当第3次使用时,收率提高到73%.此种改进方法可以缩短反应时间、提高产品收率.同时探讨了催化剂K2 CO3的用量对合成对叔丁基杯[4]芳烃和对叔丁基杯[4]芳烃四乙酸乙酯收率的影响.结果表明,对叔丁基杯[4]芳烃与K2 CO3的最佳物质的量比为1∶11,产品收率达到74%.%p-tert - Butylcalix[4]arene was synthesized by p - tert - butylphenol and aldehyde using alkali as catalyst. An appropriate amount of ethyl acetate was added as a water carrier and the diphenyl ether was recycled as solvent. Amount of ethyl acetate and recycle times of diphenyl ether which effect on the yield of product were investigated. The results show that the addition of ethyl acetate can make the products yield increase, the dehydration time shorten and the reaction control easily. Recycle times of diphenyl ether has significant effect on the products yield. The yield increased to 73 % when diphenyl ether was reused 3 times. The improved method can shorten reaction time and increase the yield of products. In addition, the effect of the catalyst K2CO3 amount on the yield of tetraethyl p- tert- butylcalix[4]arene tetraacetate were discussed. The result shows that the yield of the product can reached 74% when the optimal mole ratio of p - tert - butylcalix[4]arene to catalyst K2CO3 was 1 : 11.

  14. Evolución metamórfica de los gabros coroníticos de El Arenal, faja máfica-ultramáfica El Destino-Las Águilas, sierra de San Luis Metamorphic evolution of the coronitic gabbrons of the El Arenal, El Destino-Las Aguilas, mafic-ultramafic belt, Sierra de San Luis

    Directory of Open Access Journals (Sweden)

    N. Brogioni


    Full Text Available Las meta-melagabronoritas coroníticas se localizan en uno de los cuerpos de El Arenal, pertenecientes a la faja máfica-ultramáfica El Destino-Las Aguilas del flanco oriental de la sierra de San Luis. Son rocas de grano fino y representan fraccionados poco evolucionados, con alto contenido de Cr-Ni y [Mg/Mg+FeT++] comprendidas entre 0,72 y 0,75, derivados de un magma toleítico olivínico de bajo Ti, cuyo emplazamiento precedió a la deformación penetrativa y metamorfismo famatinianos. Las microestructuras en coronas alrededor de olivino magnesiano y anortita registran tres estadios metamórficos de crecimiento mineral bajo condiciones de facies granulita, anfibolita y esquistos verdes que tuvieron lugar durante el ascenso y enfriamiento lento del magma favorecido por las condiciones P-T elevadas, ca. facies anfibolita, propias del nivel cortical profundo de locación. Luego de una ligera alteración deutérica de los componentes primarios, que ahora se conservan como relictos, se produjeron las transformaciones mineralógicas y microestructurales metamórficas más significativas. La desestabilización del par olivino-plagioclasa durante el estadio granulítico dio lugar a la formación de coronas de Opx y de simplectitas de Cpx + Spl. La deshidratación de las rocas de caja adyacentes, causada por el desarrollo de reacciones metamórficas, permitió durante el estadio anfibolítico la incorporación de fluidos acuosos indispensables para la cristalización de hornblenda, tanto en coronas de Amp + Spl simplectíticos como reemplazando al Opx relicto. La mineralogía de menor temperatura es relacionable con la exhumación de las rocas y representaría la última etapa de la trayectoria evolutiva antihoraria experimentada por las mismas durante el Paleozoico inferior.The coronitic meta-melagabbronorites are part of the El Arenal bodies which belong to the El Destino-Las Aguilas mafic to ultramafic belt, outcroping on the eastern flank of the

  15. New self-assembled material based on Ru nanoparticles and 4-sulfocalix[4]arene as an efficient and recyclable catalyst for reduction of brilliant yellow azo dye in water: a new model catalytic reaction (United States)

    Rambabu, Darsi; Pradeep, Chullikkattil P.; Dhir, Abhimanew


    New self-assembled material ( Ru@SC) with ruthenium nanoparticles (Ru NPs) and 4-sulfocalix[4]arene (SC) is synthesized in water at room temperature. Ru@SC is characterized by thermal gravimetric analysis, FT-IR, powder x-ray diffraction, TEM and SEM analysis. The size of Ru nanoparticles in the self-assembly is approximately 5 nm. The self-assembled material Ru@SC shows an efficient catalytic reduction of toxic `brilliant yellow' (BY) azo dye. The reduced amine products were successfully separated and confirmed by single-crystal XRD, NMR and UV-Vis spectroscopy. Ru@SC showed a better catalytic activity in comparison with commercial catalysts Ru/C (ruthenium on charcoal 5 %) and Pd/C (palladium on charcoal 5 and 10 %). The catalyst also showed a promising recyclability and heterogeneous nature as a catalyst for reduction of `BY' azo dye.

  16. Solvent Extraction of Some Divalent Metal Cations into Nitrobenzene by Using a Synergistic Mixture of Strontium Dicarbollylcobaltate and p-tert-Butylcalix[4]arene-tetrakis (N,N-Diethylacetamide). (United States)

    Makrlík, Emanuel; Budka, Jan; Vaňura, Petr; Selucký, Pavel


    From extraction experiments and g-activity measurements, the exchange extraction constants corresponding to the general equilibrium M2+(aq) + 1•Sr2+(nb) 1•M2+(nb) + Sr2+(aq) taking place in the two-phase water-nitrobenzene system (M2+ = Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Mn2+, Co2+, Ni2+; 1 = p-tert-butylcalix[4]arene-tetrakis(N,N-diethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) were determined. Further, the stability constants of the 1•M2+ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the series of Cu2+ < Ba2+ < Zn2+ < Ni2+ < UO22+ < Co2+ < Mn2+ < Cd2+ < Ca2+ < Pb2+.

  17. Determination of Vanadyl Porphyrins by Liquid-liquid Microextraction and Nano-baskets of p-tert-Calix[4]arene Bearing Di-[N-(X)sulfonye Carboxamide] and Di-(1-propoxy) in Ortho-cone Conformation

    Institute of Scientific and Technical Information of China (English)



    Dispersive liquid-liquid microextraction technique was introducd to remove the centrifuging step and conduct inclusion microextraction of charged porphyrins by nano-baskets.For nano-baskets ofp-tert-calix[4]arene bearing di-[N-(X)sulfonyl carboxamide] and di-(1-propoxy) in ortho-cone conformation was synthesized and used.The related parameters including ligand concentration,the volume of water disperser,salt effect,and extraction time were optimized.The linear range,detection limit(S/N=3) and precision(RSD,n=6) were determined to be 0.2-50,0.07 μg/L and 5.3%,respectively.The results reveal that the new approach is competitive analytical tool and an alternative of the traditional methods in the crude oil and related systems.

  18. 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. (United States)

    Grau-Campistany, Ariadna; Massaguer, Anna; Carrion-Salip, Dolors; Barragán, Flavia; Artigas, Gerard; López-Senín, Paula; Moreno, Virtudes; Marchán, Vicente


    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.

  19. Le arene politiche del corpo

    Directory of Open Access Journals (Sweden)

    Mariella Pandolfi


    Full Text Available L’antropologia contemporanea ha da tempo costruito intorno alla categoria “corpo” una zona di riflessione particolarmente porosa a ogni contaminazione disciplinare e a una più attenta sensibilità verso i nuovi paradigmi identitari emersi dagli anni Ottanta in poi. In tutti i suoi settori di ricerca, dall’antropologia medica al femminismo, da quella giuridica allo spazio politico, dall’etnopsichiatria al post-strutturalismo, la voce “corpo” si è imposta come luogo privilegiato per cercare di abbattere o per lo meno di rendere meno radicali le querelle disciplinari.

  20. Sacroiliac joint involvement in psoriasis. (United States)

    Kaçar, Cahit; Sezer, Ilhan; Kocabaş, Hilal; Cay, Hasan Fatih; Cevikol, Can; Alpsoy, Erkan; Melikoğlu, Meltem Alkan; Akman, Ayşe


    Psoriasis is a skin disorder that is associated with arthritis. Sacroiliac joint involvement is considered to be less frequent than the other types of psoriatic arthritis. Additionally, the psoriatic sacroiliitis is considered to be asymmetric in general. We aimed to define the frequency and type of sacroiliac involvement in patients with psoriasis. Patients with psoriasis were included the study. Characteristics of skin, nail and articular involvement were noted. Psoriasis area and severity index was calculated. Antero-posterior pelvic X-rays were obtained and graded by two rheumatologists and a radiologist independently. One hundred and thirty-three patients were included. Thirty-seven of patients (27%) have articular involvement symptomatically. The sacroiliac joint involvement was observed in 34 (26%) of patients. More than one-half of sacroiliac involvement was bilateral while less than one-half was in symptomatic patients regarding sacroiliitis. Fifty-seven percentages of all patients have psoriatic nail involvement. Sacroiliac joint involvement did not show any significant association with psoriatic nail involvement or the severity of skin disease. We found higher frequency of sacroiliac joint involvement and bilateral sacroiliitis in patients with psoriasis. This is in contrast to present information about the association of psoriasis and sacroiliitis. These findings need confirmation by further studies and with more sophisticated techniques such as magnetic resonance imaging.

  1. Monoarticular Hip Involvement in Pseudogout

    Directory of Open Access Journals (Sweden)

    Figen Kocyigit


    Full Text Available Pseudogout is the acutest form of arthritis in the elderly. Although clinical manifestations vary widely, polyarticular involvement is typical mimicking osteoarthritis or rheumatoid arthritis. Monoarticular involvement is relatively rare and is generally provoked by another medical condition. There are reported cases of hip involvement by pseudogout in monoarticular form. However, all of the cases were presented as septic arthritis. In this report, we present a case of monoarticular hip involvement mimicking soft tissue abscess. We confirmed the pseudogout diagnosis after ultrasonographic evaluation of the involved hip joint and pathological and biochemical analysis of synovial fluid analysis. Diagnosis is important to avoid unnecessary medical and surgical treatment in cases of the bizarre involvement of hip in pseudogout.

  2. Skin involvement in Dupuytren's disease.


    Wade, R.; Igali, L; Figus, A


    Whether the palmar skin has a role in the development, propagation or recurrence of Dupuytren's disease remains unclear. Clinical assessment for skin involvement is difficult and its correlation with histology uncertain. We prospectively biopsied the palmar skin of consecutive patients undergoing single digit fasciectomy (for primary Dupuytren's disease without clinically involved skin) and dermofasciectomy (for clinically involved skin or recurrence) in order to investigate this relationship...

  3. 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


      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.

  4. Direct Employee Involvement Quality (DEIQ)

    NARCIS (Netherlands)

    Torka, Nicole; Woerkom, van Marianne; Looise, Jan-Kees


    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

  5. Involvement of inositol in reproduction.

    NARCIS (Netherlands)

    Beemster, P.; Groenen, P.; Steegers-Theunissen, R.P.M.


    Inositol is involved in several aspects of reproduction. It affects overall embryogenesis, may prevent neural tube defects, and stimulates the production of lung surfactant. This article will review the involvement of inositol in reproduction. After describing the biologic function of inositol and i

  6. Preparing Teachers for Parent Involvement. (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…

  7. Citizen Involvement in Public Television. (United States)

    Wenner, Lawrence A.

    The purpose of this study was to evaluate the amount and quality of citizen involvement in public television. From the perspective of the "average citizen," the concept of involvement is considered with regard to the Carnegie Commission, the Corporation for Public Broadcasting (CPB) borad of directors, the National Citizens Committee for…

  8. Parental Involvement and Academic Achievement (United States)

    Goodwin, Sarah Christine


    This research study examined the correlation between student achievement and parent's perceptions of their involvement in their child's schooling. Parent participants completed the Parent Involvement Project Parent Questionnaire. Results slightly indicated parents of students with higher level of achievement perceived less demand or invitations…

  9. Ocular involvement in pemphigus vulgaris. (United States)

    Akhyani, Maryam; Keshtkar-Jafari, Alireza; Chams-Davatchi, Cheyda; Lajevardi, Vahide; Beigi, Sara; Aghazadeh, Nessa; Rayati Damavandi, Maede; Arami, Shabnam


    Pemphigus vulgaris (PV) is an autoimmune disorder affecting the skin and mucous membranes. Ocular involvement in PV has been reported but its prevalence and clinical characteristics are not well defined. This prospective cross-sectional study of 103 PV patients was designed to determine the prevalence, clinical types and epidemiological trends of ocular involvement in a population of Iranian patients with PV. Ocular involvement was present in 17 (16.5%) patients. Conjunctivitis was the most prevalent type of ocular involvement (9/17, 52.9%), followed by erosion of the palpebral conjunctiva (7/17, 41.2%). Erosion of the bulbar conjunctiva was noted in only one patient (5.9%). The most commonly reported symptoms were eye irritation (76.5%) and redness (76.5%). No significant relation was found between ocular involvement and disease activity (partial remission or relapse). Mucoid discharge was significantly more common in patients with conjunctival erosions as compared to patients with conjunctivitis (P = 0.038). We conclude that ocular involvement is not rare in PV; 16.5% of PV patients develop ocular disease independent of the disease activity and extension. Conjunctivitis is the most common type of involvement, however, palpebral conjunctival erosion is more frequent than previously realized.


    Directory of Open Access Journals (Sweden)



    Full Text Available 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 inthe consumption behavior is made through fees and taxes that are applied on income. Fees andtaxes are applied to the different forms of income but in this article we will be focused only onthe influence of them on wages. In order to analyze the involvement of government expenses onconsumption behavior an utility model will be used.

  11. 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


    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.

  12. 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


    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.

  13. User Involvement And Entrepreneurial Action

    Directory of Open Access Journals (Sweden)

    Eva Heiskanen


    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.

  14. 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. (United States)

    Mizani, Farhang; Shamsipur, Mojtaba; Yaftian, Mohammad R; Matt, Dominique


    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.

  15. In vitro characterization of a novel C,N-cyclometalated benzimidazole Ru(II) arene complex: stability, intracellular distribution and binding, effects on organic osmolyte homeostasis and induction of apoptosis. (United States)

    Støving Dam, Celina; Alejo Perez Henarejos, Sergio; Tsolakou, Theodosia; Alexander Segato, Christian; Gammelgaard, Bente; Yellol, Gorakh S; Ruiz, José; Lambert, Ian Henry; Stürup, Stefan


    In the present work a novel C,N-cyclometalated benzimidazole Ru(ii) arene complex (GY34) was characterized by applying an alternative, diverse approach considering both chemical and biological aspects. RP-HPLC-ICP-MS and RP-HPLC-ESI-MS analysis proved that GY34 in both RPMI-1640 cell medium and ammonium acetate buffer was transformed into several subspecies and the importance of evaluating and controlling analyte stability throughout experiments was demonstrated. Applying a novel cell fractionation protocol GY34 was found to target cell nuclei and mitochondria in Ehrlich Lettré Ascites (ELA) cells, with the intracellular distribution depending on GY34 concentration in the cell medium during incubation. In ELA cells 96 ± 0.2% of cytosolic GY34 was bound to high-molecular species. Furthermore, using the tracer technique GY34 was found to reduce uptake and increase release of the organic osmolyte taurine in ELA cells, with innate resistance to Cisplatin and in A2780 human ovarian cancer cells, with acquired resistance to Cisplatin. Importantly, FACS analysis revealed that GY34 induced apoptosis in ELA cells. The present data suggest the potential of GY34 in overcoming Cisplatin resistance. The methodology applied can be used as a general protocol and an additional tool in the initial evaluation of novel metal-based drugs.

  16. 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


      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.

  17. Differentiating phosphates by an Mg(2+) complex of the conjugate of calix[4]arene via the formation of ternary species and causing changes in the aggregation: spectroscopy, microscopy, and computational modeling. (United States)

    Nehra, Anita; Yarramala, Deepthi S; Hinge, Vijaya Kumar; Samanta, Kushal; Rao, Chebrolu Pulla


    A phenylene diimine capped conjugate of 1,3-calix[4]arene (L) was synthesized and characterized, and its Mg(2+) complex has been isolated and characterized. The chemo sensing ensemble of Mg(2+) bound L provides distinguishable features of response toward phosphates, viz., HPO4(2-), P2O7(4-), and AMP(2-) (Set A) and H2PO4(-), ATP(2-), and ADP(2-) (Set B). While the Set A shows the formation of ternary complex, the Set B does not exhibit any intermediate complex, but both show the release of Mg(2+) and L at different equivalents. The structures of {L + Mg(2+)} and its phosphate bound ternary complexes have been established by computational calculations, and the corresponding results agree well with the experimental ones. The microscopy studies show an aggregation-disaggregation phenomenon in the presence of different equivalents of phosphates in both of the sets. Using the fluorescence data, an INHIBIT logic gate has been built.

  18. 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


    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.

  19. 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


      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。

  20. Strategy Innovation with Employee Involvement

    DEFF Research Database (Denmark)

    Friis, Ole Uhrskov; Koch, Christian


    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....

  1. Involving Employees in Strategy innovation

    DEFF Research Database (Denmark)

    Friis, Ole Uhrskov; Koch, Christian


    some of its employees. Even if managers still dominate, some processes of direct involvement of employees occur. The employees are in particular active in supplementing overall strategic goals and directly shaping one sub strategy, that of ‘process’. Strategy practices include planning, Porterian......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...... and Balanced Score Card consultancy, an ‘open space’ workshop and organized strategy projects. Especially the latter two are important in facilitating the employee involvement. The case however also exhibit enterprise situated praxis’s like mitigation of taboos....

  2. User involvement in care work

    DEFF Research Database (Denmark)

    Dybbroe, Betina; Kamp, Annette

    effectiveness and shared responsibility for care pathways. While NPM position users as consumers making their free choice, the user involvement paradigm underlines the users’ active participation in the mastering of their problems and disease. Research is scarce on this theme, and has until now primarily......In recent years user involvement has become a paradigm for transforming the health and social care sector. This development–also labelled empowerment, co-creation, partnership, patient-centeredness - is seen as a means to reform organizations in ways that enhance quality, economic cost...... addressed the way this paradigm affects the users, in specific sectors. However user involvement also affects working life. It may imply change and redistribution of tasks and identities between users and professionals, and may also transform the relations of care. In this paper we explore the possible...

  3. Gastrointestinal involvement in systemic sclerosis. (United States)

    Savarino, Edoardo; Furnari, Manuele; de Bortoli, Nicola; Martinucci, Irene; Bodini, Giorgia; Ghio, Massimo; Savarino, Vincenzo


    Systemic sclerosis is an autoimmune chronic disease characterised by microvascular, muscular and immunologic abnormalities that lead to progressive and systemic deposition of connective tissue in the skin and internal organs. The gastrointestinal tract is often overlooked by physicians but it is the most affected organ after the skin, from the mouth to the anus. Indeed, 80% of SSc patients may present with gastrointestinal involvement. Gastrointestinal manifestations range from bloating and heartburn to dysphagia and anorectal dysfunction to severe weight loss and malabsorption. However, the gastrointestinal involvement is rarely the direct cause of death, but has great impact on quality of life and leads to several comorbidities that subsequently affect patients' survival. Treatments, including nutritional support and prokinetics provide limited benefits and do not arrest the progressive course of the disease, but earlier detection of gastrointestinal involvement may reduce the risk of complications such as malnutrition.

  4. [Heel involvement in rheumatoid polyarthritis]. (United States)

    Bouysset, M; Tebib, J G; Vianey, J C; Berthier, M; Nemoz, J C; Chaumentin, G; Schnepp, J; Llorca, G; Bouvier, M


    Calcaneus involvement during the course of RA is poorly known. A clinical and radiological study of 408 consecutive rheumatoid feet are then reported. If talalgia was seldomly noted (3.7 p. cent), plantar calcaneitis was found in 29.7 p. cent as plantar spur. Similarly, posterior exostosis was displayed in 30.5 p. cent of patients. These radiological abnormalities are increased in RA but appeared more as a consequence of the statical modification of the foot secondary to RA process than as a direct involvement. Logical orthopedic therapeutics are then proposed.

  5. Multisystem involvement in neuromyelitis optica

    Directory of Open Access Journals (Sweden)

    Megan M Langille


    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.

  6. Vertebral osteomyelitis without disc involvement

    Energy Technology Data Exchange (ETDEWEB)

    Kamani, I.; Syed, I.; Saifuddin, A. E-mail:; Green, R.; MacSweeney, F


    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.

  7. 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)


    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.).

  8. Promoting Active Involvement in Classrooms (United States)

    Conderman, Greg; Bresnahan, Val; Hedin, Laura


    This article presents a rationale for using active involvement techniques, describes large- and small-group methods based on their documented effectiveness and applicability to K-12 classrooms, and illustrates their use. These approaches include ways of engaging students in large groups (e.g., unison responses, response cards, dry-erase boards,…

  9. Parent Involvement as Ritualized Practice (United States)

    Doucet, Fabienne


    This article examines parent involvement (PI) as a ritual system using Turner's concept of root paradigms. Through a twofold analysis, I argue that the highly ritualized nature of PI practices creates a group identity among mainstream parents and schools that marginalizes diverse families. First, I point out three root paradigms in the ritual…

  10. 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)


    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.)

  11. Managing Parent Involvement during Crisis (United States)

    Merriman, Lynette S.


    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…

  12. Liver involvement in systemic infection

    Institute of Scientific and Technical Information of China (English)

    Masami; Minemura; Kazuto; Tajiri; Yukihiro; Shimizu


    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.

  13. Inclusive Briefing and User Involvement

    DEFF Research Database (Denmark)

    Jensen, Per Anker


    Briefing is not just about specifying needs as requirements but also about evaluating how well design proposals fulfil needs and aspirations. Furthermore, briefing is not only about building design. Briefing starts at the preproject stage to create a basis for the project decision and can include...... a number of different processes with varying purposes before and during the design and construction activities. Thus, briefing can be regarded as a continuous process but it should also be an inclusive and interactive process with the involvement of all stakeholders, including end users. This article...... includes a literature study on briefing and user involvement in building projects, and presents a case study of a major building project of a new headquarters and media centre for the Danish Broadcasting Corporation in Copenhagen. The building project was actively used as part of a corporate change process...

  14. 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)


    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.)

  15. Cardiac involvement in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    V. De Gennaro Colonna


    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.

  16. Laryngeal Involvement of Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Ariel B. Grobman


    Full Text Available The objectives of this paper are to discuss a rare cause of laryngeal multiple myeloma, to review unique pathologic findings associated with plasma cell neoplasms, to discuss epidemiology, differential diagnosis, and treatment options for plasma cell neoplasms of the larynx. Laryngeal multiple myeloma, also noted in the literature as “metastatic” multiple myeloma, presenting as a de novo laryngeal mass is extremely rare with few reported cases. Laryngeal involvement of extramedullary tumors is reported to be between 6% and 18% with the epiglottis, glottis, false vocal folds, aryepiglottic folds, and subglottis involved in decreasing the order of frequency. We present the case of a 58-year-old male with a history of IgA smoldering myeloma who presented to a tertiary care laryngological practice with a two-month history of dysphonia, which was found to be laryngeal involvement of multiple myeloma. We review the classification of and differentiation between different plasma cell neoplasms, disease workups, pathologic findings, and treatment options.

  17. 重整C9芳烃分馏塔冷凝潜热综合利用新工艺%Integrated utilizing process for condensation latent heat of reforming C9 arene fractionating column

    Institute of Scientific and Technical Information of China (English)

    赵永祥; 侯敏; 杜颖


    基于重整C9芳烃分离装置塔顶油气冷凝潜热的特点,分析对比现有换热工艺及几种新的节能新工艺,研究发现,利用二塔塔顶油气生产0.4 MPa饱和水蒸气,二塔塔釜分别设加热热源工艺和分馏塔热集成与塔顶油气生产0.4 MPa水蒸气联合运用工艺,二者节能效果相当,但是后者装置外提供的一次能量较前者小,因此分馏塔热集成与塔顶油气生产0.4 MPa水蒸气联合运用工艺更好.文中提出对于新建的重整C9芳烃分离装置可以采用分馏塔热集成与塔顶油气冷凝潜热生产水蒸气联合节能工艺,可以直接利用其分馏塔顶油气冷凝潜热生产水蒸气,以降低能耗,由重整C9芳烃塔顶油气潜热所生产的0.4 MPa水蒸气可以直接使用,也可以通过压缩机进行提温提压后,并入低压蒸汽管网;对于现有装置可以通过改造,直接利用分馏塔顶油气生产水蒸气,其节能效果也十分明显.%Based on the condensation latent heat characteristics of fractionating column top oil gas in C9 arenes separating unit, the existing heat transfer technologies and several new energy-saving technologies were analyzed and compared. The research shows that the technology with 0.4 Mpa saturated steam produced from two-column top oil gas and two-column bottom heated with different heat sources and the technology with 0.4 Mpa saturated steam produced from two-column top oil gas and utilizing integrated heat from fractionating column both are obviously agreed in energy saving. But, the latter needs less primary power provided from outside apparatus. So this technology is better. Both heat-integrated distillation technology and steam production technology by using latent heat energy can be used in new C9 arenes distillation plant, from which the vapor can be produced directly from condensation latent heat to decrease energy consumption. The produced 0.4 Mpa steam can be directly used in the plant or sent into the low

  18. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H


    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...

  19. Modeling interdisciplinary activities involving Mathematics

    DEFF Research Database (Denmark)

    Iversen, Steffen Møllegaard


    In this paper a didactical model is presented. The goal of the model is to work as a didactical tool, or conceptual frame, for developing, carrying through and evaluating interdisciplinary activities involving the subject of mathematics and philosophy in the high schools. Through the terms...... domains (Michelsen, 2001, 2005a, 2005b). Furthermore the theoretical description rest on a series of qualitative interviews with teachers from the Danish high school (grades 9-11) conducted recently. The special case of concrete interdisciplinary activities between mathematics and philosophy is also...

  20. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H;


    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......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...

  1. 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)


    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.)

  2. 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


    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.


    CERN Multimedia


    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.

  4. Metronidazole neurotoxicity: Sequential neuroaxis involvement

    Directory of Open Access Journals (Sweden)

    Kyung-Il Park


    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.

  5. Charmless B decays involving baryons (United States)

    Gronau, Michael; Rosner, Jonathan L.


    Predictions are made for the fraction of B-meson decays involving specific final states of NN¯+nπ (n>=0), as functions of (a) decay dynamics, (b) models for multipion production, (c) the isospin of the final state, and (d) the ratio ||Vbu/Vbc|| of Kobayashi-Maskawa matrix elements. From recent observations of B+-->pp¯π+(+c.c.) and B0-->pp¯π+π- by the ARGUS Collaboration, it is concluded that ||Vbu/Vbc||>~0.08, similar to the ARGUS Collaboration's own estimate of 0.07. However, a more likely value for this ratio is near its present experimental upper limit. Predictions are made for further final states in NN¯+nπ and in other charmless B decays. We also comment briefly on prospects for observing CP violation in B-->NN¯+nπ.

  6. Measuring Purchase‐decision involvement ,

    Directory of Open Access Journals (Sweden)

    Naser Azad


    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.

  7. Kidney involvement in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    P. Lazzarini


    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

  8. Drug hypersensitivity reactions involving skin. (United States)

    Hausmann, Oliver; Schnyder, Benno; Pichler, Werner J


    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

  9. Forced twin-chair conformation in 7-benzoyl- and 7-phenylacetyl-r-2,c-4,t-6,t-8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonanes with 1,3-diaxial phenyl groups in the piperidine ring: single- and double-layered supramolecular sheets built from C-H...O and C-H...pi(arene) hydrogen bonds. (United States)

    Sakthivel, Chinniah; Jeyaraman, Ramasubbu


    The crystal structures of 7-benzoyl-r-2,c-4,t-6,t-8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonane, C(38)H(33)NOS, (I), and r-2,c-4,t-6,t-8-tetraphenyl-7-phenylacetyl-3-thia-7-azabicyclo[3.3.1]nonane [systematic name: 2-phenyl-1-(r-2,c-4,t-6,t-8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonan-7-yl)ethanone], C(39)H(35)NOS, (II), both reveal a forced twin-chair conformation with the 1,3-diaxial phenyl groups in the piperidine ring, and flattening at the N-atom end of the piperidine ring of the bicyclic system. In the crystal structure of (I), molecules are linked into sheets by a combination of two weak C-H...O and one C-H...pi(arene) hydrogen bond, while in the crystal structure of (II), the molecules extend into double-layered sheets assisted by three C-H...pi(arene) hydrogen bonds.


    Directory of Open Access Journals (Sweden)

    D. V. Bestaev


    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.

  11. SNAr-Derived Decomposition By-products Involving Pentafluorophenyl Triazolium Carbenes. (United States)

    Zhao, Xiaodan; Glover, Garrett S; Oberg, Kevin M; Dalton, Derek M; Rovis, Tomislav


    Pentafluorophenyl triazolium carbenes, widely used in NHC-catalysis, can decompose by several mechanisms. Under high concentration conditions, the azolium may undergo a pentafluorophenyl exchange by a proposed SNAr mechanism to give an inactive salt. In the presence of appropriate substrates, cyclization on the ortho-position of the arene can occur, also by SNAr. These adducts provide a potential pathway for catalyst decomposition and serve as a caveat to the development of new reactions and catalysts.

  12. Evaluating Parent Involvement. Issue Paper No. 1. (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…

  13. Defining Parental Involvement: Perception of School Administrators (United States)

    Young, Clara Y.; Austin, Sheila M.; Growe, Roslin


    There remains a plaguing question of how to get parents involved with their child's education. Many parents and educators have different perceptions of what parental involvement means. Miscommunication between the two groups often exists because of how parental involvement is conceptualized. While educators define parental involvement as…

  14. Cardiovascular involvement in psoriatic arthritis

    Directory of Open Access Journals (Sweden)

    V. De Gennaro Colonna


    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.

  15. Evolución metamórfica de los gabros coroníticos de El Arenal, faja máfica-ultramáfica El Destino-Las Águilas, sierra de San Luis

    Directory of Open Access Journals (Sweden)

    N. Brogioni


    Full Text Available Las meta-melagabronoritas coroníticas se localizan en uno de los cuerpos de El Arenal, pertenecientes a la faja máfica-ultramáfica El Destino-Las Aguilas del flanco oriental de la sierra de San Luis. Son rocas de grano fino y representan fraccionados poco evolucionados, con alto contenido de Cr-Ni y [Mg/Mg+FeT++] comprendidas entre 0,72 y 0,75, derivados de un magma toleítico olivínico de bajo Ti, cuyo emplazamiento precedió a la deformación penetrativa y metamorfismo famatinianos. Las microestructuras en coronas alrededor de olivino magnesiano y anortita registran tres estadios metamórficos de crecimiento mineral bajo condiciones de facies granulita, anfibolita y esquistos verdes que tuvieron lugar durante el ascenso y enfriamiento lento del magma favorecido por las condiciones P-T elevadas, ca. facies anfibolita, propias del nivel cortical profundo de locación. Luego de una ligera alteración deutérica de los componentes primarios, que ahora se conservan como relictos, se produjeron las transformaciones mineralógicas y microestructurales metamórficas más significativas. La desestabilización del par olivino-plagioclasa durante el estadio granulítico dio lugar a la formación de coronas de Opx y de simplectitas de Cpx + Spl. La deshidratación de las rocas de caja adyacentes, causada por el desarrollo de reacciones metamórficas, permitió durante el estadio anfibolítico la incorporación de fluidos acuosos indispensables para la cristalización de hornblenda, tanto en coronas de Amp + Spl simplectíticos como reemplazando al Opx relicto. La mineralogía de menor temperatura es relacionable con la exhumación de las rocas y representaría la última etapa de la trayectoria evolutiva antihoraria experimentada por las mismas durante el Paleozoico inferior.

  16. Preparation of amide-t-butylcalix[8] arene/polyacrylonitrile nanofibers by electrospinning%对叔丁基酰胺化杯[8]芳烃/聚丙烯腈纳米纤维的制备

    Institute of Scientific and Technical Information of China (English)

    高春; 房伟; 陈铭; 刁国旺


    Amide-t-butylcalix[8] arene/polyacrylonitrile (Amide-Cal[8]/PAN) nanofibers were prepared by electrospinning. The nanofibers were characterized by fourier transform infrared spectros-copy (FTIR), field emission scanning electron microscope (FE-SEM), conductivity meter, torque rheometer. The results showed that Amide-Cal[8]/PAN was successfully prepared by electrospinning. The diameter of nanofibers was smaller than that of the blank PAN nanofibers. Moreover, the surface of nanofibers was smooth and uniform, but with the Amide-Cal[8] content increased, diameter of nanofibers and the surface roughness were increased. Rheometer results indicated that the viscosities of Amide-Cal[8]/PAN spinning solutions were increased with the increase of Amide-Cal[8] content. Conductivity results showed that the electrical conductivities of Amide-Cal[8]/ PAN spinning solution were higher than that of pure PAN solution and it was conducive to electrospinning.%采用静电纺丝技术制备了对叔丁基酰胺化杯[8]芳烃/聚丙烯腈(Amide-Cal[8]/PAN)复合纳米纤维,并通过傅里叶变换红外光谱(FTIR)仪、场发射扫描电镜(FE-SEM)、电导率仪、转矩流变仪对其结构与性质进行表征.实验结果表明:①Amide-Cal[8]/PAN纳米纤维的直径较空白的PAN纳米纤维小;②随着Amide-Cal[8]含量的增加,纳米纤维的直径先减小后增大,且纤维表面的粗糙程度逐渐增加,粗细不均;Amide-Cal[8]/PAN电纺溶液的黏度随着Amide-Cal[8]含量的增加而线性增大;③Amide-Cal[8]/PAN电纺溶液比PAN溶液的电导率大,有利于静电纺丝.

  17. Patient involvement in Danish health care

    DEFF Research Database (Denmark)

    Vrangbaek, Karsten


    PURPOSE: The purpose of this paper is to investigate different types of patient involvement in Denmark, and to discuss the potential implications of pursuing several strategies for patient involvement simultaneously. DESIGN/METHODOLOGY/APPROACH: The paper presents a preliminary framework...... 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...... 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....

  18. Quality assurance - how to involve the employees

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard


    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....

  19. Involving Nepali academics in health research

    DEFF Research Database (Denmark)

    Neupane, Dinesh; van Teijlingen, E; Khanal, V;


    Many academics from Nepal do not involve in research activities. There are several factors hindering the involvement such as inadequate human resources and lack of financial resources. Despite limited human and financial resources, we believe it is still possible to attract many Nepali academics...... in health research. This paper purposes some ideas to increase involvement of Nepali academics in health research....

  20. Community Involvement and Disadvantaged Students: A Review. (United States)

    Nettles, Saundra Murray


    Community involvement is conceptualized as a typology of the following processes of social change: (1) conversion; (2) mobilization; (3) allocation of resources; and (4) instruction. The effects of these forms of involvement are considered in a review of 13 evaluations of programs for disadvantaged youth involving the community. (SLD)

  1. Parental Involvement in Traditional and Online Education (United States)

    Chang, Cheng-Sian; Chen, Hsi-Mei


    While parental involvement benefits the learning performance of elementary students and the internet changes the learning environment, few studies have examined how parents are involved in the virtual world. This two-year project analysed the effects of parental involvement at home, in school and on internet use. The first stage of our research…

  2. Parental Involvement in Special Education Curriculum (United States)

    Westwood-Robinette, Nicole M.


    Educators and researchers have long considered parental involvement an integral part in the success of students and researchers have concluded that there is a connection between parental involvement and the retention rates of students who are involved in regular education curriculum. However, much less information is available regarding the…

  3. 36 CFR 1010.12 - Public involvement. (United States)


    ... 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...

  4. Brainstem involvement in subacute sclerosing panencephalitis

    Directory of Open Access Journals (Sweden)

    Pawan Sharma


    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.

  5. Who and What Does Involvement Involve? A Multi-Sited Field Study of Involvement of Relatives in Danish Psychiatry. (United States)

    Oute, Jeppe; Petersen, Anders; Huniche, Lotte


    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 system-a family site, a clinical site and a policy site-the first author (J.O.) investigated how, and on what grounds, involvement of relatives is perceived in Danish psychiatry. Paradoxically, the current understanding of involvement of relatives fails to take into consideration the perspectives of the relatives per se and families that were being studied. By analyzing involvement from a discourse 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 is constituted by a broader discourse of neoliberalism and market orientation, which justifies involvement as a subtle institutionalization of social control. The article highlights that the role of the relative as a co-therapist may be contested by the families' discourse, which emphasizes issues concerning the responsibility toward the mental health of the ill individual as well as toward the psychological milieu of the family.

  6. Adsorption Effect of AmberliteXAD-4 Resin Based Calix[4]arene on Bilirubin in Aqueous Medium%杯【4】芳烃修饰Amberlite XAD-4树脂对水介质中胆红素的吸附性能

    Institute of Scientific and Technical Information of China (English)

    熊振湖; 朱乐; 王月


    通过偶氮化反应将杯【4】芳烃接枝到AmberliteXAD-4树脂上,采用FTIR、SEM等方法,表征了杯【4】芳烃修饰AmbertiteXAD-4树脂的结构.吸附实验表明,杯【4】芳烃修饰AmberliteXAD-4树脂对胆红素的吸附容量远远大于单纯AmberliteXAD-4树脂.在温度为25℃,胆红素浓度为20mg/L、吸附时间为2h的条件下,胆红素的平衡去除率在90%以上;而相同条件下的单纯AmberliteXAD-4树脂对胆红素的去除率仅为32.8%.水溶液中修饰树脂达到吸附平衡的时间为2h左右,而且温度越高达到平衡吸附的时间越短.在近中性(pH=5~7)条件下修饰树脂对胆红素的吸附容量达到最大值,为2.1medg,但随pH的降低或增大吸附容量均迅速降低.%The calix[4]arene is connected to Amberlite XAD-4 resin covalently through a diazotization reaction. The structure of Amberlite XAD-4 resin based on calix[4]arene is characterized using FT-IR, SEM. The sorption results show that Amberlite XAD-4 resin based on calix[4]arene has much better removal to the bilirubin in aqueous solutions than Amberlite XAD-4 resin which are presence alone in aqueous solutions. The removal rate of bilirubin is over 90% at equilibrium, at the conditions of 25℃, the concentration of bilirubin is 20 mg/L and the adsorption time is 2 h. At the same conditions, the removal of bilirubin from Amberlite XAD-4 resin is 2.8% alone. The equilibrium time is 2h and decreases with an increase in temperature. When the aqueous solution stays near the neutral (pH = 5 - 7), the adsorption capacity of Amberlite XAD-4 resin modified with calix[4]arene to the bilirubin reaches maximum value, which is 2.1 mg/g but the value decreases rapidly when the pH increases or decreases

  7. Judd–Ofelt parameters of diglycolamide-functionalized calix[4]arene Eu{sup 3+} complexes in room temperature ionic liquid for structural analysis: Effects of solvents and ligand stereochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Arijit [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Godbole, Shrikant V. [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Laboratory of Molecular Nanofabrication, MESA Institute for Nanotechnology, University of Twente, P. O. Box 217, 7500 AE Enschede (Netherlands); Mohapatra, Prasanta K., E-mail: [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Iqbal, Mudassir; Huskens, Jurriaan; Verboom, Willem [Laboratory of Molecular Nanofabrication, MESA Institute for Nanotechnology, University of Twente, P. O. Box 217, 7500 AE Enschede (Netherlands)


    The complexation behavior of several diglycolamide (DGA)-functionalized calix [4]arene ligands (C4DGA) with Eu{sup 3+} in C{sub 8}mimNTf{sub 2} (1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide) was studied by time resolved laser fluorescence spectroscopy (TRLFS). The high intensity emission peaks of Eu{sup 3+} at 614 and 619 nm, which are due to the {sup 5}D{sub 0}→{sup 7}F{sub 2} transition, sensitive to the local environment around Eu{sup 3+}, suggest that Eu{sup 3+} sits in a highly asymmetric environment. The metal-ligand stoichiometry of the complexes is 1:1, while there was no inner sphere water molecule around Eu{sup 3+}. The splitting pattern of the individual transitions of Eu{sup 3+} indicates that the local site symmetry around Eu{sup 3+} is C{sub 4V}. Though the emission characteristics of the complexes in C{sub 8}mimNTf{sub 2} and a 1:5 acetonitrile-water mixture were similar, the smaller linewidth in C{sub 8}mimNTf{sub 2} can be attributed to the restricted motion of the Eu{sup 3+} complex. Judd and Ofelt parameters (Ω{sub 2}, Ω{sub 4}) were calculated for all Eu{sup 3+}–C4DGA complexes. Steric crowding around the ligating sites decreases the proximity of Eu{sup 3+} with the carbonyl oxygens. This is evident from a decrease in the Ω{sub 2} value, which is a signature of the increase in the bond length and concomitant decrease in the covalent interactions. Higher transition probabilities (A{sub md}, A{sub 2ed}, A{sub 4ed}) of the Eu{sup 3+}–C4DGA complexes in C{sub 8}mim·NTf{sub 2} compared to a 1:5 acetonitrile-water mixture point to more mixing of the metal f orbitals with the ligand orbitals. The transition probability of the electric-dipole transition of {sup 5}D{sub 0}→{sup 7}F{sub 2} is three times more than the magnetic-dipole transition probability and twice that of the electric-dipole transition of {sup 5}D{sub 0}→{sup 7}F{sub 4}. Alkyl substituents on the amidic nitrogen atoms increase the quantum efficiency as it

  8. Top Management Involvement in New Product Development

    DEFF Research Database (Denmark)

    Felekoglu, Burcu; Maier, Anja; Moultrie, James


    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...... 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...

  9. Dual Headquarters Involvement in Subsidiary Innovation

    DEFF Research Database (Denmark)

    Dellestrand, Henrik; Kappen, Philip; Nell, Phillip Christopher


    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...

  10. 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)


    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.)

  11. Electronically Active Cyclocarborane-Metal-Arene Assemblies (United States)


    Boron," Organometallics, 1990, 9, 1177. J. H. Davis, Jr., M. A. Benvenuto , and R. N. Grimes, "Organotransition-Metal Metalla- carboranes. 18. rY6, nl...3061. M. A. Benvenuto and R. N. Grimes, "Organotransition-Metal Metallacarboranes. 20. Bu 4N*F Fluoride-Catalyzed C-Si Bond Cleavage in Cp*Co(MeSi...Organometallic Synthesis", Chem. Rev. 1992, 92 251. M. A. Benvenuto and R. N. Grimes, "Organotransition-Metal Metallacarboranes. 28. Controlled Substitution at

  12. Sulfur-containing trinuclear arene ruthenium clusters


    Tschan, Mathieu; Therrien, Bruno; Chérioux, Frédéric; Süss-Fink, Georg


    The single-crystal X-ray structure analyses of [HRu3(C6H6)(C6Me6)2(μ3-SC6H4Me)(μ2-O)][BF4]2 ([1][BF4]2), [HRu3(C6H6)(C6Me6)2(μ3-SC6H4Me)(μ2-S)][PF6]2 ([2][PF6]2) and [H2Ru3(1,2,4,5-Me4C6H2)3(μ2-S)(Cl)]PF6([3][PF6]) are presented. The structures show the sulfur ligands to act as bridges between ruthenium atoms. In [1][BF4]2 and [2][PF6]2 the metallic core adopts a nido framework. However, in [3][PF6] the absence of a μ3-SR ligand combined with the presence of one terminal chloro unit gives ris...

  13. When salaries aren't secret. (United States)

    Case, J


    No one seemed to think Treece McDavitt was a malevolent employee. "Just mischievous," one person said. Whatever her motivation, the day before Treece was to leave RightNow!, an off-price women's fashion retailer, the 26-year-old computer wizard accessed HR's files and e-mailed employees' salaries to the entire staff. Now everyone knows what everyone else is making; they are either infuriated that they are making too little or embarrassed that they are making too much. Salary disparities are out there for everyone to see, and CEO Hank Adamson has to do something to smooth things over. Hank's trusted advisers talk extensively with the CEO about his options, ultimately coming down on two sides. Charlie Herald, vice president of human resources, takes a "You get a lemon, you make lemonade" approach: keep making the salaries public to ensure fairness and to push employees to higher performance, he advises. Meanwhile, CFO Harriet Duval sees the need for damage control: apologize, clean up the company's compensation system, and continue to keep--or at least try to keep--salaries private, she says. Should Hank side with Charlie or Harriet? Or perhaps find a compromise between their two views? What should he do about this serious salary debacle? Four commentators offer their advice on the problem presented in this fictional case study.

  14. Why Organizations Still Aren't Learning. (United States)

    Training, 1999


    In an interview, Peter Senge discusses results of efforts to turn companies into learning organizations, how to effect change, systems thinking, the importance of a powerful head of an organization, and the difference between organizational learning and a learning organization. (JOW)

  15. Aren't All Children Gifted? (United States)

    Myers, David G.; Ridl, Jack


    One danger created by labeling is that a label can create its own reality. Labels are not merely descriptive, but connote superiority or inferiority and can be self-confirming. Giftedness is only a concept artificially defined by testing scores which may not be accurate. (JN)

  16. Perceptions of Parent Involvement in Academic Achievement (United States)

    DePlanty, Jennifer; Coulter-Kern, Russell; Duchane, Kim A.


    The authors sought to understand the types of parent involvement that teachers, parents, and students believe affect the academic achievement of adolescent learners at the junior high school level. Research that included focus groups, interviews, and surveys indicated that teachers and students believed that parent involvement at school was…

  17. Involving Migrant Families in Education. ERIC Digest. (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…

  18. Citizen Involvement in Local Security Networks

    NARCIS (Netherlands)

    Terpstra, J.B.


    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

  19. Involving Program Constituencies in the Evaluation Process. (United States)

    Deshler, David


    Two case studies provide examples of citizen and program participant involvement in program evaluation. The Reflective Appraisal of Programs at Cornell Cooperative Extension involves volunteer interviewers of participants; the Lancaster County (Pennsylvania) Office of Mental Health/Mental Retardation is reviewed by a volunteer citizens' committee.…

  20. Bullying Prevention and the Parent Involvement Model (United States)

    Kolbert, Jered B.; Schultz, Danielle; Crothers, Laura M.


    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…

  1. Turkish Early Childhood Educators on Parental Involvement (United States)

    Hakyemez, Sevcan


    Research conducted over recent decades show that parental involvement plays a significant role in children's academic achievement as well as their cognitive, social and emotional development. For effective parental involvement, understanding the conceptualization of early childhood educators should be significant. This research investigated the…

  2. Examining Teacher's Comfort Level of Parental Involvement (United States)

    Jensen, Deborah Ann


    The connection between home and school is of utmost importance. Therefore, an important concern for those educating teachers is to help teachers recognize the need for and importance of establishing parental involvement and to help them create avenues in which communication can occur. Knowing that parental involvement is important and putting that…

  3. Defining stakeholder involvement in participatory design processes

    NARCIS (Netherlands)

    Vink, P.; Imada, A.S.; Zink, K.J.


    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

  4. Secret-involved Information System Security Audit

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Ya-lan


    Secret-involved information system security audit is a network security technology developing rapidly in recent years.It uses various technical to detect the problem of secret-involved information system,and uses certain audit methods to analyze all kinds of suspicious behavior and irregularities.

  5. Strategic Management: Managing Change by Employee Involvement

    Directory of Open Access Journals (Sweden)

    Dr. Fareeha Zafar


    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.

  6. Peer Involvement in Adolescent Dating Violence (United States)

    Stephenson, Pam S.; Martsolf, Donna; Draucker, Claire Burke


    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…

  7. Macrodystrophia lipomatosa of foot involving great toe. (United States)

    Gaur, A K; Mhambre, A S; Popalwar, H; Sharma, R


    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.

  8. The psychology of male (non) involvement. (United States)


    The primary reason for male involvement in family planning is that the current approach of focusing all family planning attention on women is not working. Unwanted pregnancy continues to increase despite the advent of the oral contraceptive and the IUD and despite the great amount of money and effort that have been invested in making women better contraceptors. Whether or not a contraceptive is effectively used depends a lot on the attitude of the man. The great majority of the studies conducted on male attitudes toward ocntraception indicates that boys and men are interested in the subject. Despite the discrepancy between what people say and what they actually do, there is a vast population of men who are receptive to education and guidance. If the approach is right, the majority of men are willing to become involved. The men who are resistant to involvement in family planning are a minority, and probably nothing can be done about this group. Although the majority of men are not resistant, they see no reason for involvement. In the last 20 years men have been taught that contraception is none of their business. This teaching has been done by the media, family planning agencies, some feminist writers and by women themselves. Most of the resistance to male involvement comes from family planning agencies rather than from the men. How to get men involved in actually a small issues. If there is a change in thinking in the agencies and a willingness to involve men, many effective ways will be found.

  9. Liver Involvement with Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Emily Mathews


    Full Text Available Liver involvement with acute myeloid leukemia (AML is rarely reported. The majority of published cases suggest a cholestatic picture and obstructive jaundice at presentation. On the contrary, our patient presented with transaminitis without cholestasis. Elevated liver function tests persisted in our patient despite cholecystectomy; however, they normalized with chemotherapy administration, suggesting that AML was the causative effect of the hepatitis-like picture. Our review of the literature revealed that most reported cases of AML with liver involvement had short-lived remissions and an overall ominous prognosis. In our opinion, patients who have liver involvement with AML should be offered alternative investigational therapies with a low hepatic toxicity profile.

  10. Peer Effects and Academics’ Industry Involvement

    DEFF Research Database (Denmark)

    Aschhoff, Birgit; Grimpe, Christoph

    This study explores the interaction between professional imprinting and age in the context of industry-science collaboration. Specifically, we examine the impact of localized and personal peer effects on academics’ involvement with industry and how these effects are moderated by the career age...... 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...

  11. Fires and Burns Involving Home Medical Oxygen (United States)

    ... 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 ...

  12. Nurses' political involvement: responsibility versus privilege. (United States)

    Boswell, Carol; Cannon, Sharon; Miller, Joyce


    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.


    Directory of Open Access Journals (Sweden)

    Yu-Jia Hu


    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.

  14. 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....

  15. Testicular Involvement of Tuberculous Epididymitis : Sonographic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jae Joon; Kim, Myeong Jin; Yoo, Hyung Sik; Lee, Jong Tae; Lee, Yong Hee [Yonsei University College of Medicine, Seoul (Korea, Republic of); Park, Joong Hwa [Yonsei University Wonju College of Medicine, Wonju (Korea, Republic of); Lee, Yeon Hee [Dankook University Hospital, Cheonan (Korea, Republic of)


    To report the sonographic findings of testicular involvement of tuberculous epididymitis. The sonographic findings of testicular involvement in twelve patients with histologically proven tuberculous epididymitis were retrospectively reviewed. The sonographic findings of testicular lesions are 1) an ill defined hypoechoic lesion (3 cases, 25.0%), 2) a well-demarcated hypoechoic lesion (3 cases, 25.0%),3) multiple and small hypoechoic nodules in the enlarged testis (2 cases, 16.7%), 4) indistinct margin between the testis and epididymis (2 cases, 16.7%) and 5) a diffusely enlarged testis with hypoechogenicity (2 cases, 16.7%).Nine patients had ipsilateral epididymitis, and 3 patients had bilateral epididymitis. Pus discharge through the draining sinus tract was noted in 4 cases (33.3%), and hydrocele in 8 cases (66.7%). No parenchymal calcification was seen in the involved testis. Sonographic findings of testicular involvement in tuberculous epididymitis were various

  16. [Unusual muscular involvement in ankylosing spondylitis]. (United States)

    Wattiaux, M J; Rondier, J; Bletry, O; Godeau, P; Cayla, J


    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.

  17. Guidance for Catastrophic Emergency Situations Involving Asbestos (United States)

    This document addresses the types of asbestos issues that may arise during catastrophic events and how EPA has addressed such issues. It replaces the Guidelines for Catastrophic Emergency Situations Involving Asbestos which was issued in 1992.

  18. Central Nervous System Involvement in Whipple Disease


    Compain, Caroline; Sacre, Karim; Puéchal, Xavier; Klein, Isabelle; Vital-Durand, Denis; Houeto, Jean-Luc; De Broucker, Thomas; Raoult, Didier; Papo, Thomas


    Abstract Whipple disease (WD) is a rare multisystemic infection with a protean clinical presentation. The central nervous system (CNS) is involved in 3 situations: CNS involvement in classic WD, CNS relapse in previously treated WD, and isolated CNS infection. We retrospectively analyzed clinical features, diagnostic workup, brain imaging, cerebrospinal fluid (CSF) study, treatment, and follow-up data in 18 patients with WD and CNS infection. Ten men and 8 women were included with a median ag...

  19. Eosinophilic gastroenteritis with ascites and colon involvement. (United States)

    Levinson, J D; Ramanathan, V R; Nozick, J H


    The case of a 39-year old white man with eosinophilic gastroenteritis is presented. The major clinical features were gastric outlet obstruction, diarrhea and massive ascites. At surgery, significant involvement of the entire gastrointestinal tract from the gastric antrum to the sigmoid colon was found. Histologic documentation of colon involvement was obtained. The response to corticosteroids was prompt and sustained. At present, he is maintained on an alternating day schedule of steroid administration.


    Energy Technology Data Exchange (ETDEWEB)



    This Community Involvement Plan has been prepared by the Brookhaven National Laboratory's Community Involvement Office with the input of the community, Laboratory employees and representatives of the U.S. Department of Energy. The process to develop the plan began with the formation of a focus group consisting of representatives from: the community at large; special interest groups within the community; the business community; Laboratory retirees; senior and line management from the Laboratory; and the U.S. Department of Energy. The focus group reviewed an initial outline developed by the Office of Community involvement, held in-depth roundtable discussions of community involvement needs, and created a draft plan based on their discussions. A workshop was held to present the draft Community Involvement Plan to a wider audience for their input and insights on how Brookhaven should involve the community in decision making. This workshop was advertised in local newspapers and within the Laboratory. It was attended by community members, special interest group representatives, Laboratory employees and managers, U.S. Department of Energy-Brookhaven Group management, and members of the Laboratory's Community Advisory Council. The results of the workshop discussions are incorporated in this plan.

  1. Conceptions of Ability and Related Affects in Task Involvement and Ego Involvement. (United States)

    Jagacinski, Carolyn M.; Nicholls, John G.


    Five studies were conducted to determine if college students employ different conceptions of ability in self-referenced (task-involving) and interpersonally competitive (ego-involving) situations. Competence and positive affects were associated with higher effort in task-involving situations but negatively associated with higher effort in…

  2. Bacterial degradation of recalcitrant PAHs: metabolic studies and application to pyrene degradation in a freshwater sediment

    Energy Technology Data Exchange (ETDEWEB)

    Jouanneau, Y.; Demaneche, S.; Meyer, Ch.; Willison, J.C. [CEA-Grenoble, UMR 5092 CNRS-CEA-UJF, 38 - Grenoble (France)


    Cost-effective bio-remediation strategies have been proposed to remove toxic chemicals, including polycyclic aromatic hydrocarbons (PAHs), from contaminated sites. However, the efficiency of these strategies is often limited, due to the resistance of certain chemicals to microbial degradation. Our studies deal with the biodegradation of four-ring PAHs using two recently isolated bacteria, Mycobacterium strain 6PY1, which can mineralize pyrene and phenanthrene, and Sphingomonas strain CHY-1, which mineralizes chrysene and various three-ring PAHs. The metabolic pathways for the biodegradation of PAHs have been investigated using GC-MS to identify and assay metabolites. Also, several enzymes involved in PAH catabolism have been identified by a combination of proteomic and genetic approaches. In Mycobacterium 6PY1, two ring-hydroxylating di-oxygenases which catalyze the initial attack of PAHs have been overproduced in E. coli, isolated and characterized. The selectivity of the two enzymes showed marked differences, since one di-oxygenase preferentially oxidized 2- or 3- ring PAHs whereas the other attacked pyrene and 3-ring PAHs exclusively. In Sphingomonas CHY-1, a single di-oxygenase, called PhnI, was found to convert seven PAHs, including chrysene, to the corresponding dihydro-diols. It is the first enzyme to be described which is able to attack the four-ring PAHs chrysene and benz[a]anthracene.. The fate of pyrene was examined in a sediment taken from a freshwater lake of the French Alps. Experiments were carried out in microcosms containing a layer of sediment which was spiked with {sup 14}C-pyrene. Pyrene mineralization was monitored over 61 days by measuring the {sup 14}CO{sub 2} evolved from the microcosms. Some microcosms were planted with young reeds (Phragmites australis), while other were inoculated with Mycobacterium 6PY1. P. australis reeds promoted a significant increase of pyrene degradation, which most likely resulted from a root-mediated increase of

  3. 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


    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

  4. [Pulmonary involvement in connective tissue disease]. (United States)

    Bartosiewicz, Małgorzata


    The connective tissue diseases are a variable group of autoimmune mediated disorders characterized by multiorgan damage. Pulmonary complications are common, usually occur after the onset of joint symptoms, but can also be initially presenting complaint. The respiratory system may be involved in all its component: airways, vessels, parenchyma, pleura and respiratory muscles. Lung involvement is an increasing cause of morbidity and mortality in the connective tissue diseases. Clinical course is highly variable - can range from mild to rapidly progressive, some processes are reversible, while others are irreversible. Thus, the identification of reversible disease , and separately progressive disease, are important clinical issues. The frequency, clinical presentation, prognosis and responce to therapy are different, depending on the pattern of involvement as well as on specyfic diagnostic method used to identify it. High- resolution computed tompography plays an important role in identifying patients with respiratory involvement. Pulmonary function tests are a sensitive tool detecting interstitial lung disease. In this article, pulmonary lung involvement accompanying most frequently apperaing connective tissue diseases - rheumatoid arthritis, systemic sclerosis, lupus erythematosus, polymyositis/dermatomyositis, Sjögrens syndrome and mixed connective tissue disaese are reviewed.

  5. Microwave-assisted synthesis of arene Ru(Ⅱ) complex [(η6-C6H5) Ru(PIP) Cl]Cl·2H2O%微波辅助合成芳烃钌(Ⅱ)配合物[(η6-C6H5)Ru(PIP)Cl]Cl·2H2O

    Institute of Scientific and Technical Information of China (English)

    陈艾纯; 吴琼; 陈燕华; 梅文杰; 吴韦黎; 胡晓莹; 吴剑; 汪保国


    目的 探讨应用微波辅助合成技术制备芳烃钌(Ⅱ)化合物[(η6-C6H6)Ru(PIP) Cl] Cl·2H2O(3).方法 首先以RuCl3·nH2O、1,3-环己二烯和1,10-邻菲哕啉为原料微波辐射下制备得到芳烃钌前体[(η6-C6H6)RuCl2]2(1)和2-苯基-咪唑并[4,5f][1,10]菲哕啉(PIP,2),然后,在二氯甲烷溶液中,微波辐射1与2制备芳烃钌(Ⅱ)配合物3;采用ESI-MS、IR、1H-NMR、13C-NMR对目标配合物进行表征.结果 60℃条件下,化合物1与2在二氯甲烷溶液微波辐射30 min,制备得到了芳烃钌配合物3,反应产率为90.3%;目标产物经ESI-MS、IR、1H-NMR和13C-NMR表征,实验值与理论值基本一致.结论 与传统加热方法相比,微波辅助合成芳烃钌配合物明显缩短了反应时间,提高了反应产率.%Objective To research the preparation of arene Ru( Ⅱ ) complex [η6-C6H6)RU(PIP)Cl]Cl· 2H2O(3) by using microwave-assisted synthesis technology. Methods [ ( η6 -C6H6 ) RuCl2 ]2 (1) was synthesized from RuCl2 · nH2O and 1,3-cyclohexadiene by using microwave-assisted synthesis technology, and 2-phenyl-imidazole[4,5/] [1,10]phenanthroline (PIP,2) also synthesized from 1,10-phenanthroline-5 ,6-dione and benzaldehyde under microwave irradiation, and then 2 and 3 were mixed in CH2Cl2 solution to prepare [ (η6-C6H6)Ru( PIP) Cl] Cl · 2H2O (3) under the irradiation microwave. The target complex 3 was characterized by using ESI-MS, IR,1H-NMR and 13C-NMR spectra. Results Arene Ru( Ⅱ ) complex 3 was prepared from 1 and 2 in CH2Cl2 at 60℃ for 30 min under microwave irradiation with a yield of 90. 3%,and characterized by ESI-MS, IR,1H-NMR and 13C-NMR spectra. Conclusion A novel arene ruthenium ( Ⅱ ) complexes 3 have been synthesized under the irradiation of microwave, and with far more less time and higher yield compared with the conventional method.

  6. Microwave-assisted Synthesis of Arene Ru(Ⅱ) Complex [(η6-C6H6) Ru(H2iiP) Cl] Cl in SiC Vessel%SiC管中微波辅助芳烃钌(Ⅱ)化合物[(η6-C6H6)Ru(H2iiP)Cl]Cl的合成

    Institute of Scientific and Technical Information of China (English)

    吴琼; 梅文杰; 吴韦黎; 陈燕华; 曾玲莉; 郑文杰


    使用SiC管为反应容器,在微波辐射条件下以[(6-C6H6)RuCl2]2为原料与2-(吲哚基)咪唑[4,5-f]-[1,10]菲啰啉(H2iiP)反应,制得芳烃钌(Ⅱ)化合物[(η6-C6H6)Ru(H2iiP) C1]Cl(1),并对其进行了表征.采用正交实验法确定反应的最佳合成条件为:投料比n([(η6-C6 H6)RuCl2]2)∶n(H2iiP)=1∶2.2,反应温度90℃,微波辐射时间30 min.该反应的平均产率达到96.0%,反应产率的相对标准偏差(RSD)为1.28%,说明微波辐射条件下,在SiC管中能够高产率地制备芳烃钌化合物,并且反应具有良好的重现性.进一步采用MTT方法研究发现,芳烃钌(Ⅱ)化合物1能够选择性抑制MCF-7乳腺癌的生长.%Arene Ru(Ⅱ) complex [(η6-C6H6) Ru(H2iiP) Cl] Cl(1) was synthesized using [(η6-C6H6)·RuCl2] 2 and 2-indole-3-imidazole [4,5-f] [1,10] phenanthroline (H2 iiP) as raw material under microwave irradiation.The target compound was characterized by means of elemental analysis,ESI-MS,IR and NMR.The best craft condition determined by orthogonal test is that reactant molar ratio of 1.0 ∶ 2.2,the reaction temperature of 90 ℃ and the microwave irradiation time of 30 min.Then the average yield of 96.0% and RSD of 1.28% confirmed that microwave-assisted synthesis of arene Ru(Ⅱ) complex in SiC vessel gives a good stability and reiteration.The antitumor activity of arene Ru (Ⅱ) complex 1 was determined by MTT assay and the results showed that complex 1 could selectively inhibit the growth of MCF-7,indicating its potential utility in chemotherapy.

  7. User involvement in the innovation process

    DEFF Research Database (Denmark)

    Christensen, Dan Saugstrup


    User involvement in the innovation process is not a new phenomenon. However, combined with the growing individualisation of demand and with highly competitive and dynamic environments, user involvement in the innovation process and thereby in the design, development, and manufacturing process, can...... nevertheless provide a competitive advantage. This is the case as an intensified user involvement in the innovation process potentially results in a more comprehensive understanding of the user needs and requirements and the context within which these are required, and thereby provides the possibility...... as a foundation for developing better and more supportive service and application concepts within the information and communication technology domain. Three interrelated research areas are deployed within the theoretical framework, which combined constitute and highlight the intertwined and complex interaction...

  8. Creating Learning at Conferences Through Participant Involvement

    DEFF Research Database (Denmark)

    Ravn, Ib; Elsborg, Steen

    in Denmark to introduce a variety of simple learning techniques related to the design principles at thirty real conferences of some 100-200 participants each. We present twelve of these techniques and the data evaluating them and conclude that by spending a fraction of the time at a conference on involving......The typical conference is brimming with PowerPoint presentations that leave very little time for participant involvement. Students of learning have long abandoned the transfer model that underlies this massive show of one-way communication. We propose an alternative theory of the conference...... as a forum for learning, mutual inspiration and "human co-flourishing." We offer five design principles that specify how conferences may involve participants more and hence increase their learning. In the research and development effort reported here, our team collaborated with conference organizers...

  9. Parental involvement with their working teens. (United States)

    Runyan, Carol W; Vladutiu, Catherine J; Schulman, Michael D; Rauscher, Kimberly J


    Adolescents work in varied environments and are exposed to hazards. Parents of these working adolescents have an opportunity to help them select jobs and address worker safety issues with employers. The present study conducted telephonic interviews among a national sample of 922 working adolescents along with one parent of each to examine the involvement of parents in their children's employment and safety issues. Over 70% of parents were found who helped their children identify job opportunities, consider questions about work hours or tasks, fill out job applications, prepare for interviews, or handle difficult safety issues. Parents suggested stronger actions in response to hypothetical situations than when confronted with real problems. Mean level of parental involvement did not vary by the number of hazards reported by teen workers. Parents were involved in helping their teens with work. Further research should explore how to enhance parental effectiveness by making work safe for teens.

  10. Pulmonary Involvement in Rheumatic Diseases: HRCT Findings

    Directory of Open Access Journals (Sweden)

    Serhat Avcu


    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. 

  11. Langerhans Cell Histiocytosis Involving Maxilla and Mandible

    Directory of Open Access Journals (Sweden)

    M. Guna Shekhar


    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.

  12. Supporting Active User Involvment in Prototyping

    DEFF Research Database (Denmark)

    Grønbæk, Kaj


    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...... activities. Examples of such tools are given and the ways that they support cooperative prototyping within various use domains are discussed.......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...

  13. Modeling fault among motorcyclists involved in crashes. (United States)

    Haque, Md Mazharul; Chin, Hoong Chor; Huang, Helai


    Singapore crash statistics from 2001 to 2006 show that the motorcyclist fatality and injury rates per registered vehicle are higher than those of other motor vehicles by 13 and 7 times, respectively. The crash involvement rate of motorcyclists as victims of other road users is also about 43%. The objective of this study is to identify the factors that contribute to the fault of motorcyclists involved in crashes. This is done by using the binary logit model to differentiate between at-fault and not-at-fault cases and the analysis is further categorized by the location of the crashes, i.e., at intersections, on expressways and at non-intersections. A number of explanatory variables representing roadway characteristics, environmental factors, motorcycle descriptions, and rider demographics have been evaluated. Time trend effect shows that not-at-fault crash involvement of motorcyclists has increased with time. The likelihood of night time crashes has also increased for not-at-fault crashes at intersections and expressways. The presence of surveillance cameras is effective in reducing not-at-fault crashes at intersections. Wet-road surfaces increase at-fault crash involvement at non-intersections. At intersections, not-at-fault crash involvement is more likely on single-lane roads or on median lane of multi-lane roads, while on expressways at-fault crash involvement is more likely on the median lane. Roads with higher speed limit have higher at-fault crash involvement and this is also true on expressways. Motorcycles with pillion passengers or with higher engine capacity have higher likelihood of being at-fault in crashes on expressways. Motorcyclists are more likely to be at-fault in collisions involving pedestrians and this effect is higher at night. In multi-vehicle crashes, motorcyclists are more likely to be victims than at-fault. Young and older riders are more likely to be at-fault in crashes than middle-aged group of riders. The findings of this study will help

  14. Isolated lingual involvement in Wilson's disease. (United States)

    Choudhary, Neera; Joshi, Laxmikant; Duggal, Ashish; Puri, Vinod; Khwaja, Geeta Anjum


    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. Autophagy and proteins involved in vesicular trafficking. (United States)

    Amaya, Celina; Fader, Claudio Marcelo; Colombo, María Isabel


    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.

  16. Schools Seek to Channel Parent Involvement (United States)

    Keller, Bess


    Schools flush with students' parents showing up and helping out have long been the envy of those where classrooms echo on back-to-school night. But in recent years, incidents reported in the news media have dabbed shadows on that glowing picture of parent involvement, raising issues about whether demanding adults have made teachers' jobs harder…

  17. Pulmonary involvement in early rheumatoid arthritis patients. (United States)

    Habib, Hisham M; Eisa, Ashraf A; Arafat, Waleed R; Marie, Mohamed A


    Pulmonary involvement in rheumatoid arthritis (RA) is common and can be due to the disease itself as well as to the therapies used to treat it. The purpose of this study was to disclose the pulmonary involvement in early RA patients not more than 2 years disease duration using the computed tomography (CT) as well as the pulmonary function tests as ways of pulmonary involvement assessment. Forty patients aged 37.6 ± 10.3 with early rheumatoid arthritis not more than 2 years of disease duration were recruited for the study. All patients were assessed clinically for their RA with DAS28, which was utilized for disease activity determination. Ten percent of our patients were found to be clinically involved by interstitial lung disease (ILD), where 27% have abnormal HRCT finding and 32.5% with abnormal PFT. Predilection for clinically manifest ILD was evident in active RA patients with high DAS28 score, seropositive RA patients, and in patients receiving steroids and anti-TNFα therapy. ILD occurs early in the course of RA, with more predilection for clinically active RA disease.

  18. User involvement in mental health rehabilitation

    DEFF Research Database (Denmark)

    Petersen, Kirsten; Hounsgaard, Lise; Borg, Tove


    Abstract Aim: The study aimed to explore service user involvement in supported housing schemes as experienced by adults with mental illness in interplay with professionals during rehabilitation. Method: The study was designed as a field study in two supported housing schemes, using an ethnographic...

  19. Ocular Involvement in Systemic Autoimmune Diseases. (United States)

    Generali, Elena; Cantarini, Luca; Selmi, Carlo


    Eye involvement represents a common finding in patients with systemic autoimmune diseases, particularly rheumatoid arthritis, Sjogren syndrome, seronegative spondyloarthropathy, and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The eye is a privileged immune site but commensal bacteria are found on the ocular surface. The eye injury may be inflammatory, vascular or infectious, as well as iatrogenic, as in the case of hydroxychloroquine, chloroquine, corticosteroids, and bisphosphonates. Manifestations may affect different components of the eye, with episcleritis involving the episclera, a thin layer of tissue covering the sclera; scleritis being an inflammation of the sclera potentially leading to blindness; keratitis, referring to corneal inflammation frequently associated with scleritis; and uveitis as the inflammation of the uvea, including the iris, ciliary body, and choroid, subdivided into anterior, posterior, or panuveitis. As blindness may result from the eye involvement, clinicians should be aware of the possible manifestations and their management also independent of the ophthalmologist opinion as the therapeutic approach generally points to the underlying diseases. In some cases, the eye involvement may have a diagnostic implication, as for episcleritis in rheumatoid arthritis, or acute anterior uveitis in seronegative spondyloarthritis. Nonetheless, some conditions lack specificity, as in the case of dry eye which affects nearly 30 % of the general population. The aim of this review is to elucidate to non-ophthalmologists the major ocular complications of rheumatic diseases and their specific management and treatment options.

  20. Community Involvement in School Management in Portugal (United States)

    Veloso, Luísa; Craveiro, Daniela; Rufino, Isabel


    This article discusses the ways in which the community is involved in Portuguese school management. It is based on an analysis of the external evaluation reports of 298 Portuguese schools for the academic years 2006-07, 2007-08 and 2008-09. The corpus analysed allowed the identification of two main aspects of the participation processes: (1) local…