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Sample records for trans mixed ligand

  1. Synthesis, Photophysical and Electrochemical Properties of a Mixed Bipyridyl-Phenanthrolyl Ligand Ru(II Heteroleptic Complex Having trans-2-Methyl-2-butenoic Acid Functionalities

    Directory of Open Access Journals (Sweden)

    Adewale O. Adeloye

    2011-09-01

    Full Text Available In this work, two ligands: 4-(trans-2-Methyl-2-butenoic acid-2,2'-bipyridine (L1 and 5-(trans-2-methyl-2-butenoic acid-1,10-phenanthroline (L2, with the corresponding mixed-ligand heteroleptic Ru(II complex were synthesized and characterized by FT-IR, 1H-, 13C-NMR spectroscopy and elemental analysis. The influence of the mixed functionalized polypyridyl ruthenium(II complex on the photophysical and electrochemical properties were investigated and compared to individual single-ligand homoleptic complexes. Interestingly, the mixed-ligand complex formulated as [RuL1L2(NCS2] exhibits broad and intense metal-to-ligand charge transfer (MLCT absorption with a high molar extinction coefficient (λmax = 514 nm, ε = 69,700 M−1 cm−1, better than those of individual single-ligand complexes, [Ru(L12(NCS2] and [Ru(L22(NCS2], and a strong photoluminescence intensity ratio in the red region at λem = 686 nm. The electrochemical properties of the complex indicated that the redox processes are ligand-based.

  2. Trans-ligand-dependent arrangement (bent or linear) of Pt II-bound dialkylcyanamide ligands: Molecular structure of trans-dichloro(dimethylcyanamide)(dimethyl sulfoxide)platinum(II)

    Science.gov (United States)

    Anisimova, Tatyana B.; Bokach, Nadezhda A.; Fritsky, Igor O.; Haukka, Matti

    2011-11-01

    The title compound, trans-[PtCl 2(NCNMe 2)(Me 2SO)], is the first example of the structurally characterized Pt II species having the nitrile and the sulfoxide ligands in the trans-position to each other. The most significant feature of this structure is the non-linear arrangement of the Pt sbnd N1 sbnd C1 fragment providing the rare case of the bent form of the dialkylcyanamide ligand.

  3. Synthesis and characterization of mixed ligand chiral nanoclusters

    KAUST Repository

    Guven, Zekiye P.

    2016-06-22

    Chiral mixed ligand silver nanoclusters were synthesized in the presence of a chiral and an achiral ligand. While the chiral ligand led mostly to the formation of nanoparticles, the presence of the achiral ligand drastically increased the yield of nanoclusters with enhanced chiral properties. © 2016 The Royal Society of Chemistry.

  4. Synthesis and characterization of mixed ligand chiral nanoclusters

    KAUST Repository

    Guven, Zekiye P.; Ustbas, Burcin; Harkness, Kellen M.; Coskun, Hikmet; Joshi, Chakra Prasad; Besong, Tabot M.D.; Stellacci, Francesco; Bakr, Osman; Akbulut, Ozge

    2016-01-01

    Chiral mixed ligand silver nanoclusters were synthesized in the presence of a chiral and an achiral ligand. While the chiral ligand led mostly to the formation of nanoparticles, the presence of the achiral ligand drastically increased the yield of nanoclusters with enhanced chiral properties. © 2016 The Royal Society of Chemistry.

  5. Mixed ligand chelates of rare earths in aqueous solution

    International Nuclear Information System (INIS)

    Lakhani, S.U.; Thakur, G.S.; Sangal, S.P.

    1981-01-01

    Mixed ligand chelates of the 1:1 trivalent lanthanoids-EDTA, HEDTA and NTA chelates-1, 2-Dihydroxybenzene (Pyrocatechol) have been investigated at 35degC and 0.2 M ionic strength maintained by NaC10 4 . The formation of mixed ligand chelates has been found in all cases. The formation of mixed ligand chelates with EDTA shows the coordination number of lanthanoids to be eight, while the mixed ligand chelates with HEDTA and NTA shows the coordination number to be seven and six respectively. The stability constants of mixed ligand chelates are smaller than the binary complexes. The order of stability constants with respect to primary ligands follows the order NTA>HEDTA>EDTA. With respect to metal ions the stability constants increases with the decrease in ionic radii such as Gd< Er< Yb. (author)

  6. Two novel mixed-ligand complexes containing organosulfonate ligands.

    Science.gov (United States)

    Li, Mingtian; Huang, Jun; Zhou, Xuan; Fang, Hua; Ding, Liyun

    2008-07-01

    The structures reported herein, viz. bis(4-aminonaphthalene-1-sulfonato-kappaO)bis(4,5-diazafluoren-9-one-kappa(2)N,N')copper(II), [Cu(C(10)H(8)NO(3)S)(2)(C(11)H(6)N(2)O)(2)], (I), and poly[[[diaquacadmium(II)]-bis(mu-4-aminonaphthalene-1-sulfonato)-kappa(2)O:N;kappa(2)N:O] dihydrate], {[Cd(C(10)H(8)NO(3)S)(2)(H(2)O)(2)].2H(2)O}(n), (II), are rare examples of sulfonate-containing complexes where the anion does not fulfill a passive charge-balancing role, but takes an active part in coordination as a monodentate and/or bridging ligand. Monomeric complex (I) possesses a crystallographic inversion center at the Cu(II) atom, and the asymmetric unit contains one-half of a Cu atom, one complete 4-aminonaphthalene-1-sulfonate (ans) ligand and one 4,5-diazafluoren-9-one (DAFO) ligand. The Cu(II) atom has an elongated distorted octahedral coordination geometry formed by two O atoms from two monodentate ans ligands and by four N atoms from two DAFO molecules. Complex (II) is polymeric and its crystal structure is built up by one-dimensional chains and solvent water molecules. Here also the cation (a Cd(II) atom) lies on a crystallographic inversion center and adopts a slightly distorted octahedral geometry. Each ans anion serves as a bridging ligand linking two Cd(II) atoms into one-dimensional infinite chains along the [010] direction, with each Cd(II) center coordinated by four ans ligands via O and N atoms and by two aqua ligands. In both structures, there are significant pi-pi stacking interactions between adjacent ligands and hydrogen bonds contribute to the formation of two- and three-dimensional networks.

  7. Mixed ligand chelate therapy for plutonium and cadmium poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J; Derr, S K [Hope Coll., Holland, MI (USA)

    1978-09-28

    Some experiments with mice are described in which complete removal of tissue deposits of /sup 239/Pu and prevention of mortality in animals given lethal doses of Cd were achieved using a mixed ligand chelate treatment (MLC). The mixed ligand consisted of diethylenetriaminepentaacetic acid and salicylic acid.

  8. Mixed-Ligand Complexes Of Nickel (II) With 2-Acetylpyridine ...

    African Journals Online (AJOL)

    The preparation and spectral properties of five nickel (II) mixed-ligands complexes (Ni [2-Actsc.Y]CI2), derived from 2-acetylpyridinethiosermicarbazones and some nitrogen/sulphur monodentate ligands such as thiophene, ammonia, picoline, pyridine and aniline are described. The complexes have been characterized on ...

  9. Fringe proteins modulate Notch-ligand cis and trans interactions to specify signaling states.

    Science.gov (United States)

    LeBon, Lauren; Lee, Tom V; Sprinzak, David; Jafar-Nejad, Hamed; Elowitz, Michael B

    2014-09-25

    The Notch signaling pathway consists of multiple types of receptors and ligands, whose interactions can be tuned by Fringe glycosyltransferases. A major challenge is to determine how these components control the specificity and directionality of Notch signaling in developmental contexts. Here, we analyzed same-cell (cis) Notch-ligand interactions for Notch1, Dll1, and Jag1, and their dependence on Fringe protein expression in mammalian cells. We found that Dll1 and Jag1 can cis-inhibit Notch1, and Fringe proteins modulate these interactions in a way that parallels their effects on trans interactions. Fringe similarly modulated Notch-ligand cis interactions during Drosophila development. Based on these and previously identified interactions, we show how the design of the Notch signaling pathway leads to a restricted repertoire of signaling states that promote heterotypic signaling between distinct cell types, providing insight into the design principles of the Notch signaling system, and the specific developmental process of Drosophila dorsal-ventral boundary formation.

  10. Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems ...

    African Journals Online (AJOL)

    Speciation of Zinc Mixed Ligand Complexes in Salt Water Systems. ... method has been used to study heavy metal interaction in model lake water in KNO3 ... is of no consequential effect because in its normal state, the [OH-] of the lake water is ...

  11. Gas adsorption and gas mixture separations using mixed-ligand MOF material

    Science.gov (United States)

    Hupp, Joseph T [Northfield, IL; Mulfort, Karen L [Chicago, IL; Snurr, Randall Q [Evanston, IL; Bae, Youn-Sang [Evanston, IL

    2011-01-04

    A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

  12. Can mixed ligand therapy completely remove plutonium from the body

    Energy Technology Data Exchange (ETDEWEB)

    Volf, V [Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Genetik und Toxikologie von Spaltstoffen

    1980-08-01

    Results of experiments to determine the effects of mixed ligand chelate treatment on tissue levels of /sup 238/Pu in rats after injection of /sup 238/Pu citrate are presented and discussed. It is concluded that when attempting to remove Pu from the body there seems to be no reason for combining Ca-DTPA, the present chelate of choice, with catechol or Tiron, or with salicylate and its derivatives.

  13. Mixed-ligand complexes of dioxouranium(VI)

    International Nuclear Information System (INIS)

    Ahuja, Renu; Dwivedi, K.

    1995-01-01

    A number of mixed ligand complexes of UO 2 2+ ion have been studied with aminopolycarboxylic acids, such as ethylenediaminetetraacetic acid with coordination number (CN) = 6, nitrilotriacetic acid with CN = 4 and iminodiacetic acid with CN = 3. Ethyleneglycol-bis-2-aminoethylether tetraacetic acid (EGTA) is an octadentate aminopolycarboxylic acid and forms stable binary complexes with many metal ions at low pH. In this paper the results obtained for the study of 1:1:1 UO 2 VI -EGTA-aspartic acid/glutamic acid systems are studied. (author). 7 refs., 1 fig., 1 tab

  14. Mixed ligand lanthanide complexes with dipivaloylmethane and acetic acid

    International Nuclear Information System (INIS)

    Lyu Fehnkhua; Kuz'mina, N.P.; Mazo, G.N.; Martynenko, L.I.

    1995-01-01

    Methods of elemental, X-ray phase, thermal analyses and infrared spectroscopy were used to characterize solid products, formed in MDpm 3 -HAcet-H-hexane systems (M = Pr, Nd, Eu, Gd, Ho, Er, Yb, HDpm -dipivaloylmethane, HAcet - acetic acid). It was established that prepared mixed ligand complexes (MLC) had MDpm 2 Acet composition for all studied rare earths. Differenced in properties of cerium and yttrium rare earths are manifested in processes of MLC thermal dissociation, proceeding at low pressure and 170 deg C. 6 refs., 4 tabs

  15. Trans labilization of am(m)ine ligands from platinum(II) complexes by cancer cell extracts.

    Science.gov (United States)

    Kasherman, Yonit; Sturup, Stefan; Gibson, Dan

    2009-03-01

    Cisplatin, cis-[Pt(NH(3))(2)Cl(2)], is an effective anticancer agent in wide clinical use whose efficacy is affected by cellular interactions with sulfur-containing nucleophiles. These interactions can potentially enhance the efficacy of the drug by mediating its delivery to nuclear DNA or inactivate the drug by binding to it irreversibly or by labilizing the NH(3) ligands. Despite the potential importance of trans-labilization reactions in the mechanism of action of the drug, few detailed studies on trans labilization of the ammines have been conducted. We used 2D NMR to show that some trans labilization occurs in proliferating cells and that aqueous extracts of cancer cells labilized 20% of the amine ligands of cis-[PtCl(2)((13)CH(3)NH(2))(2)] after a 12-h incubation. Both low molecular mass nucleophiles (less than 3 kDa) and high molecular mass nucleophiles (more than 3 kDa) labilize the amines with similar efficiency. Studies with model compounds show that thiols and thioethers bind to platinum(II) at similar rates, but thioethers are significantly more efficient at labilizing the am(m)ine at lower pH. N-Acetylcysteine is a more efficient trans-labilizer than glutathione, suggesting that the displacement of the amine proceeds through an associative mechanism. The lag time, the time that elapses from the formation of the Pt-S bond till the release of the amine trans to the sulfur, depends on the pH (for thiols), increasing at lower pH. Quantification of the platinum adducts obtained from incubation of cisplatin with cell extracts indicates that two thirds of the platinum is bound to cellular components with molecular mass greater than 3 kDa.

  16. Rigid nonproteinogenic cyclic amino acids as ligands for glutamate receptors: trans-tris(homoglutamic) acids

    DEFF Research Database (Denmark)

    Meyer, Udo; Bisel, Philippe; Bräuner-Osborne, Hans

    2005-01-01

    The second-generation asymmetric synthesis of the trans-tris(homoglutamic) acids reported herein proceeds via Strecker reaction of chiral ketimines, obtained from condensation of racemic 2-ethoxycarbonylmethylcyclopentanone and commercially available (S)- and (R)-1-phenylethylamine, respectively......) yielded diastereomeric mixtures of secondary alpha-amino amido-esters, which after separation were hydrogenolyzed and hydrolyzed each to the enantiomeric trans-1-amino-2-carboxymethylcyclopentanecarboxylic acids. Their configuration was completely established by NMR methods, CD spectra, and X-ray analysis...... of the trans-1S,2R-configured secondary alpha-amino amido-ester. In receptor binding assays and functional tests, trans-1S,2R-1-amino-2-carboxymethylcyclopentanecarboxylic acid hydrochloride was found to behave as a selective mGluR(2)-antagonist without relevant binding properties at iGluRs....

  17. Preparation, Spectroscopic Investigation and Biological Activity of New Mixed Ligand Chelates

    International Nuclear Information System (INIS)

    Alassbaly, F.S.; Ajaily, M.M.E.

    2014-01-01

    Preparation and investigation of new Co(II), Ni(II), Zn(II) and Cr(III) chelates with mixed ligands including Schiff base (L1) formed from the condensation of 4-dimethylaminobenzaldehyde with 2-aminophenol and anthranilic acid (L2) were studied. The obtained Schiff base and mixed ligand chelates were subjected to several physiochemical techniques, in terms of CHN elemental analyses, molar conductivity, magnetic moment measurements, infrared, proton nuclear magnetic resonance, electronic and mass spectra. The analytical data showed the formation of the Schiff base compound and the ratio of metal to ligands of the chelates are 1:1:1(M:L1:L2). The infrared spectral data exhibited that the used ligands behaving as bidentate ligands towards the metal ions. The proton nuclear magnetic resonance spectral data showed the signals of the active groups in the ligands which entered in chelation with Zn(II) metal ion. The electronic spectral results showed the existence of pie (phenyl ring) and n = pie (C=N) of the ligands and suggested the geometrical structures of the chelates. Meanwhile, the mass spectral data revealed the fragmentations of the Schiff base, anthranilic acid and their Ni(II) mixed ligand chelate has been preformed the only chelate conducted for justification. All the prepared mixed chelates were non-electrolyte in nature. The antibacterial activity of the Schiff base, anthranilic acid, metal salts and mixed ligand chelates were studied and found to be that mixed ligand chelates have the most biological activity in comparison to the free ligands and salts. (author)

  18. One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

    KAUST Repository

    Wang, Xiaofang; Wang, Runwei; Liu, Xiaofang; Zhu, Pinwen; Qiu, Shilun

    2017-01-01

    The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H2pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd2Cl3(2-pzc)(bbbi)2] (2)) under hydrothermal conditions

  19. Mixed-ligand complexes of zirconium (IV) and uranium with salicylaldehyde and some heterocyclic azopyrazolones

    International Nuclear Information System (INIS)

    Amrallahi, A.H.

    1994-01-01

    Mixed-ligand complexes of Zr(IV) and U(IV) with salicylaldehyde (SA) and some heterocyclic azopyrazolenes have been studied spectrophotometrically. All formed chelates have ratio 1:1:1. The stoichiometry and stability of the binary mixed chelates been evaluated. Elemental analysis, molar conductance and IR spectra have been used for identification of solid mixed complexes. (author)

  20. Synthesis, resolution and radioiodination of S(-)trans-5-hydroxy-2-[N-n-propyl-N-(3'-iodo-2'-propenyl)amino]tet ralin-S(-)trans-5-OH-PIPAT: a new dopamine D2-like receptor ligand

    International Nuclear Information System (INIS)

    Chumpradit, Sumalee; Meiping Kung; Vessotskie, Janet; Kung, H.F.

    1995-01-01

    A new dopamine D2-like receptor ligand, (R,S)trans-5-hydroxy-2-[N-n0propyl-N-(3'-iodo-2'-propeny)amino]tet ralin ((R,S)trans-5-OH-PIPAT,3), based on high affinity dopamine receptor agonist 5-hydroxy-2-[N,N-(di-n-propyl)-2-amino]tetralin (5-OH-DPAT,1), was prepared. The synthesis was achieved by a reductive amination of 5-methoxy-2-tetralone with n-propylamine, followed by N-alkylation, to afford 5-methoxy-N-propyl-N-2'-aminotetralin,7. Reduction of 7 with tributyltin hydride gave the tri-n-butyl tin derivative,8, which was converted to 9 by an iododemetalation reaction. Demethylation of 9 gave the desired compound, (R,S)trans-5-OH-PIPAT,3. The resolved (R) and (S)trans-5-OH-PIPAT,3 were also quantitatively prepared. (author)

  1. EXAFS Studies of Some Copper(II) Mixed-Ligand Complexes

    International Nuclear Information System (INIS)

    Joshi, S. K.; Katare, R. K.; Shrivastava, B. D.

    2007-01-01

    X-ray K-absorption spectroscopic studies have been carried out on copper (II) mixed-ligand complexes with glutamic acid and aspartic acid as the primary ligands, where as water, pyridine, imidazole and benz-imidazole have been used as secondary ligands. Chemical shifts obtained from the X-ray absorption data have indicated that the glutamic acid complexes are more ionic as compared to their corresponding aspartic acid complexes having similar secondary ligands. Further, we have estimated the average metal-ligand bond distances from the from structure data. For the different complexes studied under the present investigation, the studies reveal that the bonding parameter α1 decreases with the increase in the percentage covalency of the metal-ligand bond. Thus, the bonding parameter α1 may be used for the estimation of percentage covalency of the metal-ligand bond in other similar complexes

  2. Further Insight into the Lability of MeCN Ligands of Cytotoxic Cycloruthenated Compounds: Evidence for the Antisymbiotic Effect Trans to the Carbon Atom at the Ru Center.

    Science.gov (United States)

    Barbosa, Ana Soraya Lima; Werlé, Christophe; Colunga, Claudia Olivia Oliva; Rodríguez, Cecilia Franco; Toscano, Ruben Alfredo; Le Lagadec, Ronan; Pfeffer, Michel

    2015-08-03

    The two MeCN ligands in [Ru(2-C6H4-2'-Py-κC,N)(Phen, trans-C)(MeCN)2]PF6 (1), both trans to a sp(2) hybridized N atom, cannot be substituted by any other ligand. In contrast, the isomerized derivative [Ru(2-C6H4-2'-Py-κC,N)(Phen, cis-C)(MeCN)2]PF6 (2), in which one MeCN ligand is now trans to the C atom of the phenyl ring orthometalated to Ru, leads to fast and quantitative substitution reactions with several monodentate ligands. With PPh3, 2 affords [Ru(2-C6H4-2'-Py-κC,N)(Phen, cis-C)(PPh3)(MeCN)]PF6 (3), in which PPh3 is trans to the C σ bound to Ru. Compound 3 is not kinetically stable, because, under thermodynamic control, it leads to 4, in which the PPh3 is trans to a N atom of the Phen ligand. Dimethylsulfoxide (DMSO) can also substitute a MeCN ligand in 2, leading to 5, in which DMSO is coordinated to Ru via its S atom trans to the N atom of the Phen ligand, the isomer under thermodynamic control being the only compound observed. We also found evidence for the fast to very fast substitution of MeCN in 2 by water or a chloride anion by studying the electronic spectra of 2 in the presence of water or NBu4Cl, respectively. An isomerization related to that observed between 3 and 4 is also found for the known monophosphine derivative [Ru(2-C6H4-2'-Py-κC,N)(PPh3, trans-C)(MeCN)3]PF6 (10), in which the PPh3 is located trans to the C of the cyclometalated 2-phenylpyridine, since, upon treatment by refluxing MeCN, it leads to its isomer 11, [Ru(2-C6H4-2'-Py-κC,N)(PPh3, cis-C)(MeCN)3]PF6. Further substitutions are also observed on 11, whereby N^N chelates (N^N = 2,2'-bipyridine and phenanthroline) substitute two MeCN ligands, affording [Ru(2-C6H4-2'-Py-κC,N)(PPh3, cis-C)(N^N)(MeCN)]PF6 (12a and 12b). Altogether, the behavior of the obtained complexes by ligand substitution reactions can be rationalized by an antisymbiotic effect on the Ru center, trans to the C atom of the cyclometalated unit, leading to compounds having the least nucleophilic ligand trans to C

  3. Bibenzimidazole containing mixed ligand cobalt(III) complex as a selective receptor for iodide

    Digital Repository Service at National Institute of Oceanography (India)

    Indumathy, R.; Parameswarana, P.S.; Aiswarya, C.V.; Nair, B.U.

    Two new mixed ligand cobalt(III) complexes containing bibenzimidazole (bbenzimH2) ligand with composition [Co(phen)2bbenzimH2](ClO4)3 (1) and [Co(bpy)2bbenzimH2](ClO4...

  4. Mixed-ligand complexes of ruthenium(II) incorporating a diazo ...

    Indian Academy of Sciences (India)

    Unknown

    Dedicated to the memory of the late Professor Bhaskar G Maiya. *For correspondence. Mixed-ligand complexes of ruthenium(II) incorporating a diazo ligand: Synthesis .... water (1 : 1) for 5 h to give a dark red solution. The solution was cooled to room temperature. After eva- poration of the solvent, the solid was collected,.

  5. Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

    International Nuclear Information System (INIS)

    Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei

    2015-01-01

    Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H_2ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H_2hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd_2(2,6-ndc)_2(bpp)(DMF)]·2DMF (1) and [Cd_3(hmdb)_3(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.

  6. Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei, E-mail: hanlei@nbu.edu.cn

    2015-12-15

    Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H{sub 2}ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H{sub 2}hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd{sub 2}(2,6-ndc){sub 2}(bpp)(DMF)]·2DMF (1) and [Cd{sub 3}(hmdb){sub 3}(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.

  7. Hexacoordinated mixed-ligand complexes of vanadium(IV) and copper(II)

    International Nuclear Information System (INIS)

    Islam, M.S.; Motahera Begum; Roy, H.N.; Haroon, S.A.Q.M.

    1996-01-01

    The literature reports simple complexes of metal ions with Schiff bases derived from amino acids. But their mixed-ligand complexes are very rare. Keeping this fact in mind, some new mixed ligand complexes of V IV and Cu II with tridentate Schiff bases derived from glycine, salicylaldehyde and amino bases, e.g. quinoline (Q), isoquinoline (IQ), 2-picoline (2-pic), 4-picoline (4-pic) and pyridine (Py) were prepared and studied. 6 refs., 1 tab

  8. Activation of trans geometry in bifunctional mononuclear platinum complexes by a non-bulky methylamine ligand

    Czech Academy of Sciences Publication Activity Database

    Frýbortová, M.; Nováková, Olga; Štěpánková, Jana; Novohradský, Vojtěch; Gibson, D.; Kašpárková, Jana; Brabec, Viktor

    2013-01-01

    Roč. 126, SEP2013 (2013), s. 46-54 ISSN 0162-0134 R&D Projects: GA ČR(CZ) GAP301/10/0598; GA ČR(CZ) GA13-08273S Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : HETEROCYCLIC AMINE LIGAND * INTERSTRAND CROSS-LINKS * DNA-BINDING MODE Subject RIV: BO - Biophysics Impact factor: 3.274, year: 2013

  9. Equilibrium studies on mixed ligand complexes of some tripositive rare earth ions

    International Nuclear Information System (INIS)

    Vimal, Rashmi; Singh, Mamta; Ram Nayan

    1996-01-01

    Interaction of the rare earth ions, La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ and Eu 3+ with the pair of ligands 1-amino-2-naphthol-4-sulphonic acid (an, H 2 A) and o-aminophenol (ap, HB) have been studied in aqueous solution at 25 degC (μ=0.1 M KNO 3 /NaCl). Equilibrium constants of the reactions involving the formations of the mixed ligand species MAB, MA 2 B 2- , MB 2 A - (M = metal ion) and the binary complexes containing up to three ligand molecules have been evaluated from the pH-metric data, and coordinating behaviour of the ligands in the formation of the mixed ligand complexes has been discussed. (author). 10 refs., 1 tab., 1 fig

  10. synthesis and spectra characterization of mixed- ligand complexes

    African Journals Online (AJOL)

    BARTH EKWUEME

    The Schiff base ligand, N-Propylidene-2-methylpyridylamine was obtained from the condensation of 2- aminomethypyridine and propanal.Also, its complexes with Cu(II),Ni(II),Zn(II),Co(II) .... determined with Thomas–Hoover capillary melting apparatus. RESULTS AND DISCUSSION. N-propylidene-2-methylpyridylamine ...

  11. Trans and cis effects of axial fluoroalkyl ligands in vitamin B12 analogues: relationship between alkyl- and fluoroalkyl-cobalamins.

    Science.gov (United States)

    Randaccio, Lucio; Brancatelli, Giovanna; Demitri, Nicola; Dreos, Renata; Hickey, Neal; Siega, Patrizia; Geremia, Silvano

    2013-12-02

    CF2HCbl, CF3Cbl , and CF3CH2Cbl have been synthesized and characterized in solution by (1)H NMR and UV-vis spectroscopy, and their X-ray crystal structures have been determined using synchrotron radiation. The structure of CF3CH2Cbl is reported for the first time, whereas those of CF2HCbl and CF3Cbl are re-examined to obtain more precise structural data. Comparison of the structural data obtained with the alkylcobalamin analogues, MeCbl and EtCbl, indicates that the Co-C and Co-NB3 bond lengths are shorter in the fluoroalkylcobalamins. The structural data of the fluoroalkylcobalamins previously reported in the literature had been conflicting in this regard. Thus, a much less dramatic shortening of the two axial bonds was found for CF3Cbl, whereas in the case of CF2HCbl, the Co-NB3 bond length is shorter than in MeCbl. Direct comparison of the structures of CF3CH2Cbl and EtCbl indicates a large distortion of the axial fragment in the former case that can be attributed to steric effects. A number of previously reported correlations of the effect of the β-ligand on the structure and properties of cobalamins are re-examined in light of the present results. Particular emphasis is placed on the axial fragment. This analysis substantially confirms and, with the new data reported here, adjusts and expands the data set for correlations between trans and cis influences of the β-ligand of cobalamins and their structure (Co-X and Co-NB3 distances and corrin fold angle) and properties (UV-vis spectra, NMR spectra, and pK(base-off)).

  12. Site-specific chemical conjugation of human Fas ligand extracellular domain using trans-cyclooctene - methyltetrazine reactions.

    Science.gov (United States)

    Muraki, Michiro; Hirota, Kiyonori

    2017-07-03

    Fas ligand plays a key role in the human immune system as a major cell death inducing protein. The extracellular domain of human Fas ligand (hFasLECD) triggers apoptosis of malignant cells, and therefore is expected to have substantial potentials in medical biotechnology. However, the current application of this protein to clinical medicine is hampered by a shortage of the benefits relative to the drawbacks including the side-effects in systemic administration. Effective procedures for the engineering of the protein by attaching useful additional functions are required to overcome the problem. A procedure for the site-specific chemical conjugation of hFasLECD with a fluorochrome and functional proteins was devised using an inverse-electron-demand Diels-Alder reaction between trans-cyclooctene group and methyltetrazine group. The conjugations in the present study were attained by using much less molar excess amounts of the compounds to be attached as compared with the conventional chemical modification reactions using maleimide derivatives in the previous study. The isolated conjugates of hFasLECD with sulfo-Cy3, avidin and rabbit IgG Fab' domain presented the functional and the structural integrities of the attached molecules without impairing the specific binding activity toward human Fas receptor extracellular domain. The present study provided a new fundamental strategy for the production of the engineered hFasLECDs with additional beneficial functions, which will lead to the developments of the improved diagnostic systems and the effective treatment methods of serious diseases by using this protein as a component of novel molecular tools.

  13. Synthesis of novel '4+1' Tc(III)/Re(III) mixed-ligand complexes with dendritically modified ligands

    International Nuclear Information System (INIS)

    Gniazdowska, E.; Kuenstler, J.U.; Stephan, H.; Pietzsch, H.J.

    2006-01-01

    Coordination chemistry of technetium and rhenium attracts a considerable interest due to the nuclear medicine applications of their radionuclides. Inert, so-called '3+1' or '4+1' technetium/rhenium mixed-ligand complexes open a new way to application of 99 mTc/ 188 Re labeled compounds in tumor diagnosis and therapy. In the presented paper, authors describe the synthesis and study of novel 99 mTc/ 188 Re complexes with dendritically functionalized tetradentate (tripodal chelator 2,2',2''-nitrilotris(ethanethiol), NS 3 and carboxyl group-bearing ligand, NS 3 (COOH) 3 ) and monodentate (dendritically modified isocyanide, CN-R(COOMe) 3 and isocyanide-modified peptide, CN-GGY) ligands. To verify the identity of the prepared n.c.a. complexes, non-radioactive analogous '4+1' Re compounds were synthesized. The experimental data show that a dendritic modification of the tetradentate/monodentate ligands changes the complex lipophilicity and does not influence its stability

  14. Some mixed ligand hydridocarbonyl and hydridophosphine complexes of ruthenium(II) and iridium(III)

    International Nuclear Information System (INIS)

    Pandey, R.N.; Kumar, Sunil; Kumar, Arun; Kumar, S.K.

    1993-01-01

    Mixed-ligand hydridocarbonyl and hydridophosphine complexes of Ru II and Ir III have been isolated from the displacement reaction of [RuH(CO)(Pφ 3 ) 3 Cl] with ligand isonicotinic acid hydrazide (INAH) in benzene medium. Most probable structures are assigned on the basis of elemental analysis, electronic, infrared and far-infrared spectral studies. In all cases bonding of INAH occurs through amino nitrogen of hydrazine residue. (author). 15 refs., 1 tab

  15. One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

    KAUST Repository

    Wang, Xiaofang

    2017-12-24

    The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H2pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd2Cl3(2-pzc)(bbbi)2] (2)) under hydrothermal conditions. Complex 1 was obtained in the absence of in situ reaction and 2 was synthesized with 2,3-H2pzdc in situ generating 2-pyrazinecarboxylate (2-pzc−). The structural details reveal that 1 has a 3D framework with dia topology, and 2 is a 2D layer structure and develops a 3D supramolecular structure via strong π⋯π stacking interactions. The ligand effects were compared for the two frameworks. In addition, fluorescence properties and thermal stabilities of 1 and 2 in the solid were studied.

  16. Potentiometric studies on mixed-ligand chelates of uranyl ion with carboxylic acid phenolic acids

    International Nuclear Information System (INIS)

    Bandiwadekar, S.P.; Chavar, A.M.

    1988-01-01

    Mixed ligand complexes of UO 2 2+ with bidentate carboxylic and phenolic acids have been studied potentiometrically at 30 ± 0.1degC and μ=0.2M (NaClO 4 ). 1:1 and 1:2 complexes of UO 2 2+ with phthalic acid (PTHA), maleic acid (MAE), malonic acid (MAL), quinolinic acid (QA), 5-sulphosalicylic acid (5-SSA), salicylic acid (SA), and only 1:1 complexes in the case of mandelic acid (MAD) have been detected. The formation of 1:1:1 mixed ligand complexes has been inferred from simultaneous equilibria in the present study. The values of ΔlogK, Ksub(DAL), Ksub(2LA) or Ksub(2AL) for the ternary complexes have been calculated. The stabilities of mixed ligand complexes depend on the size of the chelate ring and the stabilities of the binary complexes. (author). 15 refs

  17. Formation of mixed ligand complexes of UO22+ involving some nitrogen and oxygen donor ligands

    International Nuclear Information System (INIS)

    Singh, Mamta; Ram Nayan

    1996-01-01

    The complexation reactions of UO 2 2+ ion with nitrogen and oxygen donor ligands, 1-amino-2-naphthol-4-sulphonic acid, o-aminophenol (ap), 2-hydroxybenzoic acid (sa), 3-carboxy-4-hydroxybenzenesulphonic acid (ss) and 1,2-dihydroxybenzene (ca) have been investigated in aqueous solution employing the pH-titration technique. Analysis of the experimental data recorded at 25 degC and at an ionic strength of 0.10 M KNO 3 indicates formation of binary, hydroxo and ternary complexes of uranium. Formation constant values of the existing species have been evaluated and the results have been discussed. (author). 21 refs., 2 figs., 2 tabs

  18. Synthesis of mixed ligand europium complexes: Verification of predicted luminescence intensification

    International Nuclear Information System (INIS)

    Lima, Nathalia B.D.; Silva, Anderson I.S.; Gonçalves, Simone M.C.; Simas, Alfredo M.

    2016-01-01

    Mixed ligand europium complexes are predicted to be more luminescent than what would be expected from their corresponding repeating ligand compounds according to a conjecture recently advanced by our research group; a conjecture that has already been validated for strongly luminescent europium complexes. In this article, we seek to further verify the validity of this conjecture for complexes which are much more symmetric, and which thus display lower levels of luminescence. Accordingly, we synthesized complexes Eu(DBM) 3 (L) 2 , and all novel mixed ligand combinations Eu(DBM) 3 (L,L') with L and L' equal to DBSO, PTSO, and TPPO. The syntheses were carried out via displacement reactions from the starting complex Eu(DBM) 3 (H 2 O) 2 , passing through the intermediates Eu(DBM) 3 (L) 2 and finally, by displacement of L by L', arriving at Eu(DBM) 3 (L,L'). The ligands L obey the following order of displacement TPPO>PTSO>DBSO>H 2 O, which had been previously described by our group. In the present article, we further show that this displacement order could have been predicted by Sparkle/RM1 thermochemical calculations. Subsequently, we determined the radiative decay rates, A rad , for all six compounds by photophysical measurements. As expected, results show that the measured A rad values for all novel mixed ligand complexes are larger than the average of the A rad values for the corresponding repeating ligand coordination compounds. In conclusion, the present article does broaden the scope of our conjecture, which enunciates that an increase in the diversity of ligands around the europium ion tends to intensify the luminescence. - Highlights: • Mixed ligand europium complexes are predicted to be more luminescent than repeating ligand ones. • Radiative decay rates increase with structural coordination asymmetry. • The non-ionic ligands displacement order in substitution reactions is TPPO>PTSO>DBSO>H 2 O. • Sparkle/RM1 correctly predicts the

  19. Studies on mixed ligand complexes of lanthanide (III) ions

    International Nuclear Information System (INIS)

    Rajendran, G.; Usha Devi, K.G.

    2002-01-01

    As part of our research programme, we have prepared and characterized a few nitrato, thiocyanato and perchlorato complexes of lanthanide(III) ions with ligands, viz., a Schiff base derived from p-anisidine and vanillin and diphenyl sulphoxide. The complexes were characterized by the measurement of electrical conductances and magnetic susceptibilities, molecular mass and metal percentage and spectral analysis. The thermal decompositions were studied by TG and DTG techniques. The thiocyanato complexes were prepared by substitution method from nitrato complexes. p-Anisidine-vanillin (HDDA) and diphenyl sulphoxide (DPSO) are coordinated to the metal ion in unidentate fashion. All the anions were involved in coordination in these complexes. Thus they were found to have non- electrolytic behaviour with composition [Ln(HDDA) 2 (DPSO)X 3 ] where X = NO 3 ) or SCN perchlorato complexes were prepared from metal perchlorate as done in the case of nitrato complexes. They were found to have electrical conductance which corresponds to 1 : 1 electrolyte. Hence one of the perchlorate ions is outside the coordination sphere. The composition of this complex is found to be [Ln(HDDA) 3 (DPSO)(ClO 4 ) 2 ]ClO 4 . (author)

  20. Polarographic study of mixed-ligand complexes of cadmium(II) with L-amino acid and vitamin B5

    International Nuclear Information System (INIS)

    Jain, Alok K.; Khan, Farid

    1998-01-01

    A survey of literature shows that ternary complexes of Cd II with L-amino acids and vitamin B 5 have not been studied so far. The present communication reports the formation of mixed-ligand complexes of Cd II with L-amino acids as primary ligands and vitamin B 5 as secondary ligand, studied by polarographic technique. (author)

  1. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin; Xue, Ming; Song, Qingshan; Chen, Siru; Pan, Ying; Qiu, Shilun

    2014-01-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, b

  2. The concept of mixed organic ligands in metal-organic frameworks: design, tuning and functions.

    Science.gov (United States)

    Yin, Zheng; Zhou, Yan-Ling; Zeng, Ming-Hua; Kurmoo, Mohamedally

    2015-03-28

    The research on metal-organic frameworks (MOFs) has been developing at an extraordinary pace in its two decades of existence, as judged by the exponential growth of novel structures and the constant expansion of its applicability and research scope. A major part of the research and its success are due to the vital role of the concept of mixed organic ligands in the design, tuning and functions. This perspective, therefore, reviews the recent advances in MOFs based on this concept, which is generally based on employing a small polydentate ligand (here labelled as "nodal ligand") to form either clusters, rods or layers, which are then connected by a second ditopic linker ligand to form the framework. The structures of the materials can be grouped into the following three categories: layer-spacer (usually known as pillared-layer), rod-spacer, and cluster-spacer based MOFs. Depending on the size and geometry of the spacer ligands, interpenetrations of frameworks are occasionally found. These MOFs show a wide range of properties such as (a) crystal-to-crystal transformations upon solvent modifications, post-synthetic metal exchange or ligand reactions, (b) gas sorption, solvent selectivity and purification, (c) specific catalysis, (d) optical properties including colour change, luminescence, non-linear optic, (e) short- and long range magnetic ordering, metamagnetism and reversible ground-state modifications and (f) drug and iodine carriers with controlled release. In the following, we will highlight the importance of the above concept in the design, tuning, and functions of a selection of existing MOFs having mixed organic ligands and their associated structures and properties. The results obtained so far using this concept look very promising for fine-tuning the pore size and shape for selective adsorption and specificity in catalytic reactions, which appears to be one way to propel the advances in the application and commercialization of MOFs.

  3. Screening the efficient biological prospects of triazole allied mixed ligand metal complexes

    Science.gov (United States)

    Utthra, Ponnukalai Ponya; Kumaravel, Ganesan; Raman, Natarajan

    2017-12-01

    Triazole appended mixed ligand complexes (1-8) of the general formula [ML (bpy/phen)2]Cl2, where M = Cu(II), Co(II), Ni(II) and Zn(II), L = triazole appended Schiff base (E)sbnd N-(4-nitrobenzylidene)-1H-1,2,4-triazol-3-amine and bpy/phen = 2,2‧-bipyridine/1,10-phenanthroline, have been synthesized. The design and synthesis of this elaborate ligand has been performed with the aim of increasing stability and conjugation of 1,2,4 triazole, whose Schiff base derivatives are known as biologically active compounds thereby exploring their DNA binding affinity and other biological applications. The compounds have been comprehensively characterized by elemental analysis, spectroscopic methods (IR, UV-Vis, EPR, 1H and 13C NMR spectroscopy), ESI mass spectrometry and magnetic susceptibility measurements. The complexes were found to exhibit octahedral geometry. The complexes 1-8 were subjected to DNA binding techniques evaluated using UV-Vis absorption, CV, CD, Fluorescence spectroscopy and hydrodynamic measurements. Complex 5 showed a Kb value of 3.9 × 105 M-1. The DNA damaging efficacy for the complexes was observed to be high compared to the ligand. The antimicrobial screening of the compounds against bacterial and fungal strains indicates that the complexes possess excellent antimicrobial activity than the ligand. The overall biological activity of the complexes with phen as a co-ligand possessed superior potential than the ligand.

  4. Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

    Science.gov (United States)

    Abd El-Halim, Hanan F.; Mohamed, Gehad G.; Khalil, Eman A. M.

    2017-10-01

    A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV-Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats-Redfern and Horowitz-Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram-Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

  5. Mixed-ligand Al complex—a new approach for more high efficient OLEDs

    International Nuclear Information System (INIS)

    Petrova, Petia K.; Tomova, Reni L.; Stoycheva-Topalova, Rumiana T.; Kaloyanova, Stefka S.; Deligeorgiev, Todor G.

    2012-01-01

    The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq 2 Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq 3 . Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq 3 The better performance of the devices make the novel Al complex a very promising material for OLEDs. - Highlights: ► A novel electroluminescent Alq 2 Acac complex is presented as material for OLED. ► Electroluminescent emission of Alq 2 Acac is very similar to that of commercial Alq 3 . ► Devices with Alq 2 Acac show better characteristics compared to those with Alq 3 .

  6. Thermodynamics of mixed-ligand complex formation of mercury (II) ethylenediaminetetraacetate with amino acids in solution

    Energy Technology Data Exchange (ETDEWEB)

    Pyreu, Dmitrii, E-mail: pyreu@mail.ru [Department of Inorganic and Analytic Chemistry, Ivanovo State University, Ermak 39, Ivanovo 153025 (Russian Federation); Kozlovskii, Eugenii [Department of Inorganic and Analytic Chemistry, Ivanovo State University, Ermak 39, Ivanovo 153025 (Russian Federation); Gruzdev, Matvei; Kumeev, Roman [Institute of Solution Chemistry, Ivanovo (Russian Federation)

    2012-11-20

    Highlights: Black-Right-Pointing-Pointer Stable mixed ligand complexes of HgEdta with amino acids at physiological pH value. Black-Right-Pointing-Pointer The thermodynamic and NMR data evident the ambidentate coordination mode of arginine. Black-Right-Pointing-Pointer Participation of the guanidinic group of Arg in coordination process. Black-Right-Pointing-Pointer Binuclear complexes (HgEdta){sub 2}L with the bridging function of amino acid. - Abstract: The mixed-ligand complex formation in the systems Hg{sup 2+} - Edta{sup 4-} - L{sup -}(L = Arg, Orn, Ser) has been studied by means of calorimetry, pH-potentiometry and NMR spectroscopy in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO{sub 3}). The thermodynamic parameters of formation of the HgEdtaL, HgEdtaHL and (HgEdta){sub 2}L complexes have been determined. The most probable coordination mode for the complexone and the amino acid in the mixed-ligand complexes was discussed.

  7. Ionophoretic method in the study of mixed ligand ternary chelates of UO2(II), Ni(II) and Zn(II) involving nitrilotriacetate and cytosine as ligands

    International Nuclear Information System (INIS)

    Mishra, A.P.; Mishra, S.K.; Yadava, K.L.

    1987-01-01

    A novel electrophoretic technique is described for the assessment of the equilibria in mixed-ligand complex system in solution. It is based on the movement of spot of the metal ion under an electric field with the complexants added in the background electrolyte at fixed pH. The concentration of primary ligand nitrilotriacetate was constant while that of secondary ligand (cytosine) was varied. The plot of log (cytosine) against mobility was used to obtain information on the formation of the mixed complexes and to calculate its stability constants. Experimentally obtained logK values are as 5.62, 4.55 and 4.42 for mixed complexes of UO 2 (II), Ni(II) and Zn(II) respectively at μ=0.1 and temp.=35 +- 01.degC. (author). 10 refs

  8. Studies on some mixed ligand complexes of UO2(VI) in solution

    International Nuclear Information System (INIS)

    Katkar, V.S.; Munshi, K.N.

    1987-01-01

    Potentiometric studies on some mixed ligand complexes of UO 2 (VI) with ethylenediamine N,N' diacetic acid as primary ligand and succinic acid, malic acid, maleic acid, fumaric acid, malonic acid, adipic acid, itaconic acid, phthalic acid and mandelic acid as secondary ligands have been carried out employing modified form of Irving-Rossotti's pH titration technique. The study was carried out at three different temperatures, viz. 5deg, 25deg and 45degC and at fixed ionic strength of 0.2M KNO 3 . Thermodynamic parameters, e.g. ΔG, ΔH and ΔS have been evaluated and further ΔG and ΔH values have been separated into their electrostatic components, ΔGe and ΔHe and cratic components, ΔGsub(c) and ΔHsub(c). The effect of change in dielectric constant and change in ionic strength of the medium have also been investigated. The sequence of stability constants has been correlated with the properties of secondary ligands. (author). 21 refs., 5 tabs

  9. cis-dioxovanadium(V) and mixed-valence divanadium(IV, V) complexes containing β-diketonate and heterocyclic nitrogen-base ligands

    International Nuclear Information System (INIS)

    Taguchi, Hiroshi; Isobe, Kiyoshi; Nakamura, Yukio; Kawaguchi, Shinichi

    1978-01-01

    Diamagnetic dioxovanadium(V) complexes, VO 2 (β-dik)(phen or bpy), were prepared by the direct reactions of VO(β-dik) 2 with 1,10-phenanthroline and 2,2'-bipyridine in dichloromethane under aerobic conditions as well as by two other methods. These compounds were concluded to have a cis configuration on the basis of the IR and Raman data. These complexes are solvolyzed to afford the di-μ-methoxo- or di-μ-hydroxo-divanadium(V) species, and are reduced by hydrogen bromide to the oxovanadium(IV) species in dichloromethane. In methanol instead of dichloromethane, VO(acac) 2 reacted with 2,2'-bipyridine to produce a novel mixed-valence divanadium(IV, V) complex, V 2 O 3 (acac) 3 (bpy), which was revealed by the magnetic, spectral, and polarographic data to be a trans adduct of VO(acac) 2 with VO 2 (acac)(bpy) via an oxide ligand. (auth.)

  10. Studies on mixed ligand complexes of adenine and xanthine with some rare earth ions

    International Nuclear Information System (INIS)

    Rastogi, P.R.; Singh, Mamta; Nayan, Ram

    1993-01-01

    Interactions of 6-aminopurine (adenine, HA) and 2,6-dihydroxypurine (xanthine, HB) with trivalent rare earth ions Y, Tb, Dy, Ho, Er and Tm, have been studied by pH-titration methods in aqueous solution at 20 o (μ = 0.1 M KNO 3 ). The ligands in their mixtures with tripositive rare earth ions (M 3+ ) form a number of mixed ligand complexes, M 3+ -adenine-xanthine, M 3+ -(adenine) 2 -xanthine, M 3+ -adenine-(xanthine) 2 in addition to the binary complexes, M 3+ -(adenine), M 3+ -(adenine) 2 , M 3+ -(adenine) 3 , M 3+ -(xanthine), M 3+ -(xanthine) 2 and M 3+ -(xanthine) 3 . The stability constants of these complexes have been evaluated and the results discussed. (author). 13 refs., 1 fig., 1 tab

  11. Mixed ligand complexes of uranyl lactate with some simple and heterocyclic amines

    International Nuclear Information System (INIS)

    Jaiswal, S.R.; Rupainwar, D.C.

    1984-01-01

    Mixed ligand complexes of uranyl lactate with simple and heterocyclic amines having a general formula UO 2 (C 3 H 5 O 3 ).nL.xH 2 O, were prepared, where n=1 and x=1 for L=ethylenediamine (En), dimethyl aniline (DMAn), diethyl amine (DEA), orthophenylenediamine (OPDA), pyridine (Py), 2-picoline(2-Pic), 3-picoline(3-Pic), 4-Picoline(4-Pic), piperidine (Pipy), 2,4-lutidine (2,4 Lut), 2-Aminopyridine (2 APy), quinoline (Quin), isoquinoline (Isoquin) but x=0 for the ligands 2,2'-bipyrldyl (Bipy) and 1,10-phenenthroline (Phen). All the compounds are bright yellow coloured with high decomposition temp. (>200deg) and were characterized by electronic and infrared spectral data. (author)

  12. Mixed-ligand Pt(II) dithione-dithiolato complexes: influence of the dicyanobenzodithiolato ligand on the second-order NLO properties.

    Science.gov (United States)

    Espa, Davide; Pilia, Luca; Marchiò, Luciano; Artizzu, Flavia; Serpe, Angela; Mercuri, Maria Laura; Simão, Dulce; Almeida, Manuel; Pizzotti, Maddalena; Tessore, Francesca; Deplano, Paola

    2012-03-28

    The mixed-ligand dithiolene complex [Pt(Bz(2)pipdt)(dcbdt)] (1) bearing the two ligands Bz(2)pipdt = 1,4-dibenzyl-piperazine-3,2-dithione and dcbdt = dicyanobenzodithiolato, has been synthesized, characterized and studied to evaluate its second-order optical nonlinearity. The dithione/dithiolato character of the two ligands gives rise to an asymmetric distribution of the charge in the molecule. This is reflected by structural data showing that in the C(2)S(2)PtS(2)C(2) dithiolene core the four sulfur atoms define a square-planar coordination environment of the metal where the Pt-S bond distances involving the two ligands are similar, while the C-S bond distances in the C(2)S(2) units exhibit a significant difference in Bz(2)pipdt (dithione) and dcbdt (dithiolato). 1 shows a moderately strong absorption peak in the visible region, which can be related to a HOMO-LUMO transition, where the dcbdt ligand (dithiolato) contributes mostly to the HOMO, and the Bz(2)pipdt one (dithione) mostly to the LUMO. Thus this transition has ligand-to-ligand charge transfer (CT) character with some contribution of the metal and undergoes negative solvatochromism and molecular quadratic optical nonlinearity (μβ(0) = -1296 × 10(-48) esu), which was determined by the EFISH (electric-field-induced second-harmonic generation) technique and compared with the values of similar complexes on varying the dithiolato ligand (mnt = maleonitriledithiolato, dmit = 2-thioxo-1,3-dithiole-4,5-dithiolato). Theoretical calculations help to elucidate the role of the dithiolato ligands in affecting the molecular quadratic optical nonlinearity of these complexes.

  13. Stability Constants of Mixed Ligand Complexes of Transition Metal(II Ions with Salicylidene-4-methoxyaniline as Primary Ligand and 5-Bromosalicylidene-4-nitroaniline as Secondary Ligand

    Directory of Open Access Journals (Sweden)

    N. G. Nadkarni

    2011-01-01

    Full Text Available Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II, Ni(II, Cu(II and Zn(II; X = salicylidene-4-methoxyaniline and Y=5-bromosalicylidene-4-nitroaniline] have been examined pH-metrically at 27±0.5 °C and at constant ionic strength, μ= 0.1 M (KCl in 75 : 25(v/v 1,4-dioxne-water medium. The stability constants for binary (M-Y and ternary (M-X-Y systems were calculated. The relative stability (Δ log KT values of the ternary complexes with corresponding binary complexes for all the metal(II ions in the present study found to be negative indicating that ternary 1:1:1 (M-X-Y complexes are less stable than binary 1:1 (M-Y complexes. In the ternary system studied, the order of stability constants of mixed ligand complexes with respect to the metal ions was found to be Cu(II > NI(II > Mn(II > Zn(II; which is same as in the corresponding binary (M-Y systems.

  14. Study of some properties of the ruthenium (II) trans-tetra-ammines with nitrogened aromatic heterocyclic ligands

    International Nuclear Information System (INIS)

    Bento, M.L.

    1985-01-01

    The ruthenium (II) complexes trans [Ru(NH 3 ) 4 LL'] (BF 4 ) 2 , where L and L' are 4-picoline, pyridine, isonicatinamide, pyrazine or 4-acetylpyridine are studied. The U.V-visible range spectra, bands in the U.V. and in the visible range is analysed. The spectra and the bands by comparison with other ruthenium (II) ammines are discussed, and a qualitative molecular orbital model is used. (M.J.C.) [pt

  15. Synthesis, characterization and electrochemical investigations of mixed-ligand copper(II)-organic supramolecular frameworks

    Science.gov (United States)

    Singh, Sandeep K.; Srivastava, Ashish Kumar; Srivastava, Krishna; Banerjee, Rahul; Prasad, Jagdish

    2017-11-01

    Two mixed-ligand copper(II)-organic coordination compounds with 5,5‧-dimethyl-2,2‧-bipyridine (5,5‧-Me2bpy) as a primary ligand while aliphatic malonate (Hmal) and aromatic 2-hydroxynicotinate (2-OHNA) as secondary ligands, were synthesized. These complexes are formulated as: [Cu(Hmal)(5,5‧-Me2bpy)(H2O)](ClO4) 1 and [Cu2(2-OHNA)2(5,5‧-Me2bpy)2(NO3)](NO3) 2. These two complexes were structurally characterized by single crystal X-ray diffraction analysis. Characterization was further supported by powder X-ray diffraction analysis, elemental analyses, FT-IR, FAB-MASS and TGA, DSC studies. Cyclic voltammetric and UV-visible spectral studies of these two complexes have also been done. The electrochemical studies of complex 1 in DMSO and DMF have shown that this complex undergoes quasi-reversible diffusion-controlled one-electron transfer reaction without any chemical complication while complex 2 in DMSO undergoes quasi-reversible diffusion-controlled one electron transfer reaction, following EC mechanism. The electrochemical behaviour of complex 2 in DMF is complicated probably due to presence of more than one species in solution phase.

  16. Mixed-ligand Al complex-a new approach for more high efficient OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Petrova, Petia K., E-mail: petia@clf.bas.bg [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Tomova, Reni L.; Stoycheva-Topalova, Rumiana T. [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G Bonchev st., bl. 109, 1113 Sofia (Bulgaria); Kaloyanova, Stefka S.; Deligeorgiev, Todor G. [Applied Organic Chemistry, Faculty of Chemistry, University of Sofia, Sofia 1164 (Bulgaria)

    2012-02-15

    The mixed-ligand Aluminum bis(8-hydroxyquinoline) acetylacetonate (Alq{sub 2}Acac) complex was presented and its performance as electroluminescent and electron transporting layer for OLED was studied. The photophysical properties of the novel complex were investigated and compared with the properties of the parent Alq{sub 3}. Highly efficient OLED based on the mixed-ligand Al complex was developed with two times higher luminescence and efficiency compared to the identical OLED based on the conventional Alq{sub 3} The better performance of the devices make the novel Al complex a very promising material for OLEDs. - Highlights: Black-Right-Pointing-Pointer A novel electroluminescent Alq{sub 2}Acac complex is presented as material for OLED. Black-Right-Pointing-Pointer Electroluminescent emission of Alq{sub 2}Acac is very similar to that of commercial Alq{sub 3}. Black-Right-Pointing-Pointer Devices with Alq{sub 2}Acac show better characteristics compared to those with Alq{sub 3}.

  17. Stability constants of mixed ligand complexes of dioxouranium(II) and thorium(IV) with complexones and isomeric alanines

    International Nuclear Information System (INIS)

    Singh, R.K.; Saxena, M.C.

    1992-01-01

    The present work reports on the stability sequence between UO 2 II and Th IV ions for their mixed ligands complexes with the two isomeric alanines, α-alanine (α-ala) and β-alanine (β-ala) containing a complexone as primary ligand. The complexones used are iminodiacetate (IMDA), nitrilotricetate (NTA), 2-hydroxyethylenediaminetriacetate (HEDTA), ethylenediaminetetraacetate (EDTA), 1,2-diaminocyclohexanetraacetate (CDTA) and diethylenetriminepentaacetate (DTPA). (author). 9 refs., 1 tab

  18. Selective extraction of trivalent actinides with hard-soft mixed donor ligands: role of intra-ligand synergism

    International Nuclear Information System (INIS)

    Ghanty, Tapan K.

    2016-01-01

    In recent years, considerable attention has been given to understand the coordination chemistry of trivalent lanthanide (Ln) and actinide (An) with various ligands because of its close link with the nuclear waste management processes. It is well known that lanthanide-actinide separation is a challenging and difficult task because of very similar chemical properties of these two series of ions, which are associated with similar ionic radii and coordination numbers. Recently, we have introduced a new concept, 'intra-ligand synergism', where hard donor atom, such as, oxygen preferentially binds to trivalent actinides (An(III)) as compared to the valence iso-electronic trivalent lanthanides (Ln(III)) in presence of another soft donor centre. In the present work, the conventional concept of selective complexation of actinides with soft donor ligands (either S or N donor) has been modified through exploiting this concept, and thereby the higher selectivity of 1,10-phenanthroline-2,9-dicarboxylamide (PDAM) based ligands, namely PDAM and its isobutyl and decyl derivatives towards Am(III) ion has been predicted theoretically through density functional calculations. Subsequently, several such amide derivatives have been synthesized to optimize the solubility of the ligands in organic phase. Finally, solvent extraction experiments have been carried out to validate the theoretical prediction on the selectivity of oxygen donor ligands towards Am(III) as compared to Eu(III), and a maximum separation factor of about 51 has been achieved experimentally using 2,9-bis(N-decylaminocarbonyl)-1,10-phenanthroline ligand. The separation factor is increased with the decrease in pH, which is very interesting since extraction of the Am 3+ ion is considered to be important under highly acidic conditions from the nuclear waste management point of view. (author)

  19. Potential role of nuclear receptor ligand all-trans retinoic acids in the treatment of fungal keratitis

    Directory of Open Access Journals (Sweden)

    Hong-Yan Zhou

    2015-08-01

    Full Text Available Fungal keratitis (FK is a worldwide visual impairment disease. This infectious fungus initiates the primary innate immune response and, later the adaptive immune response. The inflammatory process is related to a variety of immune cells, including macrophages, helper T cells, neutrophils, dendritic cells, and Treg cells, and is associated with proinflammatory, chemotactic and regulatory cytokines. All-trans retinoic acids (ATRA have diverse immunomodulatory actions in a number of inflammatory and autoimmune conditions. These retinoids regulate the transcriptional levels of target genes through the activation of nuclear receptors. Retinoic acid receptor α (RAR α, retinoic acid receptor γ (RAR γ, and retinoid X receptor α (RXR α are expressed in the cornea and immune cells. This paper summarizes new findings regarding ATRA in immune and inflammatory diseases and analyzes the perspective application of ATRA in FK.

  20. Carbon dioxide selective adsorption within a highly stable mixed-ligand Zeolitic Imidazolate Framework

    KAUST Repository

    Huang, Lin

    2014-08-01

    A new mixed-ligand Zeolitic Imidazolate Framework Zn4(2-mbIm) 3(bIm)5·4H2O (named JUC-160, 2-mbIm = 2-methylbenzimidazole, bIm = benzimidazole and JUC = Jilin University China) was synthesized with a solvothermal reaction of Zn(NO3) 2·6H2O, bIm and 2-mbIm in DMF solution at 180 °C. Topological analysis indicated that JUC-160 has a zeolite GIS (gismondine) topology. Study of the gas adsorption and thermal and chemical stability of JUC-160 demonstrated its selective adsorption property for carbon dioxide, high thermal stability, and remarkable chemical resistance to boiling alkaline water and organic solvent for up to one week. © 2014 Elsevier B.V.

  1. Mixed-ligand complexes of copper (II with ditiolfenols and heterocyclic diamines

    Directory of Open Access Journals (Sweden)

    K. A. Kuliev

    2017-01-01

    Full Text Available By the methods spectrophotometric methods was investigated complex formation of copper with 2,6-ditiolphenol and its derivatives (2,6-ditiol-4-methylphenol, 2,6-ditiol-4-ethylphenol and 2,6-ditiol-4-tert-buthylphenol in the presence of heterocyclic diamines. As heterocyclic diamines phenantroline (Fen, batophenantroline and dipyridile were used. It was established, that mixedligand complex were formed in weak acidic medium (pHop=6,0-8,5. Maximum of light absorption observed at (=522–550 nm. Molar coefficient of light absorption was ( = (3.08–4.92?104. The stoichiometry of complexes had been discovered using shift the equilibrium and relative yield methods. During the extraction of copper(II complexes with ditiol-phenols with the presence of heterocyclic diamines there was discovered that there is no chlorophorm molecules in the composition of the extracted complexes. IR spectra shows that hydroxyl group is involved to the formation of a bond with the metal and that phenantroline is included in the composition of the copper complex. In the organic phase mixed-ligand complexes have the monomeric form and can’t polymerize; that fact can be proved by calculations. By dint of spectrophotometric, IR-spectroscopic, thermogravimetric experiments and some published data we were able to determine the structural formula of complexes. Also had been determined main spectrophotometric characteristics of copper(II mixed-ligand complexes: pH of the beginning of the deposition, optimal pH, detection limit and sensivity. For separation and finding copper, we studied the effect of interfering foreign ions: alkali, alkaline earth and rare earth elements, as well as acid anions selected masking reagents. On the base of the results was offered photometric method for determination of copper in steel different trade-marks and in food. This method characterized by good reproduction (relatively standard deviation no more 0.05 and low limit of discovery.

  2. The synthesis, structures and characterisation of new mixed-ligand manganese and iron complexes with tripodal, tetradentate ligands

    NARCIS (Netherlands)

    van Gorkum, R.; Berding, J.; Mills, A.M.; Kooijman, H.; Tooke, D.M.; Spek, A.L.; Mutikainen, I.; Turpeinen, U.; Reedijk, J.; Bouwman, E.

    2008-01-01

    The preparation of new manganese and iron complexes with the general formula [M(tripod)(anion)] is described, where M = FeIII or MnIII, “tripod” is a dianionic tetradentate tripodal ligand and the anion is a chelating β-diketonate, 8-oxyquinoline or acetate. The synthesis of this type of complexes

  3. Solution stabilities of some mixed ligand complexes of UO22+ and Th4+ with complexones and salicylic acids

    International Nuclear Information System (INIS)

    Singh, R.K.; Saxena, M.C.

    1991-01-01

    Formation constants (log Ksub(MAL)sup(MA)) of mixed ligands complexes (MAL), where M = UO 2 2+ or Th 4+ , A = IMDA, NTA, HEDTA, EDTA, CDTA or DTPA, L = salicylic acid (SA) or 5-sulphosalicylic acid (SSA), have been determined by pH titrations using Irving-Rossotti approach at 25 o C and at I =0.2 (mol dm -3 , KNO 3 ). The solution stabilities exhibit the sequence (i) Th 4+ >UO 2 2+ , (ii) IMDA>NTA>HEDTA>EDTA>CDTA>DTPA, and (iii) SA>SSA with respect to metal ions, primary ligands and secondary ligands, respectively. The formation constants log Ksub(ML)sup(M) and log Ksub(ML 2 )sup(ML) have also been determined. The Δlog K values have been found to be negative-increasing numerically with the negative charge on the deprotonated primary ligand (A n- ). (author). 17 refs., 1 tab

  4. Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

    International Nuclear Information System (INIS)

    Kolhe, Vishnu; Dwivedi, K.

    1996-01-01

    Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

  5. Synthesis of high specific activity tritium labelled 1S,2S-(-)-trans-2-isothiocyanato-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)benzene acetamide, a specific irreversible ligand for kappa opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    Costa, B.R. de; Thurkauf, A.; Rothman, R.R. (National Inst. of Mental Health, Bethesda, MD (USA)); Jacobson, A.E.; Rice, K.C. (National Inst. of Digestive Diabetes, and Kidney Diseases, Bethesda, MD (USA))

    1990-11-01

    Optically pure tritium labeled 1S,2S-(-)-trans-2-isothiocyanato-N-methyl-N-(2-(1-pyrrolidinyl)cyclohexyl )benzeneacetamide, an affinity ligand specific for the kappa opioid receptor was synthesized from optically pure 1S,2S-(-)-trans-2-amino-N-methyl-N-(2-(1-pyrrolidinyl)cyclohexyl)benzeneacetamide via the sequence of dibromination (57%) followed by catalytic tritiation of the dibromide. The resulting tritium labelled aniline (14% yield, specific activity 31.2 Ci/mmol) was transformed to the title compound in 13.3% yield and 99+% radiochemical purity by treatment with thiophosgene. (author).

  6. Deviation from the trans -Effect in Ligand-Exchange Reactions of Zeise’s Ions PtCl3(C2H4)- with Heavier Halides (Br, I- )

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Gao-Lei [Physical; Govind, Niranjan [Environmental; Xantheas, Sotiris S. [Advanced; Department; Wang, Xue-Bin [Physical

    2018-01-16

    Four new Zeise’s family ions with mixed-halide ligands, i.e., PtClnX3-n(C2H4)- (X = Br, I; n = 1, 2), were synthesized via ligand-exchange reactions of KX salts with KPtCl3(C2H4) in aqueous solutions, and were detected in vacuum via electrospray ionization mass spectrometry. Their photoelectron spectra reveal a series of well-resolved spectral peaks with their electron binding energies (EBEs) decreasing with increasing halide size, with I having a much stronger effect than Br, i.e., 4.57 (–Cl3) > 4.56 (–Cl2Br) > 4.53 (–ClBr2) > 4.34 (–Cl2I) > 4.30 eV (–ClI2). Ab initio electronic structure calculations including spin-orbit coupling (SOC) predict that the cis- and trans-isomers are nearly isoenergetic with the cis-isomer for –Cl2X, and the trans-isomer for –ClX2 slightly favored, respectively. Excited-state spectra calculated with time-dependent density functional theory (TDDFT), and their comparison with the observed ones, suggest that for each species, both the cis- and trans-configurations coexist in the experiments and contribute to the observed spectra, a fact that clearly violates the prediction of the widely accepted trans-effect, which suggests that only one isomer would have formed.

  7. Mechanism of redox reactions induced by light and electron pulse in solutions of mixed ligand iron(II) complex cyanides

    International Nuclear Information System (INIS)

    Horvath, A.; Szoeke, J.; Wojnarovits, L.

    1991-01-01

    Redox reactions induced by light and electron pulse have been studied in aqueous solutions of mixed ligand iron(II) complex cyanides. The short lived intermediates have been identified by time resolved specroscopy, the results of detailed kinetic analysis have been discussed. (author) 6 refs.; 3 figs.; 2 tabs

  8. Synthesis and Optical Characterization of Mixed Ligands Beryllium Complexes for Display Device Applications

    Directory of Open Access Journals (Sweden)

    Vandna Nishal

    2015-01-01

    Full Text Available Synthesis and photoluminescent behaviour of mixed ligand based beryllium complexes with 2-(2-hydroxyphenylbenzoxazole (HPB and 5-chloro-8-hydroxyquinoline (Clq or 5,7-dichloro-8-hydroxyquinoline (Cl2q or 2-methyl-8-hydroxyquinoline (Meq or 8-hydroxyquinoline (q are reported in this work. These complexes, that is, [BeHPB(Clq], [BeHPB(Cl2q], [BeHPB(Meq], and [BeHPB(q], were prepared and their structures were confirmed by elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and thermal analysis. The beryllium complexes exhibited good thermal stability up to ~300°C temperature. The photophysical properties of beryllium complexes were studied using ultraviolet-visible absorption and photoluminescence emission spectroscopy. The complexes showed absorption peaks due to π-π∗ and n-π∗ electronic transitions. The complexes emitted greenish blue light with peak wavelength at 496 nm, 510 nm, 490 nm, and 505 nm, respectively, consisting of high intensity. Color tuning was observed with changing the substituents in quinoline ring ligand in metal complexes. The emitted light had Commission Internationale d’Eclairage color coordinates values at x=0.15 and y=0.43 for [BeHPB(Clq], x=0.21 and y=0.56 for [BeHPB(Cl2q], x=0.14 and y=0.38 for [BeHPB(Meq], x=0.17 and y=0.41 for [BeHPB(q]. Theoretical calculations using DFT/B3LYP/6-31G(d,p method were performed to reveal the three-dimensional geometries and the frontier molecular orbital energy levels of these synthesized metal complexes.

  9. Expanding the family of uranium(III) alkyls. Synthesis and characterization of mixed-ligand derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Matson, Ellen M.; Kiernicki, John J.; Fanwick, Phillip E.; Bart, Suzanne C. [Department of Chemistry, Purdue University, West Lafayette, IN (United States)

    2016-06-15

    The generation of uranium(III) alkyls supported by hydrotris(pyrazolyl)borate (Tp) and pentamethylcyclopentadienyl (Cp*) ligands is reported. Mixed ancillary ligand frameworks were synthesized by treating TpUI{sub 2}(THF){sub 3} (1) and Cp*UI{sub 2}(THF){sub 3} with potassium hydrotris(pyrazolyl)borate salts. Addition of one equivalent of potassium hydrotris(3,5-dimethylpyrazolyl)borate (Tp*) generated TpTp*UI (2), while treatment of Cp*UI{sub 2}(THF){sub 3} with either KTp or KTp* resulted in the respective formation of Cp*TpUI(THF) (3) or Cp*Tp*UI(THF) (4). Alkylation of 2 with KCH{sub 2}Ph or NaCH{sub 2}SiMe{sub 3} furnished TpTp*UCH{sub 2}Ph (2-CH{sub 2}Ph) or TpTp*UCH{sub 2}SiMe{sub 3} (2-CH{sub 2}SiMe{sub 3}). Similarly, treatment of 3 with NaCH{sub 2}SiMe{sub 3} formed Cp*TpUCH{sub 2}SiMe{sub 3} (3-CH{sub 2}SiMe{sub 3}), whereas treatment of 4 with KCH{sub 2}Ph generated Cp*Tp*UCH{sub 2}Ph (4-CH{sub 2}Ph). All compounds were characterized by multinuclear NMR, IR, and electronic absorption spectroscopy. Compounds 2-CH{sub 2}Ph, 3, and 3-CH{sub 2}SiMe{sub 3} were structurally characterized using X-ray crystallography as well. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Novel mixed ligand technetium complexes as 5-HT1A receptor imaging agents

    International Nuclear Information System (INIS)

    Leon, A.; Rey, A.; Mallo, L.; Pirmettis, I.; Papadopoulos, M.; Leon, E.; Pagano, M.; Manta, E.; Incerti, M.; Raptopoulou, C.; Terzis, A.; Chiotellis, E.

    2002-01-01

    The synthesis, characterization and biological evaluation of two novel 3 + 1 mixed ligand 99m Tc-complexes, bearing the 1-(2-methoxyphenylpiperazine) moiety, a fragment of the true 5-HT 1A antagonist WAY 100635, is reported. Complexes at tracer level 99m TcO[(CH 3 CH 2 ) 2 NCH 2 CH 2 N(CH 2 CH 2 S) 2 ][o-CH 3 OC 6 H 4 N(CH 2 CH 2 ) 2 NCH 2 CH 2 S], 99m Tc-1, and 99m TcO[((CH 3 ) 2 CH) 2 NCH 2 CH 2 N(CH 2 CH 2 S) 2 ][o-CH 3 OC 6 H 4 N (CH 2 CH 2 ) 2 NCH 2 CH 2 S], 99m Tc-2, were prepared using 99m Tc-glucoheptonate as precursor. For structural characterization, the analogous oxorhenium complexes, Re-1 and Re-2, were prepared by ligand exchange reaction using ReOCl 3 (PPh 3 ) 2 as precursor, and characterized by elemental analysis and spectroscopic methods. Complex Re-1 was further characterized by crystallographic analysis. Labeling was performed with high yield (>85%) and radiochemical purity (>90%) using very low ligand concentration. The structure of 99m Tc complexes was established by comparative HPLC using the well-characterized oxorhenium analogues as references. In vitro binding assays demonstrated the affinity of these complexes for 5-HT 1A receptors (IC 50 : 67 and 45 nM for Re-1 and Re-2 respectively). Biological studies in mice showed the ability of 99m Tc-1 and 99m Tc-2 complexes to cross the intact blood-brain barrier (1.4 and 0.9% dose/g, respectively at 1 min post-inj.). The distribution of these complexes in various regions in rat brain is inhomogeneous. The highest ratio between areas reach and poor in 5-HT 1A receptors was calculated for complex Tc-1 at 60 min p.i. (hippocampus/cerebellum = 1.7).

  11. Novel mixed ligand technetium complexes as 5-HT1A receptor imaging agents.

    Science.gov (United States)

    León, A; Rey, A; Mallo, L; Pirmettis, I; Papadopoulos, M; León, E; Pagano, M; Manta, E; Incerti, M; Raptopoulou, C; Terzis, A; Chiotellis, E

    2002-02-01

    The synthesis, characterization and biological evaluation of two novel 3 + 1 mixed ligand 99mTc-complexes, bearing the 1-(2-methoxyphenylpiperazine) moiety, a fragment of the true 5-HT1A antagonist WAY 100635, is reported. Complexes at tracer level 99mTcO[(CH3CH2)2NCH2CH2N(CH2CH2S)2][o-CH3OC6H4N(CH2CH2)2NCH2CH2S], 99mTc-1, and 99mTcO[((CH3)2CH)2NCH2CH2N(CH2CH2S)2][o-CH3OC6H4N (CH2CH2)2NCH2CH2S], 99mTc-2, were prepared using 99mTc-glucoheptonate as precursor. For structural characterization, the analogous oxorhenium complexes, Re-1 and Re-2, were prepared by ligand exchange reaction using ReOCl3(PPh3)2 as precursor, and characterized by elemental analysis and spectroscopic methods. Complex Re-1 was further characterized by crystallographic analysis. Labeling was performed with high yield (>85%) and radiochemical purity (>90%) using very low ligand concentration. The structure of 99mTc complexes was established by comparative HPLC using the well-characterized oxorhenium analogues as references. In vitro binding assays demonstrated the affinity of these complexes for 5-HT1A receptors (IC50 : 67 and 45 nM for Re-1 and Re-2 respectively). Biological studies in mice showed the ability of 99mTc-1 and 99mTc-2 complexes to cross the intact blood-brain barrier (1.4 and 0.9% dose/g, respectively at 1 min post-inj.). The distribution of these complexes in various regions in rat brain is inhomogeneous. The highest ratio between areas reach and poor in 5-HT1A receptors was calculated for complex Tc-1 at 60 min p.i. (hippocampus/cerebellum = 1.7).

  12. Novel mixed ligand technetium complexes as 5-HT{sub 1A} receptor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Leon, A.; Rey, A. E-mail: arey@bilbo.edu.uy; Mallo, L.; Pirmettis, I.; Papadopoulos, M.; Leon, E.; Pagano, M.; Manta, E.; Incerti, M.; Raptopoulou, C.; Terzis, A.; Chiotellis, E

    2002-02-01

    The synthesis, characterization and biological evaluation of two novel 3 + 1 mixed ligand {sup 99m}Tc-complexes, bearing the 1-(2-methoxyphenylpiperazine) moiety, a fragment of the true 5-HT{sub 1A} antagonist WAY 100635, is reported. Complexes at tracer level {sup 99m}TcO[(CH{sub 3}CH{sub 2}){sub 2}NCH{sub 2}CH{sub 2}N(CH{sub 2}CH{sub 2}S){sub 2}][o-CH{sub 3}OC{sub 6}H{sub 4}N(CH{sub 2}CH{sub 2}){sub 2}NCH{sub 2}= CH{sub 2}S], {sup 99m}Tc-1, and {sup 99m}TcO[((CH{sub 3}){sub 2}CH){sub 2}NCH{sub 2}CH{sub 2}N(CH{sub 2}CH{sub 2}S){sub 2}][o-CH{sub 3}OC{sub 6}H{sub 4}N (CH{sub 2}CH{sub 2}){sub 2}NCH{sub 2}CH{sub 2}S], {sup 99m}Tc-2, were prepared using {sup 99m}Tc-glucoheptonate as precursor. For structural characterization, the analogous oxorhenium complexes, Re-1 and Re-2, were prepared by ligand exchange reaction using ReOCl{sub 3}(PPh{sub 3}){sub 2} as precursor, and characterized by elemental analysis and spectroscopic methods. Complex Re-1 was further characterized by crystallographic analysis. Labeling was performed with high yield (>85%) and radiochemical purity (>90%) using very low ligand concentration. The structure of {sup 99m}Tc complexes was established by comparative HPLC using the well-characterized oxorhenium analogues as references. In vitro binding assays demonstrated the affinity of these complexes for 5-HT{sub 1A} receptors (IC{sub 50} : 67 and 45 nM for Re-1 and Re-2 respectively). Biological studies in mice showed the ability of {sup 99m}Tc-1 and {sup 99m}Tc-2 complexes to cross the intact blood-brain barrier (1.4 and 0.9% dose/g, respectively at 1 min post-inj.). The distribution of these complexes in various regions in rat brain is inhomogeneous. The highest ratio between areas reach and poor in 5-HT{sub 1A} receptors was calculated for complex Tc-1 at 60 min p.i. (hippocampus/cerebellum = 1.7)

  13. Synthesis and properties of mixed-ligand ruthenium(II) complexes containing 2-(2-pyridyl)-benzimidazole and related ligands

    Energy Technology Data Exchange (ETDEWEB)

    Haga, M [Mie Univ., Tsu (Japan); Tanaka, T

    1979-07-01

    Mixed-ligand ruthenium(II) complexes of the (Ru(bpy)/sub 2/L)sup(n+) (ClO/sub 4/)sub(n) type, where bpy= 2,2'-bipyridine; L= 2-(2-pyridyl)-benzimidazole (PBImH) when n= 2, and L= 2-(2-pyridyl)-benzimidazolate (PBIm) and 2-(o-hydroxyphenyl)-benzimidazole (OBImH) when n= 1, were prepared. Anodic peak potentials and ruthenium-to-bipyridine charge transfer bands of these complexes are rationalized in terms of the donor ability of L.

  14. Synthesis and properties of mixed-ligand ruthenium(II) complexes containing 2-(2-pyridyl)-benzimidazole and related ligands

    International Nuclear Information System (INIS)

    Haga, Masaaki; Tanaka, Toshio.

    1979-01-01

    Mixed-ligand ruthenium(II) complexes of the [Ru(bpy) 2 L]sup(n+) (ClO 4 )sub(n) type, where bpy= 2,2'-bipyridine; L= 2-(2-pyridyl)-benzimidazole (PBImH) when n= 2, and L= 2-(2-pyridyl)-benzimidazolate (PBIm) and 2-(o-hydroxyphenyl)-benzimidazole (OBImH) when n= 1, were prepared. Anodic peak potentials and ruthenium-to-bipyridine charge transfer bands of these complexes are rationalized in terms of the donor ability of L. (author)

  15. X-ray absorption near edge structure (XANES) study of some hydroxamic mixed ligand copper complexes

    International Nuclear Information System (INIS)

    Mishra, A; Parsai, N; Shrivastava, B D; Soni, N

    2012-01-01

    With the advent of modern bright synchrotron radiation sources, X-ray absorption spectra has emerged as a powerful technique for local structure determination, which can be applied to any type of material. The X-ray absorption measurements of four hydroxamic mixed ligand copper complexes have been performed at the recently developed BL-8 Dispersive EXAFS beamline at 2.5 GeV Indus-2 synchrotron at RRCAT, Indore, India. The X-ray absorption near edge structure (XANES) data obtained has been processed using data analysis program Athena. The energies of the K absorption edge, chemical shifts, edge-widths, shifts of the principal absorption maximum in the complexes have been determined. The values of the chemical shift suggest that copper is in oxidation state +2 in all of the complexes. The chemical shift data has been utilized to estimate effective nuclear charge on copper atom. The order of the chemical shifts has been correlated to the relative ionic character of the bonding in these complexes.

  16. Thermodynamics of mixed-ligand complex formation of zinc nitrilotriacetate with amino acids and dipeptides in solution

    International Nuclear Information System (INIS)

    Pyreu, Dmitrii; Gruzdev, Matvey; Kumeev, Roman; Gridchin, Sergei

    2014-01-01

    Highlights: • Stable mixed ligand complexes of ZnNta with amino acids and dipeptides. • Histamine-like coordination mode of His in the complex ZnNtaHis. • Glycine-like coordination of Lys and Orn in the complexes ZnNtaL and ZnNtaHL • NH 2 , CO-coordination mode of GlyGly in the complex ZnNtaGG. • NH 2 , N − or NH2, N − , COO-coordination modes of GlyGly in the complex ZnNtaGGH −1 . - Abstract: The isothermal calorimetry, pH-potentiometric titration and 1 H and 13 C NMR methods has been used to study the mixed-ligand complex formation in the systems Zn 2+ –Nta 3– –L − (L = His, Orn, Lys, GlyGly, AlaAla) in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO 3 ). The thermodynamic parameters of formation of the mixed complexes have been determined. The relationship between the probable coordination modes of the complexone and amino acid or dipeptide molecules in the mixed-ligand complex and the thermodynamic parameters has been discussed

  17. Thermodynamics of mixed-ligand complex formation of zinc nitrilotriacetate with amino acids and dipeptides in solution

    Energy Technology Data Exchange (ETDEWEB)

    Pyreu, Dmitrii, E-mail: pyreu@mail.ru [Department of Inorganic and Analytic Chemistry, Ivanovo State UniversityErmak 39, Ivanovo 153025 (Russian Federation); Gruzdev, Matvey; Kumeev, Roman [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Gridchin, Sergei [Ivanovo State University of Chemistry and Technology, Ivanovo (Russian Federation)

    2014-10-20

    Highlights: • Stable mixed ligand complexes of ZnNta with amino acids and dipeptides. • Histamine-like coordination mode of His in the complex ZnNtaHis. • Glycine-like coordination of Lys and Orn in the complexes ZnNtaL and ZnNtaHL • NH{sub 2}, CO-coordination mode of GlyGly in the complex ZnNtaGG. • NH{sub 2}, N{sup −} or NH2, N{sup −}, COO-coordination modes of GlyGly in the complex ZnNtaGGH{sub −1}. - Abstract: The isothermal calorimetry, pH-potentiometric titration and {sup 1}H and {sup 13}C NMR methods has been used to study the mixed-ligand complex formation in the systems Zn{sup 2+}–Nta{sup 3–}–L{sup −} (L = His, Orn, Lys, GlyGly, AlaAla) in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO{sub 3}). The thermodynamic parameters of formation of the mixed complexes have been determined. The relationship between the probable coordination modes of the complexone and amino acid or dipeptide molecules in the mixed-ligand complex and the thermodynamic parameters has been discussed.

  18. Oxotechnetium and Oxorhenium 3+1 mixed ligand complexes as potential melanoma targeting gents

    International Nuclear Information System (INIS)

    Rey, A.; Giglio, J.; Leon, E.; Paolino, A.; Fernandez, R.; Manta, E.; Leon, A.; Pirmettis, I.; Papadopoulos, M.; Schreiber, F.; Chabalgoity, J.

    2005-01-01

    Tc-99m '3+1' mixed ligand complexes with potential affinity for melanoma have been designed by an integrated approach using N-alkyl substituted benzamides as leader structure. This paper presents the preparation of a series of complexes with general formula Tc-99m O[(CH 3 CH 2 ) 2 N(CH 2 ) 2 N (CH 2 CH 2 ) 2 S) 2 ][RS] and their 'in vivo' evaluation as potential melanoma targeting agents. Tc-99m complexes Tc1, Tc2, Tc3 and Tc4 were prepared by combining the tridentate ligand N,N-bis(2-mercaptoethyl)-N',N'-diethylethylenediamine with 4 different modentate thiols. Labelling was performed by substitution using Tc-99m-glucoheptonate as precursor. All complexes were obtained with high yield ( 85%) and high radiochemical purity (90%). Identity of Tc compounds was corroborated by HPLC coinjection with the analogous rhenium complexes. Biodistribution studies were performed on the murine C57B16 mouse melanoma model obtained by subcutaneous inoculation of melanoma cells B16F1. After intravenous injection, all complexes showed high initial blood, lung and liver uptake but clearance after 12-24 hours was almost complete. Initial tumour uptake was relatively high (0.83.4% dose/g at 2 hrs. post-injection) and retention until 24 hours significant (0.450.88% dose/g). Tumour/blood and tumour/muscle ratios were favourable from 6 to 24 hours after injection due to fast blood and soft tissue clearance. Complex Tc2 showed the best tumour/blood and tumour/muscle ratios at 12 and 24 hours post-injection (1.9-2.4 and 7.5-12.0, respectively). Early and late static gamma-camera images acquired for this compound allowed delineation of the tumour with tumour/soft tissue ratios 7.4 at 12 hours. post/inj.) Complex Tc2 was also administered subcutaneously in the peritumoral region of melanoma bearing mice, in order to avoid high liver and hepatobiliary doses. In this condition, a very high percentage of the injected dose remained in the tumour, even after 24 hours (21.5%/g) with considerably

  19. Physico-chemical characterization of mixed-ligand complexes of Mn(III based on the acetylacetonate and maleic acid and its hydroxylamine derivative

    Directory of Open Access Journals (Sweden)

    Cakić Suzana M.

    2005-01-01

    Full Text Available Two new Mn(III mixed-ligand complexes with two acetylacetonate (acac ligands and one maleate ligand and its hydroxylamine derivative of the general formula [Mn(C5H7O22L] were prepared. Their structure was established by using elemental analysis, FTIR and UV/VIS spectroscopic methods, as well as magnetic measurement. Replacement of the acetylacetonate ligand by the corresponding acid ligand has been confirmed in Mn(III acetylacetonate. Based on the obtained experimental data and literature indications, structural formulae to these compounds were assigned.

  20. Conformational isomerism in mixed-ligand complexes of 2,2'-bipyridine and triphenylphosphine with copper(I) halides

    International Nuclear Information System (INIS)

    Barron, P.F.; Engelhardt, L.M.; Healy, P.C.; Kildea, J.D.; White, A.H.

    1988-01-01

    Mixed-ligand complexes of triphenylphosphine and 2,2'-bipyridine and copper(I) halides have been synthesized. The 31 P NMR spectra of the complexes were measured and are reported along with data for complete structural characterization of the complexes. The results indicate a novel dichotomy of conformational isomers to be present in the chloride lattice. The Cu-P bond length was found to not vary with different halides. 8 refs., 4 figs., 6 tabs

  1. Synthesis and characterization of mixed ligand Cu(II) complexes of salicylic acid derivatives with 2-aminobenzotiyazol derivatives

    OpenAIRE

    İlkimen, Halil; Yenikaya, Cengiz

    2018-01-01

    In thisstudy, mixed ligand transitionmetal complexes of Cu(II)have been prepared between salicylic acid derivatives [salicylic acid (H2sal) or acetylsalicylic acid (Hasal)] and 2-aminobenzothiazole derivatives[2-aminobenzothiazole (abt) or 2-amino-6-chlorobenzothiazole (Clabt) or2-amino-6-methylbenzothiazole (Meabt)]. The structures of amorphous metalcomplexes have been proposed by evaluating the data obtained from elementalanalysis, ICP-OES, FT-IR, UV-Vis, thermal analysis, magnetic suscepti...

  2. Formation constants of lanthanide(III)- aminopolycarboxylate- ATP mixed ligand complexes and their systematics

    International Nuclear Information System (INIS)

    Verma, Sangeeta; Limaye, S.N.; Saxena, M.C.

    1993-01-01

    Formation constants (log Ksub(MAL)sup(MA), log Ksub(ML)sup(M) and log Ksub(ML)sup(ML) of mixed ligand lanthanide(III) complexes of the type [Ln(III).A.ATP[ 2 , where LN(III)=La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Tb 3+ or Dy 3+ ' A=NTA(nitrilotriacetate) or HEDTA (2-hydroxyethylethylenediamine triacetate) and ATP=adenosine 5'-triphosphate (L), and of the binary [Ln(III).ATP[ and [Ln(III).(ATP) 2 [ complexes have been determined by potentiometric pH titrations using the Irving-Rossotti approach at three temperatures 20, 30 and 40 degC and at a fixed ionic strength, I=0.2 mol dm -3 (NAclO 4 ). The solution stabilities (log Ksub(MAL)sup(MA) values) are influenced by the electrostatic effect involved in ternary complexation and increase with temperature. The enthalpy factor (ΔH) has been found to be small but unfavourable and the entropy factor (ΔS) large and favourable. The log Ksub(MAL)sup(MA) values lie in the order NTA>HEDTA with respect to A and La 3+ 3+ 3+ 3+ 3+ 3+ >Gd 3+ 3+ 3+ with respect to lanthanides. Tetrad effect is present in the formation constant values; its magnitude has been found to lie in the sequence f 7 >f 3 -f 4 ≅ f 10 -f 11 for the Ln(III) ions. Systematics in the formation constant values has been further studied by evaluating changes in the inter-electronic repulsion Racah parameters, extra stabilisation of specific 4f 9 -configurations and nephelauxetic ratio using experimental values of the formation constants. (author). 24 refs., 2 figs., 3 tabs

  3. Formation of Mixed-Ligand Complexes of Metals(II) with Monoamine Complexones and Amino Acids in Solution

    Science.gov (United States)

    Pyreu, D. F.; Gridchin, S. N.

    2018-05-01

    The formation of mixed-ligand complexes in the M(II)-Nta, Ida-L (M = Cu(II), Ni, Zn, Co(II), L = Ser, Thr, Asp, Arg, Asn) systems, where Ida and Nta are the residues of iminodiacetic and nitrilotriacetic acids, respectively, is studied using pH measurements, calorimetry and spectrophotometry. The thermodynamic parameters (log K, Δr G 0, Δr H, Δr S) of their formation at 298.15 K and ionic strength I = 0.5 (KNO3) are determined. The most likely scenario of amino acid residue coordination in the composition of mixed complexes is discussed.

  4. Synthesis characterization and biological evaluation of a novel mixed ligand 99mTc complex as potential brain imaging agent

    International Nuclear Information System (INIS)

    Rey, A.; Manta, E.; Leon, A.; Papadopoulos, M.; Pirmettis, Y.; Raptopoulou, C.; Chiotellis, E.; Leon, E.; Mallo, L.

    1998-01-01

    One approach in the design of neutral oxotechnetium complexes is based on the simultaneous substitution of a tridentate dianionic ligand and a monodentate monoanionic coligand on a [Tc(V)O] +3 precursor. Following this ''mixed ligand'' concept, a novel 99m Tc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethylethylenediamine as ligand and 1-octanethiol as coligand is prepared and evaluated as potential brain radiopharmaceutical. Preparation of the complex at tracer level was accomplished by using 99m Tc-glucoheptonate as precursor. The substitution was optimized and a coligand/ligand ratio of 5 was selected. Under this conditions the labeling yield was over 80% and a major product (with radiochemical purity > 80%) was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium complex as structural model. The Re complex was also prepared by substitution method and isolated as a crystalline product. The crystals were characterized by UV-vis and IR spectra and elemental analysis. Results were consistent with the expected ReOLC structure. X ray crystallographic study demonstrated that the complex adopts a distorted trigonal bipyramidal geometry. The basal plane is defined by the SS atoms of the ligand and the oxo group, while the N of the ligand and the S of the colligand occupy the two apical positions. All sulphur atoms underwent ionization leading to the formation of a neutral compound. 99 Tc complex was also prepared. Although it was not isolated due to the small amount of reagents employed, the HPLC profile was identical to the one observed for the rhenium complex suggesting the same chemical structure. Biodistribution in mice demonstrated early brain uptake, fast blood clearance, excretion through hepatobiliary system and a brain/blood ratio that increased significantly with time. (author)

  5. Synthesis and evaluation of ligands with mixed amide and phosphonate, phosphinoxide, and phosphonothioate sites for An(III)/Ln(III) extraction

    NARCIS (Netherlands)

    Iqbal, M.; Struijk, R.G.; Huskens, Jurriaan; Sypula, M.; Wilden, A.; Modolo, G.; Verboom, Willem

    2012-01-01

    Various organophosphorus ligands with a combination of different donor sites were synthesized and evaluated by solvent extraction studies for the complexation of Am(III)/Eu(III). Among the ligands with a glycolamide backbone, those with mixed amide and PO donor sites and a central oxygen or nitrogen

  6. Studies on the mixed ligand complexes of copper(II involving a sulfa drug and some potentially bi or tridentate ligands under physiological conditions

    Directory of Open Access Journals (Sweden)

    S. Regupathy

    2014-12-01

    Full Text Available The stability constants of mixed ligand complexes formed in the Cu(II-sulfathiazole(stz(A-glycine(gly, dl-2-aminobutanoic acid(2aba, dl-3-aminobutanoic acid(3aba, 1,2-diaminopropane(dp, 1,3-diaminopropane(tp, dl-2,3-diaminopropanoic acid(dapa, dl-2,4-diaminobutanoic acid(daba, dl-2,5-diaminopentanoic acid(ornithine, orn(B systems have been determined pH-metrically at 37 °C and I = 0.15 mol dm−3 (NaClO4 using SCOGS program. Analysis of experimental data indicates the presence of CuABH, CuAB, CuAB2H2 or CuAB2 species. The Δlog K values demonstrate higher stabilities for the mixed ligand complexes compared to the binary analogues. The CuAB complexes with B = gly, 2aba, dapa & orn systems were isolated and characterized using micro analytical, magnetic moment, ESR, electrochemical studies, TG/DTA, power XRD and SEM analysis. Magnetic susceptibility and electronic spectral studies suggest square planar geometry for the CuAB complexes. The g values indicate that the unpaired electron lies in thedx2-y2 orbital. The TG/DTA studies reveal that the complexes are non hydrated and possesses high thermal stability. The powder XRD data suggest that the complex is microcrystalline. The antimicrobial activity and CT DNA cleavage studies of the complexes are also reported.

  7. Synthesis, Characterization, and Antibacterial Studies of Mixed Ligand Dioxouranium Complexes with 8-Hydroxyquinoline and Some Amino Acids

    Science.gov (United States)

    Patil, Sunil S.; Thakur, Ganesh A.; Shaikh, Manzoor M.

    2011-01-01

    Mixed ligand complexes of dioxouranium (VI) of the type [UO2(Q)(L)·2H2O] have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and amino acids (HL) such as L-threonine, L-tryptophan, and L-isoleucine as secondary ligands. The metal complexes have been characterized by elemental analysis, electrical conductance, magnetic susceptibility measurements, and spectral and thermal studies. The electrical conductance studies of the complexes indicate their nonelectrolytic nature. Magnetic susceptibility measurements revealed diamagnetic nature of the complexes. Electronic absorption spectra of the complexes show intraligand and charge transfer transitions, respectively. Bonding of the metal ion through N- and O-donor atoms of the ligands is revealed by IR studies, and the chemical environment of the protons is confirmed by NMR studies. The thermal analysis data of the complexes indicate the presence of coordinated water molecules. The agar cup and tube dilution methods have been used to study the antibacterial activity of the complexes against the pathogenic bacteria S. aureus, C. diphtheriae, S. typhi, and E. coli. PMID:22389843

  8. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R.; Garcia-Lopez, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I., E-mail: isaac.rodriguez@usc.es [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2010-07-12

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL{sup -1} and linear responses for concentrations up to 2.5 {mu}g mL{sup -1}, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL{sup -1}. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  9. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    International Nuclear Information System (INIS)

    Montes, R.; Garcia-Lopez, M.; Rodriguez, I.; Cela, R.

    2010-01-01

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL -1 and linear responses for concentrations up to 2.5 μg mL -1 , referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL -1 . Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  10. A Mixed-Ligand Chiral Rhodium(II) Catalyst Enables the Enantioselective Total Synthesis of Piperarborenine B.

    Science.gov (United States)

    Panish, Robert A; Chintala, Srinivasa R; Fox, Joseph M

    2016-04-11

    A novel, mixed-ligand chiral rhodium(II) catalyst, Rh2(S-NTTL)3(dCPA), has enabled the first enantioselective total synthesis of the natural product piperarborenine B. A crystal structure of Rh2(S-NTTL)3(dCPA) reveals a "chiral crown" conformation with a bulky dicyclohexylphenyl acetate ligand and three N-naphthalimido groups oriented on the same face of the catalyst. The natural product was prepared on large scale using rhodium-catalyzed bicyclobutanation/ copper-catalyzed homoconjugate addition chemistry in the key step. The route proceeds in ten steps with an 8% overall yield and 92% ee. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Crystal structures and luminescence of two cadmium-carboxylate cluster-based compounds with mixed ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hui-Fang; Lei, Qian; Wang, Yu-Ling; Yin, Shun-Gao; Liu, Qing-Yan [College of Chemistry and Chemical Engineering and Key Lab. of Functional Small Organic Molecule of Ministry of Education, Jiangxi Normal Univ., Nanchang (China)

    2017-04-04

    Reactions of Cd(NO{sub 3}){sub 2}.4H{sub 2}O with 2-quinolinecarboxylic acid (H-QLC) in the presence of 1,4-benzenedicarboxylic acid (H{sub 2}-BDC) or 1,3,5-benzenetricarboxylic acid (H-BTC) in DMF/H{sub 2}O solvent afforded two compounds, namely, [Cd(QLC)(BDC){sub 1/2}(H{sub 2}O)]{sub n} (1) and [Cd(QLC)(BTC){sub 1/3}]{sub n} (2). Both compounds are two-dimensional (2D) frameworks but feature different cadmium-carboxylate clusters as a result of the presence of the polycarboxylate ligands with different geometries and coordination preference. The dinuclear Cd{sub 2}(QLC){sub 2} units in 1 are bridged by the pairs of bridging water ligands to give a one-dimensional (1D) chain, which is further linked by the second ligand of BDC{sup 2-} to form a 2D structure. Compound 2 is constructed from unique hexanuclear macrometallacyclic Cd{sub 6}(QLC){sub 6} clusters, which are linked by the surrounding BTC{sup 3-} ligands to generate a 2D structure. Photoluminescence studies showed both compounds exhibit ligand-centered luminescent emissions with emission maxima at 405 and 401 nm, respectively. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Mix-and-match: ligand-receptor pairs in stomatal development and beyond.

    Science.gov (United States)

    Torii, Keiko U

    2012-12-01

    Stomata are small valves on the plant epidermis balancing gas exchange and water loss. Stomata are formed according to positional cues. In Arabidopsis, two EPIDERMAL PATTERNING FACTOR (EPF) peptides, EPF1 and EPF2, are secreted from stomatal precursors enforcing proper stomatal patterning. Here, I review recent studies revealing the ligand-receptor pairs and revising the previously predicted relations between receptors specifying stomatal patterning: ERECTA-family and TOO MANY MOUTHS (TMM). Furthermore, EPF-LIKE9 (EPFL9/Stomagen) promotes stomatal differentiation from internal tissues. Two EPFL peptides specify inflorescence architecture, a process beyond stomatal development, as ligands for ERECTA. Thus, broadly expressed receptor kinases may regulate multiple developmental processes through perceiving different peptide ligands, each with a specialized expression pattern. TMM in the epidermis may fine-tune multiple EPF/EPFL signals to prevent signal interference. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Blood Mixing Upregulates Platelet Membrane-Bound CD40 Ligand Expression in vitro Independent of Abo Compatibility.

    Science.gov (United States)

    Huang, Go-Shine; Hu, Mei-Hua; Lin, Tso-Chou; Lin, Yi-Chang; Tsai, Yi-Ting; Lin, Chih-Yuan; Ke, Hung-Yen; Zheng, Xu-Zhi; Tsai, Chien-Sung

    2017-11-30

    Platelets play a central role in the inflammation response via CD40 ligand (CD40L) expression, which may lead to transfusion reactions. The precise role of platelet CD40L-mediated inflammation in transfusion reactions is unclear. Therefore, we assessed the effects of in vitro blood mixing on platelet CD40L expression. In addition, we examined the effect of ABO compatibility on CD40L expression. Donor packed red blood cells were acquired from a blood bank, and recipient blood was obtained from patients undergoing cardiac surgery and prepared as washed platelets. Donor blood was mixed with suspended, washed recipient platelets to obtain a final mixing ratio of 1%, 5%, or 10% (vol/vol). The blood mixtures were divided into three groups: Group M, cross-matched blood-type mixing (n = 20); Group S, ABO type-specific uncross-matched blood (n = 20); and Group I, ABO incompatibility (not ABO type-specific blood and not process cross-matched) mixing (n = 20). The blood mixtures were used to detect platelet membrane-bound CD40L expression by flow cytometry. Blood mixing resulted in an increase in CD40L expression in Group M (P role in the induction of CD40L expression.

  14. A theoretical investigation on the neutral Cu(I) phosphorescent complexes with azole-based and phosphine mixed ligand

    Science.gov (United States)

    Ding, Xiao-Li; Shen, Lu; Zou, Lu-Yi; Ma, Ming-Shuo; Ren, Ai-Min

    2018-04-01

    A theoretical study on a series of neutral heteroleptic Cu(I) complexes with different azole-pyridine-based N^N ligands has been presented to get insight into the effect of various nitrogen atoms in the azole ring on photophysical properties. The results reveal that the highest occupied molecular orbital (HOMO) levels and the emission wavelengths of these complexes are mainly governed by the nitrogen atom number in azole ring. With the increasing number of nitrogen atom , the electron density distribution of HOMO gradually extend from the N^N ligand to the whole molecule, meanwhile, the improved contribution from Cu(d) orbits in HOMO results in an effective mixing of various charge transfermodes, and hence, the fast radiative decay(kr) and the slow non-radiative decay rate(knr) are achieved. The photoluminescence quantum yield (PLQY) show an apparent dependence on the nitrogen atom number in the five-membered nitrogen heterocycles. However, the increasing number of nitrogen atoms is not necessary for increasing PLQY. The complex 3 with 1,2,4-triazole-pyridine-based N^N ligands is considered to be a potential emitter with high phosphorescence efficiency. Finally, we hope that our investigations will contribute to systematical understanding and guiding for material molecular engineering.

  15. Four Mixed-Ligand Zn(II Three-Dimensional Metal-Organic Frameworks: Synthesis, Structural Diversity, and Photoluminescent Property

    Directory of Open Access Journals (Sweden)

    Chih-Chieh Wang

    2017-11-01

    Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.

  16. DNA binding and biological activity of mixed ligand complexes of Cu(II, Ni(II and Co(II with quinolones and N donor ligand

    Directory of Open Access Journals (Sweden)

    S.M M Akram

    2015-10-01

    Full Text Available  AbstractMixed ligand complexes of  Cu(II, Ni(II and Co(II have been synthesized by using levofloxacin and bipyridyl and characterized using spectral and analytical techniques. The binding behavior of the Ni(II and Cu(II complexes with herring sperm DNA(Hs-DNA were determined using electronic absorption titration, viscometric measurements and cyclic voltammetry measurements. The binding constant calculated  for Cu(II and Ni(II complexes are 2.0 x 104 and 4.0 x 104 M-1 respectively. Detailed analysis reveals that these metal complexes interact with DNA through intercalative binding mode. The nuclease activity of  Cu(II and Ni(II complexes with ct-DNA was carried out using agarose gel electrophoresis technique. The antioxidant activities for the synthesized complexes have been tested and the antibacterial activity for Ni(II complex was also checked.Key words: Intercalation, hypochromism, red shift and  peak potential.

  17. Lanthanide mixed ligand chelates for DNA profiling and latent fingerprint detection

    Science.gov (United States)

    Menzel, E. R.; Allred, Clay

    1997-02-01

    It is our aim to develop a universally applicable latent fingerprint detection method using lanthanide (rare-earth) complexes as a source of luminescence. Use of these lanthanide complexes offers advantages on several fronts, including benefits from large Stokes shifts, long luminescence lifetimes, narrow emissions, ability of sequential assembly of complexes, and chemical variability of the ligands. Proper exploitation of these advantages would lead to a latent fingerprint detection method superior to any currently available. These same characteristics also lend themselves to many of the problems associated with DNA processing in the forensic science context.

  18. Theoretical and experimental evidence for a new kind of spin-coupled singlet species: Isomeric mixed-valent complexes bridged by a radical anion ligand

    Czech Academy of Sciences Publication Activity Database

    Sarkar, B.; Patra, S.; Fiedler, Jan; Sunoj, R. B.; Janardanan, D.; Mobin, S. M.; Niemeyer, M.; Lahiri, G. K.; Kaim, W.

    2005-01-01

    Roč. 44, č. 35 (2005), s. 5655-5658 ISSN 0044-8249 R&D Projects: GA AV ČR IAA400400505; GA ČR GA203/03/0821; GA MŠk LC510 Institutional research plan: CEZ:AV0Z40400503 Keywords : azobispyridine * bridging ligands * mixed-valed complexes * N-ligands Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Constructing two new crystalline metal–organic frameworks based on a mixed-donor ligand

    KAUST Repository

    Wang, Xiaofang; Xue, Ming; Wu, Gang; Pan, Ying; Qiu, Shilun

    2016-01-01

    © 2015 Elsevier B.V. All Rights Reserved. The self-assembly of a prominent ligand, 5-(4-(1H-tetrazolyl)phen)isophthalic acid (H3TZPI), with Zn2 +/Cu2 + centres generates two new MOFs, [Zn2(TZPI)(μ3-OH)(H2O)2]·2H2O (JUC-161) and [Cu(HTZPI)(μ2-H2O)0.5(H2O)1.5]·5(H2O) (JUC-162). JUC-161 exhibits fascinating three-dimensional structures containing rectangular channels with dimensions of 6.5 × 3.0 Å2, and JUC-162 displays 3D supramolecular structures with 12.5 × 14.6 Å2 hexagonal channels. The observed structural diversity in these frameworks is due to the two distinct coordinating moieties of the H3TZPI ligand. The photoluminescence of JUC-161 and the magnetic properties of JUC-162 are also measured at room temperature. Photoluminescence investigations reveal that JUC-161 displays a strong main emission spectrum peak at 388 nm. JUC-162 is found to exhibit an antiferromagnetic interaction between Cu2 + ions.

  20. Constructing two new crystalline metal–organic frameworks based on a mixed-donor ligand

    KAUST Repository

    Wang, Xiaofang

    2016-02-01

    © 2015 Elsevier B.V. All Rights Reserved. The self-assembly of a prominent ligand, 5-(4-(1H-tetrazolyl)phen)isophthalic acid (H3TZPI), with Zn2 +/Cu2 + centres generates two new MOFs, [Zn2(TZPI)(μ3-OH)(H2O)2]·2H2O (JUC-161) and [Cu(HTZPI)(μ2-H2O)0.5(H2O)1.5]·5(H2O) (JUC-162). JUC-161 exhibits fascinating three-dimensional structures containing rectangular channels with dimensions of 6.5 × 3.0 Å2, and JUC-162 displays 3D supramolecular structures with 12.5 × 14.6 Å2 hexagonal channels. The observed structural diversity in these frameworks is due to the two distinct coordinating moieties of the H3TZPI ligand. The photoluminescence of JUC-161 and the magnetic properties of JUC-162 are also measured at room temperature. Photoluminescence investigations reveal that JUC-161 displays a strong main emission spectrum peak at 388 nm. JUC-162 is found to exhibit an antiferromagnetic interaction between Cu2 + ions.

  1. Hydrothermal syntheses, crystal structures, and photophysical properties of two coordination polymers with mixed ligands

    Science.gov (United States)

    Yan, Li; Liu, Chun-Ling

    2017-10-01

    Two novel metal-organic coordination polymers [Cd(ipdt)(m-BDC)·3H2O]n (1) and [Pb(mip)2(NTC) ·2H2O]n (2) [ipdt = 2,6-Dimethoxy-4-(1H-1,3,7,8-tetraaza-cyclopenta[l]phenanthren-2-yl)-phenol, mip = 2-(3-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, m-BDC = isophthalic acid, NTC = nicotinic acid] have been synthesized by hydrothermal reactions and characterized by elemental analysis, thermogravimetric (TG) analysis, infrared spectrum (IR) and single-crystal X-ray diffraction. Single-crystal X-ray diffraction reveals that 1 exhibits two-dimensional (2D) layer architecture, and 2 shows 1D chain architecture. TG analysis shows clear courses of weight loss, which corresponds to the decomposition of different ligands. The luminescent properties for the ligand ipdt, mip and complexes 1-2 are also discussed in detail, which should be acted as potential luminescent material.

  2. Recoil implantation reactions in binary mixtures of catcher complexes and in mixed ligand catchers

    International Nuclear Information System (INIS)

    Sekine, Tsutomu; Sano, Masaaki; Yoshihara, Kenji

    1989-01-01

    Recoil implantation reactions were studied in binary mixtures of catcher complexes of tris(β-diketonato)metal(III) and in single-component catcher complexes of Cr(acac) n (dbm) 3-n where n=1 and 2. For the mixtures of M(acac) 3 and M(dbm) 3 , the products of 51 Cr(acac) 3 and 51 Cr(dbm) 3 were obtained as major components while 51 Cr(acac) 2 (dbm) and 51 Cr(acac)(dbm) 2 were seen as minor components. For the single component catcher complexes, predominant chemical species were parent retention type compounds. In addition to retentions there were product distributions which indicated a strong preference for acac pickup. The results were interpreted by a model which involves displacement reaction as a main process and ligand pickup reactions as side processes. (orig.)

  3. Volatile mixed-ligand lanthanum (3) complex with acetylacetone and 1,10-phenanthroline

    International Nuclear Information System (INIS)

    Kuz'mina, N.P.; Chuparov, N.V.; Pisarevskij, A.P.; Martynenko, L.I.

    1997-01-01

    La(Acac) 3 Phen complex is synthetized, its X-tray structure analysis is carried out. Crystals are monoclinic ones, sp.gr. P2 1 /n, a=17.11 (12), b=18.16 (3), c=17.86 (2) A, β=91.32 (2) deg, V=5548 (13) A 3 , Z=8. Structure contains two crystallographically non-equivalent types of molecules differing in interatomic distances and valent angles, as well as, in angles between ligand planes. Behaviour of La(Acac) 3 Phen at heating in vacuum (0.1-0.01 mm Hg) is studied. It is shown that under those conditions processes of Phen splitting, of sublimation and polymerization of La(Acac) 3 lanthanum acetylacetonate formed following Phen splitting and that under 220 deg C during 30 min quantitative transition of La(Acac) 3 Phen into gas phase is reached. 10 refs., 2 figs., 3 tabs

  4. Mixed ligand complexes of essential metal ions with L-glutamine and succinic acid in SLS-water mixtures

    Directory of Open Access Journals (Sweden)

    Bindu Hima Gandham

    2012-01-01

    Full Text Available Speciation of mixed ligand complexes of Co(II, Ni(II and Cu(II with L-glutamine and succinic acid was studied in varying amounts (0.0-2.5% w/v of sodium lauryl sulphate in aqueous solutions maintaining an ionic strength of 0.16 mol L-1 (NaCl at 303.0 K. Titrations were carried out in the presence of different relative concentrations (M : L : X = 1 : 2 : 2, 1 : 4 : 2, 1 : 2 : 4 of metal (M to L-glutamine (L to succinic acid (X with sodium hydroxide. Stability constants of ternary complexes were refined with MINIQUAD75. The best-fit chemical models were selected based on statistical parameters and residual analysis. The species detected were ML2X, MLX, MLXH and MLXH2 for Co(II, Ni(II and Cu(II. Extra stability of ternary complexes compared to their binary complexes was believed to be due to electrostatic interactions of the side chains of ligands, charge neutralization, chelate effect, stacking interactions and hydrogen bonding. The species distribution with pH at different compositions of SLS and plausible equilibria for the formation of species were also presented.

  5. Synthesis, structure, spectroscopy and redox energetics of a series of uranium(4) mixed-ligand metallocene complexes

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, R.K.; Scott, B.L.; Morris, D.E.; Kiplinger, J.L. [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2010-06-15

    A series of uranium(IV) mixed-ligand amide-halide/pseudo-halide complexes (C{sub 5}Me{sub 5}){sub 2}U[N(SiMe{sub 3}){sub 2}](X) (X = F (1), Cl (2), Br (3), I (4), N{sub 3} (5), NCO (6)), (C{sub 5}Me{sub 5}){sub 2}U(NPh{sub 2})(X) (X = Cl (7), N{sub 3} (8)), and (C{sub 5}Me{sub 5}){sub 2}U[N(Ph)(SiMe{sub 3})](X) (X Cl (9), N{sub 3} (10)) have been prepared by one electron oxidation of the corresponding uranium(III) amide precursors using either copper halides, silver iso-cyanate, or triphenylphosphine gold(I)azide. Agostic U---H-C interactions and {eta}{sub 3}-(N,C,C') coordination are observed for these complexes in both the solid-state and solution. There is a linear correlation between the chemical shift values of the C{sub 5}Me{sub 5} ligand protons in the {sup 1}H NMR spectra and the U(IV)/U(III) reduction potentials of the (C{sub 5}Me{sub 5}){sub 2}U[N(SiMe{sub 3}){sub 2}](X) complexes, suggesting that there is a common origin, that is overall {sigma}-/{pi}-donation from the ancillary (X) ligand to the metal, contributing to both observables. Optical spectroscopy of the series of complexes 1-6 is dominated by the (C{sub 5}Me{sub 5}){sub 2}U[N(SiMe{sub 3}){sub 2}] core, with small variations derived from the identity of the halide/pseudo-halide. The considerable {pi}-donating ability of the fluoride ligand is reflected in both the electrochemistry and UV-visible-NIR spectroscopic behavior of the fluoride complex (C{sub 5}Me{sub 5}){sub 2}U[N(SiMe{sub 3}){sub 2}](F) (1). The syntheses of the new trivalent uranium amide complex, (C{sub 5}Me{sub 5}){sub 2}U[N(Ph)(SiMe{sub 3})](THF), and the two new weakly-coordinating electrolytes, [Pr{sub 4}N][B{l_brace}3,5-(CF{sub 3}){sub 2}C{sub 6}H{sub 3{r_brace}4}] and [Pr{sub 4}N][B(C{sub 6}F{sub 5}){sub 4}], are also reported. (authors)

  6. A novel extended architecture with 4 6·6 4 topology based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units

    Science.gov (United States)

    Tong, Ruizhan; Ren, Xiaoyu; Li, Zuoxi; Liu, Bin; Hu, Huaiming; Xue, Ganglin; Fu, Feng; Wang, Jiwu

    2010-09-01

    A novel inorganic-organic hybrid compound based on mixed-valence Wells-Dawson arsenotungstate and mixed-ligand Cu(I) units, Cu 8I(imi) 4(bpy) 6(H 2O)[As 2VW 2VW 16VlO 62]·2H 2O ( 1) (bpy=4,4'-bipydine; imi=imidazole), has been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, luminescent spectrum and single crystal X-ray diffraction. Single-crystal X-ray diffraction revealed that four terminal and three bridging oxygen atoms of the Wells-Dawson cluster are coordinated to Cu(I) ions and form an unprecedented hepta-supporting polyoxometalate. The functionalized arsenotungstates are further connected by two kinds of tridentate linkers, Imi-Cu-(bpy)-Cu-(bpy)-Cu-(bpy)-Cu-Imi and Imi-Cu-(bpy)-Cu-(bpy)-Cu-H 2O, to construct a 3D framework with 4 6·6 4 topology. The hybrid material has an intense emission at about 397 nm.

  7. Synthesis, Characterization, Luminescence and Biological Activity of Two Lanthanide Complexes Involving Mixed Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Deyun; Guo, Haifu; Qin, Liang [Zhaoqing Univ., Zhaoqing (China); Xu, Jun [Jinan Univ., Guangzhou (China)

    2013-09-15

    Two new isostructural dinuclear complexes, Ln{sub 2}(4-cpa){sub 6}(bpy){sub 2} (Ln = Eu (1); Tb (2), 4-cpa = 4-chlorophenyl-acetate, bpy = 2,2'-bipyridine), have been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. The lanthanide ions are bridged by two bidentate and two terdentate carboxylate groups to give centrosymmetric dimers with Ln···Ln separations of 3.967(2) and 3.956(3) A, respectively. Each metal atom is nine-coordinate and exhibits a distorted tricapped trigonal prismatic geometry. Three-dimensional fluorescence spectra show that both 1 and 2 emit bright red and green luminescence at room temperature, with long lifetimes of up to 0.369 ms (at 614 nm) and 0.432 ms (at 543 nm), respectively. Moreover, poor luminescence efficiency has been noted for complex 2. The 4-Hcpa ligand and complexes 1-2 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-P-ethyl.

  8. Cyclic GMP-AMP Containing Mixed Phosphodiester Linkages Is An Endogenous High Affinity Ligand for STING

    Science.gov (United States)

    Zhang, Xu; Shi, Heping; Wu, Jiaxi; Zhang, Xuewu; Sun, Lijun; Chen, Chuo; Chen, Zhijian J.

    2013-01-01

    The presence of microbial or self DNA in the cytoplasm of mammalian cells is a danger signal detected by the DNA sensor cyclic-GMP-AMP (cGAMP) synthase (cGAS), which catalyzes the production of cGAMP that in turn serves as a second messenger to activate innate immune responses. Here we show that endogenous cGAMP in mammalian cells contains two distinct phosphodiester linkages, one between 2′-OH of GMP and 5′-phosphate of AMP, and the other between 3′-OH of AMP and 5′-phosphate of GMP. This molecule, termed 2′3′-cGAMP, is unique in that it binds to the adaptor protein STING with a much greater affinity than cGAMP molecules containing other combinations of phosphodiester linkages. The crystal structure of STING bound to 2′3′-cGAMP revealed the structural basis of this high-affinity binding and a ligand-induced conformational change in STING that may underlie its activation. PMID:23747010

  9. Co-precipitation of oppositely charged nanoparticles: the case of mixed ligand nanoparticles

    International Nuclear Information System (INIS)

    Moglianetti, Mauro; Ponomarev, Evgeniy; Szybowski, Maxime; Stellacci, Francesco; Reguera, Javier

    2015-01-01

    Colloid stability is of high importance in a multitude of fields ranging from food science to biotechnology. There is strong interest in studying the stability of small particles (of a size of a few nanometres) with complex surface structures, that make them resemble the complexity of proteins and other natural biomolecules, in the presence of oppositely charged nanoparticles. While for nanoparticles with homogeneously charged surfaces an abrupt precipitation has been observed at the neutrality of charges, data are missing about the stability of nanoparticles when they have more complex surface structures, like the presence of hydrophobic patches. To study the role of these hydrophobic patches in the stability of nanoparticles a series of negatively charged nanoparticles has been synthesized with different ratios of hydrophobic content and with control on the structural distribution of the hydrophobic moiety, and then titrated with positively charged nanoparticles. For nanoparticles with patchy nanodomains, the influence of hydrophobic content was observed together with the influence of the size of the nanoparticles. By contrast, for nanoparticles with a uniform distribution of hydrophobic ligands, size changes and hydrophobic content did not play any role in co-precipitation behaviour. A comparison of these two sets of nanoparticles suggests that nanodomains present at the surfaces of nanoparticles are playing an important role in stability against co-precipitation. (paper)

  10. Three new Ag(I) coordination architectures based on mixed ligands: Syntheses, structures and photoluminescent properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yamin, E-mail: liyamin@henu.edu.cn [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Xiao, Changyu; Li, Shu; Chen, Qi; Li, Beibei; Liao, Qian; Niu, Jingyang [Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004 (China)

    2013-04-15

    Three new silver (I) coordination complexes, [Ag{sub 2}(1,2-bdc)(phdat)]{sub n} (1), [Ag{sub 2}(NO{sub 2}-bdc)(phdat)]{sub n} (2), [Ag{sub 4}(nta){sub 3}(phdat)NO{sub 3}]{sub n} (3) (1,2-bdc=phthalic acid dianion, NO{sub 2}-bdc=5-nitro-1,3-benzenedicarboxylic acid dianion, nta=nicotinic acid anion, phdat=2,4-diamine-6-phenyl-1,3,5-triazine) have been hydrothermally synthesized by the reactions of silver nitrate and phdat with the homologous ligands 1,2-H{sub 2}bdc, NO{sub 2}-H{sub 2}bdc, and Hnta, respectively, and characterized by single-crystal X-ray diffractions, IR spectra, elemental analyses thermogravimetric analyses (TGA). The compound 1 exhibits a chiral 3D network with cbs/CrB self-dual topological net, which contains two kinds of single helical chains. For compound 2, the 3D network is comprised of two kinds of similar 2D sheets with the topological symbol of sql-type packed in AABBAA mode by Ag–N/O weakly contacts. And compound 3 has 2D double layer architecture, consisting of the 2D plane with hcb-type topological symbol connected by Ag–O weakly coordinations. The photoluminescent properties associated with the crystal structures of three compounds have also been measured. - Graphical abstract: Three new silver(I) coordination complexes 1–3 have been synthesized and characterized by single-crystal X-ray diffractions, IR spectra, elemental analyses, thermogravimetric analyses (TGA) and photoluminescent spectra. Highlights: ► The compound 1 exhibits a novel chiral 3D network with two kinds of single helical chains. ► 3D or 2D new Ag coordination complexes. ► The photoluminescent properties have been measured.

  11. Synthesis, structure, DNA binding and anticancer activity of mixed ligand ruthenium(II) complex

    Science.gov (United States)

    Gilewska, Agnieszka; Masternak, Joanna; Kazimierczuk, Katarzyna; Trynda, Justyna; Wietrzyk, Joanna; Barszcz, Barbara

    2018-03-01

    In order to obtain a potential chemotherapeutic which is not affected on the normal BALB/3T3 cell line, a new arene ruthenium(II) complex {[RuCl(L1)(η6-p-cymene)]PF6}2 · H2O has been synthesized by a direct reaction of precursor, [{(η6-p-cymene)Ru(μ-Cl)}2Cl2], with N,N-chelating ligand (L1 - 2,2‧-bis(4,5-dimethylimidazole). The compound has been fully characterized by elemental analysis, X-ray diffraction, IR, UV-Vis and 1H, 13C NMR spectroscopies. X-ray analysis have confirmed that the compound crystallized in the monoclinic group Cc as an inversion twin. The asymmetric unit contains two symmetrically independent cationic complexes [RuCl(L1)(η6-p-cymene)]+ whose charge is balanced by two PF6- counterions. The shape of each cationic coordination polyhedral can be described as a distorted dodecahedron and shows a typical piano-stool geometry. In addition, an analysis of the crystal structure and the Hirshfeld surface analysis were used to detect and visualize important hydrogen bonds and intermolecular interaction. Moreover, the antiproliferative behavior of the obtained complex was assayed against three human cells: MV-4-11, LoVo, MCF-7 and BALB/3T3 - normal mice fibroblast cells. To predict a binding mode, a potential interaction of ruthenium complex with calf thymus DNA (CT-DNA) has been explored using UV absorption and circular dichroism (CD).

  12. Thermostability and photophysical properties of mixed-ligand carboxylate/benzimidazole Zn(II)-coordination polymers

    International Nuclear Information System (INIS)

    Barros, Bráulio Silva; Chojnacki, Jaroslaw; Macêdo Soares, Antonia Alice; Kulesza, Joanna; Lourenço da Luz, Leonis; Júnior, Severino Alves

    2015-01-01

    The reaction between Zn(NO 3 ) 2 ·6H 2 O or Zn(CH 3 COO) 2 ·2H 2 O and isophthalic acid (1,3-H 2 bdc) in the presence of benzimidazole (Hbzim) in dimethylformamide (DMF)/ethanol (EtOH)/H 2 O solvent mixture at room temperature yielded two structurally different coordination polymers: [Zn 2 (1,3-bdc) 2 (Hbzim) 2 ] (1) and [Zn 2 (1,3-bdc)(bzim) 2 ] (2). (1) is a 2D-layered framework with a molecule of benzimidazole coordinated to the Zn center, whereas (2) is a 3D framework with benzimidazolate species acting as a co-ligand and bridging two Zn(II) ions. Reactions performed at 90 °C led to the formation of coordination polymers structurally similar to (2), independently of the Zn(II) source used. In the absence of benzimidazole, the reaction between ZnAc 2 .2H 2 O and 1,3-H 2 bdc at 90 °C resulted in the formation of (3), a 3D coordination polymer Zn(HCOO) 3 (Me 2 NH 2 + ). It was observed that the thermostability and the photophysical properties of (1) and (2) are strongly dependent on the coordination modes and packing of benzimidazole in the solid state. These materials present photoluminescence in the wide range of the spectrum, from UV to IR. A full understanding of a physical process occurring in these intriguing systems, including complete energy level diagrams with possible transitions were provided. - Graphical abstract: Display Omitted - Highlights: • Structurally different Zn(II)-coordination polymers were prepared. • The formation of frameworks was counter anion and temperature dependent. • Photoluminescence in the wide range of the spectrum, from UV to IR was observed. • Thermostability and luminescence depended on bzim packing in the structure

  13. X-ray structures of progesterone receptor ligand binding domain in its agonist state reveal differing mechanisms for mixed profiles of 11beta-substituted steroids.

    NARCIS (Netherlands)

    Lusher, S.J.; Raaijmakers, H.C.A.; Vu-Pham, D.; Kazemier, B.; Bosch, R.; McGuire, R.; Azevedo, R.; Hamersma, H.; Dechering, K.; Oubrie, A.; Duin, M. van; Vlieg, J. de

    2012-01-01

    We present here the x-ray structures of the progesterone receptor (PR) in complex with two mixed profile PR modulators whose functional activity results from two differing molecular mechanisms. The structure of Asoprisnil bound to the agonist state of PR demonstrates the contribution of the ligand

  14. Reversible and pH dependent photophysical properties of mixed-ligand Ru(II) complexes containing 2,20-bipyridine and nitrosobarbiturate: Experimental and theoretical approach

    Czech Academy of Sciences Publication Activity Database

    Dixit, N.; Záliš, Stanislav; Maiti, B.; Mishra, L.

    2013-01-01

    Roč. 404, AUG 2013 (2013), s. 123-130 ISSN 0020-1693 Institutional support: RVO:61388955 Keywords : Mixed-ligand Ru(II) complex * spectroscopy * X-ray diffraction Subject RIV: CF - Physical ; The oretical Chemistry Impact factor: 2.041, year: 2013

  15. Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

    International Nuclear Information System (INIS)

    Wang, Chao; Zhao, Jun; Xia, Liang; Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan

    2016-01-01

    Three new coordination polymers, namely, {[Ni(H 2 L)(bix)(H 2 O) 2 ]·2h 2 O} n (1), {[Ni(HL)(Hdpa)(H 2 O) 2 ]·H 2 O} n (2), {[Ni(L) 0.5 (bpp)(H 2 O)]·H 2 O} n (3) (H 4 L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H 4 L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6 6 -dia-type framework with H 4 L ligand adopts a μ 2 -bridging mode with two symmetry-related carboxylate groups in μ 1 -η 1 :η 0 monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, in which the H 4 L ligand adopts a μ 2 -bridging mode with two carboxylate groups in μ 1 -η 1 :η 1 and μ 1 -η 1 :η 0 monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H 4 L ligand displays a μ 4 -bridging coordination mode. The H 4 L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6 6 -dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)] n ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled” strategy is significant potential for network design.

  16. Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); Zhao, Jun, E-mail: junzhao08@126.com [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Xia, Liang [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002 (China); Wu, Xue-Qian; Wang, Jian-Fang; Dong, Wen-Wen; Wu, Ya-Pan [College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002 (China)

    2016-06-15

    Three new coordination polymers, namely, {[Ni(H_2L)(bix)(H_2O)_2]·2h_2O}{sub n} (1), {[Ni(HL)(Hdpa)(H_2O)_2]·H_2O}{sub n} (2), {[Ni(L)_0_._5(bpp)(H_2O)]·H_2O}{sub n} (3) (H{sub 4}L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H{sub 4}L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6{sup 6}-dia-type framework with H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two symmetry-related carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 0} monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, in which the H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 1} and μ{sub 1}-η{sup 1}:η{sup 0} monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H{sub 4}L ligand displays a μ{sub 4}-bridging coordination mode. The H{sub 4}L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6{sup 6}-dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled

  17. Polymer complexes.. XXXX. Supramolecular assembly on coordination models of mixed-valence-ligand poly[1-acrylamido-2-(2-pyridyl)ethane] complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; El-Bindary, A. A.; Diab, M. A.

    2003-02-01

    The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [( 11)+( 12)] in the paper and in mononuclear polymer complexes ( 1)-( 5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX 2 and KPtCl 4 in the presence of N-heterocyclic base consisting of polymer complexes ( 9)+( 10), and in monouclear compounds ( 6)-( 8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds ( 13)+( 14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.

  18. Trans* Leadership.

    Science.gov (United States)

    Jourian, T J; Simmons, Symone L

    2017-06-01

    Focusing on emerging literature on trans* and gender-nonconforming students and their leadership, this chapter outlines the ways trans* students are engaged in leadership in educational institutions and outside of them and discusses implications for staff and faculty regarding how to support and engage these students and their leadership. © 2017 Wiley Periodicals, Inc., A Wiley Company.

  19. INTERACTION OF IRON(II MIXED-LIGAND COMPLEXES WITH DNA: BASE-PAIR SPECIFICITY AND THERMAL DENATURATION STUDIES

    Directory of Open Access Journals (Sweden)

    Mudasir Mudasir

    2010-06-01

    Full Text Available A research about base-pair specificity of the DNA binding of [Fe(phen3]2+, [Fe(phen2(dip]2+ and [Fe(phen(dip2]2+ complexes and the effect of calf-thymus DNA (ct-DNA binding of these metal complexes on thermal denaturation of ct-DNA has been carried out. This research is intended to evaluate the preferential binding of the complexes to the sequence of DNA (A-T or G-C sequence and to investigate the binding strength and mode upon their interaction with DNA. Base-pair specificity of the DNA binding of the complexes was determined by comparing the equilibrium binding constant (Kb of each complex to polysynthetic DNA that contain only A-T or G-C sequence. The Kb value of the interaction was determined by spectrophotometric titration and thermal denaturation temperature (Tm was determined by monitoring the absorbance of the mixture solution of each complex and ct-DNA at λ =260 nm as temperature was elevated in the range of 25 - 100 oC. Results of the study show that in general all iron(II complexes studied exhibit a base-pair specificity in their DNA binding to prefer the relatively facile A-T sequence as compared to the G-C one. The thermal denaturation experiments have demonstrated that Fe(phen3]2+ and [Fe(phen2(dip]2+ interact weakly with double helical DNA via electrostatic interaction as indicated by insignificant changes in melting temperature, whereas [Fe(phen2(dip]2+  most probably binds to DNA in mixed modes of interaction, i.e.: intercalation and electrostatic interaction. This conclusion is based on the fact that the binding of [Fe(phen2(dip]2+ to ct-DNA moderately increase the Tm value of ct- DNA   Keywords: DNA Binding, mixed-ligand complexes

  20. Mixed-ligand Ru(II) complexes with 2,2'-bipyridine and aryldiazo-beta-diketonato auxillary ligands: synthesis, physico-chemical study and antitumour properties.

    Science.gov (United States)

    Mishra, Lallan; Yadaw, Ajay K; Bhattacharya, Subrato; Dubey, Santosh K

    2005-05-01

    The complexes of Ru(II)-2,2'-bipyridyl with substituted diazopentane-2,4-diones (L1H-L5H) were synthesized and characterized by elemental analyses, conductance, FAB (fast atom bombardment) mass and spectral (IR, UV/Vis (UV/visible), NMR) studies. Molecular geometry optimization of the complexes was also made. None of the complexes luminesce. However, facilitated oxidation of Ru(II) to Ru(III) was evidenced from their lower reduction potential data. The ligands and their complexes were tested for their antitumour activity against a variety of tumour cell lines. Though activity is found to vary with the type of tumour cell lines used, yet complex 5 with naphtyldiazopentane-2,4-dione as co-ligand was found to be a potential compound as it showed in general significant activity against all cell lines studied.

  1. Crystal structure of a mixed-ligand terbium(III coordination polymer containing oxalate and formate ligands, having a three-dimensional fcu topology

    Directory of Open Access Journals (Sweden)

    Chainok Kittipong

    2016-01-01

    Full Text Available The title compound, poly[(μ3-formato(μ4-oxalatoterbium(III], [Tb(CHO2(C2O4]n, is a three-dimensional coordination polymer, and is isotypic with the LaIII, CeIII and SmIII analogues. The asymmetric unit contains one TbIII ion, one formate anion (CHO2− and half of an oxalate anion (C2O42−, the latter being completed by application of inversion symmetry. The TbIII ion is nine-coordinated in a distorted tricapped trigonal–prismatic manner by two chelating carboxylate groups from two C2O42− ligands, two carboxylate oxygen atoms from another two C2O42− ligands and three oxygen atoms from three CHO2− ligands, with the Tb—O bond lengths and the O—Tb—O bond angles ranging from 2.4165 (19 to 2.478 (3 Å and 64.53 (6 to 144.49 (4°, respectively. The CHO2− and C2O42− anions adopt μ3-bridging and μ4-chelating-bridging coordination modes, respectively, linking adjacent TbIII ions into a three-dimensional 12-connected fcu topology with point symbol (324.436.56. The title compound exhibits thermal stability up to 623 K, and also displays strong green photoluminescence in the solid state at room temperature.

  2. Synthesis, Characterization and in Vitro Antibacterial Activities of CdO Nanoparticle and Nano-sheet Mixed-ligand of Cadmium(ІІ Complex

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    Zohreh Rashidi Ranjbar

    2016-07-01

    Full Text Available Here, we report the synthesis of a Schiff-base mixed-ligand complex of cadmium(ІІ in bulk and nano-scales via the precipitation and sonochemical methods, respectively. The complex formula is [Cd(3-bpdh(3-bpdbCl2]n (1, where the ligands are 3-bpdh = 2,5-bis(3-pyridyl-3,4-diaza-2,4-hexadiene and 3-bpdb = 1,4-bis(3-pyridyl-2,3-diaza-1,3-butadiene. The structure of mixed-ligand complex (1 was characterized by IR, 1H NMR and elemental analyses. Cadmium(ІІ oxide nanoparticles were prepared by direct thermolysis from nanosheet of complex (1. The cadmium(ІІ oxide structure was characterized by X-ray Diffraction (XRD and Energy Dispersive X-ray  analyses (EDAX. Size, morphology and structural dispersion of all obtained nanostructures were characterized by Scanning Electron Microscopy (SEM. The Schiff-base ligands, bulk and nano-scales of complex (1 and cadmium(ІІ oxide nanoparticles were analyzed for antibacterial activities against Bacillus alvei (bacteria causing the honey bee European foulbrood disease. The Minimum Inhibitory Concentrations (MIC has been shown moderate antibacterial activities compared with some other standard drugs. Known antibiotics like penicillin and SXT (Trimethoprim/sulfamethoxazole were used as positive control.

  3. A new donor atom system [(SNN)(S)] for the synthesis of neutral oxotechnetium(V) mixed ligand complexes

    International Nuclear Information System (INIS)

    Papadopoulos, M.S.; Pirmettis, I.C.; Spyriounis, D.M.

    1996-01-01

    Oxotechnetium complexes ligated in a 3 + 1 inch fashion yielding TcOL1L2 complexes were prepared. The L1 tridentate ligand binds with a SNN donor set of atoms. L2 corresponds to a monodentate thiol ligand. Representative members of this group of compounds were chemically characterized by NMR and X-ray diffraction

  4. Synthesis of an S T = 7 [Mn 3 ] Mixed-Valence Complex Based on 1,3-Propanediol Ligand Derivatives and Its One-Dimensional Assemblies

    KAUST Repository

    Huang, Jian; Wu, Gang; Bai, Jiaquan; Jiang, Yuan; Li, Guanghua; Qiu, Shilun; Clé rac, Rodolphe

    2013-01-01

    . In this work, a new ST = 7 trinuclear mixed-valence Mn complex, [MnIIIMnII 2(LA) 2(Br)4(CH3OH)6] ·Br· (CH3OH)1.5·(H2O)0.5 (1), is reported using a pyridinium-functionalized 1,3-propanediol ligand (H 2LABr = 1-(3-bromo-2,2-bis

  5. Group IB Organometallic Chemistry XIX.Synthesis and characterization of mixed-organocopper cluster compounds R4R'2Cu6 containing aryl and acetylide ligands.

    NARCIS (Netherlands)

    Koten, G. van; Hoedt, R.W.M. ten; Noltes, J.G.

    1977-01-01

    Mixed-organocopper cluster compounds Ar4Cu6(CCR)2 (Ar = 2-Me2NC6H4, R = phenyl, 4-tolyl, 2,4-xylyl or mesityl) have been prepared in high yield by the ligand-substitution reaction of Ar4Cu6Br2 with two equivalents of LiCCR. Ar4Cu6(CCC6H4CH3-4)2 has also been prepared via the aryl¡ªarylacetylide

  6. High Molar Extinction Coefficient Ru(II-Mixed Ligand Polypyridyl Complexes for Dye Sensitized Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Malapaka Chandrasekharam

    2011-01-01

    Full Text Available Two new ruthenium(II mixed ligand terpyridine complexes, “Ru(Htcterpy(NCS(L1 (N(C4H94, mLBD1” and Ru(Htcterpy(NCS(L2(N(C4H94, mLBD2 were synthesized and fully characterized by UV-Vis, emission, cyclic voltammogram, and other spectroscopic means, and the structures of the compounds are confirmed by 1H-NMR, ESI-MASS, and FT-IR spectroscopes. The influence of the substitution of L1 and L2 on solar-to-electrical energy conversion efficiency (η of dye-sensitized solar cells (DSSCs was evaluated relative to reference black dye. The dyes showed molar extinction coefficients of 17600 M−1 cm−1 for mLBD1 and 21300 M−1 cm−1 for mLBD2 both at λ maximum of 512 nm, while black dye has shown 8660 M−1 cm−1 at λ maximum of 615 nm. The monochromatic incident photon-to-collected electron conversion efficiencies of 60.71% and 75.89% were obtained for mLBD1 and mLBD2 dyes, respectively. The energy conversion efficiencies of mLBD1 and mLBD2 dyes are 3.15% (SC=11.86 mA/cm2, OC=613 mV, ff=0.4337 and 3.36% (SC=12.71 mA/cm2, OC=655 mV, ff=0.4042, respectively, measured at the AM1.5G conditions, the reference black dye-sensitized solar cell, fabricated and evaluated under identical conditions exhibited η-value of 2.69% (SC=10.95 mA/cm2, OC=655 mV, ff=0.3750.

  7. Formation of Mixed-Ligand Complexes of Pd2+ with Nucleoside 5'-Monophosphates and Some Metal-Ion-Binding Nucleoside Surrogates

    Directory of Open Access Journals (Sweden)

    Oleg Golubev

    2014-10-01

    Full Text Available Formation of mixed-ligand Pd2+ complexes between canonical nucleoside 5'-monophosphates and five metal-ion-binding nucleoside analogs has been studied by 1H-NMR spectroscopy to test the ability of these nucleoside surrogates to discriminate between unmodified nucleobases by Pd2+-mediated base pairing. The nucleoside analogs studied included 2,6-bis(3,5-dimethylpyrazol-1-yl-, 2,6-bis(1-methylhydrazinyl- and 6-(3,5-dimethylpyrazol-1-yl-substituted 9-(β-d-ribofuranosylpurines 1–3, and 2,4-bis(3,5-dimethylpyrazol-1-yl- and 2,4-bis(1-methylhydrazinyl-substituted 5-(β-d-ribofuranosyl-pyrimidines 4–5. Among these, the purine derivatives 1-3 bound Pd2+ much more tightly than the pyrimidine derivatives 4, 5 despite apparently similar structures of the potential coordination sites. Compounds 1 and 2 formed markedly stable mixed-ligand Pd2+ complexes with UMP and GMP, UMP binding favored by 1 and GMP by 2. With 3, formation of mixed-ligand complexes was retarded by binding of two molecules of 3 to Pd2+.

  8. Bonds broken and formed during the mixed-linkage glucan : xyloglucan endotransglucosylase reaction catalysed by Equisetum hetero-trans-β-glucanase.

    Science.gov (United States)

    Simmons, Thomas J; Fry, Stephen C

    2017-03-08

    Mixed-linkage glucan∶xyloglucan endotransglucosylase (MXE) is one of the three activities of the recently characterised hetero-trans-β-glucanase (HTG), which among land plants is known only from Equisetum species. The biochemical details of the MXE reaction were incompletely understood - details that would promote understanding of MXE's role in vivo and enable its full technological exploitation. We investigated HTG's site of attack on one of its donor substrates, mixed-linkage (1→3),(1→4)-β-d-glucan (MLG), with radioactive oligosaccharides of xyloglucan as the acceptor substrate. Comparing three different MLG preparations, we showed that the enzyme favours those with a high content of cellotetraose blocks. The reaction products were analysed by enzymic digestion, thin-layer chromatography (TLC), high-pressure liquid chromatography (HPLC) and gel-permeation chromatography (GPC). Equisetum HTG consistently cleaved the MLG at the third consecutive β-(1→4)-bond following (towards the reducing terminus) a β-(1→3)-bond. It then formed a β-(1→4)-bond between the MLG and the non-reducing terminal glucose residue of the xyloglucan oligosaccharide, consistent with its xyloglucan endotransglucosylase/hydrolase subfamily membership. Using size-homogeneous barley MLG as the donor substrate, we showed that HTG does not favour any particular region of the MLG chain relative to the polysaccharide's reducing and non-reducing termini; rather, it selects its target cellotetraosyl unit stochastically along the MLG molecule. This work improves our understanding of how enzymes can exhibit promiscuous substrate specificities and provides the foundations to explore strategies for engineering novel substrate specificities into transglycanases. © 2017 The Author(s).

  9. Mixed adenine/guanine quartets with three trans-a2 Pt(II) (a=NH(3) or MeNH(2)) cross-links: linkage and rotational isomerism, base pairing, and loss of NH(3).

    Science.gov (United States)

    Albertí, Francisca M; Rodríguez-Santiago, Luis; Sodupe, Mariona; Mirats, Andrea; Kaitsiotou, Helena; Sanz Miguel, Pablo J; Lippert, Bernhard

    2014-03-17

    Of the numerous ways in which two adenine and two guanines (N9 positions blocked in each) can be cross-linked by three linear metal moieties such as trans-a2 Pt(II) (with a=NH3 or MeNH2 ) to produce open metalated purine quartets with exclusive metal coordination through N1 and N7 sites, one linkage isomer was studied in detail. The isomer trans,trans,trans-[{Pt(NH3 )2 (N7-9-EtA-N1)2 }{Pt(MeNH2 )2 (N7-9-MeGH)}2 ][(ClO4 )6 ]⋅3H2 O (1) (with 9-EtA=9-ethyladenine and 9-MeGH=9-methylguanine) was crystallized from water and found to adopt a flat Z-shape in the solid state as far as the trinuclear cation is concerned. In the presence of excess 9-MeGH, a meander-like construct, trans,trans,trans-[{Pt(NH3 )2 (N7-9-EtA-N1)2 }{Pt(MeNH2 )2 (N7-9-MeGH)2 }][(ClO4 )6 ]⋅[(9-MeGH)2 ]⋅7 H2 O (2) is formed, in which the two extra 9-MeGH nucleobases are hydrogen bonded to the two terminal platinated guanine ligands of 1. Compound 1, and likewise the analogous complex 1 a (with NH3 ligands only), undergo loss of an ammonia ligand and formation of NH4 (+) when dissolved in [D6 ]DMSO. From the analogy between the behavior of 1 and 1 a it is concluded that a NH3 ligand from the central Pt atom is lost. Addition of 1-methylcytosine (1-MeC) to such a DMSO solution reveals coordination of 1-MeC to the central Pt. In an analogous manner, 9-MeGH can coordinate to the central Pt in [D6 ]DMSO. It is proposed that the proton responsible for formation of NH4 (+) is from one of the exocyclic amino groups of the two adenine bases, and furthermore, that this process is accompanied by a conformational change of the cation from Z-form to U-form. DFT calculations confirm the proposed mechanism and shed light on possible pathways of this process. Calculations show that rotational isomerism is not kinetically hindered and that it would preferably occur previous to the displacement of NH3 by DMSO. This displacement is the most energetically costly step, but it is compensated by the proton

  10. Synthesis and Spectroscopic Studies of Mixed Ligand Complexes of Pt(II and Pd(II with Ethyl-α-Isonitrosoacetoacetate and Dienes

    Directory of Open Access Journals (Sweden)

    Anita Krishankant Taksande

    2015-12-01

    Full Text Available The mixed ligand complexes of the kind [M(L1 (L2] where M= Pt(II, Pd(II.L1 = primary ligand ethyl-α-isonitrosoacetoacetate derived from reaction between ethyl acetoacetate, acetic acid and sodium nitrite and L2=secondary ligand para-phenyldiamine (PPD are synthesized. All the prepared complexes were identified and confirmed by elemental analysis, molar conductance measurements, and infrared electronic absorption. Their complexes has been made based on elemental analysis, molar conductivity, UV-Vis, FT-IR and 1HNMR spectroscopy and magnetic moment measurements as well as thermal analysis (TGA and DTA. The elemental analysis information recommends that the stoichiometry of the complexes to be 1:2:1. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral information showed the coordination sites of the free ligand with the central metal particle. The electronic absorption spectral information disclosed the existence of an octahedral geometry for Pt(II and Pd(II complexes. DOI: http://dx.doi.org/10.17807/orbital.v7i4.633 

  11. Synthesis, characterization, DNA interaction and antimicrobial screening of isatin-based polypyridyl mixed-ligand Cu(II and Zn(II complexes

    Directory of Open Access Journals (Sweden)

    NATARAJAN RAMAN

    2010-06-01

    Full Text Available Several mixed ligand Cu(II/Zn(II complexes using 3-(phenyl-imino-1,3-dihydro-2H-indol-2-one (obtained by the condensation of isatin and aniline as the primary ligand and 1,10-phenanthroline (phen/2,2’-bipyridine (bpy as an additional ligand were synthesized and characterized analytically and spectroscopically by elemental analyses, magnetic susceptibility and molar conductance measurements, as well as by UV–Vis, IR, NMR and FAB mass spectroscopy. The interaction of the complexes with calf thymus (CT DNA was studied using absorption spectra, cyclic voltammetric and viscosity measurements. They exhibit absorption hypochromicity, and the specific viscosity increased during the binding of the complexes to calf thymus DNA. The shifts in the oxidation–reduction potential and changes in peak current on addition of DNA were shown by CV measurements. The Cu(II/Zn(II complexes were found to promote cleavage of pUC19 DNA from the supercoiled form I to the open circular form II and linear form III. The complexes show enhanced antifungal and antibacterial activities compared with the free ligand.

  12. Preparation and characterisation of mixed ligand complexes of Co(III), Fe(III) and Cr(III) containing phthalimide and phenols

    International Nuclear Information System (INIS)

    Miah, M.A.J.; Islam, M.S.; Pal, S.C.; Barma, T.K.

    1996-01-01

    Some novel mixed ligand complexes of Co(III), Fe(III) and Cr(III) containing phthalimide as primary and 2-aminophenol and 3-aminophenol as secondary ligands have been synthesized and characterised on the basis of elemental analyses, conductivity and magnetic measurements and infrared and electronic spectral studies. Complexes containing 2-aminophenol are 1:1 electrolyte in N,N dimethylformamide. Spectral studies indicate that all the complexes exhibit octahedral geometry. The complexes have the general composition; K[M(pim)/sub 2/(L)/sub 2/]; where m=Co(III), Fe(III) and Cr(III), pim-anion of phthalimamide and L=anion of 2-aminophenol and 3-aminophenol. (author)

  13. Crystal and molecular structure of mixed-ligand calcium, strontium and barium complexes with dipivaloylmethane and 1,10-phenanthroline of composition MDpm2Phen2

    International Nuclear Information System (INIS)

    Soboleva, I.E.; Troyanov, S.I.; Kuz'mina, N.P.; Ivanov, V.K.; Martynenko, L.I.; Struchkov, Yu.T.; AN SSSR, Moscow

    1995-01-01

    Mixed-ligand complexes (MLC) of MDpm P hen 2 composition were prepared for the first time in result of interaction of calcium and strontium dipivaloylmethane (MDpm 2 ) with 1,10-phenanthroline (Phen · H 2 O) in benzene-acetonitrile mixture. Method of x-ray diffraction analysis was used to establish, that they were crystallized in monoclinic syngony with C2/c space group for CaDpm 2 Phen 2 and P2 1 /n space group for SrDpm 2 Phen 2 and were composed of monomeric molecules. The central atom (Ca,Sr) coordinates 4 oxygen atoms of two dipivaloylmethane ligands and 4 nitrogen atoms of two 1,10-phenanthroline molecules. Correlation with x-ray diffraction data for similar MZC of barium (BaDpm 2 Phen 2 ) was conducted. 4 refs.; 4 tabs

  14. Crystal structure of a mixed-ligand silver(I complex of the non-steroidal anti-inflammatory drug diclofenac and pyrimidine

    Directory of Open Access Journals (Sweden)

    Sevim Hamamci Alisir

    2016-10-01

    Full Text Available In the title mixed-ligand silver(I coordination polymeric complex with the non-steroidal anti-inflammatory drug diclofenac (C14H11Cl2NO2 (diclH and pyrimidine (pym, namely poly[{μ2-2-[2-(2,6-dichloroanilinophenyl]acetato-κ2O:O′}(μ2-pyrimidine-κ2N1:N3silver(I], [Ag(C14H10Cl2NO2(C4H4N2]n or [Ag(μ-dicl(μ-pym]n, the very distorted tetrahedral AgN2O2 coordination centres comprise two N-atom donors from bridging pym ligands [Ag—N = 2.381 (3 and 2.412 (3 Å] and two carboxylate O-atom donors from dicl ligands [Ag—O = 2.279 (2 and 2.280 (2 Å], which bridge Ag atoms, giving a centrosymmetric dinuclear units with a short Ag...Ag separation [2.8931 (5 Å]. Within the units are short intraligand C—Cl...π(pym interactions [3.6409 (15 Å]. The units are linked through the bridging N atoms of the pym ligand into a two-dimensional sheet–polymer structure lying parallel to (100 and stabilized by inter-ring π–π interactions between the pym ligands [Cg...Cg = 3.4199 (17 Å]. Additional inter-unit C—H...O and C—H...Cg hydrogen-bonding interactions between the sheets give an overall three-dimensional structure.

  15. Influence of ligand polarizability on the reversible binding of O2 by trans-[Rh(X)(XNC)(PPh3)2] (X = Cl, Br, SC6F5, C2Ph; XNC = xylyl isocyanide). Structures and a kinetic study.

    Science.gov (United States)

    Carlton, Laurence; Mokoena, Lebohang V; Fernandes, Manuel A

    2008-10-06

    The complexes trans-[Rh(X)(XNC)(PPh 3) 2] (X = Cl, 1; Br, 2; SC 6F 5, 3; C 2Ph, 4; XNC = xylyl isocyanide) combine reversibly with molecular oxygen to give [Rh(X)(O 2)(XNC)(PPh 3) 2] of which [Rh(SC 6F 5)(O 2)(XNC)(PPh 3) 2] ( 7) and [Rh(C 2Ph)(O 2)(XNC)(PPh 3) 2] ( 8) are sufficiently stable to be isolated in crystalline form. Complexes 2, 3, 4, and 7 have been structurally characterized. Kinetic data for the dissociation of O 2 from the dioxygen adducts of 1- 4 were obtained using (31)P NMR to monitor changes in the concentration of [Rh(X)(O 2)(XNC)(PPh 3) 2] (X = Cl, Br, SC 6F 5, C 2Ph) resulting from the bubbling of argon through the respective warmed solutions (solvent chlorobenzene). From data recorded at temperatures in the range 30-70 degrees C, activation parameters were obtained as follows: Delta H (++) (kJ mol (-1)): 31.7 +/- 1.6 (X = Cl), 52.1 +/- 4.3 (X = Br), 66.0 +/- 5.8 (X = SC 6F 5), 101.3 +/- 1.8 (X = C 2Ph); Delta S (++) (J K (-1) mol (-1)): -170.3 +/- 5.0 (X = Cl), -120 +/- 13.6 (X = Br), -89 +/- 18.2 (X = SC 6F 5), -6.4 +/- 5.4 (X = C 2Ph). The values of Delta H (++) and Delta S (++) are closely correlated (R (2) = 0.9997), consistent with a common dissociation pathway along which the rate-determining step occurs at a different position for each X. Relative magnitudes of Delta H (++) are interpreted in terms of differing polarizabilities of ligands X.

  16. A one-dimensional cadmium(II complex supported by a sulfur–nitrogen mixed-donor ligand

    Directory of Open Access Journals (Sweden)

    Qian Gao

    2009-07-01

    Full Text Available In the title compound, catena-poly[cadmium(II-bis(μ-5-amino-1,3,4-thiadiazole-2-thiolato-κ2N3:S2;κ2S2:N3], [Cd(C2H2N3S22]n, the CdII ion is coordinated by two N atoms of the 1,3,4-thiadiazole rings from two ligands and two S atoms of sulfhydryl from two other ligands in a slightly distorted tetrahedral geometry. The ligands bridge CdII ions, forming one-dimensional chains along [001], which are connected by N—H...N and N—H...S hydrogen bonds into a three-dimensional network.

  17. Synthesis and structure of a 2D Zn complex with mixed ligands stacked in offset ABAB manner

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Ling, E-mail: qinling0924013@163.com; Wang, Yan-Qing; Ni, Gang [Hefei University of Technology, Department of chemical engineering and food processing, Xuancheng Campus (China)

    2016-07-15

    The title complex, ([Zn(ODIB){sub 1/2}(bpdc)]·2DMF){sub n} was prepared under hydrothermal conditions (dimethylformamide and water) based on two ligands, namely, 1,1′-oxy-bis[3,5-diimidazolyl-benzene] (ODIB) and biphenyldicarboxylic acid (H{sub 2}bpdc). ODIB ligands link Zn cations to give layers in crystal. bpdc{sup 2–} anions coordinate to Zn atoms, however, their introduction does not increase the dimension of the structure. Each layer is partially passes through the adjacent layers in the offset ABAB manner.

  18. Synthesis, characterization and biological evaluation of a novel "3 + 1" mixed ligand 99mTc complex having an aliphatic thiol as coligand.

    Science.gov (United States)

    Rey, A; Papadopoulos, M; Leon, E; Mallo, L; Pirmettis, Y; Manta, E; Raptopoulou, C; Chiotellis, E; Leon, A

    2001-03-01

    A novel "3 + 1" mixed ligand 99mTc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethyl-ethilenediamine as ligand and 1-octanethiol as coligand was prepared and evaluated as potential brain radiopharmaceutical. Preparation at tracer level was accomplished by substitution, using 99mTc-glucoheptonate as precursor and a coligand/ligand ratio of 5. Under these conditions the labeling yield was over 80% and a major product with radiochemical purity >80% was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium and 99gTc complexes. Results were consistent with the expected "3 + 1" structure and X-ray diffraction study demonstrated that the complex adopted a distorted trigonal bipyramidal geometry. All sulphur atoms underwent ionization leading to the formation of a neutral compound. Biodistribution in mice demonstrated early brain uptake, fast blood clearance and excretion through hepatobiliary system. Although brain/blood ratio increased significantly with time, this novel 99mTc complex did not exhibit ideal properties as brain perfusion radiopharmaceutical since brain uptake was too low.

  19. Synthesis, characterization and biological evaluation of a novel ''3+1'' mixed ligand 99mTc complex having an aliphatic thiol as coligand

    International Nuclear Information System (INIS)

    Rey, A.; Papadopoulos, M.; Leon, E.; Mallo, L.; Pirmettis, Y.; Manta, E.; Raptopoulou, C.; Chiotellis, E.; Leon, A.

    2001-01-01

    A novel ''3+1'' mixed ligand 99m Tc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethyl-ethilenediamine as ligand and 1-octanethiol as coligand was prepared and evaluated as potential brain radiopharmaceutical. Preparation at tracer level was accomplished by substitution, using 99m Tc-glucoheptonate as precursor and a coligand/ligand ratio of 5. Under these conditions the labeling yield was over 80% and a major product with radiochemical purity >80% was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium and 99g Tc complexes. Results were consistent with the expected ''3+1'' structure and X-ray diffraction study demonstrated that the complex adopted a distorted trigonal bipyramidal geometry. All sulphur atoms underwent ionization leading to the formation of a neutral compound. Biodistribution in mice demonstrated early brain uptake, fast blood clearance and excretion through hepatobiliary system. Although brain/blood ratio increased significantly with time, this novel 99m Tc complex did not exhibit ideal properties as brain perfusion radiopharmaceutical since brain uptake was too low

  20. Efficient preparation of {sup 99m}Tc(III) '4+1' mixed-ligand complexes for peptide labeling with high specific activity

    Energy Technology Data Exchange (ETDEWEB)

    Kunstler, Jens-Uwe [Biotectid GmbH, Deutscher Platz 5c, 04103 Leipzig (Germany); Seidel, Gesine [Institute of Radiopharmacy, Forschungszentrum Dresden-Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Pietzsch, Hans-Jurgen, E-mail: h.j.pietzsch@fzd.d [Institute of Radiopharmacy, Forschungszentrum Dresden-Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany)

    2010-09-15

    An improved labeling procedure for peptides attached to organometallic {sup 99m}Tc(III) '4+1' mixed-ligand complexes in which the radiometal is coordinated by a tripodal tetradentate chelator 2,2',2''-nitrilotriethanethiol (NS{sub 3}) and a monodentate isocyanide ligand is presented. The labeling procedure was evaluated by the synthesis of [{sup 99m}Tc(NS{sub 3})(L2-RGD)]. The containing radiopharmaceutically interesting RGD-peptide cyclo[Arg-Gly-Asp-D-Tyr-Lys] was modified with 4-isocyanobutanoic acid (L2) as linker conjugated to N{sup 6}-Lys to get the monodentate ligand L2-RGD. The structural identity of the {sup 99m}Tc-conjugate was confirmed by comparison to a Re reference compound. The Tc- and Re-conjugates had matching retention times under identical HPLC conditions. The {sup 99m}Tc-labeling was performed in a novel one-step procedure using the eluate of a {sup 99}Mo/{sup 99m}Tc generator, NS{sub 3}, the isocyanide modified peptide, SnCl{sub 2}, Na{sub 2}EDTA, mannitol and ascorbic acid in the reaction mixture. Using optimized reagents it is possible to label 50 nmol peptide with {sup 99m}Tc within 60 min at room temperature with a radiochemical yield higher than 95% and a specific activity of {approx}20 GBq/{mu}mol.

  1. Mixed-Valent Metals Bridged by a Radical Ligand: Fact, or Fiction Based on Structure-Oxidation State Correlations

    Czech Academy of Sciences Publication Activity Database

    Sarkar, B.; Patra, S.; Fiedler, Jan; Sunoj, R. B.; Janardanan, D.; Lahiri, G. K.; Kaim, W.

    2008-01-01

    Roč. 130, č. 11 (2008), s. 3532-3542 ISSN 0002-7863 R&D Projects: GA MŠk 1P05OC068; GA MŠk OC 140 Institutional research plan: CEZ:AV0Z40400503 Keywords : electron transfer series * quinone-related ligand s * ruthenium complexes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 8.091, year: 2008

  2. Synthesis of mixed-ligand cobalt complexes and their applications in high cis-1,4-selective butadiene polymerization

    KAUST Repository

    Liu, Wen

    2015-08-03

    Incomplete oxidation of (N-di-tert-butylphosphino)-6-(2-methyl-2’H-benzoimidazole)-2-aminepyridine dichlorocobalt (PN3CoCl2) in DMF results in a unique co-crystal I formed with three parts including DMF, unit A and unit B complex with Co1 and Co2, respectively, (PN3 ligand in unit A: (N-di-tert-butylphosphino)-6-(2’-methyl-2’H-benzoimidazole)-2-aminepyridine, and O=PN3 ligand in unit B: (N-di-tert-butylphosphinoxide)-6-(2’-methyl-2’H-benzoimidazole)-2-aminepyridine) with 1:1:1 molar ratio. Co1 and Co2 complexes both display a five-coordinated distorted-square-pyramidal geometry around the metal center. The Co1 center is coordinated with PN3 ligand via two N atoms from pyridine, benzoimidazole moiety as well as one P atom, and the Co2 center is coordinated with the oxidized ligandO=PN3 via two N atoms from pyridine, benzoimidazole moiety as well as one O atom from DMF molecule, while the oxidized phosphine moiety (O=P) being excluded from the coordination sphere. Activated with AlEt2Cl, the co-crystallized complexes I are able to actively convert butadiene to polybutadiene, affording cis-1,4 polybutadiene with cis-1,4 unit up to 95.5-97.8% and number average molecular weight of cal. 105g/mol. The high cis-1,4 selectivity and monomodal GPC curve of resultant polymer imply that the identical active species generated from two distinctive cobalt centers.

  3. Synthesis of mixed-ligand cobalt complexes and their applications in high cis-1,4-selective butadiene polymerization

    KAUST Repository

    Liu, Wen; Pan, Weijing; Wang, Peng; Li, Wei; Mu, Jingshan; Weng, Gengsheng; Jia, Xiaoyu; Gong, Dirong; Huang, Kuo-Wei

    2015-01-01

    Incomplete oxidation of (N-di-tert-butylphosphino)-6-(2-methyl-2’H-benzoimidazole)-2-aminepyridine dichlorocobalt (PN3CoCl2) in DMF results in a unique co-crystal I formed with three parts including DMF, unit A and unit B complex with Co1 and Co2, respectively, (PN3 ligand in unit A: (N-di-tert-butylphosphino)-6-(2’-methyl-2’H-benzoimidazole)-2-aminepyridine, and O=PN3 ligand in unit B: (N-di-tert-butylphosphinoxide)-6-(2’-methyl-2’H-benzoimidazole)-2-aminepyridine) with 1:1:1 molar ratio. Co1 and Co2 complexes both display a five-coordinated distorted-square-pyramidal geometry around the metal center. The Co1 center is coordinated with PN3 ligand via two N atoms from pyridine, benzoimidazole moiety as well as one P atom, and the Co2 center is coordinated with the oxidized ligandO=PN3 via two N atoms from pyridine, benzoimidazole moiety as well as one O atom from DMF molecule, while the oxidized phosphine moiety (O=P) being excluded from the coordination sphere. Activated with AlEt2Cl, the co-crystallized complexes I are able to actively convert butadiene to polybutadiene, affording cis-1,4 polybutadiene with cis-1,4 unit up to 95.5-97.8% and number average molecular weight of cal. 105g/mol. The high cis-1,4 selectivity and monomodal GPC curve of resultant polymer imply that the identical active species generated from two distinctive cobalt centers.

  4. NMR Spectroscopic Characterization of Methylcobalt(III) Compounds with Classical Ligands. Crystal Structures of [Co(NH(3))(5)(CH(3))]S(2)O(6), trans-[Co(en)(2)(NH(3))(CH(3))]S(2)O(6) (en = 1,2-Ethanediamine), and [Co(NH(3))(6)]-mer,trans-[Co(NO(2))(3)(NH(

    DEFF Research Database (Denmark)

    Kofod, Pauli; Harris, Pernille; Larsen, Sine

    1997-01-01

    magnetic resonance spectroscopy and by absorption spectroscopy. Single-crystal X-ray structure determinations at 122.0(5) K were performed on [Co(NH(3))(5)(CH(3))]S(2)O(6) (1), trans-[Co(en)(2)(NH(3))(CH(3))]S(2)O(6) (2), and [Co(NH(3))(6)]-mer,trans-[Co(NO(2))(3)(NH(3))(2)(CH(3))](2)-trans-[Co(NO(2...

  5. Synthesis and characterization of new mixed ligand complexes of ruthenium(II) containing triphenylphosphine and 2'-hydroxychalcones

    International Nuclear Information System (INIS)

    Dharmaraj, N.; Natarajan, K.

    1994-01-01

    A few hexacoordinated ruthenium(II) complexes of the type [RuCl(CO) (HLL')(PPh 3 ) 2 ] and [RuCl(CO)(HLL')(B) (PPh 3 )] (where HLL' 2'-hydroxychalcone, 2'-hydroxy-4-methoxychalcone, 2'-hydroxy-3,4-dimethoxychalcone and B=pyridine(Py), piperidine(Pip), morpholine (Morph)) have been synthesised and characterized on the basis of their analytical and spectral data (IR, electronic and 1 H NMR). In all these complexes, the 2'-hydroxychalcones behave as a uninegative bidentate (OO - ) chelating ligand. (author). 17 refs., 1 tab

  6. Synthesis, Characterization, and Physicochemical Studies of Mixed Ligand Complexes of Inner Transition Metals with Lansoprazole and Cytosine

    Directory of Open Access Journals (Sweden)

    Sarika Verma

    2013-01-01

    Full Text Available Few complexes of inner transition metals [Th(IV, Ce(IV, Nd(III, Gd(III] have been synthesized by reacting their metal salts with lansoprazole, 2-([3-methyl-4-(2,2,2-trifluoroethoxypyridin-2-yl]methylsulfinyl-1H-benzoimidazole and cytosine. All the complexes were synthesized in ethanolic medium. The yield percentage rangs from 80 to 90%. The complexes are coloured solids. The complexes were characterized through elemental analyses, conductance measurements, and spectroscopic methods (FT IR, FAB Mass, 1H NMR and UV. An IR spectrum indicates that the ligand behaves as bidentate ligands. The metal complexes have been screened for their antifungal activity towards Aspergillus niger fungi. The interaction of inner transition metals with lansoprazole, in presence of cytosine, has also been investigated potentiometrically at two different temperatures 26±1°C and 36±1°C and at 0.1 M (KNO3 ionic strength. The stability constants of ternary complexes indicate the stability order as Th(IV < Ce(IV < Gd(III < Nd(III. logK values obtained are positive and suggest greater stabilization of ternary complexes. The values of thermodynamic parameters (free energy (ΔG, enthalpy (ΔH, and entropy (ΔS are also calculated.

  7. Synthesis of an S T = 7 [Mn 3 ] Mixed-Valence Complex Based on 1,3-Propanediol Ligand Derivatives and Its One-Dimensional Assemblies

    KAUST Repository

    Huang, Jian

    2013-10-07

    Controlled organization of high-spin complexes and single-molecule magnets is a great challenge in molecular magnetism in order to study the effect of the intercomplex magnetic interactions on the intrinsic properties of a given magnetic object. In this work, a new ST = 7 trinuclear mixed-valence Mn complex, [MnIIIMnII 2(LA) 2(Br)4(CH3OH)6] ·Br· (CH3OH)1.5·(H2O)0.5 (1), is reported using a pyridinium-functionalized 1,3-propanediol ligand (H 2LABr = 1-(3-bromo-2,2-bis(hydroxymethyl)propyl)pyridinium bromide). Using azido anions as bridging ligands and different pyridinium-functionalized 1,3-propanediol ligands (H2LBBr = 1-(3-bromo-2,2-bis(hydroxymethyl)propyl)-4-picolinium bromide; H 2LCBr = 1-(3-bromo-2,2-bis(hydroxymethyl)propyl)-3,5- lutidinium bromide), the linear [MnIIIMnII 2L2X4]+ building block has been assembled into one-dimensional coordination networks: [MnIIIMn II 2(LA)2(Br)4(CH 3OH)4(N3)]·((C2H 5)2O)1.25 (2∞), [MnIIIMn II 2(LB)2(Br)4(C 2H5OH)(CH3OH)(H2O) 2(N3)]·(H2O)0.25 (3∞), and [MnIIIMnII 2(LC) 2(Cl)3.8(Br)0.2(C2H 5OH)3(CH3OH)(N3)] (4∞). The syntheses, characterization, crystal structures, and magnetic properties of these new [Mn3]-based materials are reported. © 2013 American Chemical Society.

  8. Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes

    Science.gov (United States)

    Bhattacharjee, Chira R.; Goswami, Pankaj; Pramanik, Harun A. R.; Paul, Pradip C.; Mondal, Paritosh

    2011-05-01

    Two new mixed-ligand iron(III) complexes, [Fe(L n)(acac)(C 2H 5OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac) 3] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H 2L 1) or 2-aminobenzoic acid (H 2L 2). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L n)(acac)X] ( n = 1, 2; X = Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, 1H and 13C NMR spectroscopy. Room temperature magnetic susceptibility measurements ( μeff ˜ 5.8 B.M.) are consistent with spin-free octahedral iron(III) complexes. Cyclic voltammetry of ethanol complexes revealed a quasi-reversible one electron redox response (Δ Ep > 100 mV) for the Fe(III)/Fe(II) couple. Low half wave redox potential ( E1/2) values suggested easy redox susceptibility. The ground state geometries of the ethanol and imidazole complexes have been ascertained to be distorted octahedral by density functional theory using DMol3 program at BLYP/DNP level.

  9. Nonlinear optical and G-Quadruplex DNA stabilization properties of novel mixed ligand copper(II) complexes and coordination polymers: Synthesis, structural characterization and computational studies

    Science.gov (United States)

    Rajasekhar, Bathula; Bodavarapu, Navya; Sridevi, M.; Thamizhselvi, G.; RizhaNazar, K.; Padmanaban, R.; Swu, Toka

    2018-03-01

    The present study reports the synthesis and evaluation of nonlinear optical property and G-Quadruplex DNA Stabilization of five novel copper(II) mixed ligand complexes. They were synthesized from copper(II) salt, 2,5- and 2,3- pyridinedicarboxylic acid, diethylenetriamine and amide based ligand (AL). The crystal structure of these complexes were determined through X-ray diffraction and supported by ESI-MAS, NMR, UV-Vis and FT-IR spectroscopic methods. Their nonlinear optical property was studied using Gaussian09 computer program. For structural optimization and nonlinear optical property, density functional theory (DFT) based B3LYP method was used with LANL2DZ basis set for metal ion and 6-31G∗ for C,H,N,O and Cl atoms. The present work reveals that pre-polarized Complex-2 showed higher β value (29.59 × 10-30e.s.u) as compared to that of neutral complex-1 (β = 0.276 × 10-30e.s.u.) which may be due to greater advantage of polarizability. Complex-2 is expected to be a potential material for optoelectronic and photonic technologies. Docking studies using AutodockVina revealed that complex-2 has higher binding energy for both G-Quadruplex DNA (-8.7 kcal/mol) and duplex DNA (-10.1 kcal/mol). It was also observed that structure plays an important role in binding efficiency.

  10. Reversible Single-Crystal-to-Single-Crystal Structural Transformation in a Mixed-Ligand 2D Layered Metal-Organic Framework: Structural Characterization and Sorption Study

    Directory of Open Access Journals (Sweden)

    Chih-Chieh Wang

    2017-12-01

    Full Text Available A 3D supramolecular network, [Cd(bipy(C4O4(H2O2]·3H2O (1 (bipy = 4,4′-bipyridine and C4O42− = dianion of H2C4O4, constructed by mixed-ligand two-dimensional (2D metal-organic frameworks (MOFs has been reported and structurally determined by the single-crystal X-ray diffraction method and characterized by other physicochemical methods. In 1, the C4O42− and bipy both act as bridging ligands connecting the Cd(II ions to form a 2D layered MOF, which are then extended to a 3D supramolecular network via the mutually parallel and interpenetrating arrangements among the 2D-layered MOFs. Compound 1 shows a two-step dehydration process with weight losses of 11.0% and 7.3%, corresponding to the weight-loss of three guest and two coordinated water molecules, respectively, and exhibits an interesting reversible single-crystal-to-single-crystal (SCSC structural transformation upon de-hydration and re-hydration for guest water molecules. The SCSC structural transformation have been demonstrated and monitored by single-crystal and X-ray powder diffraction, and thermogravimetic analysis studies.

  11. pH-metric studies on the mixed ligand-chelates of oxovanadium(IV) with 2,2'-bipyridyl and dicarboxylic or hydroxy acids

    Energy Technology Data Exchange (ETDEWEB)

    Jain, A K; Kumari, V; Chaturvedi, G K [Agra Coll. (India)

    1978-12-01

    The interaction of vanadyl ion with 2,2'-bipyridyl and some dicarboxylic or hydroxy acids (where dicarboxylic acid = oxalic (OX), malonic (MALN), phthalic (PHA), maleic (MAL) acids; hydroxy acids salicylic (SA), 5-sulfosalicylic (5-SSA), mandelic (MAND) and glycollic (HG) acids was studied potentiometrically. pH-titrations of the reaction mixtures containing vanadyl sulphate, 2,2'-bipyridyl and one of the dicarboxylic or hydroxy acids (OX, MALN, PHA, MAL, SA, 5-SSA, MAND and HG acids) in equimolar ratio exhibited the formation of 1:1:1 mixed ligand chelates. The formation constants of the resulting biligand chelates were calculated, at 35/sup +/-1/sup 0/ and 45/sup +/-1/sup 0/ and also the thermodynamic functions viz. ..delta..F, ..delta..H and ..delta..S (..mu..=0.1M KNO/sub 3/) (auth.).

  12. pH-metric studies on the mixed ligand-chelates of oxovanadium(IV) with 2,2'-bipyridyl and dicarboxylic or hydroxy acids

    International Nuclear Information System (INIS)

    Jain, A.K.; Kumari, V.; Chaturvedi, G.K.

    1978-01-01

    The interaction of vanadyl ion with 2,2'-bipyridyl and some dicarboxylic or hydroxy acids (where dicarboxylic acid = oxalic (OX), malonic (MALN), phthalic (PHA), maleic (MAL) acids; hydroxy acids salicylic (SA), 5-sulfosalicylic (5-SSA), mandelic (MAND) and glycollic (HG) acids was studied potentiometrically. pH-titrations of the reaction mixtures containing vanadyl sulphate, 2,2'-bipyridyl and one of the dicarboxylic or hydroxy acids (OX, MALN, PHA, MAL, SA, 5-SSA, MAND and HG acids) in equimolar ratio exhibited the formation of 1:1:1 mixed ligand chelates. The formation constants of the resulting biligand chelates were calculated, at 35 + -1 0 and 45 + -1 0 and also the thermodynamic functions viz. ΔF, ΔH and ΔS (μ=0.1M KNO 3 ) (auth.)

  13. Photocytotoxic trans-diam(m)ine platinum(IV) diazido complexes more potent than their cis isomers.

    Science.gov (United States)

    Farrer, Nicola J; Woods, Julie A; Munk, Vivienne P; Mackay, Fiona S; Sadler, Peter J

    2010-02-15

    The photocytotoxicity of a series of anticancer trans-dihydroxido [Pt(N(3))(2)(OH)(2)(NH(3))(X)] (X = alkyl or aryl amine) platinum(IV) diazido complexes has been examined, and the influence of cis-trans isomerism has been investigated. A series of photoactivatable Pt(IV)-azido complexes has been synthesized: The synthesis, characterization, and photocytotoxicity of six mixed-ligand ammine/amine Pt(IV) diazido complexes, cis,trans,cis-[Pt(N(3))(2)(OH)(2)(NH(3))(X)] where X = propylamine (4c), butylamine (5c), or pentylamine (6c) and aromatic complexes where X = pyridine (7c), 2-methylpyridine (8c), or 3-methylpyridine (9c) are reported. Six all-trans isomers have also been studied where X = methylamine (2t), ethylamine (3t), 2-methylpyridine (8t), 4-methylpyridine (10t), 3-methylpyridine (9t), and 2-bromo-3-methylpyridine (11t). All of the complexes exhibit intense azide-to-Pt(IV) LMCT bands (ca. 290 nm for trans and ca. 260 nm for cis). When irradiated with UVA light (365 nm), the Pt(IV) complexes undergo photoreduction to Pt(II) species, as monitored by UV-vis spectroscopy. The trans isomers of complexes containing aliphatic or aromatic amines were more photocytotoxic than their cis isomers. One of the cis complexes (9c) was nonphotocytotoxic despite undergoing photoreduction. Substitution of NH(3) ligands by MeNH(2) or EtNH(2) results in more potent photocytotoxicity for the all-trans complexes. The complexes were all nontoxic toward human keratinocytes (HaCaT) and A2780 human ovarian cancer cells in the dark, apart from the 3-methylpyridine (9t), 2-bromo-3-methylpyridine (11t), and 4-methylpyridine (10t) derivatives.

  14. Cyclic GMP-AMP containing mixed phosphodiester linkages is an endogenous high-affinity ligand for STING.

    Science.gov (United States)

    Zhang, Xu; Shi, Heping; Wu, Jiaxi; Zhang, Xuewu; Sun, Lijun; Chen, Chuo; Chen, Zhijian J

    2013-07-25

    The presence of microbial or self DNA in the cytoplasm of mammalian cells is a danger signal detected by the DNA sensor cyclic-GMP-AMP (cGAMP) synthase (cGAS), which catalyzes the production of cGAMP that in turn serves as a second messenger to activate innate immune responses. Here we show that endogenous cGAMP in mammalian cells contains two distinct phosphodiester linkages, one between 2'-OH of GMP and 5'-phosphate of AMP, and the other between 3'-OH of AMP and 5'-phosphate of GMP. This molecule, termed 2'3'-cGAMP, is unique in that it binds to the adaptor protein STING with a much greater affinity than cGAMP molecules containing other combinations of phosphodiester linkages. The crystal structure of STING bound to 2'3'-cGAMP revealed the structural basis of this high-affinity binding and a ligand-induced conformational change in STING that may underlie its activation. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Synthesis, characterization and thermal studies of nickel (II), copper (II), zinc (II) and cadmium (II) complexes with some mixed ligands

    International Nuclear Information System (INIS)

    Mitra, Samiran; Kundu, Parimal; Singh, Rajkumar Bhubon

    1998-01-01

    Dichloro-(DCA) and trichloroacetate(TCA) -cyclic ligand morpholine (Morph)/thiomorpholine (Tmorph)/methylmorpholine (Mmorph)/dimethyl-piperazine (DMP) complexes of nickel (II), copper (II), zinc (II) and cadmium (II) with the compositions [Ni(tmorph) 2 (DCA) 2 ], [Ni(tmorph) 2 (TCA) 2 ].2H 2 O, [Cu(DMP) 2 (TCA) 2 ],[ML 2 X 2 ].nH 2 O where M=Zn II or Cd II , L=Morph, DMP or tmorph and X=DCA or TCA and n=O except in case of [Cd (Morph) 2 (TCA) 2 ] where n=1 have been synthesised. Some intermediate complexes have been isolated by temperature arrest technique (pyrolysis) and characterised. Configurational and conformational changes have been studied by elemental analyses, IR and electronic spectra, magnetic moment data (in the case of Ni(II) and Cu(II) complexes) and thermal analysis. E a * , ΔH, and ΔS for the decomposition reaction of these complexes are evaluated and the stability of the complexes with respect to activation energy has also been compared. The linear correlation has been found between E a * and ΔS for the decomposition of the complexes. (author)

  16. Extraction of uranium and lead from mixed waste debris using a variety of metal/ligand complexes

    International Nuclear Information System (INIS)

    Needham, D.A.; Duran, B.L.; Ehler, D.S.; Sauer, N.N.

    1997-01-01

    To ensure the safety of our Nation's nuclear stockpile, Los Alamos National Laboratory is in the process of constructing the DARHT (Dual Axis Radiographic Hydrodynamic Test) facility. DARHT will examine the effects of aging and the stability of our stockpile. Contained testing will be phased in to reduce the impact of these tests, which contain depleted uranium, on our environment. The main focus of this research is to develop a treatment scheme for the recovery of depleted uranium and lead from shot debris that will result from these tests. The goals of this research are to optimize the conditions on a bench scale using a commercially available water soluble polymer to bind the lead and a variety of metal/ligand complexes such as 4,5-dihydroxy-1,3-benzene-disulfonic acid, dithionite, sodium carbonate/bicarbonate, and sodium hypochlorite to bind the uranium. Studies were conducted on a mixture of debris, such as wood, cable, paper towels, and tubing that contained both uranium and lead ranging in concentration from 10-1000's of ppm of contaminants. Experiments were done varying combinations and successions of extractant solutions as well as a number of sequential extractions. Studies show that a mixture of sodium hypochlorite and carbonate removed 90+% of both uranium and lead. We then focused on a separation scheme for the lead and uranium

  17. Mixed ligand chelate therapy for plutonium and toxic metals from energy power production. Final report, April 15, 1977-October 14, 1980

    International Nuclear Information System (INIS)

    Schubert, J.

    1980-01-01

    The results of experiments are summarized on the ability of combinations of chelating agents to modify the genotoxicity or tissue distributions. The mutagenicities of Cr and of chelating agents were determined. The metals described in the report are Pu(IV), Cd(II), Cr(III), and Cr(VI). Accurate measurements were made of the ability of CaNa 2 EDTA, CaNa 3 DTPA, and DMPS to reduce mortality in mice given doses (i.p.) of CdCl 2 well above the 100% lethal level. The efficacy in terms of the mmoles/kg needed to reduce the mortality was: DTPA > EDTA > DMPS. The combination of DTPA + DMPS proved most promising though little evidence for mixed complex formation was noted. Potentiometric titration studies the case of Pu(IV) a few combinations proved effective, but only when given shortly after Pu administration and then only in the liver but not the skeleton. It is recommended that metabolically stable chelating agents be used in combinations, especially for those combinations which may form very stable mixed ligand chelates

  18. Syntheses, crystal structures, and properties of four coordination polymers based on mixed multi-N donor and polycarboxylate ligands

    Science.gov (United States)

    Chen, Shui-Sheng; Guo, Xing-Zhe; Zhao, Yue; Li, Wei-Dong

    2018-02-01

    Four new coordination polymers [Ni2(HL1)2(L1)3(BTC)2]·6H2O (1), [Ni2(L1)3(HBTC)2]·4H2O (2), [Cd2(L2)(BTC)(H2O)3]·2H2O (3) and [Cd2(HL2)(BTCA)] (4) were synthesized by reactions of nickel(II)/ cadmium(II) salts with rigid ligands of 1,4-di(1H-imidazol-4-yl)benzene (L1), 1,3-di(1-imidazolyl)-5-(4H-tetrazol-5-yl)benzene (HL2) and polycarboxylic acids of 1,3,5-benzenetricarboxylic acid (H3BTC), 1,2,4,5-benzenetetracarboxylic acid (H4BTCA), respectively. The structures of the complexes were determined by single crystal X-ray diffraction analysis. The complex 1 is one-dimensional (1D) chain while 2 is a (4, 4)-connected two-dimensional (2D) layered structure with 2D → 2D parallel interpenetration. Complex 3 is a rare tetranodal (3,4)-connected three-dimensional (3D) CrVTiSc architecture with Point (Schläfli) symbol of (4·82)(4·84·10)(42·82·102)(83), and compound 4 has the 2D network with (4,4) topology based on the [Cd2(COO)4] SBUs. The weak interactions such as hydrogen bonds and π···π stacking contribute to stabilize crystal structure and extend the low-dimensional entities into high-dimensional frameworks. The UV-vis absorption spectra of 1 - 4 are discussed. Moreover, the photo luminescent properties of 3 and 4 and gas sorption property of 2 have been investigated.

  19. Extent of Intramolecular pi Stacks in Aqueous Solution in Mixed-Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and 1-[2-(Phosphonomethoxy)ethyl]cytosine (PMEC), a Relative of Antivirally Active Acyclic Nucleotide Analogues (Part 72)

    Czech Academy of Sciences Publication Activity Database

    Blindauer, C. A.; Sigel, A.; Operschall, B. P.; Holý, Antonín; Sigel, H.

    2013-01-01

    Roč. 639, 8-9 (2013), s. 1661-1673 ISSN 0044-2313 Institutional support: RVO:61388963 Keywords : nucleotide analogues * antivirals * complex stabilities * isomers * equilibria * mixed ligand complexes Subject RIV: CC - Organic Chemistry Impact factor: 1.251, year: 2013

  20. Interplay of metalloligand and organic ligand to tune micropores within isostructural mixed-metal organic frameworks (M'MOFs) for their highly selective separation of chiral and achiral small molecules

    NARCIS (Netherlands)

    Das, M. C.; Guo, Q.; He, Y.; Kim, J.; Zhao, C.-G.; Hong, K.; Xiang, S.; Zhang, Z.; Thomas, K. M.; Krishna, R.; Chen, B.

    2012-01-01

    Four porous isostructural mixed-metal-organic frameworks (M′MOFs) have been synthesized and structurally characterized. The pores within these M′MOFs are systematically tuned by the interplay of both the metalloligands and organic ligands which have enabled us not only to direct their highly

  1. Crystal structure of mixed ligand compound [HgPhen{(C2H5)2NCS2}2] and character of intermolecular interaction in the structures of [MPhen{(C2H5)2NCS2}2] (M = Zn, Cd, Hg) complexes

    International Nuclear Information System (INIS)

    Klevtsova, R.F.; Glinskaya, L.A.; Zemskova, S.M.; Larionov, S.V.

    2002-01-01

    Monocrystals of mixed ligand complex [HgPhen(Et 2 NCS 2 ) 2 ] (Phen = 1, 10-phenanthroline) have been prepared and by the method of X-ray diffraction its crystal structure has been determined. The structure of mercury complex has been compared with structures of previously studied cadmium and zinc complexes similar in composition. The character of interaction between molecules of cadmium, zinc, mercury mixed ligand complexes and ways of their packing have been considered. It is shown that the structure of the complexes presents a molecular group assembled from two monomeric compounds at the expense of interaction between heterocyclic ligands contained in the mixed ligand complexes [ru

  2. Characterisation of the Novel Mixed Mu-NOP Peptide Ligand Dermorphin-N/OFQ (DeNo.

    Directory of Open Access Journals (Sweden)

    Mark F Bird

    Full Text Available Opioid receptors are currently classified as Mu (μ, Delta (δ, Kappa (κ plus the opioid related nociceptin/orphanin FQ (N/OFQ peptide receptor (NOP. Despite compelling evidence for interactions and benefits of targeting more than one receptor type in producing analgesia, clinical ligands are Mu agonists. In this study we have designed a Mu-NOP agonist named DeNo. The Mu agonist component is provided by dermorphin, a peptide isolated from the skin of Phyllomedusa frogs and the NOP component by the endogenous agonist N/OFQ.We have assessed receptor binding profile of DeNo and compared with dermorphin and N/OFQ. In a series of functional screens we have assessed the ability to (i increase Ca2+ in cells coexpressing recombinant receptors and a the chimeric protein Gαqi5, (ii stimulate the binding of GTPγ[35S], (iii inhibit cAMP formation, (iv activate MAPKinase, (v stimulate receptor-G protein and arrestin interaction using BRET, (vi electrically stimulated guinea pig ileum (gpI assay and (vii ability to produce analgesia via the intrathecal route in rats.DeNo bound to Mu (pKi; 9.55 and NOP (pKi; 10.22 and with reasonable selectivity. This translated to increased Ca2+ in Gαqi5 expressing cells (pEC50 Mu 7.17; NOP 9.69, increased binding of GTPγ[35S] (pEC50 Mu 7.70; NOP 9.50 and receptor-G protein interaction in BRET (pEC50 Mu 8.01; NOP 9.02. cAMP formation was inhibited and arrestin was activated (pEC50 Mu 6.36; NOP 8.19. For MAPK DeNo activated p38 and ERK1/2 at Mu but only ERK1/2 at NOP. In the gpI DeNO inhibited electrically-evoked contractions (pEC50 8.63 that was sensitive to both Mu and NOP antagonists. DeNo was antinociceptive in rats.Collectively these data validate the strategy used to create a novel bivalent Mu-NOP peptide agonist by combining dermorphin (Mu and N/OFQ (NOP. This molecule behaves essentially as the parent compounds in vitro. In the antonocicoeptive assays employed in this study DeNo displays only weak antinociceptive

  3. A THIOLATO-BRIDGED OCTANUCLEAR COPPER(I,II MIXED- VALENCE COMPLEX WITH N,N,S-TRIDENTATE LIGAND

    Directory of Open Access Journals (Sweden)

    Takanori Kotera

    2007-06-01

    Full Text Available Thiolato-bridged complex [CuI4CuII4(peampt4Cl8]·2H2O (Hpeampt = 1-(2-pyridylethylamino methylpropane-2-thiol has been synthesized and characterized by the elemental analysis, IR and UV-vis spectroscopies and magnetic susceptibility measurement. The X-ray crystal structure analysis of this complex shows a localized mixed-valence octanuclear cage structure made up of four trigonal-bipyramidal CuIIN2SCl2, two trigonal CuIS2Cl, and two tetrahedral CuIS2Cl2 coordination sites. Temperature dependence of magnetic susceptibility (4.5— 300 K shows that a fairly strong antiferromagnetic interaction is operating between the four CuII ions.

  4. Multispectroscopic DNA-Binding studies and antimicrobial evaluation of new mixed-ligand Silver(I) complex and nanocomplex: A comparative study

    Science.gov (United States)

    Movahedi, Elaheh; Rezvani, Ali Reza

    2018-05-01

    A novel mixed-ligand Ag(I) complex, , has been synthesized and characterized by the elemental analysis, IR spectroscopy and 1HNMR. In the formula, dian and phen are N-(4,5-diazafluoren-9-ylidene)aniline and 1,10-phenanthroline, respectively. This complex also has been prepared at nano size by sonochemical technique and characterized by the FTIR and scanning electron microscopy (SEM). To evaluate the biological preferences of the Ag(I) complex and nanocomplex and verify the relationships between the structure and biological function, in vitro DNA binding and antibacterial experiments have been carried out. DNA-complex interaction has been pursued by electronic absorption titration, luminescence titration, competitive binding experiment, effect of ionic strength, thermodynamic studies, viscometric evaluation and circular dichroism spectroscopy in the physiological pH. Each compound displays significant binding trend to the CT-DNA. The mode of binding to the CT-DNA probably is a moderate intercalation mode with the partial insertion of the planar ligands between the base stacks of double-stranded DNA. The relative viscosities and circular dichroism spectra of the CT-DNA with the complex solutions, confirm the intense interactions of the Ag(I) complex and nanocomplex with DNA. An in vitro antibacterial test of the complex and nanocomplex on a series of the Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis) and the Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) shows a remarkable antibacterial feature of the Ag(I) complex. The MIC values (minimum inhibitory concentration) of the compounds compare with silver nitrate and silver sulfadiazine. The bacterial inhibitions of the Ag(I) complex and nanocomplex are agreed to their DNA binding affinities.

  5. Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: Synthesis, X-ray crystallography and biological activity

    Science.gov (United States)

    Mokhtaruddin, Nur Shuhada Mohd; Yusof, Enis Nadia Md; Ravoof, Thahira B. S. A.; Tiekink, Edward R. T.; Veerakumarasivam, Abhi; Tahir, Mohamed Ibrahim Mohamed

    2017-07-01

    Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines.

  6. Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

    KAUST Repository

    Gong, Dirong; Jia, Xiaoyu; Wang, Baolin; Zhang, Xuequan; Huang, Kuo-Wei

    2014-01-01

    Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

  7. Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

    KAUST Repository

    Gong, Dirong

    2014-09-01

    Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

  8. Thiolato-technetium complexes. 5. Synthesis, characterization, and electrochemical properties of bis(o-phenylenebis(dimethylarsine))technetium(II) and -technetium(III) complexes with thiolato ligands. Single-crystal structural analyses of trans-[Tc(SCH3)2(DIARS)2]PF6 and trans-[Tc(SC6H5)2(DIARS)2]0

    International Nuclear Information System (INIS)

    Konno, Takumi; Heineman, W.R.; Deutsch, E.; Kirchhoff, J.R.; Heeg, M.J.; Stuckey, J.A.

    1992-01-01

    Three different thiols have been brought into reaction with trans-[Tc(OH)(O)(DIARS) 2 ] 2+ to produce initially the Tc(II) complex, [Tc(SR) 2 (DIARS) 2 ] 0 , which can be oxidized to the Tc(III) complex, [Tc(SR) 2 (DIARS) 2 ] + (DIARS = o-phenylenebis(dimethylarsine)). In the case of SR = SCH 3 and SCH 2 C 6 H 5 , the Tc(II) and Tc(III) products were found to be in the trans geometry, while for SR = SC 6 H 5 , both cis and trans isomers were generated. Two of the complexes were structurally characterized by X-ray diffraction. trans-[Tc(SCH 3 ) 2 (DIARS) 2 ]PF 6 , chemical formula TcAs 4 S 2 PF 6 C 22 H 38 , crystallizes in the monoclinic space group. The Tc atom occupies an inversion center. Representative elemental analyses, FAB mass spectra, and visible-UV spectra are reported. Electrochemical and spectroelectrochemical measurements were taken on trans-[Tc(SCH 3 ) 2 (DIARS) 2 ] + , trans-[Tc(SCH 2 C 6 H 5 ) 2 (DIARS) 2 ] + , and cis-[Tc(SC 6 H 5 ) 2 (DIARS) 2 ] + , which exhibit a reversible Tc(III/II) redox couple in the range -0.32 to -0.47 V vs. Ag/AgCl. Another redox couple is present in the range -1.22 to -1.70 V; this is ascribed to Tc(II/I) and is reversible only for SR = SCH 2 C 6 H 5 at 20C. At room temperature, chemically irreversible couples are exhibited at ca. +1.0 V for Tc(IV/III)

  9. DNA and protein binding, double-strand DNA cleavage and cytotoxicity of mixed ligand copper(II) complexes of the antibacterial drug nalidixic acid.

    Science.gov (United States)

    Loganathan, Rangasamy; Ganeshpandian, Mani; Bhuvanesh, Nattamai S P; Palaniandavar, Mallayan; Muruganantham, Amsaveni; Ghosh, Swapan K; Riyasdeen, Anvarbatcha; Akbarsha, Mohammad Abdulkader

    2017-09-01

    The water soluble mixed ligand complexes [Cu(nal)(diimine)(H 2 O)](ClO 4 ) 1-4, where H(nal) is nalidixic acid and diimine is 2,2'-bipyridine (1), 1,10-phenanthroline (2), 5,6-dimethyl-1,10-phenanthroline (3), and 3,4,7,8-tetramethyl-1,10-phenanthroline (4), have been isolated. The coordination geometry around Cu(II) in 1 and that in the Density Functional Theory optimized structures of 1-4 has been assessed as square pyramidal. The trend in DNA binding constants (K b ) determined using absorption spectral titration (K b : 1, 0.79±0.1base pair. In contrast, 3 and 4 are involved in intimate hydrophobic interaction with DNA through the methyl substituents on phen ring, which is supported by viscosity and protein binding studies. DNA docking studies imply that 4 is involved preferentially in DNA major groove binding while 1-3 in minor groove binding and that all the complexes, upon removing the axially coordinated water molecule, bind in the major groove. Interestingly, 3 and 4 display prominent double-strand DNA cleavage while 1 and 2 effect only single-strand DNA cleavage in the absence of an activator. The complexes 3 and 4 show cytotoxicity higher than 1 and 2 against human breast cancer cell lines (MCF-7). The complex 4 induces apoptotic mode of cell death in cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Mixed

    Directory of Open Access Journals (Sweden)

    Pau Baya

    2011-05-01

    Full Text Available Remenat (Catalan (Mixed, "revoltillo" (Scrambled in Spanish, is a dish which, in Catalunya, consists of a beaten egg cooked with vegetables or other ingredients, normally prawns or asparagus. It is delicious. Scrambled refers to the action of mixing the beaten egg with other ingredients in a pan, normally using a wooden spoon Thought is frequently an amalgam of past ideas put through a spinner and rhythmically shaken around like a cocktail until a uniform and dense paste is made. This malleable product, rather like a cake mixture can be deformed pulling it out, rolling it around, adapting its shape to the commands of one’s hands or the tool which is being used on it. In the piece Mixed, the contortion of the wood seeks to reproduce the plasticity of this slow heavy movement. Each piece lays itself on the next piece consecutively like a tongue of incandescent lava slowly advancing but with unstoppable inertia.

  11. Early experience with the multilayer aneurysm repair stent in the endovascular treatment of trans/infragenicular popliteal artery aneurysms: a mixed bag.

    Science.gov (United States)

    Thakar, Tejal; Chaudhuri, Arindam

    2013-06-01

    To present a preliminary experience using a multilayer flow-modulating stent for trans/infragenicular popliteal endovascular aneurysm repair. Five men (mean age 76 years, range 62-86) with 6 popliteal artery aneurysms (PAAs) measuring 22 to 39 mm in diameter (mean 30) underwent endovascular repair using the Cardiatis Multilayer Aneurysm Repair System (MARS) between June and August 2011. Radiological assessments post procedure using duplex ultrasonography and biplanar knee radiographs (additional contrast studies as necessary) sought evidence of aneurysm exclusion, graft patency, and preservation of branches and runoff vessels. Technical success was achieved in each case. There was one symptomatic stent occlusion requiring thrombectomy at 4 days, with reocclusion, and one leak via the stent struts into the sac with no branch outflow identified. Two further symptomatic stent occlusions were identified within a 6-week follow-up period, totaling 3 occlusions among the 6 devices deployed. No firm conclusion can be reached on the efficacy of the MARS in PAAs due to the inherent limitations of this small series, although a 50% thrombosis rate is a poor outcome. The risk of early thrombosis in flow-modulating stents deployed in the popliteal artery exists, as it does with earlier generation stent-grafts. Larger prospective trials and the influence of more aggressive antithrombotic/anticoagulant therapy should be considered to enable accurate evaluation of this device in popliteal artery aneurysms.

  12. Effect of lanthanide contraction on the mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien): Syntheses and characterizations of lanthanide complexes with a tetraelenidoantimonate ligand

    International Nuclear Information System (INIS)

    Zhao Jing; Liang Jingjing; Pan Yingli; Zhang Yong; Jia Dingxian

    2011-01-01

    Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en) 2 (dien)(η 2 -SbSe 4 )] (Ln=Ce(1a), Nd(1b)), [Ln(en) 2 (dien)(SbSe 4 )] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)(μ-η 1 ,η 2 -SbSe 4 )] ∞ (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)(η 2 -SbSe 4 )] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe 4 ] 3- acts as a monodentate ligand mono-SbSe 4 , a bidentate chelating ligand η 2 -SbSe 4 or a tridentate bridging ligand μ-η 1 ,η 2 -SbSe 4 to the lanthanide(III) center depending on the Ln 3+ ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with E g between 2.08 and 2.51 eV. - Graphical Abstract: Two structural types of lanthanide(III) selenidoantimonates are formed in both en-dien and en-trien mixed polyamines across lanthanide series, indicating the lanthanide contraction effect on the structures of the lanthanide(III) selenidoantimonates. Highlights: → Two structural types of lanthanide selenidoantimonates are prepared across the lanthanide series in both Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) systems. → The [SbSe 4 ] 3- anion acts as a mono-SbSe 4 , a η 2 -SbSe 4 or a μ-η 1 ,η 2 -SbSe 4 ligand to the Ln 3+ ions. → The soft base ligand [SbSe 4 ] 3- can be controlled to coordinate to the Ln 3+ ions with en+dien and en+trien as co-ligands.

  13. A two-dimensional layered Cd(II) coordination polymer with a three-dimensional supramolecular architecture incorporating mixed multidentate N- and O-donor ligands.

    Science.gov (United States)

    Huang, Qiu-Ying; Su, Ming-Yang; Meng, Xiang-Ru

    2015-06-01

    The combination of N-heterocyclic and multicarboxylate ligands is a good choice for the construction of metal-organic frameworks. In the title coordination polymer, poly[bis{μ2-1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole-κ(2)N(3):N(4)}(μ4-butanedioato-κ(4)O(1):O(1'):O(4):O(4'))(μ2-butanedioato-κ(2)O(1):O(4))dicadmium], [Cd(C4H4O4)(C9H8N6)]n, each Cd(II) ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from three carboxylate groups of three succinate (butanedioate) ligands and two N atoms from two 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) ligands. Cd(II) ions are connected by two kinds of crystallographically independent succinate ligands to generate a two-dimensional layered structure with bimt ligands located on each side of the layer. Adjacent layers are further connected by hydrogen bonding, leading to a three-dimensional supramolecular architecture in the solid state. Thermogravimetric analysis of the title polymer shows that it is stable up to 529 K and then loses weight from 529 to 918 K, corresponding to the decomposition of the bimt ligands and succinate groups. The polymer exhibits a strong fluorescence emission in the solid state at room temperature.

  14. Synthesis, characterization and biological evaluation of [{sup 188}Re(N)(cys{approx})(PNP)]{sup +/0} mixed-ligand complexes as prototypes for the development of {sup 188}Re(N)-based target-specific radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, Stefan [Institute of Radiopharmacy, Forschungszentrum Dresden Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Agostini, Stefania [Department of Pharmaceutical Sciences, University of Padua, Via Marzolo 5, 35131 Padova (Italy); Bergmann, Ralf; Pietzsch, Jens; Pietzsch, Hans-Juergen [Institute of Radiopharmacy, Forschungszentrum Dresden Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Carta, Davide; Salvarese, Nicola [Department of Pharmaceutical Sciences, University of Padua, Via Marzolo 5, 35131 Padova (Italy); Refosco, Fiorenzo [ICIS-CNR, Corso Stati Uniti 4, 35127 Padova (Italy); Bolzati, Cristina, E-mail: bolzati@icis.cnr.i [Department of Pharmaceutical Sciences, University of Padua, Via Marzolo 5, 35131 Padova (Italy); ICIS-CNR, Corso Stati Uniti 4, 35127 Padova (Italy)

    2011-04-15

    We report on an efficient procedure for the preparation of [{sup 188}Re(N)(PNP)]-based complexes (where PNP is diphosphinoamine) useful in the development of target-specific radiopharmaceuticals. The radiochemical yield of the compounds was optimized considering such reaction parameters as nature of the nitrido nitrogen donor, reaction times and pH level. The chemical identity of the {sup 188}Re agents was determined by high-performance liquid chromatography comparison with the corresponding well-characterized cold Re compounds. {sup 188}Re(N) mixed compounds have been evaluated with regard to stability toward transchelation with GSH and degradation by serum enzymes. The clearance of selected radiocompounds from normal tissues and their in vivo stability were evaluated in rats by biodistribution and imaging studies. [{sup 188}Re(N)(cys{approx})(PNP)]{sup +/0} mixed-ligand compounds were efficiently prepared in aqueous solution from perrhenate using a multistep procedure based on the preliminary formation of the labile {sup 188}Re{sup III}-EDTA species, which easily undergo oxidation/ligand exchange reaction to afford the [{sup 188}Re{sup V{identical_to}}N]{sup 2+} core in the presence of dithiocarbazate. The final mixed-ligand compounds were obtained, at 100{sup o}C, by adding the two bidentate ligands to the buffered [{sup 188}Re{sup V{identical_to}}N]{sup 2+} solution (pH 3.2-3.6). However, a relatively high amount of cys{approx} ligand was required to obtain a quantitative radiochemical yield. The complexes were stable toward reoxidation to perrhenate and ligand exchange reactions. In vivo studies showed rapid distribution and elimination of the complexes from the body. No specific uptakes in sensitive tissues/organs were detected. A positive correlation of the distribution of the complexes estimated with biodistribution studies (%ID) and with micro-SPECT semiquantification imaging analysis (standard uptake values) was observed. These results support the

  15. Trans-Planckian wimpzillas

    CERN Document Server

    Kolb, E W; Tkachev, I I

    2007-01-01

    Two previously proposed conjectures--gravitational trans-Planckian particle creation in the expanding universe, and the existence of ultra-heavy stable particles with masses up to the Planck scale (wimpzillas)--are combined in a proposal for trans-Planckian particle creation of wimpzillas. It is shown that the trans-Planckian particle creation parameter should be rather small to avoid overproduction of such particles. This ensures that wimpzillas are mainly created at the end of primordial inflation. Conditions under which trans-Planckian wimpzillas can constitute the present dark matter are determined.

  16. The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

    Science.gov (United States)

    Gregson, Matthew; Lu, Erli; Mills, David P.; Tuna, Floriana; McInnes, Eric J. L.; Hennig, Christoph; Scheinost, Andreas C.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Kerridge, Andrew; Liddle, Stephen T.

    2017-02-01

    Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal-ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle.

  17. Facts about trans fats

    Science.gov (United States)

    Trans fat is a type of dietary fat . Of all the fats, trans fat is the worst for your health. Too much ... from solid margarine to soft margarine. Ask what type of fats foods are cooked in when you eat out ...

  18. Trans as Contested Intelligibility

    DEFF Research Database (Denmark)

    Raun, Tobias

    2014-01-01

    Denne artikel rejser en række epistemologiske og metodologiske spørgsmål vedrørende læsningen af trans som identitetskategori. Disse spørgsmål er stærkt underbelyste i en skandinavisk akademisk kontekst, om end der el- lers i stigende grad produceres analyser af trans identitetsnarrativer. Artikl...

  19. Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: Synthesis, spectral characterization, antimicrobial and nuclease studies

    Science.gov (United States)

    Subbaraj, P.; Ramu, A.; Raman, N.; Dharmaraja, J.

    2014-01-01

    A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA = Schiff base and B = 2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, 1H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, 1H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

  20. Two Zinc(II) metal-organic frameworks with mixed ligands of 5-amino-tetrazolate and l,2,4,5-benzenetetracarboxylate: Synthesis, structural diversity and photoluminescent properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiao-Bing [Department of Chemistry, Shaoguan University, Shaoguan, Guangdong 512005 (China); Lu, Wen-Guan, E-mail: lwg@sgu.edu.cn [Department of Chemistry, Shaoguan University, Shaoguan, Guangdong 512005 (China); Zhong, Di-Chang [School of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou 341000 (China)

    2017-06-15

    The reactions of Zn(NO{sub 3}){sub 2}·6H{sub 2}O with mixed ligands of 5-amino-tetrazole (Hatz) and l,2,4,5-benzenetetracarboxylic acid (H{sub 4}btec) under hydro(solvo)thermal conditions, gave two three-dimensional (3D) porous metal-organic frameworks (MOFs) of ([Zn{sub 3}(atz){sub 2}(btec)(DMF){sub 2}]·DMF·2H{sub 2}O){sub n} (1) and [Zn{sub 2}(Hprz)(atz)(btec)(H{sub 2}O)]{sub n} (2) in the absence and presence of piperazine (prz), respectively. 1 and 2 were characterized by infrared spectra (IR), elemental analyses (EA) and single-crystal/powder X-ray diffraction. In 1, the adjacent 1D [Zn{sub 3}(btec)]{sub n}{sup 2n+} chains are linked together by atz{sup −} ligands to form a 3D porous MOF with 1D tetragonal channels filled with coordinated and guest DMF, and lattice water molecules. In 2, the adjacent 2D [Zn{sub 2}(btec)]{sub n} wavelike sheets are pillared through atz{sup −} ligands to generate a 3D layered-pillared porous MOF with 1D open channels, which are occupied by coordinated Hprz{sup +} cations and coordinated water molecules. Additionally, thermal stabilities and photoluminescent properties of both compounds in the solid-state at room temperature have been investigated and discussed in detail. - Graphical abstract: Two new MOFs constructed from Zn(II) salts with mixed ligands of 5-amino-tetrazole and l,2,4,5-benzenetetracarboxylic acid were synthesized under different reaction conditions. Structural diversities indicate that the reaction solvent system or the presence of organic base play crucial roles in modulating structures of these compounds. And more, their thermal stability and luminescence are also discussed. - Highlights: • Two new Zn(II) MOFs based on mixed ligands were synthesized. • The two Zn(II) MOFs exhibit different structural motifs. • The two Zn(II) MOFs are photoluminscent in the solid state at room temperature.

  1. Mixed ligand complexes of alkaline earth metals: Part XII. Mg(II, Ca(II, Sr(II and Ba(II complexes with 5-chlorosalicylaldehyde and salicylaldehyde or hydroxyaromatic ketones

    Directory of Open Access Journals (Sweden)

    MITHLESH AGRAWAL

    2002-04-01

    Full Text Available The reactions of alkaline earth metal chlorides with 5-chlorosalicylaldehyde and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been carried out in 1 : 1 : 1 mole ratio and the mixed ligand complexes of the type MLL’(H2O2 (where M = Mg(II, Ca(II, Sr(II and Ba(II, HL = 5-chlorosalicylaldehyde and HL’ = salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been isolated. These complexes were characterized by TLC, conductance measurements, IR and 1H-NMR spectra.

  2. Deprotonation induced ligand-to-metal electron transfer: Synthesis of a mixed-valence Rh(-I,I) dinuclear compound and its reaction with dioxygen

    NARCIS (Netherlands)

    Tejel, C.; Ciriano, M.A.; del Río, M.P.; van den Bruele, F.J.; Hetterscheid, D.G.H.; Tsichlis i Spithas, N.; de Bruin, B.

    2008-01-01

    Treatment of bis(2-picolyl)amine (bpa) with [{Rh(nbd)(mu-OMe))(2)] leads to unexpected and unique redox asymmetric dinuclear Rh-I, Rh+I complex [{Rh(ndb)}(2)(bpa-2H)] (2) with a pi-coordinating imine bound to a tetrahedral low valent rhodate(-I). Mono-oxygenation of the deprotonated bpa ligand in 2

  3. A two-dimensional zinc(II) coordination polymer based on mixed dimethyl succinate and bipyridine ligands: synthesis, structure, thermostability and luminescence properties.

    Science.gov (United States)

    Liu, Yang; Feng, Yong Lan; Fu, Wei Wei

    2016-04-01

    From the viewpoint of crystal engineering, the construction of crystalline polymeric materials requires a rational choice of organic bridging ligands for the self-assembly process. Multicarboxylate ligands are of particular interest due to their strong coordination activity towards metal ions, as well as their various coordination modes and versatile conformations. The structural chemistry of dicarboxylate-based coordination polymers of transition metals has been developed through the grafting of N-containing organic linkers into carboxylate-bridged transition metal networks. A new luminescent two-dimensional zinc(II) coordination polymer containing bridging 2,2-dimethylsuccinate and 4,4'-bipyridine ligands, namely poly[[aqua(μ2-4,4'-bipyridine-κ(2)N:N')bis(μ3-2,2-dimethylbutanedioato)-κ(4)O(1),O(1'):O(4):O(4');κ(5)O(1):O(1),O(4):O(4),O(4')-dizinc(II)] dihydrate], {[Zn2(C6H8O4)2(C10H8N2)(H2O)]·2H2O}n, has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction and elemental, IR and thermogravimetric analyses. In the structure, the 2,2-dimethylsuccinate ligands link linear tetranuclear Zn(II) subunits into one-dimensional chains along the c axis. 4,4'-Bipyridine acts as a tethering ligand expanding these one-dimensional chains into a two-dimensional layered structure. Hydrogen-bonding interactions between the water molecules (both coordinated and free) and carboxylate O atoms strengthen the packing of the layers. Furthermore, the luminescence properties of the complex were investigated. The compound exhibits a blue photoluminescence in the solid state at room temperature and may be a good candidate for potential hybrid inorganic-organic photoactive materials.

  4. Synthesis, characterization and biological evaluation of a novel ''3+1'' mixed ligand {sup 99m}Tc complex having an aliphatic thiol as coligand

    Energy Technology Data Exchange (ETDEWEB)

    Rey, A. E-mail: arey@bilbo.edu.uy; Papadopoulos, M.; Leon, E.; Mallo, L.; Pirmettis, Y.; Manta, E.; Raptopoulou, C.; Chiotellis, E.; Leon, A

    2001-03-01

    A novel ''3+1'' mixed ligand {sup 99m}Tc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethyl-ethilenediamine as ligand and 1-octanethiol as coligand was prepared and evaluated as potential brain radiopharmaceutical. Preparation at tracer level was accomplished by substitution, using {sup 99m}Tc-glucoheptonate as precursor and a coligand/ligand ratio of 5. Under these conditions the labeling yield was over 80% and a major product with radiochemical purity >80% was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium and {sup 99g}Tc complexes. Results were consistent with the expected ''3+1'' structure and X-ray diffraction study demonstrated that the complex adopted a distorted trigonal bipyramidal geometry. All sulphur atoms underwent ionization leading to the formation of a neutral compound. Biodistribution in mice demonstrated early brain uptake, fast blood clearance and excretion through hepatobiliary system. Although brain/blood ratio increased significantly with time, this novel {sup 99m}Tc complex did not exhibit ideal properties as brain perfusion radiopharmaceutical since brain uptake was too low.

  5. Synthesis, characterisation and antimicrobial activities of cobalt(II, copper(II and zinc(II mixed-ligand complexes containing 1,10-phenanthroline and 2,2’-bipyridine

    Directory of Open Access Journals (Sweden)

    A. Mohamadou

    2010-06-01

    Full Text Available Three new 1,10-phenanthroline and 2,2’-bipyridine mixed-ligand complexes of [Co(bpy(phen2](NO32.2H2O, [Cu(bpy(phen H2O 2]Cl2.2H2O, and [Zn(bpy2(phen]Cl2.6H2O were synthesized. The complexes were characterized by elemental, IR and visible spectroscopic analyses and the results indicate that both ligands are coordinated to the respective metal ions giving octahedral complexes. Antimicrobial studies showed that there is increased antimicrobial activity of the metal ions on coordination to the ligands. The water soluble complexes showed antimicrobial activities that are higher than those of the metal salts and 2,2’-bipyridine but lower than those of 1,10-phenanthroline. The copper complex [Cu(bpy(phen(H2O 2]Cl2.2H2O shows the highest activity.

  6. The trans influence in mer-trichloronitridobis(triphenylarsine)ruthenium(VI)

    DEFF Research Database (Denmark)

    Magnussen, Magnus; Bendix, Jesper

    2003-01-01

    The title compound, mer-[RuCl(3)N(C(18)H(15)As)(2)], is the first structurally characterized example of a nitride complex in which ruthenium is six-coordinated to monodentate ligands only. The Ru[triple-bond]N bond length [1.6161 (15) A] is relatively long, and the trans influence of the nitride...

  7. trans-Dichloridobis(3,4-dimethylpyridineplatinum(II

    Directory of Open Access Journals (Sweden)

    Alexander N. Chernyshev

    2009-01-01

    Full Text Available In the title compound, trans-[PtCl2(C7H9N2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethylpyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar.

  8. The structure of a mixed GluR2 ligand-binding core dimer in complex with (S)-glutamate and the antagonist (S)-NS1209

    DEFF Research Database (Denmark)

    Kasper, Christina; Pickering, Darryl S; Mirza, Osman

    2006-01-01

    domains has been observed. (S)-NS1209 adopts a novel binding mode, including hydrogen bonding to Tyr450 and Gly451 of D1. Parts of (S)-NS1209 occupy new areas of the GluR2 ligand-binding cleft, and bind near residues that are not conserved among receptor subtypes. The affinities of (RS)-NS1209 at the Glu....... The thermodynamics of binding of the antagonists (S)-NS1209, DNQX and (S)-ATPO to the GluR2 ligand-binding core have been determined by displacement isothermal titration calorimetry. The displacement of (S)-glutamate by all antagonists was shown to be driven by enthalpy....

  9. Cis By Trans

    OpenAIRE

    Rodovalho,Amara Moira

    2017-01-01

    Cis, trans: above all, metaphors. Cisjordan, region skirting the Jordan River. Cisplatin, Uruguay’s ancient name, region occupying one of the banks of the Prata River. Trans- Amazonian, that which crosses the Amazon; transatlantic, that which crosses the Atlantic. Cisalpine, transalpine. The geometric isomerism of Organic Chemistry, where “cis” are atoms that, when molecules are divided in half, remain on the same side, and “trans” those remaining on opposite sides. Ev...

  10. Ligand-bridged dinuclear cyclometalated Ir(III) complexes: from metallamacrocycles to discrete dimers.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Hajra, Tanima; Bera, Jitendra K; Rahaman, S M Wahidur; Satumtira, Nisa; Elbjeirami, Oussama; Omary, Mohammad A

    2012-02-06

    Metallamacrocycles 1, 2, and 3 of the general formula [{Ir(ppy)(2)}(2)(μ-BL)(2)](OTf)(2) (ppyH = 2-phenyl pyridine; BL = 1,2-bis(4-pyridyl)ethane (bpa) (1), 1,3-bis(4-pyridyl)propane (bpp) (2), and trans-1,2-bis(4-pyridyl)ethylene (bpe) (3)) have been synthesized by the reaction of [{(ppy)(2)Ir}(2)(μ-Cl)(2)], first with AgOTf to effect dechlorination and later with various bridging ligands. Open-frame dimers [{Ir(ppy)(2)}(2)(μ-BL)](OTf)(2) were obtained in a similar manner by utilizing N,N'-bis(2-pyridyl)methylene-hydrazine (abp) and N,N'-(bis(2-pyridyl)formylidene)ethane-1,2-diamine (bpfd) (for compounds 4 and 5, respectively) as bridging ligands. Molecular structures of 1, 3, 4, and 5 were established by X-ray crystallography. Cyclic voltammetry experiments reveal weakly interacting "Ir(ppy)(2)" units bridged by ethylene-linked bpe ligand in 3; on the contrary the metal centers are electronically isolated in 1 and 2 where the bridging ligands are based on ethane and propane linkers. The dimer 4 exhibits two accessible reversible reduction couples separated by 570 mV indicating the stability of the one-electron reduced species located on the diimine-based bridge abp. The "Ir(ppy)(2)" units in compound 5 are noninteracting as the electronic conduit is truncated by the ethane spacer in the bpfd bridge. The dinuclear compounds 1-5 show ligand centered (LC) transitions involving ppy ligands and mixed metal to ligand/ligand to ligand charge transfer (MLCT/LLCT) transitions involving both the cyclometalating ppy and bridging ligands (BL) in the UV-vis spectra. For the conjugated bridge bpe in compound 3 and abp in compound 4, the lowest-energy charge-transfer absorptions are red-shifted with enhanced intensity. In accordance with their similar electronic structures, compounds 1 and 2 exhibit identical emissions. The presence of vibronic structures in these compounds indicates a predominantly (3)LC excited states. On the contrary, broad and unstructured

  11. Ruthenium(II) bipyridine complexes bearing new keto-enol azoimine ligands: synthesis, structure, electrochemistry and DFT calculations.

    Science.gov (United States)

    Al-Noaimi, Mousa; Awwadi, Firas F; Mansi, Ahmad; Abdel-Rahman, Obadah S; Hammoudeh, Ayman; Warad, Ismail

    2015-01-25

    The novel azoimine ligand, Ph-NH-N=C(COCH3)-NHPh(C≡CH) (H2L), was synthesized and its molecular structure was determined by X-ray crystallography. Catalytic hydration of the terminal acetylene of H2L in the presence of RuCl3·3H2O in ethanol at reflux temperature yielded a ketone (L1=Ph-N=N-C(COCH3)=N-Ph(COCH3) and an enol (L2=Ph-N=N-C(COCH3)=N-PhC(OH)=CH2) by Markovnikov addition of water. Two mixed-ligand ruthenium complexes having general formula, trans-[Ru(bpy)(Y)Cl2] (1-2) (where Y=L1 (1) and Y=L2 (2), bpy is 2.2'-bipyrdine) were achieved by the stepwise addition of equimolar amounts of (H2L) and bpy ligands to RuCl3·3H2O in absolute ethanol. Theses complexes were characterized by elemental analyses and spectroscopic (IR, UV-Vis, and NMR (1D (1)H NMR, (13)C NMR, (DEPT-135), (DEPT-90), 2D (1)H-(1)H and (13)C-(1)H correlation (HMQC) spectroscopy)). The two complexes exhibit a quasi-reversible one electron Ru(II)/Ru(III) oxidation couple at 604 mV vs. ferrocene/ferrocenium (Cp2Fe(0/+)) couple along with one electron ligand reduction at -1010 mV. The crystal structure of complex 1 showed that the bidentate ligand L1 coordinates to Ru(II) by the azo- and imine-nitrogen donor atoms. The complex adopts a distorted trans octahedral coordination geometry of chloride ligands. The electronic spectra of 1 and 1+ in dichloromethane have been modeled by time-dependent density functional theory (TD-DFT). Copyright © 2014 Elsevier B.V. All rights reserved.

  12. DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole

    Science.gov (United States)

    Li, Mei; kong, Lin Lin; Gou, Yi; Yang, Feng; Liang, Hong

    2014-07-01

    A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.

  13. Synthesis, Spectral and Magnetic Studies of Newly Mixed-Ligand Complexes of 4-Formyl-Acetanilide Thiosemicarbazone and 3,4-Dihydrocinnamic Acid with Some Metal Ions

    Directory of Open Access Journals (Sweden)

    Shayma A. Shaker

    2010-01-01

    Full Text Available New complexes with thiosemicarbazone derivative and 3, 4-dihydrocinnamic acid were prepared and characterized by elemental analysis, determination of metal, IR, 1H NMR, electronic spectroscopy and magnetic measurements. The thiosemicarbazone derivative forms bidentate ligand complexes of the general formula, [M(Thz(Caf] where Thz = 4-formyl- acetanilide thiosemicarbazone, Caf = 3,4-dihydrocinnamic acid and M=Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+. The IR and 1H NMR spectra indicates that the (Thz was coordinated with the metal ions through the N and S atoms and the (Caf was negatively charged bidentat ligand and was coordinated with the metal ions through the two O atoms. Electronic spectra and magnetic susceptibility measurements of the solid complexes indicates the tetrahedral geometry around the Mn2+, Fe2+, Co2+, Ni2+, Zn2+, Cd2+ and irregular tetrahedral geometry around Pb2+ ion while the Cu2+ complex has squar planer geometry.

  14. The physical chemistry of coordinated aqua-, ammine-, and mixed-ligand Co2+ complexes: DFT studies on the structure, energetics, and topological properties of the electron density.

    Science.gov (United States)

    Varadwaj, Pradeep R; Marques, Helder M

    2010-03-07

    Spin-unrestricted DFT-X3LYP/6-311++G(d,p) calculations have been performed on a series of complexes of the form [Co(H(2)O)(6-n)(NH(3))(n)](2+) (n = 0-6) to examine their equilibrium gas-phase structures, energetics, and electronic properties in their quartet electronic ground states. In all cases Co(2+) in the energy-minimised structures is in a pseudo-octahedral environment. The calculations overestimate the Co-O and Co-N bond lengths by 0.04 and 0.08 A, respectively, compared to the crystallographically observed mean values. There is a very small Jahn-Teller distortion in the structure of [Co(H(2)O)(6)](2+) which is in contrast to the very marked distortions observed in most (but not all) structures of this cation that have been observed experimentally. The successive replacement of ligated H(2)O by NH(3) leads to an increase in complex stability by 6 +/- 1 kcal mol(-1) per additional NH(3) ligand. Calculations using UB3LYP give stabilisation energies of the complexes about 5 kcal mol(-1) smaller and metal-ligand bond lengths about 0.005 A longer than the X3LYP values since the X3LYP level accounts for the London dispersion energy contribution to the overall stabilisation energy whilst it is largely missing at the B3LYP level. From a natural population analysis (NPA) it is shown that the formation of these complexes is accompanied by ligand-to-metal charge transfer the extent of which increases with the number of NH(3) ligands in the coordination sphere of Co(2+). From an examination of the topological properties of the electron charge density using Bader's quantum theory of atoms in molecules it is shown that the electron density rho(c) at the Co-O bond critical points is generally smaller than that at the Co-N bond critical points. Hence Co-O bonds are weaker than Co-N bonds in these complexes and the stability increases as NH(3) replaces H(2)O in the metal's coordination sphere. Several indicators, including the sign and magnitude of the Laplacian of the

  15. The chemistry of polypyridine complexes of ruthenium. Communication 5. Electronic structure of mixed-ligand bipyridyl-diphosphine complexes of ruthenium(2)

    International Nuclear Information System (INIS)

    Sizova, O.V.; Ivanova, N.V.; Ershov, A.Yu.

    2001-01-01

    Comparative analysis of donor-acceptor abilities of diphosphine ligands for two series of complex compounds: cis-[Ru(bpy) 2 (LL) q+ [LL=2,2'-bipyridyl(bpy), o-benzoquinonediimine (bqdi), cis-1,2-bis(diphenylphosphino)ethane, cis-1,2-bis(diphenylphosphino)ethylene (dppen), (NH 3 ) 2 and (CO) 2 ] and [Ru(NH 3 ) 4 (LL)] 2+ (LL = bpy, dppen and bqdi) was carried out on the basis of results of quantum chemical calculations. It is shown that diphosphines are the strongest σ-donors; their π-acceptor abilities stemming from d-orbitals of phosphorus are comparable in value with π-acceptor abilities of 2,2'-bipyridyl, being essentially lower than those of o-benzoquinonediimine and carbonyl [ru

  16. Chapter 19. Design and evaluation of potential 99mTc radiopharmaceuticals based on the Tc-Carbonyl, 4 + 1 mixed ligand chelate system and Tc-nitrido approaches

    International Nuclear Information System (INIS)

    Giglio, J.; Muslera, A.; Leon, E.; Paolino, A.; Leon, A.; Rey, A.; Incerti, M.; Fernandez, R.; Manta, E.; Brugnini, A.; Chabalgoity, A.

    2007-01-01

    The aim of the work was to explore the possibilities of the novel labelling strategies in the development of 99m Tc labelled small biomolecules. Different steps required to fulfil this objective were undertaken: organic synthesis of glucose derivatives, optimization of labelling and in vitro and in vivo evaluation of Rd peptides and anne xin 13 derivatives using either the Hyonic bifunctional ligand, the Tc-tricarbonyl, the 4 + 1 mixed ligand or the Tc(V)-nitri do approaches. Glucose-O-hexyl bromide, glucose- O-butylbromide and glucose-O-butylamine were successfully synthesized, opening the possibility of introducing different chelators according to the desired labelling procedure. c(RGDyK) derivatives bearing different chelators were labelled with 99m Tc using novel approaches and evaluated both in vitro and in vivo in order to compare the effect of the chelator and labelling method on the physicochemical and biological behaviour. Annexin 13 peptides were also labelled using the HYNIC and Tc(I)-tricarbonyl approaches. A primary evaluation in normal animals and in a model of cardiac apoptosis is also presented. Cooperation with other participants was crucial to develop this work. (author)

  17. 3D coordination polymers with nitrilotriacetic and 4,4'-bipyridyl mixed ligands: structural variation based on dinuclear or tetranuclear subunits assisted by Na-O and/or O-H...O interactions.

    Science.gov (United States)

    Lü, Xing-Qiang; Jiang, Ji-Jun; Chen, Chun-Long; Kang, Bei-Sheng; Su, Cheng-Yong

    2005-06-27

    The reactions of Cu(II) with the mixed nitrilotriacetic acid (H3NTA) and 4,4'-bipyridyl (4,4'-bpy) ligands in different metal-to-ligand ratios in the presence of NaOH and NaClO4 afforded two complexes, Na3[Cu2(NTA)2(4,4'-bpy)]ClO4 x 5H2O (1) and [Cu2(NTA) (4,4'-bpy)2]ClO4 x 4H2O (2). The two complexes have been characterized by elemental analysis, IR, XRD, and single-crystal X-ray diffraction. 1 contains a basic doubly negatively charged [Cu2(NTA)2(4,4'-bpy)]2- dinuclear unit which was further assembled via multiple Na-O and O-H...O interactions into a three-dimensional (3D) pillared-layer structure. 2 features a two-dimensional (2D) undulated brick-wall architecture containing a basic doubly positively charged [Cu4(NTA)2(4,4'-bpy)2]2+ tetranuclear unit. The 2D network possesses large cavities hosting guest molecules and was further assembled via O-H...O hydrogen bonds into a 3D structure with several channels running in different directions.

  18. Trans-Spatial Utopias

    Science.gov (United States)

    Kramsch, Claire

    2018-01-01

    The "trans-" perspectives offered in this special issue are heady stuff. Post-structuralism (philosophy) meets the digital age (electronics), meets globalization (economics), and meets translingual practice (linguistics) to create a perfectly utopian or placeless space for future exploration. I want to first add my voice to the…

  19. Low Trans Hydrogenation

    Science.gov (United States)

    Although hydrogenation has been the technology of choice for fat formulation for many years recent concerns over the health and nutrition of trans fatty acids have had a profound effect on the edible oil industry. Since Jan. 1, 2006, TFA has been required on nutrition labels along with saturated an...

  20. Molecular Structures, Vibrational Spectroscopy, and Normal-Mode Analysis of M(2)(C&tbd1;CR)(4)(PMe(3))(4) Dimetallatetraynes. Observation of Strongly Mixed Metal-Metal and Metal-Ligand Vibrational Modes.

    Science.gov (United States)

    John, Kevin D.; Miskowski, Vincent M.; Vance, Michael A.; Dallinger, Richard F.; Wang, Louis C.; Geib, Steven J.; Hopkins, Michael D.

    1998-12-28

    on Mo(2)Cl(4)P(4), show that nu(a), nu(b), and nu(c) arise from modes of strongly mixed nu(Mo(2)), nu(MoC), and lambda(MoCC) character. The relative intensities of the resonance-Raman bands due to nu(a), nu(b), and nu(c) reflect, at least in part, their nu(M(2)) character. In contrast, the force field shows that mixing of nu(M(2)) and nu(C&tbd1;C) is negligible. The three-mode mixing is expected to be a general feature for quadruply bonded complexes with unsaturated ligands.

  1. A P,O,P′-tridentate mixed-donor scorpionate ligand: 6-[4,6-bis(diphenylphosphino-10H-phenoxazin-10-yl]hexan-1-ol

    Directory of Open Access Journals (Sweden)

    Holger B. Friedrich

    2008-10-01

    Full Text Available The title compound, C42H39NO2P2, is a P,O,P′-tridentate scorpionate-type ligand and has one molecule in the asymmetric unit. The angles involving the P atoms range from 100.21 (7 to 104.89 (7°. The N-hexanol group was found to be disordered and was refined over two positions with final occupancies of 0.683 (3 and 0.317 (3 which affected the C—O and C—N bond lengths. The bond lengths for C—O range from 1.402 (2 to 1.415 (2 Å and for C—N from 1.410 (2 to 1.448 (3 Å for the major disorder component; the corresponding ranges for the minor disorder component are 1.429 (3–1.408 (3 and 1.474 (3–1.474 (4 Å.

  2. A trans world journey

    DEFF Research Database (Denmark)

    Stender, Steen; Dyerberg, Jørn; Bysted, Anette

    2006-01-01

    to a maximum of 2% of fat content from 2004. We assessed the potential exposure of consumers to IP-TFA by analysing popular foods in Denmark, and in 25 other countries. Fifty-five servings of French fries and chicken nuggets, 87 packages of microwave popcorn, and 393 samples of biscuits....../cakes/wafers with "partially hydrogenated vegetable fat" listed high on the food label were bought between November 2004, and February 2006. The content of IP-TFA was analysed by standardized methodology. We defined a "high trans menu" as a large size serving of French fries and nuggets, 100 g of microwave popcorn, and 100 g......A high intake of industrially produced trans fatty acids (IP-TFA) is associated with increased risk of coronary heart disease (CHD), and a daily intake as low as possible is required to minimize health risks. To achieve this at the individual level in Denmark, legislation limited IP-TFA in foods...

  3. NMR spectroscopic and X-ray crystallographic study of methylcobalt(III) compounds with saturated amine ligands

    DEFF Research Database (Denmark)

    Kofod, Pauli; Harris, Pernille

    2004-01-01

    The C-13 chemical shifts of methylcobalt(III) compounds with saturated amine ligands in cis positions to the methyl group and a monodentate ligand, L = CN-, NH3, NO2, N-3(-), H2O, or OH-, in the trans position are reported. The amine ligands used, 1,2-ethanediamine (en), 1,3-propanediamine (tn), N...

  4. Heterobimetallic [NiFe] Complexes Containing Mixed CO/CN- Ligands: Analogs of the Active Site of the [NiFe] Hydrogenases.

    Science.gov (United States)

    Perotto, Carlo U; Sodipo, Charlene L; Jones, Graham J; Tidey, Jeremiah P; Blake, Alexander J; Lewis, William; Davies, E Stephen; McMaster, Jonathan; Schröder, Martin

    2018-03-05

    The development of synthetic analogs of the active sites of [NiFe] hydrogenases remains challenging, and, in spite of the number of complexes featuring a [NiFe] center, those featuring CO and CN - ligands at the Fe center are under-represented. We report herein the synthesis of three bimetallic [NiFe] complexes [Ni( N 2 S 2 )Fe(CO) 2 (CN) 2 ], [Ni( S 4 )Fe(CO) 2 (CN) 2 ], and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] that each contain a Ni center that bridges through two thiolato S donors to a {Fe(CO) 2 (CN) 2 } unit. X-ray crystallographic studies on [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ], supported by DFT calculations, are consistent with a solid-state structure containing distinct molecules in the singlet ( S = 0) and triplet ( S = 1) states. Each cluster exhibits irreversible reduction processes between -1.45 and -1.67 V vs Fc + /Fc and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] possesses a reversible oxidation process at 0.17 V vs Fc + /Fc. Spectroelectrochemical infrared (IR) and electron paramagnetic resonance (EPR) studies, supported by density functional theory (DFT) calculations, are consistent with a Ni III Fe II formulation for [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + . The singly occupied molecular orbital (SOMO) in [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + is based on Ni 3d z 2 and 3p S with the S contributions deriving principally from the apical S-donor. The nature of the SOMO corresponds to that proposed for the Ni-C state of the [NiFe] hydrogenases for which a Ni III Fe II formulation has also been proposed. A comparison of the experimental structures, and the electrochemical and spectroscopic properties of [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] and its [Ni( N 2 S 3 )] precursor, together with calculations on the oxidized [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + and [Ni( N 2 S 3 )] + forms suggests that the binding of the {Fe(CO)(CN) 2 } unit to the {Ni(CysS) 4 } center at the active site of the [NiFe] hydrogenases suppresses thiolate-based oxidative chemistry involving the bridging thiolate S donors

  5. CD8 T cell memory to a viral pathogen requires trans cosignaling between HVEM and BTLA.

    Directory of Open Access Journals (Sweden)

    Rachel Flynn

    Full Text Available Defining the molecular interactions required to program activated CD8 T cells to survive and become memory cells may allow us to understand how to augment anti-viral immunity. HVEM (herpes virus entry mediator is a member of the tumor necrosis factor receptor (TNFR family that interacts with ligands in the TNF family, LIGHT and Lymphotoxin-α, and in the Ig family, B and T lymphocyte attenuator (BTLA and CD160. The Ig family members initiate inhibitory signaling when engaged with HVEM, but may also activate survival gene expression. Using a model of vaccinia virus infection, we made the unexpected finding that deficiency in HVEM or BTLA profoundly impaired effector CD8 T cell survival and development of protective immune memory. Mixed adoptive transfer experiments indicated that BTLA expressed in CD8α+ dendritic cells functions as a trans-activating ligand that delivers positive co-signals through HVEM expressed in T cells. Our data demonstrate a critical role of HVEM-BTLA bidirectional cosignaling system in antiviral defenses by driving the differentiation of memory CD8 T cells.

  6. χ{sup (3)} measurements of axial ligand modified high valent tin(IV) porphyrins using degenarete four wave mixing at 532nm

    Energy Technology Data Exchange (ETDEWEB)

    Narendran, N. K. Siji, E-mail: sijinarendran@gmail.com; Chandrasekharan, K. [Laser and nonlinear optics laboratory, Department of Physics, National Institute of Technology Calicut, Calicut-673601, Kerala (India); Soman, Rahul; Arunkumar, Chellaiah [Bioinorganic materials laboratory, Department of Chemistry, National Institute of Technology Calicut, Calicut-673601, Kerala (India); Sudheesh, P. [Department of Physics, VTM NSS College, Dhanuvachapuram, Thiruvananthapuram (India)

    2014-10-15

    Porphyrins and metalloporphyrins are unique class of molecules for Nonlinear Optical applications because of their unique structure of altering the central metal atom, large extended π-system, high thermal stability, tunable shape, symmetry and synthetic versatility Here, we report χ{sup (3)} Measurements of a simple phenyl porphyrins and its highvalent tin(IV) porphyrins with Bromination characterized by UV-Visible spectroscopic method. In this study, we employed the Degenerate Four Wave Mixing technique using forward Boxcar geometry with an Nd:YAG nano second pulsed laser as source and it was found that the tin(IV) porphyrin with Bromination exhibits good χ{sup (3)} value and figure of merit.

  7. Synthesis, Crystal Structure, and Electroconducting Properties of a 1D Mixed-Valence Cu(I–Cu(II Coordination Polymer with a Dicyclohexyl Dithiocarbamate Ligand

    Directory of Open Access Journals (Sweden)

    Kenji Nakatani

    2015-04-01

    Full Text Available A new mixed-valence Cu(I–Cu(II 1D coordination polymer, [CuI4CuIIBr4(Cy2dtc2]n, with an infinite chain structure is synthesized by the reaction of Cu(Cy2dtc2 (Cy2dtc− = dicyclohexyl dithiocarbamate, C13H22NS2 with CuBr·S(CH32. The as-synthesized polymer consists of mononuclear copper(II units of CuII(Cy2dtc2 and tetranuclear copper(I cluster units, CuI4Br4. In the cluster unit, all the CuI ions have distorted trigonal pyramidal coordination geometries, and the CuI–CuI or CuI–CuII distances between the nearest copper ions are shorter than the sum of van der Waals radii for Cu–Cu.

  8. FACTS ABOUT TRANS FATTY ACIDS

    Directory of Open Access Journals (Sweden)

    Sedighe Asgary

    2010-12-01

    be involved in the pathogenesis of atherosclerosis, acute coronary syndromes, sudden death, insulin resistance, dyslipidemia, and heart failure. Fatty acids may also directly or indirectly modulate metabolic and inflammatory responses of the endoplasmic reticulum 31 (Figure 2. Evidence from both observational and experimental studies indicates that TFA are pro-inflammatory. Inflammation is an independent risk factor for cardiovascular diseases (CVD. Epidemiologic studies have suggested that TFA may have an adverse effect on inflammatory markers. In the Nurses’ Health Study, TFA intake, assessed by semi-quantitative food - frequency questionnaires, was  positively associated with tumor necrosis factor receptor (TNFR levels in healthy women (P for trend < 0.001, and was also associated with levels of C-reactive protein (CRP and IL-6 in women with higher BMI (P < 0.05 [32-35]. Limited evidence suggests that pro-inflammatory effects may be stronger for trans isomers of linoleic acid (trans-C18:2 and oleic acid (trans-C18:1, rather than of palmitoleic acid (trans-C16:1, but further study of potential isomer-specific effects is needed. TFA also appear to induce endothelial dysfunction. The mechanisms underlying this effect is not well-established, but may involve TFA incorporation into endothelial cell, monocyte/macrophage, or adipocyte cell membranes (affecting membrane signaling pathway relating to inflammation or ligand-dependent effects on peroxisome proliferator-activated receptor (PPAR or retinoid X receptor (RXR pathways.36,37 Activation of inflammatory responses and endothelial dysfunction may represent important mediating pathways between TFA consumption and risk of coronary heart disease, sudden death, and diabetes.16      The possibility that TFAs decrease the threshold for cardiac arrhythmias has been supported by the results from a more recent case control study of the risk of sudden cardiac death. When levels of TFAs in red blood cells as a marker for

  9. Radioiodinated ligands for dopamine receptors

    International Nuclear Information System (INIS)

    Kung, H.F.

    1994-01-01

    The dopamine receptor system is important for normal brain function; it is also the apparent action site for various neuroleptic drugs for the treatment of schizophrenia and other metal disorders. In the past few years radioiodinated ligands for single photon emission tomography (SPECT) have been successfully developed and tested in humans: [ 123 I]TISCH for D1 dopamine receptors; [ 123 I]IBZM, epidepride, IBF and FIDA2, four iodobenzamide derivatives, for D2/D3 dopamine receptors. In addition, [ 123 I]β-CIT (RTI-55) and IPT, cocaine derivatives, for the dopamine reuptake site are potentially useful for diagnosis of loss of dopamine neurons. The first iodinated ligand, (R)trans-7-OH-PIPAT, for D3 dopamine receptors, was synthesized and characterized with cloned cell lines (Spodoptera frugiperda, Sf9) expressing the D2 and D3 dopamine receptors and with rat basal forebrain membrane preparations. Most of the known iodobenzamides displayed similar potency in binding to both D2 and D3 dopamine receptors expressed in the cell lines. Initial studies appear to suggest that by fine tuning the structures it may be possible to develop agents specific for D2 and D3 dopamine receptors. It is important to investigate D2/D3 selectivity for this series of potent ligands

  10. Ligand sphere conversions in terminal carbide complexes

    DEFF Research Database (Denmark)

    Morsing, Thorbjørn Juul; Reinholdt, Anders; Sauer, Stephan P. A.

    2016-01-01

    Metathesis is introduced as a preparative route to terminal carbide complexes. The chloride ligands of the terminal carbide complex [RuC(Cl)2(PCy3)2] (RuC) can be exchanged, paving the way for a systematic variation of the ligand sphere. A series of substituted complexes, including the first...... example of a cationic terminal carbide complex, [RuC(Cl)(CH3CN)(PCy3)2]+, is described and characterized by NMR, MS, X-ray crystallography, and computational studies. The experimentally observed irregular variation of the carbide 13C chemical shift is shown to be accurately reproduced by DFT, which also...... demonstrates that details of the coordination geometry affect the carbide chemical shift equally as much as variations in the nature of the auxiliary ligands. Furthermore, the kinetics of formation of the sqaure pyramidal dicyano complex, trans-[RuC(CN)2(PCy3)2], from RuC has been examined and the reaction...

  11. Mechanism of pyridine-ligand exchanges at the different labile sites of 3d heterometallic and mixed valence mu3-oxo trinuclear clusters.

    Science.gov (United States)

    Novitchi, Ghenadie; Riblet, Fabrice; Scopelliti, Rosario; Helm, Lothar; Gulea, Aurelian; Merbach, André E

    2008-11-17

    The syntheses and single crystal X-ray structural analysis of five novel hetero- and homometallic mu 3-oxo trinuclear cluster with the formula [Fe (III) 2M (II)(mu 3-O)(mu-O 2CCH 3) 6(4-Rpy) 3]. x(4-Rpy). y(CH 3CN) where R = Ph for 1(Fe 2Mn), 2(Fe 2Fe), 3(Fe 2Co), 4(Fe 2Ni) and R = CF 3 for 5(Fe 2Co), are reported. The persistence of the structure for compounds 2- 5 in dichloromethane solution in the temperature range 190-320 K is demonstrated by (1)H and (19)F NMR spectroscopy. Even at the lowest temperature, the electron exchange in the homometallic mixed-valence compound 2(Fe 2Fe) is in the fast regime at the NMR time scale. Variable temperature and pressure NMR line broadening allowed quantifying the fast coordinated/free 4-Rpy exchanges at the two labile metal centers in these clusters: 2: Fe (III)( k (298)/10 (3) s (-1) = 16.6; Delta H (++) = 60.32 kJ mol (-1); Delta S (++) = + 34.8 J K (-1) mol (-1); Delta V (++) = + 12.5 cm (3) mol (-1)); 3: Fe (11.9; 58.92; +30.7; +10.6) and Co (2.8; 68.24; +49.8; +13.9); 4: Fe(12.2; 67.91; +61.0; -) and Ni (0.37; 78.62; +67.8; +12.3); 5: Fe (46; 58.21; +39.3; +14.2) and Co (4.7; 55.37; +11.2; +10.9). A limiting D mechanism is assigned to these exchange reactions. This assignment is based on a first-order rate law, the detection of intermediates, the positive and large entropies and volumes of activation. The order of reactivity k (Co) > k (Ni) is expected for a D mechanism at these metal centers: their low exchange rates are due to their strong binding with the 4-Rpy donor. Surrounded by oxygen donors the d (5) iron(III) usually reacts associatively; however, here due to low affinity of this ion for nitrogen the mechanism is D and the rate of exchange is very fast, even faster than on the divalent ions. There is no significant effect of the divalent ion in cluster 2, 3, and 5 on the exchange rates of 4-Phpy at the iron center, which seems to indicate that the specific electronic interactions between the three ions making

  12. Cis/trans Coordination in olefin metathesis by static and molecular dynamic DFT calculations

    KAUST Repository

    Poater, Albert

    2014-05-25

    In regard to [(N-heterocyclic carbene)Ru]-based catalysts, it is still a matter of debate if the substrate binding is preferentially cis or trans to the N-heterocyclic carbene ligand. By means of static and molecular dynamic DFT calculations, a simple olefin, like ethylene, is shown to be prone to the trans binding. Bearing in mind the higher reactivity of trans isomers in olefin metathesis, this insight helps to construct small alkene substrates with increased reactivity. © 2014 Springer Science+Business Media New York.

  13. Cis/trans Coordination in olefin metathesis by static and molecular dynamic DFT calculations

    KAUST Repository

    Poater, Albert; Correa, Andrea; Pump, Eva; Cavallo, Luigi

    2014-01-01

    In regard to [(N-heterocyclic carbene)Ru]-based catalysts, it is still a matter of debate if the substrate binding is preferentially cis or trans to the N-heterocyclic carbene ligand. By means of static and molecular dynamic DFT calculations, a simple olefin, like ethylene, is shown to be prone to the trans binding. Bearing in mind the higher reactivity of trans isomers in olefin metathesis, this insight helps to construct small alkene substrates with increased reactivity. © 2014 Springer Science+Business Media New York.

  14. Preparation and Spectral Properties of Mixed-Ligand Complexes of VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II with Dimethylglyoxime and N-acetylglycine

    Directory of Open Access Journals (Sweden)

    Shayma A. Shaker

    2010-01-01

    Full Text Available A number of mixed-ligand complexes of the general formula [M(D(G] where D=dimethylglyoximato monoanion, G=N-acetylglycinato and M=VO(IV, Ni(II, Zn(II, Pd(II, Cd(II and Pb(II were prepared. Each complex was characterized by elemental analysis, determination of metal, infrared spectra, electronic spectra, (1H and 13C NMR spectra, conductivity and magnetic moments. All these complexes were not soluble in some of the organic solvent but highly soluble in dimethylformamide. The conductivity data showed the non-electrolytic nature of the complexes. The electronic spectra exhibited absorption bands in the visible region caused by the d-d electronic transition such as VO(IV, Ni(II and Pd(II. The IR and (1H, 13C NMR spectra which have indicate that the dimethylglyoxime was coordinated with the metal ions through the N and O atoms of the oxime group and N-acetylglycine was coordinated with metal ions through the N atom and terminal carboxyl oxygen atom.

  15. Study on the ternary mixed ligand complex of palladium(II)-aminophylline-fluorescein sodium by resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectrum and its analytical application.

    Science.gov (United States)

    Chen, Peili; Liu, Shaopu; Liu, Zhongfang; Hu, Xiaoli

    2011-01-01

    The interaction between palladium(II)-aminophylline and fluorescein sodium was investigated by resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectrum. In pH 4.4 Britton-Robinson (BR) buffer medium, aminophylline (Ami) reacted with palladium(II) to form chelate cation([Pd(Ami)]2+), which further reacted with fluorescein sodium (FS) to form ternary mixed ligand complex [Pd(Ami)(FS)2]. As a result, resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering spectrum (FDS) were enhanced. The maximum scattering wavelengths of [Pd(Ami)(FS)2] were located at 300 nm (RRS), 650 nm (SOS) and 304 nm (FDS). The scattering intensities were proportional to the Ami concentration in a certain range and the detection limits were 7.3 ng mL(-1) (RRS), 32.9 ng mL(-1) (SOS) and 79.1 ng mL(-1) (FDS), respectively. Based on it, the new simple, rapid, and sensitive scattering methods have been proposed to determine Ami in urine and serum samples. Moreover, the formation mechanism of [Pd(Ami)(FS)2] and the reasons for enhancement of RRS were fully discussed. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  16. Zirconium bisamidinate complexes with sterically demanding ligands : structure, solution dynamics, and reactivity

    NARCIS (Netherlands)

    Otten, Edwin; Dijkstra, Peter; Visser, Cindy; Meetsma, Auke; Hessen, Bart

    2005-01-01

    Bisamidinate zirconium dichloride and dimethyl complexes with the sterically demanding amidinate ligands [PhC(NAr)(2))](-) (A) and [PhC(NAr)(NAr')](-) (B) (Ar = 2,6-(Pr2C6H3)-Pr-i; Ar' = 2,6-Me2C6H3) were prepared. The steric demand of ligand A induces the unusual trans geometry in

  17. The affinity of the uranyl ion for nitrogen donor ligands

    International Nuclear Information System (INIS)

    Jarvis, N.V.; De Sousa, A.S.; Hancock, R.D.

    1992-01-01

    Established ligand design principles are used to predict the solution chemistry of UO 2 2+ with nitrogen donor ligands which do not contain carboxylate donors. pK a 's of the nitrogen donors are lowered by addition of hydroxylalkyl groups causing UO 2 2+ to have a greater affinity for these ligands than for hydroxide. Potentiometric studies using the ligands N,N,N',N',N''-pentakis(2-hydroxypropyl)-1,4,7-triazaheptane; N,N,N',N',N''-pentakis(2-hydroxyethyl)-1,4,7-triazaheptane; N,N,N',N'-tetrakis(2-hydroxypropyl)1,2-diaminoethane, N,N,N',N'-tetrakis(2-hydroxyethyl)-trans-1,2-diaminocyclohexane; 1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane and N,N-bis(2-hydroxyethyl)glycine with UO 2 2+ showed that UO 2 2+ has a considerable aqueous solution chemistry with these ligands. (orig.)

  18. Strong metal-metal coupling in mixed-valent intermediates [Cl(L)Ru(mu-tppz)Ru(L)Cl](+), L = beta-diketonato ligands, tppz=2,3,5,6-tetrakis(2-pyridyl)pyrazine

    Czech Academy of Sciences Publication Activity Database

    Kundu, T.; Schweinfurth, D.; Sarkar, B.; Mondal, T. K.; Fiedler, Jan; Mobin, S. M.; Puranik, V. G.; Kaim, W.; Lahiri, G. K.

    2012-01-01

    Roč. 41, č. 43 (2012), s. 13429-13440 ISSN 1477-9226 R&D Projects: GA AV ČR IAA400400802 Institutional support: RVO:61388955 Keywords : TRIDENTATE BRIDGING LIGAND * DENSITY-FUNCTIONAL THEORY * HYDRAZONE-BASED LIGAND S Subject RIV: CG - Electrochemistry Impact factor: 3.806, year: 2012

  19. Mixed-valent and radical states of complexes [(bpy)(2)M(.mu.-abpy)M´(bpy)(2)](n+), M,M´ = Ru or Os, abpy=2,2´-azobispyridine: Electron transfer vs. hole transfer mechanism in azo ligand-bridged complexes

    Czech Academy of Sciences Publication Activity Database

    Heilmann, M.; Frantz, S.; Kaim, W.; Fiedler, Jan; Duboc, C.

    2006-01-01

    Roč. 359, č. 3 (2006), s. 821-829 ISSN 0020-1693 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400505; GA ČR GA203/03/0821 Institutional research plan: CEZ:AV0Z40400503 Keywords : mixed valency * osmium compounds * radical ligand s * ruthenium compounds * spectroslectrochemistry Subject RIV: CG - Electrochemistry Impact factor: 1.674, year: 2006

  20. Mitochondrial protection by the mixed muscarinic/σ1 ligand ANAVEX2-73, a tetrahydrofuran derivative, in Aβ25-35 peptide-injected mice, a nontransgenic Alzheimer's disease model.

    Science.gov (United States)

    Lahmy, Valentine; Long, Romain; Morin, Didier; Villard, Vanessa; Maurice, Tangui

    2014-01-01

    Alzheimer's disease (AD), the most prevalent dementia in the elderly, is characterized by progressive synaptic and neuronal loss. Mitochondrial dysfunctions have been consistently reported as an early event in AD and appear before Aβ deposition and memory decline. In order to define a new neuroprotectant strategy in AD targeting mitochondrial alterations, we develop tetrahydro-N,N-dimethyl-2,2-diphenyl-3-furanmethanamine (ANAVEX2-73, AE37), a mixed muscarinic receptor ligand and a sigma-1 receptor (σ1R) agonist. We previously reported that ANAVEX2-73 shows anti-amnesic and neuroprotective activities in mice injected intracerebroventricular (ICV) with oligomeric amyloid-β25-35 peptide (Aβ25-35). The σ1R is present at mitochondria-associated endoplasmic reticulum (ER) membranes, where it acts as a sensor/modulator of ER stress responses and local Ca(2+) exchanges with the mitochondria. We therefore evaluated the effect of ANAVEX2-73 and PRE-084, a reference σ1R agonist, on preservation of mitochondrial integrity in Aβ25-35-injected mice. In isolated mitochondria from hippocampus preparations of Aβ25-35 injected animals, we measured respiration rates, complex activities, lipid peroxidation, Bax/Bcl-2 ratios and cytochrome c release into the cytosol. Five days after Aβ25-35 injection, mitochondrial respiration in mouse hippocampus was altered. ANAVEX2-73 (0.01-1 mg/kg IP) restored normal respiration and PRE-084 (0.5-1 mg/kg IP) increased respiration rates. Both compounds prevented Aβ25-35-induced increases in lipid peroxidation levels, Bax/Bcl-2 ratio and cytochrome c release into the cytosol, all indicators of increased toxicity. ANAVEX2-73 and PRE-084 efficiently prevented the mitochondrial respiratory dysfunction and resulting oxidative stress and apoptosis. The σ1R, targeted selectively or non-selectively, therefore appears as a valuable target for protection against mitochondrial damages in AD.

  1. mixed-ligand complexes of dimethylglyoxime

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... basis of the average diameter of the colony compared to the res- pective control cultures ... ash and light green. The melting ... Dark Brown. 130. 68.2. 0.18 .... 4F term is split into three sub energy levels namely 4A2g. 4T2g and ...

  2. Mixed ligand chelates and plutonium poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, E R; Stones, V A [Medical Research Council, Harwell (UK). Radiobiological Research Unit

    1980-07-01

    The recent claim that a combination of DTPA with sodium salicylate (DTPA/SA) cleared plutonium completely from all mouse tissues, (Schubert and Derr, Nature 275,311-313,1978), aroused considerable interest. The experiments described here were designed to test this claim and have shown that DTPA/SA is at best no more effective than DTPA.

  3. Radical feminists & trans activists truce

    OpenAIRE

    Mackay, F.

    2014-01-01

    #GenderWeek: Truce! When radical feminists and trans feminists empathise\\ud Feminist Times\\ud By Finn Mackay \\ud read all #GenderWeek articles.\\ud We wanted to explore the ground between the polarised, entrenched positions in the so-called “TERF-war”. Radical feminists on one pole, trans-inclusionary feminists and trans activists on the other. The disputed territory being women-only space, language and the ever changing legal framework surrounding gender.\\ud Entrenchment leads to stalemate. S...

  4. trans-Dichlorido­bis(3,4-dimethyl­pyridine)platinum(II)

    Science.gov (United States)

    Chernyshev, Alexander N.; Bokach, Nadezhda A.; Izotova, Youlia A.; Haukka, Matti

    2009-01-01

    In the title compound, trans-[PtCl2(C7H9N)2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethyl­pyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar. PMID:21581530

  5. Spectroscopic manifestation of trans- effect in tungsten (6) octahedral complexes

    Energy Technology Data Exchange (ETDEWEB)

    Buslaev, Yu A; Tsivadze, A Yu; Kharitonov, Yu Ya; Kokunov, Yu V; Gustyakova, M P [AN SSSR, Moscow. Inst. Obshchej i Neorganicheskoj Khimii

    1977-10-01

    The vibration spectra are studied of the following WOF/sub 4/ acetonitrile solutions in the presence of L ligands: formamide, acetamide, propioamide, butyric acid amide, dimethyl formamide, dimethyl acetamide, oxymethyl nicotinamide, diethyl nicotinamide, benzamide, salicylic acid amide, acetal acetamide, hydrorubean acid, hexamethyl phosphorus triamide, tetramethyl urea, TBP, DMSO and diethyl amine, molar ratio of WOF/sub 4/:L = 1:1. Infrared absorption spectra (400-4000 cm/sup -1/) and combination scattering spectra (50-4000 cm/sup -1/) were recorded. A decline in the vibration frequency ..nu..(WO) was caused by a lesser strength constant in the WO bond during exchange of CH/sub 3/CN for L. A slight weakening of the WO bond depending on the nature of the trans-ligands of L on the L-W-O coordinate is representative of the trans-effect of coordinated ligands in the octahedral complexes of tungsten, WOF/sub 4/xL.

  6. Strong ligand field effects of blue phosphorescent Ir(III) complexes with phenylpyrazole and phosphines.

    Science.gov (United States)

    Park, Se Won; Ham, Ho Wan; Kim, Young Sik

    2012-04-01

    In the paper, we describe new Ir complexes for achieving efficient blue phosphorescence. New blue-emitting mixed-ligand Ir complexes comprising one cyclometalating, two phosphines trans to each other such as Ir(dppz)(PPh3)2(H)(L) (Ll= Cl, NCMe+, CN), [dppz = 3,5-Diphenylpyrazole] were synthesized and studied to tune the phosphorescence wavelength to the deep blue region and to enhance the luminescence efficiencies. To gain insight into the factors responsible for the emission color change and the variation of luminescence efficiency, we investigate the electron-withdrawing capabilities of ancillary ligands using DFT and TD-DFT calculations on the ground and excited states of the complexes. To achieve deep blue emission and increase the emission efficiency, (1) we substitute the phenyl group on the 3-position of the pyrazole ring that lowers the triplet energy enough that the quenching channel is not thermally accessible and (2) change the ancillary ligands coordinated to iridium atom to phosphine and cyano groups known as very strong field ligands. Their inclusion in the coordination sphere can increase the HOMO-LUMO gap to achieve the hypsochromic shift in emission color and lower the HOMO and LUMO energy level, which causes a large d-orbital energy splitting and avoids the quenching effect to improve the luminescence efficiency. The maximum emission spectra of Ir(dppz)(PPh3)2(H)(CI) and Ir(dppz)(PPh3)2(H)(CN) were in the ranges of 439, 432 nm, respectively.

  7. Reduction of dinitrogen ligands

    International Nuclear Information System (INIS)

    Richards, R.L.

    1983-01-01

    Processes of dinitrogen ligand reduction in complexes of transition metals are considered. The basic character of the dinitrogen ligand is underlined. Data on X-ray photoelectronic spectroscopy and intensities of bands ν (N 2 ) in IR-spectra of nitrogen complexes are given. The mechanism of protonation of an edge dinitrogen ligand is discussed. Model systems and mechanism of nitrogenogenase are compared

  8. N6-Benzyladenosine Derivatives as Novel N-Donor Ligands of Platinum(II Dichlorido Complexes

    Directory of Open Access Journals (Sweden)

    Ján Vančo

    2013-06-01

    Full Text Available The platinum(II complexes trans-[PtCl2(Ln2]∙xSolv 1–13 (Solv = H2O or CH3OH, involving N6-benzyladenosine-based N-donor ligands, were synthesized; Ln stands for N6-(2-methoxybenzyladenosine (L1, involved in complex 1, N6-(4-methoxy-benzyladenosine (L2, 2, N6-(2-chlorobenzyladenosine (L3, 3, N6-(4-chlorobenzyl-adenosine (L4, 4, N6-(2-hydroxybenzyladenosine (L5, 5, N6-(3-hydroxybenzyl-adenosine (L6, 6, N6-(2-hydroxy-3-methoxybenzyladenosine (L7, 7, N6-(4-fluoro-benzyladenosine (L8, 8, N6-(4-methylbenzyladenosine (L9, 9, 2-chloro-N6-(3-hydroxy-benzyladenosine (L10, 10, 2-chloro-N6-(4-hydroxybenzyladenosine (L11, 11, 2-chloro-N6-(2-hydroxy-3-methoxybenzyladenosine (L12, 12 and 2-chloro-N6-(2-hydroxy-5-methylbenzyladenosine (L13, 13. The compounds were characterized by elemental analysis, mass spectrometry, IR and multinuclear (1H-, 13C-, 195Pt- and 15N- and two-dimensional NMR spectroscopy, which proved the N7-coordination mode of the appropriate N6-benzyladenosine derivative and trans-geometry of the title complexes. The complexes 1–13 were found to be non-toxic in vitro against two selected human cancer cell lines (HOS and MCF7; with IC50 > 50.0 µM. However, they were found (by ESI-MS study to be able to interact with the physiological levels of the sulfur-containing biogenic biomolecule L-methionine by a relatively simple 1:1 exchange mechanism (one Ln molecule was replaced by one L-methionine molecule, thus forming a mixed-nitrogen/sulfur-ligand dichlorido-platinum(II coordination species.

  9. Ligands in PSI structures

    International Nuclear Information System (INIS)

    Kumar, Abhinav; Chiu, Hsiu-Ju; Axelrod, Herbert L.; Morse, Andrew; Elsliger, Marc-André; Wilson, Ian A.; Deacon, Ashley

    2010-01-01

    A survey of the types and frequency of ligands that are bound to PSI structures is analyzed as well as their utility in functional annotation of previously uncharacterized proteins. Approximately 65% of PSI structures report some type of ligand(s) that is bound in the crystal structure. Here, a description is given of how such ligands are handled and analyzed at the JCSG and a survey of the types, variety and frequency of ligands that are observed in the PSI structures is also compiled and analyzed, including illustrations of how these bound ligands have provided functional clues for annotation of proteins with little or no previous experimental characterization. Furthermore, a web server was developed as a tool to mine and analyze the PSI structures for bound ligands and other identifying features

  10. An Approach to Preparation of trans-DHQs via Ring-Opening of meso-N-Sulfonylaziridines

    DEFF Research Database (Denmark)

    Nolsøe, Jens Mortansson Jelstrup; Riegert, David; Müller, Paul

    2011-01-01

    As an approach to the enantioselective synthesis of trans-decahydroquinolines (DHQs), desymmetrization of meso-aziridine (5) with various carbon nucleophiles under catalytic conditions was investigated. By applying TMSCN in the presence of YbCl3 and chiral nonracemic ligands, nitrile 13 was obtai......As an approach to the enantioselective synthesis of trans-decahydroquinolines (DHQs), desymmetrization of meso-aziridine (5) with various carbon nucleophiles under catalytic conditions was investigated. By applying TMSCN in the presence of YbCl3 and chiral nonracemic ligands, nitrile 13...

  11. Synthesis, characterisation and antimicrobial studies of mixed nickel ...

    African Journals Online (AJOL)

    Conductance values indicated a 1:1 electrolyte for the complexes. The antimicrobial activities of the ligands and their mixed ligand complexes were screened using Agar diffusion method. It was found that the mixed metal complexes have higher antimicrobial activity than the free ligands. Keywords: Benzylhydrazone ...

  12. Trans fatty acid isomers and the trans-9/trans-11 index in fat containing foods

    Science.gov (United States)

    Kuhnt, Katrin; Baehr, Melanie; Rohrer, Carsten; Jahreis, Gerhard

    2011-01-01

    To determine trans fatty acid (TFA) distribution of contemporary foods, especially regarding individual trans octadecenoic acids (trans C18:1), 339 German foods of six categories (semi-solid fats, deep-fried potato products, bakery products, confectioneries, instant products and butter) were analysed using two GC methods. Results showed a high variation of TFA content between and within the categories containing between 0 and 40.5% of FAME except in butter, which is a source of natural TFA. The mean TFA values were below 2.0% of FAME, however, bakery products contained 4.5% and butter fat 3.2%, respectively. In addition, the distribution of individual trans C18:1 differed. In samples containing ruminant fat (butter and various confectioneries), vaccenic acid (t11-C18:1, t11) predominated, while in foods containing industrially hydrogenated fats, elaidic acid (trans-9, t9-) and t10-C18:1 were the major trans isomers.. This was reflected by a low t9/t11 index of 0.3 and 0.5 in butter and ruminant fat containing confectioneries, respectively, whilst the highest index was observed in shortenings and deep-fried potato products at 5.2 and 6.8, respectively. In conclusion, the TFA content of foods available on the German market is generally declining, but substantial variations are present. The t9/t11 index could be used as an indicator to determine ruminant fat. Practical applications: A number of studies provide evidence that a high TFA intake, particularly of industrial origin, adversely affects human health. The TFA content of foods could be reduced due to the introduction of several mandatory regulations and modifications regarding the hydrogenation process of oils. The most abundant dietary TFA are the isomers of trans C18:1. Unfortunately, the differentiation of these isomers is not yet very common, though the trans C18:1 profile differs depending on its origin (bacterial hydrogenation in the rumen or industrial hydrogenation). To date, data for TFA content

  13. Spectra of fluorinated rare earth. beta. -diketonates with added ligands

    Energy Technology Data Exchange (ETDEWEB)

    Khomenko, V.S.; Lozinskij, M.O.; Fialkov, Yu.A.; Rasshinina, T.A.; Krasovskaya, L.I. (AN Belorusskoj SSR, Minsk. Inst. Fiziki; AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    1984-01-01

    Different-ligand rare earth complexes are synthesized. Fluorated ..beta..-diketones, triethylphosphine oxide and trifluoracetic acid are used as active ligands. Mass-spectra of low and high resolution are taken at the energy of ionizing electrons of 70 eV, as well as luminescence spectra of complexes. Fragmentation ways of complexes decomposition under electron shock are studied. A series of changing the bound strength of additional ligands with europium in mixed complexes is determined. It is shown that the introduction of additional ligands can purposefully change physical and chemical properties of complexes.

  14. Analogy of the Coordination Chemistry of Alkaline Earth Metal and Lanthanide Ln²⁺ Ions: The Isostructural Zoo of Mixed Metal Cages [IM(OtBu)₄{Li(thf)}₄(OH)] (M=Ca, Sr, Ba, Eu), [MM′₆(OPh)₈(thf)₆] (M=Ca, Sr, Ba, Sm, Eu, M′=Li, Na), and their Derivatives with 1,2-Dimethoxyethane

    OpenAIRE

    Maudez, William; Meuwly, Markus; Fromm, Katharina M.

    2008-01-01

    As previously shown, alkali and alkaline earth metal iodides in nonaqueous, aprotic solvents behave like transition metal halides, forming cis- and trans-dihalides with various neutral O-donor ligands. These compounds can be used as precursors for the synthesis of new mixed alkali/alkaline earth metal aggregates. We show here that Ln²⁺ ions form isostructural cluster compounds. Thus, with LiOtBu, 50 % of the initial iodide can be replaced in MI₂, M=Ca, Sr, Ba, Eu, to generate the mixed-metal ...

  15. Oxovanadium(IV) complexes with tridentate dibasic schiff base ligands and 2-(2'-pyridyl) benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, R N; Chakravortty, V; Dash, K C [Utkal Univ., Bhubaneswar (India). Dept. of Chemistry

    1991-05-01

    The present work deals with the monomeric, six-coordinated mixed-ligand complexes of oxovanadium(IV) with dibasic tridentate schiff base ligands(ONO donor set) and the bidentate chelating ligand 2-(2'-pyridyl)benzimidazole (PBH) containing N{sub 2} donor set. (author). 1 tab., 22 refs.

  16. Schiff base ligand

    Indian Academy of Sciences (India)

    Unknown

    Low-temperature stoichiometric Schiff base reaction in air in 3 : 1 mole ratio between benz- aldehyde and triethylenetetramine (trien) in methanol yields a novel tetraaza µ-bis(bidentate) acyclic ligand L. It was .... electrochemical work was performed as reported in ..... change in ligand shape through change in oxidation.

  17. What a Difference Ancillary Thienyl Makes: Unexpected Additional Stabilization of the Diruthenium(III,II) but Not the Diosmium(III,II) Mixed-Valent State in Tetrazine Ligand-Bridged Complexes

    Czech Academy of Sciences Publication Activity Database

    Sarkas, B.; Kaim, W.; Klein, A.; Schwederski, B.; Fiedler, Jan; Duboc-Toia, C.; Lahiri, G. K.

    2003-01-01

    Roč. 42, č. 20 (2003), s. 6172-6174 ISSN 0020-1669 R&D Projects: GA MŠk OC D15.10; GA MŠk OC D14.20 Institutional research plan: CEZ:AV0Z4040901 Keywords : donor ligand s * Ru * dimers Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.389, year: 2003

  18. Characterization of the Mixed-Valent Intermediate (n = 3) of the Complex Series {(.mu., .eta.3:.eta.3-L)[(Ru(terpy)]2}n+ with the Unsaturated Bridging Ligand N,N´-Bis-(.alpha.-picolinoyl)hydrazido(2-) = L2-

    Czech Academy of Sciences Publication Activity Database

    Knödler, A.; Fiedler, Jan; Kaim, W.

    2004-01-01

    Roč. 23, č. 4 (2004), s. 701-707 ISSN 0277-5387 R&D Projects: GA ČR GA203/03/0821; GA MŠk OC D15.10 Institutional research plan: CEZ:AV0Z4040901 Keywords : EPR spectroscopy * hydrazido ligand * spectroelectrochemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.586, year: 2004

  19. Ligand modeling and design

    Energy Technology Data Exchange (ETDEWEB)

    Hay, B.P. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-10-01

    The purpose of this work is to develop and implement a molecular design basis for selecting organic ligands that would be used in the cost-effective removal of specific radionuclides from nuclear waste streams. Organic ligands with metal ion specificity are critical components in the development of solvent extraction and ion exchange processes that are highly selective for targeted radionuclides. The traditional approach to the development of such ligands involves lengthy programs of organic synthesis and testing, which in the absence of reliable methods for screening compounds before synthesis, results in wasted research effort. The author`s approach breaks down and simplifies this costly process with the aid of computer-based molecular modeling techniques. Commercial software for organic molecular modeling is being configured to examine the interactions between organic ligands and metal ions, yielding an inexpensive, commercially or readily available computational tool that can be used to predict the structures and energies of ligand-metal complexes. Users will be able to correlate the large body of existing experimental data on structure, solution binding affinity, and metal ion selectivity to develop structural design criteria. These criteria will provide a basis for selecting ligands that can be implemented in separations technologies through collaboration with other DOE national laboratories and private industry. The initial focus will be to select ether-based ligands that can be applied to the recovery and concentration of the alkali and alkaline earth metal ions including cesium, strontium, and radium.

  20. trans-Carbonylchloridobis[diphenyl(4-vinylphenylphosphane-κP]rhodium(I

    Directory of Open Access Journals (Sweden)

    Reinout Meijboom

    2012-05-01

    Full Text Available In the title compound, trans-[RhCl(C20H17P2(CO], the RhI atom is situated on a center of symmetry, resulting in a statistical 1:1 disorder of the chloride [Rh—Cl = 2.383 (2 Å] and carbonyl [Rh—C = 1.752 (7 Å] ligands. The distorted trans square-planar environment is completed by two P atoms [Rh—P = 2.3251 (4 Å] from two diphenyl(4-vinylphenylphosphane ligands. The vinyl group is disordered over two sets of sites in a 0.668 (10:0.332 (10 ratio. The crystal packing exhibits weak C—H...Cl and C—H...O hydrogen bonds and π–π interactions between the phenyl rings of neighbouring molecules, with a centroid–centroid distance of 3.682 (2 Å.

  1. trans-Tetracarbonylbis[tris(3-fluorophenylphosphane]chromium(0

    Directory of Open Access Journals (Sweden)

    M. N. Norlidah

    2011-12-01

    Full Text Available In the title compound, [Cr(C18H12F3P2(CO4], the Cr atom is octahedrally coordinated by four carbonyl ligands and the two tertiary phosphanes, which are trans to each other. The three benzene rings in one phosphane ligand make dihedral angles of 53.50 (9, 75.51 (10 and 80.63 (10° with each other, while in the other ligand these angles are 51.92 (10, 78.56 (11 and 86.80 (10°. C—H...O and C—H...F interactions link the molecules into a three-dimensional network. Each of the F atoms is disordered over two positions with refined occupancies of 0.944 (3:0.056 (3, 0.702 (4:0.298 (4, 0.829 (4:0.171 (4, 0.567 (4:0.433 (4, 0.545 (4:0.455 (4 and 0.920 (4:0.080 (4.

  2. The affinity plutonium(IV) for nitrogen donor ligands

    International Nuclear Information System (INIS)

    Jarvis, N.V.; Hancock, R.D.

    1994-01-01

    Established ligand design principles are used to predict the solution chemistry of Pu(IV) with nitrogen donor ligands which do not contain carboxylate donors. pK a 's of the nitrogen donors are lowered by addition of hydroxyalkyl groups causing Pu(IV) to have a greater affinity for these ligands than for hydroxide. Potentiometric studies using the ligands N,N,N'N',N''-pentakis(2-hydroxypropyl)-1,4,7-triazaheptane; N,N,N',N',N''-pentakis(2-hydroxyethyl)-1,4,7-triazaheptane; N,N,N',N',N'-tetrakis(2-hydroxyethyl)-1,2-diaminoethane; N,N,N',N'-tetrakis(2-hydroxyethyl)-trans-1,2-diaminocyclohexane; 1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane and N,N-bis(2-hydroxyethyl)glycine with Pu(IV) showed that Pu(IV) has a considerable aqueous solution chemistry with these ligands. Data were processed by the ESTA library of programs and stability constants for all the systems are reported. Implications for selective ligand design for Pu(IV) are discussed. (orig.)

  3. TransForm: TransAlta 2000 annual report

    International Nuclear Information System (INIS)

    2001-01-01

    Financial information from TransAlta Corp. was presented along with a review of their operations throughout 2000 and a summary of the how the electric utility is doing in terms of power generation, independent power producers, transmission and energy marketing. The utility has changed from a regulated vertically integrated utility into one of Canada's largest non-regulated electric power generators. The utility sold its retail businesses in Alberta and New Zealand and now focuses on coal and hydro generation, gas generation, high-voltage transmission and energy marketing. The newly constructed Centralia, Washington generation facility was brought on line with 1,340 MW in May 2000, on time and on budget. This was the platform to diversify their generation into the United States. The utility reported a solid financial year with $177.9 million in earnings from continuing operations, an 83 per cent increase from 1999, driven mostly by the results of Centralia and power marketing and trading businesses. A financial loss was suffered when the Wabamum power plant in Alberta was shut down for several months to repair a boiler. The utility made excellent progress toward their goal of 15,000 megawatts by 2005 by starting with the construction of what will be one of Canada's largest cogeneration facilities at Sarnia, Ontario. TransAlta also commissioned a 360 MW cogeneration facility at Poplar Creek at Suncor's Fort McMurray oil sand facility. TransAlta also has an excellent track record in developing power generation projects internationally. refs., tabs., figs

  4. Trans and cis influences and effects in cobalamins and in their simple models.

    Science.gov (United States)

    De March, Matteo; Demitri, Nicola; Geremia, Silvano; Hickey, Neal; Randaccio, Lucio

    2012-11-01

    The interligand interactions in coordination compounds have been principally interpreted in terms of cis and trans influences and effects, which can be defined as the ability of a ligand X to affect the bond of another ligand, cis or trans to X, to the metal. This review analyzes these effects/influences in cobalamins (XCbl) and their simple models cobaloximes, LCo(chel)X. Important properties of these complexes, such as geometry, stability, and reactivity, can be rationalized in terms of steric and electronic factors of the ligands. Experimental evidence of normal and inverse trans influence is described in alkylcobaloximes for the first time. The study of simple B(12) models has complemented that on the more complex cobalamins, with particular emphasis on the properties of the axial L-Co-X moiety. Some of the conclusions reached for the axial fragment of simple models have also been qualitatively detected in cobalamins and have furnished new insight into the as yet unestablished mechanism for the homolytic cleavage of the Co - C bond in the AdoCbl-based enzymes. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Synthesis through Trans-disciplinarity

    DEFF Research Database (Denmark)

    Hansen, Hanne Tine Ring

    2006-01-01

    synthesis is a requirement for creating successful ‘environmentally sustainable' architecture through the application of trans-disciplinarity, which leads to an increased awareness of the differences in decision-making as well as that of communication barriers between the different professions......When looking up the word ‘synthesis' in a dictionary, one comes across the following definition: "The combining of separate elements or substances to form a coherent whole."[1] Based on this definition one could argue that all great architectureis achieved through synthesis in one way or another...

  6. Trans issues in Liz Lochhead's 'Not Changed'

    OpenAIRE

    Kaličanin Milena M.

    2017-01-01

    The paper is divided into four sections. In the first section entitled 'Introducing and Defining Trans (Issues)', the basic terms of transgender, transvestite, and transsexual are defined by relying on Stryker's Transgender History (2008). The second part of the paper, 'Trans Studies: In-Between Feminist and Queer Theory?', places transgender studies into an academic context by referring to the theoretical framework provided by trans theorists Stryker, Stone, and Ranck who unanimously claim t...

  7. The Danish trans-fatty acids ban

    DEFF Research Database (Denmark)

    Vallgårda, Signild

    2017-01-01

    In 2003 an executive order was issued banning industrially produced trans-fatty acids above a low level in food items in Denmark. To date, only a few other countries have followed Denmark’s example. The way health consequences of trans fats were translated by the different actors enabled the crea......In 2003 an executive order was issued banning industrially produced trans-fatty acids above a low level in food items in Denmark. To date, only a few other countries have followed Denmark’s example. The way health consequences of trans fats were translated by the different actors enabled...

  8. Synthesis and Structures of Two Lanthanide Complexes Containing a Mixed Ligand System: [Ln(Phen)2(L)3(HL)]·H2O [Ln = La, Ce; Phen = Phenanthroline; HL = Salicylic Acid

    International Nuclear Information System (INIS)

    Iravani, Effat; Nami, Navabeh; Nabizadeh, Fatemeh; Bayani, Elham; Neumueller, Bernhard

    2013-01-01

    The reaction of LnCl 3 ·7H 2 O [Ln = La (1), Ce (2)] with salicylic acid (HL) and 1,10-phenanthroline (Phen) at 20 .deg. C in H 2 O/ethanol gave after work-up and recrystallization two novel lanthanide complexes with general formula [Ln(Phen) 2 (L) 3 (HL)]·H 2 O. Compounds 1 and 2 were characterized by IR and UV-Vis spectroscopy, TGA, CHN as well as by X-ray analysis. According to these results, compounds 1 and 2 are isostructural and contain Ln 3+ ions with coordination number nine. Complexes 1 and 2 consist of two Phen, one neutral HL and three L anions (two L anions act as monodentate ligands and the third one is chelating to Ln 3+ ). Thermal decomposition led to primary loss of the Phen molecules. Then HL molecules and finally L moieties left the material to give Ln 2 O 3

  9. Effect of an in-plane ligand on the electronic structures of bromo-bridged nano-wire Ni-Pd mixed-metal complexes, [Ni(1-x)Pd(x)(bn)2Br]Br2 (bn = 2S,3S-diaminobutane).

    Science.gov (United States)

    Sasaki, Mari; Wu, Hashen; Kawakami, Daisuke; Takaishi, Shinya; Kajiwara, Takashi; Miyasaka, Hitoshi; Breedlove, Brian K; Yamashita, Masahiro; Kishida, Hideo; Matsuzaki, Hiroyuki; Okamoto, Hiroshi; Tanaka, Hisaaki; Kuroda, Shinichi

    2009-08-03

    Single crystals of quasi-one-dimensional bromo-bridged Ni-Pd mixed-metal complexes with 2S,3S-diaminobutane (bn) as an in-plane ligand, [Ni(1-x)Pd(x)(bn)(2)Br]Br(2), were obtained by using an electrochemical oxidation method involving mixed methanol/2-propanol (1:1) solutions containing different ratios of [Ni(II)(bn)(2)]Br(2) and [Pd(II)(bn)(2)]Br(2). To investigate the competition between the electron-correlation of the Ni(III) states, or Mott-Hubbard states (MH), and the electron-phonon interaction of the Pd(II)-Pd(IV) mixed valence states, or charge-density-wave states (CDW), in the Ni-Pd mixed-metal compounds, X-ray structure analyses, X-ray oscillation photograph, and Raman, IR, ESR, and single-crystal reflectance spectra were analyzed. In addition, the local electronic structures of Ni-Pd mixed-metal single crystals were directly investigated by using scanning tunneling microscopy (STM) at room temperature and ambient pressure. The oxidation states of [Ni(1-x)Pd(x)(bn)(2)Br]Br(2) changed from a M(II)-M(IV) mixed valence state to a M(III) MH state at a critical mixing ratio (x(c)) of approximately 0.8, which is lower than that of [Ni(1-x)Pd(x)(chxn)(2)Br]Br(2) (chxn = 1R,2R-diaminocyclohexane) (x(c) approximately 0.9) reported previously. The lower value of x(c) for [Ni(1-x)Pd(x)(bn)(2)Br]Br(2) can be explained by the difference in their CDW dimensionalities because the three-dimensional CDW ordering in [Pd(bn)(2)Br]Br(2) observed by using X-ray diffuse scattering stabilizes the Pd(II)-Pd(IV) mixed valence state more than two-dimensional CDW ordering in [Pd(chxn)(2)Br]Br(2) does, which has been reported previously.

  10. Studies on coordination and addition compounds and anti microbial activity of some mixed ligand complexes of Au(III), Mo(II), Co(II) and Cd(II) with dibasic acid and heterocyclic amines and addition compounds of As(III) and Sb(III) halides with benzamide and acetophenon

    International Nuclear Information System (INIS)

    Hossain, M.; Sultana, C.; Saidul Islam, M.; Zakaria, C.M.

    2008-06-01

    Three new mixed ligand complexes of Au(III) and Mo(II) with dibasic acid e.g., homophthalic acid, oxalic acid and heterocylic amines e.g., quinonine, iso-quinonine, bipyridine, Phenylanaline and the two new addition compounds of As(III) and Sb(III) halides with N-donor ligands viz. benzamide and acetophenone and one complex [Cd(DPH)(IQ) 2 ], where IQ = Iso-quinoline and DPH = Deprotonated phthalic acid have been prepared according to the procedure in the literature. Their conventional physical and chemical analyses have been done. Their antibacterial studies against nine gram positive and five gram negative pathogenic bacteria and antifungal activities against eight plant and three human fungi have been evaluated. Kanamycin and Nystatin have been used as a standard for carrying out experiments of antibacterial and antifungal activities, respectively. The minimum inhibitory concentration (MIC) values of these compounds, as antibiotic against two gram positive and two gram negative pathogenic bacteria, have also been carried out and in this case, Amoxacilin antibiotic has been used as a standard antibiotic. (author)

  11. The affinity of the uranyl ion for nitrogen donor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, N.V. (Atomic Energy Corp. of South Africa Ltd., Pretoria (South Africa). Dept. of Process Technology); De Sousa, A.S.; Hancock, R.D. (Univ. of the Witwatersrand, Johannesburg (South Africa). Centre for Molecular Design)

    1992-01-01

    Established ligand design principles are used to predict the solution chemistry of UO[sub 2][sup 2+] with nitrogen donor ligands which do not contain carboxylate donors. pK[sub a]'s of the nitrogen donors are lowered by addition of hydroxylalkyl groups causing UO[sub 2][sup 2+] to have a greater affinity for these ligands than for hydroxide. Potentiometric studies using the ligands N,N,N',N',N''-pentakis(2-hydroxypropyl)-1,4,7-triazaheptane; N,N,N',N',N''-pentakis(2-hydroxyethyl)-1,4,7-triazaheptane; N,N,N',N'-tetrakis(2-hydroxypropyl)1,2-diaminoethane, N,N,N',N'-tetrakis(2-hydroxyethyl)-trans-1,2-diaminocyclohexane; 1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane and N,N-bis(2-hydroxyethyl)glycine with UO[sub 2][sup 2+] showed that UO[sub 2][sup 2+] has a considerable aqueous solution chemistry with these ligands. (orig.).

  12. Oxidation of nitrite by a trans-dioxoruthenium(VI) complex: direct evidence for reversible oxygen atom transfer.

    Science.gov (United States)

    Man, Wai-Lun; Lam, William W Y; Wong, Wai-Yeung; Lau, Tai-Chu

    2006-11-15

    Reaction of trans-[Ru(VI)(L)(O)(2)](2+) (1, L = 1,12-dimethyl-3,4:9,10-dibenzo-1,12-diaza-5,8-dioxacyclopentadecane, a tetradentate macrocyclic ligand with N(2)O(2) donor atoms) with nitrite in aqueous solution or in H(2)O/CH(3)CN produces the corresponding (nitrato)oxoruthenium(IV) species, trans-[Ru(IV)(L)(O)(ONO(2))](+) (2), which then undergoes relatively slow aquation to give trans-[Ru(IV)(L)(O)(OH(2))](2+). These processes have been monitored by both ESI/MS and UV/vis spectrophotometry. The structure of trans-[Ru(IV)(L)(O)(ONO(2))](+) (2) has been determined by X-ray crystallography. The ruthenium center adopts a distorted octahedral geometry with the oxo and the nitrato ligands trans to each other. The Ru=O distance is 1.735(3) A, the Ru-ONO(2) distance is 2.163(4) A, and the Ru-O-NO(2) angle is 138.46(35) degrees . Reaction of trans-[Ru(VI)(L)((18)O)(2)](2+) (1-(18)O(2)) with N(16)O(2)(-) in H(2)O/CH(3)CN produces the (18)O-enriched (nitrato)oxoruthenium(IV) species 2-(18)O(2). Analysis of the ESI/MS spectrum of 2-(18)O(2) suggests that scrambling of the (18)O atoms has occurred. A mechanism that involves linkage isomerization of the nitrato ligand and reversible oxygen atom transfer is proposed.

  13. Trans Ova Genetics, L.C.

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Trans Ova Genetics, L.C., a business located at 2938 380th Street Sioux Center, IA 51250, for alleged violations at the Trans Ova Genetics, L.C.’s facility located in 12425

  14. Unscripting Curriculum: Toward a Critical Trans Pedagogy

    Science.gov (United States)

    Keenan, Harper Benjamin

    2017-01-01

    In this essay, Harper B. Keenan draws on his own experience as a white queer and trans educator to consider the meaning of a critical trans pedagogy. Amid dissonant narratives of equal rights and subjection, he explores how his classroom teaching is shaped by his own experience of gender conditioning as well as by the contemporary political…

  15. TransAlta: More than a utility

    International Nuclear Information System (INIS)

    Mikalson, D.A.

    1991-01-01

    TransAlta Utilities Corporation is Canada's largest privately owned utility and is also a major coal mining company. In 1989, TransAlta produced 20.9% of all coal mined in Canada. A brief history of TransAlta is presented along with TransAlta's present coal operations and plans for the next three years. An overview is presented of how TransAlta Fuel Supply is organized to utilize contracted mining operation, engineering and environmental services and in-house capabilities. Recent strategic initiatives to improve organizational efficiency and the mining operations are discussed. These range from developing a common departmental vision to modifying major mining equipment. TransAlta's proactive role in clean coal combustion such as low NOx-SOx burner, integrated combined cycle gasification, and other energy research projects is reviewed. A summary is provided of recent participation of TransAlta in environmental management initiatives. Recent successes of TransAlta's unregulated subsidiary in the development of cogeneration facilities and the future of this area of business are discussed. 8 refs., 4 figs

  16. Synthesis, characterization and antimicrobial activity of mixed ...

    African Journals Online (AJOL)

    A new series of Mn(II), Fe(II), Co(II), Cu(II) and Zn(II) mixed ligands-metal complexes derived from salicylic acid (SA) and 1,10-phenanthroline (PHEN) have been synthesized and characterized by spectroscopic studies. The coordination of the two ligands towards central metal ions has been proposed in the light of ...

  17. Trans fat consumption and aggression.

    Directory of Open Access Journals (Sweden)

    Beatrice A Golomb

    Full Text Available Dietary trans fatty acids (dTFA are primarily synthetic compounds that have been introduced only recently; little is known about their behavioral effects. dTFA inhibit production of omega-3 fatty acids, which experimentally have been shown to reduce aggression. Potential behavioral effects of dTFA merit investigation. We sought to determine whether dTFA are associated with aggression/irritability. METHODOLGY/PRINICPAL FINDINGS: We capitalized on baseline dietary and behavioral assessments in an existing clinical trial to analyze the relationship of dTFA to aggression. Of 1,018 broadly sampled baseline subjects, the 945 adult men and women who brought a completed dietary survey to their baseline visit are the target of this analysis. Subjects (seen 1999-2004 were not on lipid medications, and were without LDL-cholesterol extremes, diabetes, HIV, cancer or heart disease. Outcomes assessed adverse behaviors with impact on others: Overt Aggression Scale Modified-aggression subscale (primary behavioral endpoint; Life History of Aggression; Conflict Tactics Scale; and self-rated impatience and irritability. The association of dTFA to aggression was analyzed via regression and ordinal logit, unadjusted and adjusted for potential confounders (sex, age, education, alcohol, and smoking. Additional analyses stratified on sex, age, and ethnicity, and examined the prospective association. Greater dTFA were strongly significantly associated with greater aggression, with dTFA more consistently predictive than other assessed aggression predictors. The relationship was upheld with adjustment for confounders, was preserved across sex, age, and ethnicity strata, and held cross-sectionally and prospectively.This study provides the first evidence linking dTFA with behavioral irritability and aggression. While confounding is always a concern in observational studies, factors including strength and consistency of association, biological gradient, temporality, and

  18. Glutamate receptor ligands

    DEFF Research Database (Denmark)

    Guldbrandt, Mette; Johansen, Tommy N; Frydenvang, Karla Andrea

    2002-01-01

    Homologation and substitution on the carbon backbone of (S)-glutamic acid [(S)-Glu, 1], as well as absolute stereochemistry, are structural parameters of key importance for the pharmacological profile of (S)-Glu receptor ligands. We describe a series of methyl-substituted 2-aminoadipic acid (AA...

  19. Efficient hierarchical trans-dimensional Bayesian inversion of magnetotelluric data

    Science.gov (United States)

    Xiang, Enming; Guo, Rongwen; Dosso, Stan E.; Liu, Jianxin; Dong, Hao; Ren, Zhengyong

    2018-06-01

    This paper develops an efficient hierarchical trans-dimensional (trans-D) Bayesian algorithm to invert magnetotelluric (MT) data for subsurface geoelectrical structure, with unknown geophysical model parameterization (the number of conductivity-layer interfaces) and data-error models parameterized by an auto-regressive (AR) process to account for potential error correlations. The reversible-jump Markov-chain Monte Carlo algorithm, which adds/removes interfaces and AR parameters in birth/death steps, is applied to sample the trans-D posterior probability density for model parameterization, model parameters, error variance and AR parameters, accounting for the uncertainties of model dimension and data-error statistics in the uncertainty estimates of the conductivity profile. To provide efficient sampling over the multiple subspaces of different dimensions, advanced proposal schemes are applied. Parameter perturbations are carried out in principal-component space, defined by eigen-decomposition of the unit-lag model covariance matrix, to minimize the effect of inter-parameter correlations and provide effective perturbation directions and length scales. Parameters of new layers in birth steps are proposed from the prior, instead of focused distributions centred at existing values, to improve birth acceptance rates. Parallel tempering, based on a series of parallel interacting Markov chains with successively relaxed likelihoods, is applied to improve chain mixing over model dimensions. The trans-D inversion is applied in a simulation study to examine the resolution of model structure according to the data information content. The inversion is also applied to a measured MT data set from south-central Australia.

  20. Mixed-ligand complexes of technetium-III. Synthesis and characterization of [bis(diphenylphosphino)ethane]tetrakis(trimethylphosphite)tech netium(I) hexafluorophosphate, [Tc(DPPE)(TMP)4]PF6

    International Nuclear Information System (INIS)

    Abram, U.; Beyer, R.; Muenze, R.; Stach, J.; Kaden, L.; Lorenz, B.; Findeisen, M.

    1989-01-01

    The diamagnetic technetium(I) complex [Tc(DPPE)(TMP) 4 ]PF 6 was prepared from [Tc(N 2 )H(DPPE) 2 ] and characterized by elemental analysis. 1 H- and 99 Tc-NMR spectroscopy and fast atom bombardment mass spectrometry. [Tc(DPPE)(TMP) 4 ]PF 6 is a prototype compound for technetium complexes with mixed phosphine-phosphite coordination spheres. (author)

  1. Fragile X mental retardation protein regulates trans-synaptic signaling in Drosophila

    Directory of Open Access Journals (Sweden)

    Samuel H. Friedman

    2013-11-01

    Fragile X syndrome (FXS, the most common inherited determinant of intellectual disability and autism spectrum disorders, is caused by loss of the fragile X mental retardation 1 (FMR1 gene product (FMRP, an mRNA-binding translational repressor. A number of conserved FMRP targets have been identified in the well-characterized Drosophila FXS disease model, but FMRP is highly pleiotropic in function and the full spectrum of FMRP targets has yet to be revealed. In this study, screens for upregulated neural proteins in Drosophila fmr1 (dfmr1 null mutants reveal strong elevation of two synaptic heparan sulfate proteoglycans (HSPGs: GPI-anchored glypican Dally-like protein (Dlp and transmembrane Syndecan (Sdc. Our recent work has shown that Dlp and Sdc act as co-receptors regulating extracellular ligands upstream of intracellular signal transduction in multiple trans-synaptic pathways that drive synaptogenesis. Consistently, dfmr1 null synapses exhibit altered WNT signaling, with changes in both Wingless (Wg ligand abundance and downstream Frizzled-2 (Fz2 receptor C-terminal nuclear import. Similarly, a parallel anterograde signaling ligand, Jelly belly (Jeb, and downstream ERK phosphorylation (dpERK are depressed at dfmr1 null synapses. In contrast, the retrograde BMP ligand Glass bottom boat (Gbb and downstream signaling via phosphorylation of the transcription factor MAD (pMAD seem not to be affected. To determine whether HSPG upregulation is causative for synaptogenic defects, HSPGs were genetically reduced to control levels in the dfmr1 null background. HSPG correction restored both (1 Wg and Jeb trans-synaptic signaling, and (2 synaptic architecture and transmission strength back to wild-type levels. Taken together, these data suggest that FMRP negatively regulates HSPG co-receptors controlling trans-synaptic signaling during synaptogenesis, and that loss of this regulation causes synaptic structure and function defects characterizing the FXS disease state.

  2. MICROEMULSION OF MIXED CHLORINATED SOLVENTS USING FOOD GRADE (EDIBLE) SURFACTANTS

    Science.gov (United States)

    Ground water contamination frequently consists of mixed chlorinated solvents [e.g., tetrachloroethylene (PCE), trichloroethylene (TCE), and trans-1,2- dichloroethylene (DCE)]. In this research, mixtures of the food grade (edible) surfactants bis(2-ethylhexyl) sodium sulfosuccinat...

  3. Synthesis and Structures of Two Lanthanide Complexes Containing a Mixed Ligand System: [Ln(Phen){sub 2}(L){sub 3}(HL)]·H{sub 2}O [Ln = La, Ce; Phen = Phenanthroline; HL = Salicylic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Iravani, Effat [UNiv. of Applied Science and Technology, Tehran (Iran, Islamic Republic of); Nami, Navabeh; Nabizadeh, Fatemeh; Bayani, Elham [Islamic Azad Univ., Mazandaran (Iran, Islamic Republic of); Neumueller, Bernhard [Philipps-Universitat Marburg, Marburg (Germany)

    2013-11-15

    The reaction of LnCl{sub 3}·7H{sub 2}O [Ln = La (1), Ce (2)] with salicylic acid (HL) and 1,10-phenanthroline (Phen) at 20 .deg. C in H{sub 2}O/ethanol gave after work-up and recrystallization two novel lanthanide complexes with general formula [Ln(Phen){sub 2}(L){sub 3}(HL)]·H{sub 2}O. Compounds 1 and 2 were characterized by IR and UV-Vis spectroscopy, TGA, CHN as well as by X-ray analysis. According to these results, compounds 1 and 2 are isostructural and contain Ln{sup 3+} ions with coordination number nine. Complexes 1 and 2 consist of two Phen, one neutral HL and three L anions (two L anions act as monodentate ligands and the third one is chelating to Ln{sup 3+}). Thermal decomposition led to primary loss of the Phen molecules. Then HL molecules and finally L moieties left the material to give Ln{sub 2}O{sub 3}.

  4. Effect of 2-chloro-substitution of adenine moiety in mixed-ligand gold(I triphenylphosphine complexes on anti-inflammatory activity: the discrepancy between the in vivo and in vitro models.

    Directory of Open Access Journals (Sweden)

    Jan Hošek

    Full Text Available A series of gold(I triphenylphosphine (PPh3 complexes (1-9 involving 2-chloro-N6-(substituted-benzyladenine derivatives as N-donor ligands was synthesized and thoroughly characterized by relevant methods, including electrospray-ionization (ESI mass spectrometry and multinuclear NMR spectroscopy. The anti-inflammatory and antiedematous effects of three representatives 1, 5 and 9 were evaluated by means of in vitro model based on the expression of pro- and anti-inflammatory cytokines and influence of the complexes on selected forms of matrix metalloproteinases secreted by LPS-activated THP-1 monocytes and in vivo model evaluating the antiedematous effect of the complexes in the carrageenan-induced rat hind-paw edema model. In addition to the pharmacological observations, the affected hind paws were post mortem subjected to histological and immunohistochemical evaluations. The results of both in vivo and ex vivo methods revealed low antiedematous and anti-inflammatory effects of the complexes, even though the in vitro model identified them as promising anti-inflammatory acting compounds. The reason for this discrepancy lies probably in low stability of the studied complexes in biological environment, as demonstrated by the solution interaction studies with sulfur-containing biomolecules (cysteine and reduced glutathione using the ESI mass spectrometry.

  5. AMPA receptor ligands

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Mellor, Ian

    2004-01-01

    Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPAR), subtype of the ionotropic glutamate receptors (IGRs), mediate fast synaptic transmission in the central nervous system (CNS), and are involved in many neurological disorders, as well as being a key player in the f......Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPAR), subtype of the ionotropic glutamate receptors (IGRs), mediate fast synaptic transmission in the central nervous system (CNS), and are involved in many neurological disorders, as well as being a key player...... in the formation of memory. Hence, ligands affecting AMPARs are highly important for the study of the structure and function of this receptor, and in this regard polyamine-based ligands, particularly polyamine toxins, are unique as they selectively block Ca2+ -permeable AMPARs. Indeed, endogenous intracellular...

  6. Radiobiology with DNA ligands

    International Nuclear Information System (INIS)

    Weinreich, R.; Argentini, M.; Guenther, I.; Koziorowski, J.; Larsson, B.; Nievergelt-Egido, M.C.; Salt, C.; Wyer, L.; Dos Santos, D.F.; Hansen, H.J.

    1997-01-01

    The paper deals with the following topics: labelling of DNA ligands and other tumour-affinic compounds with 4.15-d 124 I, radiotoxicity of Hoechst 33258 and 33342 and of iodinated Hoechst 33258 in cell cultures, preparation of 76 Br-, 123 I-, and 221 At-labelled 5-halo-2'-deoxyuridine, chemical syntheses of boron derivatives of Hoechst 33258.III., Gadolinium neutron capture therapy

  7. Identification of absolute geometries of cis and trans molecular isomers by Coulomb Explosion Imaging.

    Science.gov (United States)

    Ablikim, Utuq; Bomme, Cédric; Xiong, Hui; Savelyev, Evgeny; Obaid, Razib; Kaderiya, Balram; Augustin, Sven; Schnorr, Kirsten; Dumitriu, Ileana; Osipov, Timur; Bilodeau, René; Kilcoyne, David; Kumarappan, Vinod; Rudenko, Artem; Berrah, Nora; Rolles, Daniel

    2016-12-02

    An experimental route to identify and separate geometric isomers by means of coincident Coulomb explosion imaging is presented, allowing isomer-resolved photoionization studies on isomerically mixed samples. We demonstrate the technique on cis/trans 1,2-dibromoethene (C 2 H 2 Br 2 ). The momentum correlation between the bromine ions in a three-body fragmentation process induced by bromine 3d inner-shell photoionization is used to identify the cis and trans structures of the isomers. The experimentally determined momentum correlations and the isomer-resolved fragment-ion kinetic energies are matched closely by a classical Coulomb explosion model.

  8. The Trans-Pacific Partnership

    Directory of Open Access Journals (Sweden)

    Voon Tania

    2016-12-01

    Full Text Available This article provides an overview of the recently concluded Trans-Pacific Partnership Agreement (TPP, a treaty the parties have described as comprehensive and ambitious, yet also representing a balance of competing interests. The article focuses on the TPP’s chapters relating to investment, services, intellectual property and regulatory coherence, each of which provides insight into the motivations that drove the conclusion of the TPP and the negotiating dynamics that determined its final content. In areas such as investment, the TPP takes a more balanced approach than many earlier agreements, providing greater safeguards for the regulatory autonomy of states while still embodying core protections for foreign investors. In relation to intellectual property and services, the TPP goes beyond earlier agreements in several key respects, such as preventing the imposition of local presence requirements for service providers or requiring longer copyright terms than those demanded by other international treaties. The TPP chapter on regulatory coherence is one of the most novel features of the treaty, as regulatory coherence is not frequently included in earlier trade agreements, demonstrating the increased focus of states on addressing regulatory barriers to trade and investment. While all of these elements of the TPP are interesting in their own right, given the number and size of the parties involved in the agreement, they also provide valuable guidance about the direction of other ongoing and future preferential trade agreement negotiations, such as the proposed Transatlantic Trade and Investment Partnership (TTIP and Trade in Services Agreement (TiSA.

  9. The synergistic effect of complex ligands for radioactive metal salts decontamination in supercritical CO2

    International Nuclear Information System (INIS)

    Go, M. S.; Park, K. H.; Kim, H. W.; Kim, H. D.

    2004-01-01

    The organophosphorus and dithiocarbamate ligands were used to extract five metal ions (Cd 2+ , Co 2+ , Cu 2+ , Pb 2+ , Zn 2+ ) in supercritical CO 2 so as to decontaminate the radioactive contaminants. The experiments confirmed that the ligands mixed together in a variety of the mixing ratios efficiently extracted all metal ions by more than 90% due to its synergistic effect. The UV-Vis spectrometer installed in a high-pressurized cell showed that the NaDDC was decomposed in supercritical CO 2 containing the water. It also proved that the synergistic effect improved the deprotonation of the organophosphorus ligand when NaDDC was used together with. In addition, we mixed organophosphorus ligand together with diethylamine, the decomposed NaDDC, to obtain the same extraction result of more than 90% as with NaDDC. The enhanced extraction efficiency shows the synergistic effect that is produced by combining two ligands together

  10. Transsynaptic Mapping of Second-Order Taste Neurons in Flies by trans-Tango.

    Science.gov (United States)

    Talay, Mustafa; Richman, Ethan B; Snell, Nathaniel J; Hartmann, Griffin G; Fisher, John D; Sorkaç, Altar; Santoyo, Juan F; Chou-Freed, Cambria; Nair, Nived; Johnson, Mark; Szymanski, John R; Barnea, Gilad

    2017-11-15

    Mapping neural circuits across defined synapses is essential for understanding brain function. Here we describe trans-Tango, a technique for anterograde transsynaptic circuit tracing and manipulation. At the core of trans-Tango is a synthetic signaling pathway that is introduced into all neurons in the animal. This pathway converts receptor activation at the cell surface into reporter expression through site-specific proteolysis. Specific labeling is achieved by presenting a tethered ligand at the synapses of genetically defined neurons, thereby activating the pathway in their postsynaptic partners and providing genetic access to these neurons. We first validated trans-Tango in the Drosophila olfactory system and then implemented it in the gustatory system, where projections beyond the first-order receptor neurons are not fully characterized. We identified putative second-order neurons within the sweet circuit that include projection neurons targeting known neuromodulation centers in the brain. These experiments establish trans-Tango as a flexible platform for transsynaptic circuit analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Interpretation of electronic spectra of ruthenium nitroso complexes with N-heterocyclic ligands

    International Nuclear Information System (INIS)

    Sizova, O.V.; Ivanova, N.V.; Lyubimova, O.O.; Nikol'skij, A.B.

    2004-01-01

    Relaying on ab initio and semiempirical CINDO/CI calculations of free ligands L and complexes trans-[Ru(NO)(NH 3 ) 4 (L)] 3+ (L=pyridine, pyrazine, nicotinamide, l-histidine, imidazole), electronic absorption spectra of nitroso complexes with nitrogen-containing heterocyclic ligands L have been analyzed. Spectral manifestations of strong covalent bond Ru-NO was pointed out and the conclusion was made about advisability of presentation of Ru and NO oxidation states in grouping RuNO 3+ as Ru(III) and NO 0 . Introduction of nitroso group into inner coordination sphere of Ru(II) complexes with nitrogen-containing heterocyclic ligands results in essential rearrangement of the entire structure and deprives ligands L of their ability to manifest chromophore properties [ru

  12. Formation of trans fats during food preparation.

    Science.gov (United States)

    Przybylski, Oman; Aladedunye, Felix A

    2012-01-01

    An investigation was completed to determine how typical cooking procedures used in food preparation, such as baking and stir-frying, affect trans fats formation. Canola oil was used as the main fat ingredient. Zucchini cake and gingersnap cookies were baked at 180o C and 200o C, while stir-fried chicken was prepared at 200o C and 275o C. The lipids from the food were extracted following the Folch procedure, and analyzed for trans fatty acids according to ISO official method 15304. Minimal changes were observed in the amount of trans fats during baking. Application of extreme temperatures during baking, which caused carbonization of the outer layer of products, yielded an insignificant increase in the amount of trans isomers. As with baking, stir-frying did not result in significant isomerization of the fatty acids, even when the oil was heated to 275o C and smoking heavily before the food was placed in it. Irrespective of the cooking procedure, linolenic acid was the most prone to isomerization with the highest amount of trans isomers formation. Baking and stir-frying at normal and/or extreme temperatures do not significantly affect the amounts of trans fats. Likewise, heating oil to the smoking point during stir-frying may decrease the amount of polyunsaturated fatty acids because of oxidative degradation.

  13. Assembly of bicyclic or monocyclic clusters from [(η5-C5Me5)2Mo2(μ3-S)4(CuMeCN)2]2+ with tetraphosphine or N,P mixed ligands: syntheses, structures and enhanced third-order NLO performances.

    Science.gov (United States)

    Ren, Zhi-Gang; Sun, Sha; Dai, Min; Wang, Hui-Fang; Lü, Chun-Ning; Lang, Jian-Ping; Sun, Zhen-Rong

    2011-09-07

    Reactions of the preformed cluster [(η(5)-C(5)Me(5))(2)Mo(2)(μ(3)-S)(4)Cu(2)(MeCN)(2)](ClO(4))(2) (1) with two tetraphosphine ligands, 1,4-N,N,N',N'-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda) and N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylene diamine (dppeda), produced two bicyclic clusters {[(η(5)-C(5)Me(5))(2)Mo(2)(μ(3)-S)(4)Cu(2)](2)(L)}(ClO(4))(4) (3: L = dpppda; 4: L = dppeda). Analogous reactions of 1 or [(η(5)-C(5)Me(5))(2)Mo(2)(μ(3)-S)(4)Cu(2)(MeCN)(2)](PF(6))(2) (2) with two N,P mixed ligands, N,N-bi(diphenylphosphanylmethyl)-2-aminopyridine (bdppmapy) and N-diphenylphosphanylmethyl-4-aminopyridine (dppmapy), afforded two monocyclic clusters {[(η(5)-C(5)Me(5))(2)Mo(2)(μ(3)-S)(4)Cu(2)](2)(L)(2)}X(4) (5: L = bdppmapy, X = ClO(4); 6: L = dppmapy, X = PF(6)). Compounds 3-6 were fully characterized by elemental analysis, IR spectra, UV-vis spectra, (1)H and (31)P{(1)H} NMR spectra, ESI-MS and single-crystal X-ray crystallography. In the tetracations of 3-6, two cubane-like [Mo(2)(μ(3)-S)(4)Cu(2)] cores are linked either by one dpppda or dppeda bridge to form a bicyclic structure or by a pair of bdppmapy or dppmapy bridges to afford a monocyclic structure. The third-order nonlinear optical (NLO) properties of 1 and 3-6 in MeCN were also investigated by femtosecond degenerate four-wave mixing (DFWM) technique with a 50 fs pulse width at 800 nm. Compounds 3-6 exhibited enhanced third-order NLO performances relative to that of 1. This journal is © The Royal Society of Chemistry 2011

  14. Bexarotene ligand pharmaceuticals.

    Science.gov (United States)

    Hurst, R E

    2000-12-01

    Bexarotene (LGD-1069), from Ligand, was the first retinoid X receptor (RXR)-selective, antitumor retinoid to enter clinical trials. The company launched the drug for the treatment of cutaneous T-cell lymphoma (CTCL), as Targretin capsules, in the US in January 2000 [359023]. The company filed an NDA for Targretin capsules in June 1999, and for topical gel in December 1999 [329011], [349982] specifically for once-daily oral administration for the treatment of patients with early-stage CTCL who have not tolerated other therapies, patients with refractory or persistent early stage CTCL and patients with refractory advanced stage CTCL. The FDA approved Targretin capsules at the end of December 1999 for once-daily oral treatment of all stages of CTCL in patients refractory to at least one prior systemic therapy, at an initial dose of 300 mg/m2/day. After an NDA was submitted in December 1999 for Targretin gel, the drug received Priority Review status for use as a treatment of cutaneous lesions in patients with stage IA, IB or IIA CTCL [354836]. The FDA issued an approvable letter in June 2000, and granted marketing clearance for CTCL in the same month [370687], [372768], [372769], [373279]. Ligand had received Orphan Drug designation for this indication [329011]. At the request of the FDA, Ligand agreed to carry out certain post-approval phase IV and pharmacokinetic studies [351604]. The company filed an MAA with the EMEA for Targretin Capsules to treat lymphoma in November 1999 [348944]. The NDA for Targretin gel is based on a multicenter phase III trial that was conducted in the US, Canada, Europe and Australia involving 50 patients and a multicenter phase I/II clinical program involving 67 patients. Targretin gel was evaluated for the treatment of patients with early stage CTCL (IA-IIA) who were refractory to, intolerant to, or reached a response plateau for at least 6 months on at least two prior therapies. Efficacy results exceeded the protocol-defined response

  15. Does your organization use gender inclusive forms? Nurses' confusion about trans* terminology.

    Science.gov (United States)

    Carabez, Rebecca; Pellegrini, Marion; Mankovitz, Andrea; Eliason, Mickey; Scott, Megan

    2015-11-01

    To describe nurses confusion around trans* terminology and to provide a lesson in Trans* 101 for readers. Of the estimated 9 million persons in the United States of America who are identified as lesbian, gay, bisexual and transgender, about 950,000 (0.2-0.5% of adult population) are identified as trans* (a term that encompasses the spectrum, including transgender, transsexual, trans man, trans woman and other terms). The Institute of Medicine (2011, The health of lesbian, gay, bisexual and transgender people: Building a foundation for better understanding. The National Academies Press, Washington, DC) identified transgender persons as an understudied population with significant need for health research, yet the nursing literature contains little guidance for educating nurses on trans* issues. This is a mixed methods structured interview design with nurse key informants. The scripted interview was based on the Health Care Equality Index, which evaluates patient-centred care to lesbian, gay, bisexual and transgender patients and families. These data were part of a larger research study that explored the current state of lesbian, gay, bisexual and transgender-sensitive nursing practice. Undergraduate nursing students recruited and interviewed 268 nurse key informants about gender inclusive forms (capable of identifying trans* patients) at their agencies. Only 5% reported use of gender inclusive forms, 44% did not know about inclusive forms, 37% did not understand what a gender inclusive form was and 14% confused gender with sexual orientation. The study demonstrated a critical need for education in gender identity and sexual orientation terminology. The lack of understanding of concepts and terminology may affect basic care of lesbian, gay, bisexual and transgender patients especially those who identify as transgender. © 2015 John Wiley & Sons Ltd.

  16. "There's no chasing involved": cis/trans relationships, "tranny chasers," and the future of a sex-positive trans politics.

    Science.gov (United States)

    Tompkins, Avery Brooks

    2014-01-01

    This article adds to a small, but growing, body of work on trans sexualities and partnerships, and provides a much-needed inquiry into the complex and contested politics of desire when we take trans identities, bodies, and sexualities into account. Using digital ethnographic data from YouTube videos along with in-person observational data from LGBTQ and trans conferences in the U.S., Tompkins argues that a sex-positive trans politics cannot emerge in trans and trans-allied communities if the rhetoric of the "tranny chaser" continues to inform discourses of desire and attraction to trans people.

  17. trans-Bis(perchlorato-κOtetrakis(1H-pyrazole-κN2copper(II

    Directory of Open Access Journals (Sweden)

    Viktor Zapol'skii

    2008-10-01

    Full Text Available The title compound, [Cu(ClO42(C3H4N24], was obtained unexpectedly by the reaction of copper(II perchlorate hexahydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octahedrally coordinated Cu2+ ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu—N distance is 2.000 (1 Å. Two perchlorate ions are coordinated to copper in trans positions [Cu—O = 2.4163 (11 Å].

  18. Effect of Trans, Trans-Farnesol on Pseudogymnoascus destructans and Several Closely Related Species.

    Science.gov (United States)

    Raudabaugh, Daniel B; Miller, Andrew N

    2015-12-01

    Bat white-nose syndrome, caused by the psychrophilic fungus Pseudogymnoascus destructans, has dramatically reduced the populations of many hibernating North American bat species. The search for effective biological control agents targeting P. destructans is of great importance. We report that the sesquiterpene trans, trans-farnesol, which is also a Candida albicans quorum sensing compound, prevented in vitro conidial germination for at least 14 days and inhibited growth of preexisting hyphae of five P. destructans isolates in filtered potato dextrose broth at 10 °C. Depending on the inoculation concentrations, both spore and hyphal inhibition occurred upon exposure to concentrations as low as 15-20 µM trans, trans-farnesol. In contrast, most North American Pseudogymnoascus isolates were more tolerant to the exposure of trans, trans-farnesol. Our results suggest that some Candida isolates may have the potential to inhibit the growth of P. destructans and that the sesquiterpene trans, trans-farnesol has the potential to be utilized as a biological control agent.

  19. Synthesis, characterization and antimicrobial activity of mixed ...

    African Journals Online (AJOL)

    Synthesis, characterization and antimicrobial activity of mixed ascorbic acid - nicotinamide metal complexes. ... The result of the antimicrobial studies showed that the mixed complexes have higher inhibitory activity than the original ligands against the tested bacteria and fungi species. KEY WORDS: Ascorbic acid, ...

  20. Electron and ligand transfer reactions between cyclometallated platinum(II) compounds and thallium(III) carboxylates

    NARCIS (Netherlands)

    Koten, G. van; Ploeg, A.F.M.J. van der; Vrieze, K.

    1982-01-01

    Reaction of trans-[(2-Me{2}NCH{2}C{6}H{4}{2}Pt}I{}I{] with Tl}I{}I{}I{(O{2}CR){3} (R = Me, i-Pr) gave direct elimination of Tl}I{(O{2}CR) and formation of the oxidative addition product [(2-Me{2}NCH{2}C{6}H{4}){2}Pt}I{}V{ (O{2}CR){2}], in two isomeric forms. A structure with the carbon ligands in

  1. A latent ruthenium based olefin metathesis catalyst with a sterically demanding NHC ligand

    KAUST Repository

    Leitgeb, Anita; Abbas, Mudassar E.; Fischer, Roland C.; Poater, Albert; Cavallo, Luigi; Slugovc, Christian

    2012-01-01

    An olefin metathesis catalyst featuring a SIPr NHC and an ester chelating carbene ligand is introduced. In contrast to its previously published SIMes analogue, only the trans dichloro configurated isomer was obtained. The two counterparts are tested in various olefin metathesis reactions, revealing a striking superiority of the new complex in the cross metathesis of olefins with methyl vinyl ketone allowing for full conversion with only 500 ppm catalyst loading. © 2012 The Royal Society of Chemistry.

  2. Synthesis of cis - and trans-diisothiocyanato-bis(NHC) complexes of nickel(II) and applications in the Kumada-Corriu reaction

    KAUST Repository

    Jothibasu, Ramasamy

    2010-09-13

    Metathetical reaction of AgSCN with a series of trans-dihalido-bis(carbene) nickel(II) complexes in CH3CN readily afforded the novel diisothiocyanato-bis(carbene) complexes [Ni(NCS)2(NHC)2] (trans-2a, NHC = 1,3-diisopropylbenzimidazolin-2-ylidene; trans-2b, NHC = 1,3-diisobutylbenzimidazolin-2-ylidene; trans-2c, NHC = 1,3- dibenzylbenzimidazolin-2-ylidene; cis-2d, NHC = 1,3-di(2-propenyl) benzimidazolin-2-ylidene; cis-2e, NHC = 1-propyl-3-methylbenzimidazolin-2- ylidene) as greenish-yellow powders in moderate to good yields. While dihalido-bis(carbene) Ni(II) complexes exclusively form trans-complexes, a trans-cis isomerization occurs upon halido-isothiocyanato exchange with complexes bearing less bulky carbene ligands, i.e., cis-2d/e. DFT calculations indicated that this isomerization can be attributed to a reduced energy difference between trans- and cis-isomers of diisothiocyanato complexes. All complexes have been characterized by multinuclear NMR spectroscopy, ESI mass spectrometry, and X-ray diffraction analysis. A catalytic study revealed that cis-complexes generally exhibit greater activities in the Kumada-Corriu coupling reaction. © 2010 American Chemical Society.

  3. Cis-trans photoisomerization of abscisic acid

    International Nuclear Information System (INIS)

    Brabham, D.E.; Biggs, R.H.

    1981-01-01

    An important regulator of numerous physiological processes in higher plants is abscisic acid (ABA), which is photoisomerized from the more biologically active cis isomer to the nearly inactive trans isomer by natural sunlight. It is possible that this photoisomerization is a UV control mechanism in functions regulated by ABA. The quantum yields of both the cis to trans and trans to cis photoisomerizations were measured under various conditions of pH and oxygen concentration at room temperature. The yield for photoisomerization of cis-ABA ranged from 0.25 at pH 3.0 to 0.11 at pH 7.0. Oxygen partially quenched the process. The quantum yield varied only slightly with wavelength. The quantum yield of photolysis of cis-ABA was reported for pH 3.0 as 0.06. This yield also varied slightly with wavelength and was relatively insensitive to oxygen. This relatively high yield explains the loss of potency of ABA during UV irradiation. Phosphorescence of cis- and trans-ABA was observed in methanol at 77 K. Onset of the emission was at 350 nm. The emission spectra were the same for both isomers. From these results a mechanism of UV action on plants based on the photoisomerization of the inactive trans-ABA to the biologically active cis isomer is proposed. (author)

  4. Trans Women Doing Sex in San Francisco.

    Science.gov (United States)

    Williams, Colin J; Weinberg, Martin S; Rosenberger, Joshua G

    2016-10-01

    This research investigates the sexuality of trans women (individuals who were assigned male status at birth who currently identify as women), by focusing on the "bodily techniques" (Crossley, 2006) they use in "doing" sexuality. The "doing sexuality" framework not only is modeled after the "doing gender" approach of West and Zimmerman (1987), but also utilizes the idea of "sexual embodiment" to emphasize the agency of trans women as they conceptualize and organize their sexuality in a socially recognized way. This is often difficult as they confront discrimination from medical and legal professionals as well as intimate partners who may find it difficult to adapt to the trans woman's atypical body and conception of gender. However, with a study group of 25 trans women from San Francisco, we found the study participants to be adept at overcoming such hurdles and developing techniques to "do" their sexuality. At the same time, we found trans women's agency constrained by the erotic habitus (Green, 2008) of the wider society. The interplay between innovation and cultural tradition provides an opportunity to fashion a more general model of "doing" sexuality.

  5. Trans issues in Liz Lochhead's 'Not Changed'

    Directory of Open Access Journals (Sweden)

    Kaličanin Milena M.

    2017-01-01

    Full Text Available The paper is divided into four sections. In the first section entitled 'Introducing and Defining Trans (Issues', the basic terms of transgender, transvestite, and transsexual are defined by relying on Stryker's Transgender History (2008. The second part of the paper, 'Trans Studies: In-Between Feminist and Queer Theory?', places transgender studies into an academic context by referring to the theoretical framework provided by trans theorists Stryker, Stone, and Ranck who unanimously claim that transgender studies should have a place of its own within the academia and that trans theory should solely be written by transsexuals. These ideas are applied in the interpretation of Lochhead's story 'Not Changed' in the third segment of the paper. The critical insights of Butler (Gender Trouble, 1990; Undoing Gender, 2004 are found to be most helpful in the interpretation of Lochhead's story about Michael who has willingly undergone Hormone Replacement Therapy to become transsexual Michele. Finally, in the concluding remarks, Lochhead's story is viewed as a trans woman manifesto, urging both non-transsexual and transsexual persons to embrace new beginnings in their relationship.

  6. Spectra of fluorinated rare earth β-diketonates with added ligands

    International Nuclear Information System (INIS)

    Khomenko, V.S.; Lozinskij, M.O.; Fialkov, Yu.A.; Rasshinina, T.A.; Krasovskaya, L.I.; AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    1984-01-01

    Different-ligand rare earth complexes are synthesized. Fluorated β-diketones, triethylphosphine oxide and trifluoracetic acid are used as active ligands. Mass-spectra of low and high resolution are taken at the energy of ionizing electrons of 70 eV, as well as luminescence spectra of complexes. Fragmentation ways of complexes decomposition under electron shock are studied. A series of changing the bound strength of additional ligands with europium in mixed complexes is determined. It is shown that the introduction of additional ligands can purposefully change physical and chemical properties of complexes

  7. Ligand Depot: a data warehouse for ligands bound to macromolecules.

    Science.gov (United States)

    Feng, Zukang; Chen, Li; Maddula, Himabindu; Akcan, Ozgur; Oughtred, Rose; Berman, Helen M; Westbrook, John

    2004-09-01

    Ligand Depot is an integrated data resource for finding information about small molecules bound to proteins and nucleic acids. The initial release (version 1.0, November, 2003) focuses on providing chemical and structural information for small molecules found as part of the structures deposited in the Protein Data Bank. Ligand Depot accepts keyword-based queries and also provides a graphical interface for performing chemical substructure searches. A wide variety of web resources that contain information on small molecules may also be accessed through Ligand Depot. Ligand Depot is available at http://ligand-depot.rutgers.edu/. Version 1.0 supports multiple operating systems including Windows, Unix, Linux and the Macintosh operating system. The current drawing tool works in Internet Explorer, Netscape and Mozilla on Windows, Unix and Linux.

  8. Attenuation of eph receptor kinase activation in cancer cells by coexpressed ephrin ligands.

    Directory of Open Access Journals (Sweden)

    Giulia Falivelli

    Full Text Available The Eph receptor tyrosine kinases mediate juxtacrine signals by interacting "in trans" with ligands anchored to the surface of neighboring cells via a GPI-anchor (ephrin-As or a transmembrane segment (ephrin-Bs, which leads to receptor clustering and increased kinase activity. Additionally, soluble forms of the ephrin-A ligands released from the cell surface by matrix metalloproteases can also activate EphA receptor signaling. Besides these trans interactions, recent studies have revealed that Eph receptors and ephrins coexpressed in neurons can also engage in lateral "cis" associations that attenuate receptor activation by ephrins in trans with critical functional consequences. Despite the importance of the Eph/ephrin system in tumorigenesis, Eph receptor-ephrin cis interactions have not been previously investigated in cancer cells. Here we show that in cancer cells, coexpressed ephrin-A3 can inhibit the ability of EphA2 and EphA3 to bind ephrins in trans and become activated, while ephrin-B2 can inhibit not only EphB4 but also EphA3. The cis inhibition of EphA3 by ephrin-B2 implies that in some cases ephrins that cannot activate a particular Eph receptor in trans can nevertheless inhibit its signaling ability through cis association. We also found that an EphA3 mutation identified in lung cancer enhances cis interaction with ephrin-A3. These results suggest a novel mechanism that may contribute to cancer pathogenesis by attenuating the tumor suppressing effects of Eph receptor signaling pathways activated by ephrins in trans.

  9. Metal-ligand interactions

    Science.gov (United States)

    Ervin, Kent M.

    Experimental studies of the interactions of small transition-metal cluster anions with carbonyl ligands are reviewed and compared with neutral and cationic clusters. Under thermal conditions, the reaction rates of transition-metal clusters with carbon monoxide are measured as a function of cluster size. Saturation limits for carbon monoxide addition can be related to the geometric structures of the clusters. Both energy-resolved threshold collision-induced dissociation experiments and time-resolved photodissociation experiments are used to measure metal-carbonyl binding energies. For platinum and palladium trimer anions, the carbonyl binding energies are assigned to different geometric binding sites. Platinum and palladium cluster anions catalyse the oxidation of carbon monoxide to carbon dioxide in a full catalytic cycle at thermal energies.

  10. Melatonin: functions and ligands.

    Science.gov (United States)

    Singh, Mahaveer; Jadhav, Hemant R

    2014-09-01

    Melatonin is a chronobiotic substance that acts as synchronizer by stabilizing bodily rhythms. Its synthesis occurs in various locations throughout the body, including the pineal gland, skin, lymphocytes and gastrointestinal tract (GIT). Its synthesis and secretion is controlled by light and dark conditions, whereby light decreases and darkness increases its production. Thus, melatonin is also known as the 'hormone of darkness'. Melatonin and analogs that bind to the melatonin receptors are important because of their role in the management of depression, insomnia, epilepsy, Alzheimer's disease (AD), diabetes, obesity, alopecia, migraine, cancer, and immune and cardiac disorders. In this review, we discuss the mechanism of action of melatonin in these disorders, which could aid in the design of novel melatonin receptor ligands. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Technical aspects of trans reduction in margarines

    Directory of Open Access Journals (Sweden)

    Van Duijn Gerrit

    2000-01-01

    Full Text Available The opinion of nutritional science on the effect of trans fatty acids on blood cholesterol has drastically changed during the last decade. As a reaction to these new findings, the European margarine industry decided in the mid nineties to eliminate trans containing components from their margarine fat phase compositions. This excluded practically the use of partially hydrogenated oils and fats. Trans-free margarines have been introduced with optimised fat crystal structures stabilising a maximum of water in oil emulsion with a minimum of solid fat phase. These fat crystal structures are formed by fat phase components obtained from interesterification and/or fractionation of non-hydrogenated and/or fully hydrogenated feedstocks.

  12. Physics of Trans-Planckian Gravity

    CERN Document Server

    Dvali, Gia; Germani, Cristiano

    2011-01-01

    We study aspects of the phenomenon of gravitational UV-self-completeness and its implications for deformations of Einstein gravity. In a ghost-free theory flowing to Einstein gravity in the IR trans-Planckian propagating quantum degrees of freedom cannot exist. The only physical meaning of a trans-Planckian pole is the one of a classical state (Black Hole) which is fully described by the light IR quantum degrees of freedom and gives exponentially-suppressed contributions to virtual processes. In this sense Einstein gravity is UV self-complete, although not Wilsonian. We show that this UV/IR correspondence puts a severe constraint on any attempt of conventional Wilsonian UV-completion of trans-Planckian gravity. In particular, there is no well-defined energy domain in which gravity could become asymptotically weak or safe.

  13. Macrocyclic G-quadruplex ligands

    DEFF Research Database (Denmark)

    Nielsen, M C; Ulven, Trond

    2010-01-01

    are macrocyclic structures which have been modeled after the natural product telomestatin or from porphyrin-based ligands discovered in the late 1990s. These two structural classes of G-quadruplex ligands are reviewed here with special attention to selectivity and structure-activity relationships, and with focus...

  14. Effects of ligand substitution on the excited state dynamics of the Ru(dcbpy)(CO) 2I 2 complex

    Science.gov (United States)

    Lehtovuori, Viivi; Kallioinen, Jani; Myllyperkiö, Pasi; Haukka, Matti; Korppi-Tommola, Jouko

    2003-11-01

    Spectroscopic evidence suggest [PCCP 3 (2001) 1992] that illumination with visible light of the [ trans-I-Ru(dcbpy)(CO) 2I 2] (dcbpy= 4,4 '-dicarboxy-2,2 '-bipyridine) complex in solution induces dissociation of a CO group followed by reorganization of the ligands and attachment of a solvent molecule. In the present study, we report results on excited state dynamics of this ruthenium complex and its photoproduct. Femtosecond transient absorption measurements reveal dominance of excited state absorption of the reactant and the photoproduct [ cis-I-Ru(dcbpy)(CO)(Sol)I 2] (Sol=ethanol or acetonitrile) in the visible spectral region. The time-resolved measurements for the reactant at 77 K indicate interligand charge transfer from mixed Ru-I states to empty dcbpy orbitals. For the photoproduct, no such transfer was observed. In both complexes recovery from the lowest energy excited triplet state to the ground state occurs via two channels: radiative relaxation and a parallel barrier controlled non-radiative relaxation. The barrier is much higher in the reactant (about 850 cm -1) than in the product. A combination of DFT and ZINDO/CI calculations was used to estimate excited singlet and triplet spectra of the reactant and the product molecules. Calculated singlet-triplet difference spectra qualitatively match the observed transient spectra 500 fs after excitation supporting the idea that observed excited state relaxation occurs from the triplet states in both complexes.

  15. Effects of ligand substitution on the excited state dynamics of the Ru(dcbpy)(CO)2I2 complex

    International Nuclear Information System (INIS)

    Lehtovuori, Viivi; Kallioinen, Jani; Myllyperkioe, Pasi; Haukka, Matti; Korppi-Tommola, Jouko

    2003-01-01

    Spectroscopic evidence suggest [PCCP 3 (2001) 1992] that illumination with visible light of the [trans-I-Ru(dcbpy)(CO) 2 I 2 ] (dcbpy4,4 ' -dicarboxy-2,2 ' -bipyridine) complex in solution induces dissociation of a CO group followed by reorganization of the ligands and attachment of a solvent molecule. In the present study, we report results on excited state dynamics of this ruthenium complex and its photoproduct. Femtosecond transient absorption measurements reveal dominance of excited state absorption of the reactant and the photoproduct [cis-I-Ru(dcbpy)(CO)(Sol)I 2 ] (Sol=ethanol or acetonitrile) in the visible spectral region. The time-resolved measurements for the reactant at 77 K indicate interligand charge transfer from mixed Ru-I states to empty dcbpy orbitals. For the photoproduct, no such transfer was observed. In both complexes recovery from the lowest energy excited triplet state to the ground state occurs via two channels: radiative relaxation and a parallel barrier controlled non-radiative relaxation. The barrier is much higher in the reactant (about 850 cm -1 ) than in the product. A combination of DFT and ZINDO/CI calculations was used to estimate excited singlet and triplet spectra of the reactant and the product molecules. Calculated singlet-triplet difference spectra qualitatively match the observed transient spectra 500 fs after excitation supporting the idea that observed excited state relaxation occurs from the triplet states in both complexes

  16. cis,trans-Dicarbonyldichlorido(1,10-phenanthroline-5,6-dione-κ2N,N′ruthenium(II

    Directory of Open Access Journals (Sweden)

    Tsugiko Takase

    2017-02-01

    Full Text Available In the title compound, [RuCl2(C12H6N2O2(CO2], the RuII atom (site symmetry ..2 adopts a distorted octahedral coordination sphere defined by two carbonyl C atoms, two Cl− anions and two N atoms from the chelating 1,10-phenanthroline-5,6-dione (phendione ligand. The carbonyl ligands are cis to each other, while the Cl atoms are trans. In the phendione ligand, the C=O [1.239 (5 Å] and the C—C [1.537 (5 Å] bond lengths in the diketone moiety have typical values. In the crystal, C—H...Cl and C—H...O hydrogen bonds lead to the formation of a three-dimensional supramolecular network.

  17. Ruminant and industrially produced trans fatty acids

    DEFF Research Database (Denmark)

    Stender, Steen; Astrup, Arne; Dyerberg, Jørn

    2008-01-01

    % of the fatty acids in trans form compared to the content in ruminant fat which generally does not exceed 6%. In Western Europe, including Scandinavia, the average daily intake of IP-TFA has decreased during the recent decade due to societal pressure and a legislative ban, whereas the intake of RP-TFA has......Fatty acids of trans configuration in our food come from two different sources - industrially produced partially hydrogenated fat (IP-TFA) used in frying oils, margarines, spreads, and in bakery products, and ruminant fat in dairy and meat products (RP-TFA). The first source may contain up to 60...

  18. A ligand channel through the G protein coupled receptor opsin.

    Directory of Open Access Journals (Sweden)

    Peter W Hildebrand

    Full Text Available The G protein coupled receptor rhodopsin contains a pocket within its seven-transmembrane helix (TM structure, which bears the inactivating 11-cis-retinal bound by a protonated Schiff-base to Lys296 in TM7. Light-induced 11-cis-/all-trans-isomerization leads to the Schiff-base deprotonated active Meta II intermediate. With Meta II decay, the Schiff-base bond is hydrolyzed, all-trans-retinal is released from the pocket, and the apoprotein opsin reloaded with new 11-cis-retinal. The crystal structure of opsin in its active Ops* conformation provides the basis for computational modeling of retinal release and uptake. The ligand-free 7TM bundle of opsin opens into the hydrophobic membrane layer through openings A (between TM1 and 7, and B (between TM5 and 6, respectively. Using skeleton search and molecular docking, we find a continuous channel through the protein that connects these two openings and comprises in its central part the retinal binding pocket. The channel traverses the receptor over a distance of ca. 70 A and is between 11.6 and 3.2 A wide. Both openings are lined with aromatic residues, while the central part is highly polar. Four constrictions within the channel are so narrow that they must stretch to allow passage of the retinal beta-ionone-ring. Constrictions are at openings A and B, respectively, and at Trp265 and Lys296 within the retinal pocket. The lysine enforces a 90 degrees elbow-like kink in the channel which limits retinal passage. With a favorable Lys side chain conformation, 11-cis-retinal can take the turn, whereas passage of the all-trans isomer would require more global conformational changes. We discuss possible scenarios for the uptake of 11-cis- and release of all-trans-retinal. If the uptake gate of 11-cis-retinal is assigned to opening B, all-trans is likely to leave through the same gate. The unidirectional passage proposed previously requires uptake of 11-cis-retinal through A and release of photolyzed all-trans

  19. Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

    International Nuclear Information System (INIS)

    Schmidt, Tobias; Bertermann, Rüdiger; Rusch, George M.; Tveit, Ann; Dekant, Wolfgang

    2013-01-01

    trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using 19 F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t 1/2 1/2 < 6 h). ► Glutathione adduct as predominant in vitro metabolite in all tested species. ► Toxic metabolites could not be detected in any great extent

  20. trans-Methylpyridine cyclen versus cross-bridged trans-methylpyridine cyclen. Synthesis, acid-base and metal complexation studies (metal = Co2+, Cu2+, and Zn2+).

    Science.gov (United States)

    Bernier, Nicolas; Costa, Judite; Delgado, Rita; Félix, Vítor; Royal, Guy; Tripier, Raphaël

    2011-05-07

    The synthesis of the cross-bridged cyclen CRpy(2) {4,10-bis((pyridin-2-yl)methyl)-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane}, a constrained analogue of the previously described trans-methylpyridine cyclen Cpy(2) is reported. The additional ethylene bridge confers to CRpy(2) proton-sponge type behaviour which was explored by NMR and potentiometric studies. Transition metal complexes have been synthesized (by complexation of both ligands with Co(2+), Cu(2+) and Zn(2+)) and characterized in solution and in the solid state. The single crystal X-ray structures of [CoCpy(2)](2+), [CuCpy(2)](2+) and [ZnCpy(2)](2+) complexes were determined. Stability constants of the complexes, including those of the cross-bridged derivative, were determined using potentiometric titration data and the kinetic inertness of the [CuCRpy(2)](2+) complex in an acidic medium (half-life values) was evaluated by spectrophotometry. The pre-organized structure of the cross-bridged ligand imposes an additional strain for the complexation leading to complexes with smaller thermodynamic stability in comparison with the related non-bridged ligand. The electrochemical study involving cyclic voltammetry underlines the importance of the ethylene cross-bridge on the redox properties of the transition metal complexes.

  1. Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Tobias [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany); Bertermann, Rüdiger [Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg (Germany); Rusch, George M.; Tveit, Ann [Honeywell, P.O. Box 1057, Morristown, NJ 07962-1057 (United States); Dekant, Wolfgang, E-mail: dekant@toxi.uni-wuerzburg.de [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany)

    2013-05-01

    trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using {sup 19}F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t{sub 1/2} < 6 h) and the extent of biotransformation of trans-HCFO-1233zd was determined as approximately 0.01% of received dose in rabbits and approximately 0.002% in rats. trans-HCFO-1233zd undergoes both oxidative biotransformation and glutathione conjugation at very low rates. The low extent of biotransformation and the rapid excretion of metabolites formed are consistent with the very low potential for toxicity of trans-HCFO-1233zd in mammals. - Highlights: ► No lethality and clinical signs were observed. ► Glutathione S-transferase and cytochrome P-450 dependent

  2. Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal.

    Science.gov (United States)

    Li, Xin; Wang, Jun; Zhang, Xiaojian; Chen, Chao

    2015-06-01

    Powdered activated carbon (PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal (HDE) and trans,trans-2,4-decadienal (DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated an exothermic and spontaneous adsorption process. PAC dosage, pH, and natural organic matter (NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of pH had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at pH9. The presence of NOM, especially the fraction with molecular weight less than 1k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did. Copyright © 2015. Published by Elsevier B.V.

  3. Trans-kingdom cross-talk

    DEFF Research Database (Denmark)

    Knip, Marijn; Constantin, Maria-Ermioni; Thordal-Christensen, Hans

    2014-01-01

    This review focuses on the mobility of small RNA (sRNA) molecules from the perspective of trans-kingdom gene silencing. Mobility of sRNA molecules within organisms is a well-known phenomenon, facilitating gene silencing between cells and tissues. sRNA signals are also transmitted between organism...

  4. The european Trans-Tools transport model

    NARCIS (Netherlands)

    Rooijen, T. van; Burgess, A.

    2008-01-01

    The paper presents the use of ArcGIS in the Transtools Transport Model, TRANS-TOOLS, created by an international consortium for the European Commission. The model describe passenger as well as freight transport in Europe with all medium and long distance modes (cars, vans, trucks, train, inland

  5. Mixed-ligand binuclear copper(II) complex of 5 ...

    Indian Academy of Sciences (India)

    The title compound was obtained as dark green ... tals were sorted using polarizing microscope (Leica. DMLSP). Crystals ... minimum peak heights of 0.405 and –0.285 e Å. −3. , respectively. .... placed in a centre of inversion. Each unit of the ...

  6. Speciation of cadmium mixed ligand complexes in salt water lakes

    Directory of Open Access Journals (Sweden)

    John L. Kituyi

    2003-06-01

    Full Text Available Amalgam voltammetry has been used to study heavy metal interaction in model lake water in KNO3 at 23 oC at concentration levels of genuine lake water. The hanging drop amalgam electrode was prepared in situ before exchanging the medium for the sample solution. Half-wave potentials at two metal ion concentrations were measured, one at the actual concentration in the lake while the other at a much lower one. The experimentally determined shifts in half-wave potentials are used to compute several formation constants. At the natural [CO32-] of 0.5 M in the lake, the main contributor to the speciation of cadmium is [Cd(CO3Cl2]2-. At high [Cd2+], the DPASV detects the presence of free Cd2+ ions, hence, potential polluting effect, while the amalgam reports [Cd(CO32Cl] 3- to be dominant above [CO32-] = 0.8 M. There is a variation in the number of complexes detected, their stabilities and percentage distribution in the two methods. Cd2+ ion concentration also affects the number of complexes formed and their stabilities.

  7. Speciation of cadmium mixed ligand complexes in salt water lakes ...

    African Journals Online (AJOL)

    The experimentally determined shifts in half-wave potentials are used to compute several formation constants. At the natural [CO32-] of 0.5 M in the lake, the main contributor to the speciation of cadmium is [Cd(CO3Cl2)]2-. At high [Cd2+], the DPASV detects the presence of free Cd2+ ions, hence, potential polluting effect, ...

  8. Trans-Kullo jagatakse tükkideks / Kadrin Karner

    Index Scriptorium Estoniae

    Karner, Kadrin

    2008-01-01

    Primos OÜ omanik ja Trans-Kullo osanik Endel Siff ütles, et Trans-Kullo on aktsionäride erinevate ärihuvide tõttu läinud jagunemisele, mis võib lõppeda ettevõtte likvideerimisega. Lisa: Trans-Kullo

  9. Correcting ligands, metabolites, and pathways

    NARCIS (Netherlands)

    Ott, M.A.; Vriend, G.

    2006-01-01

    BACKGROUND: A wide range of research areas in bioinformatics, molecular biology and medicinal chemistry require precise chemical structure information about molecules and reactions, e.g. drug design, ligand docking, metabolic network reconstruction, and systems biology. Most available databases,

  10. Mixed Metal Complexes of Isoniazid and Ascorbic Acid: Chelation ...

    African Journals Online (AJOL)

    HP

    these ligands and their metal complexes have revealed the bi-dentate coordination of isoniazid ligand to ... of the drugs on coordination with a metal is enhanced ..... James, O.O., Nwinyi, C.O. and. Allensela, M.A. (2008). Cobalt(II) complexes of mixed antibiotics: Synthesis,. Characterization, antimicrobial potential and their.

  11. Comparison of the ligand binding properties of two homologous rat apocellular retinol-binding proteins expressed in Escherichia coli.

    Science.gov (United States)

    Levin, M S; Locke, B; Yang, N C; Li, E; Gordon, J I

    1988-11-25

    Cellular retinol-binding protein (CRBP) and cellular retinol-binding protein II (CRBP II) are 132-residue cytosolic proteins which have 56% amino acid sequence identity and bind all-trans-retinol as their endogenous ligand. They belong to a family of cytoplasmic proteins which have evolved to bind distinct hydrophobic ligands. Their patterns of tissue-specific and developmental regulation are distinct. We have compared the ligand binding properties of rat apo-CRBP and apo-CRBP II that have been expressed in Escherichia coli. Several observations indicate that the E. coli-derived apoproteins are structurally similar to the native rat proteins: they co-migrate on isoelectric focusing gels; and when complexed with all-trans-retinol, their absorption and excitation/emission spectra are nearly identical to those of the authentic rat holoproteins. Comparative lifetime and acrylamide quenching studies suggest that there are differences in the conformations of apo-CRBP and apo-CRBP II. The interaction of E. coli-derived apo-CRBP and apo-CRBP II with a variety of retinoids was analyzed using spectroscopic techniques. Both apoproteins formed high affinity complexes with all-trans-retinol (K'd approximately 10 nM). In direct binding assays, all-trans-retinal bound to both apoproteins (K'd approximately 50 nM for CRBP; K'd approximately 90 nM for CRBP II). However, all-trans-retinal could displace all-trans-retinol bound to CRBP II but not to CRBP. These observations suggests that there is a specific yet distinct interaction between these two proteins and all-trans-retinal. Apo-CRBP and apo-CRBP II did not demonstrate significant binding to either retinoic acid or methyl retinoate, an uncharged derivative of all-trans-retinoic acid. This indicates that the carboxymethyl group of methyl retinoate cannot be sterically accommodated in their binding pockets and that failure to bind retinoic acid probably is not simply due to the negative charge of its C-15 carboxylate group

  12. Production of Methyl Ester (Biodiesel from Used Cooking Oils via Trans-esterification process

    Directory of Open Access Journals (Sweden)

    Sameer Mohammed Salman

    2016-06-01

    Full Text Available Used cooking oil was undergoing trans-esterification reaction to produce biodiesel fuel. Method of production consisted of pretreatment steps, trans-esterification, separation, washing and drying. Trans-esterification of treated oils was studied at different operation conditions, the methanol to oil mole ratio were 6:1, 8:1, 10:1, and 12:1, at different temperature 30, 40, 50, and 60 º C, reaction time 40, 60, 80, and 120 minutes, amount of catalyst 0.5, 1, 1.5, and 2 wt.% based on oil and mixing speed 400 rpm. The maximum yield of biodiesel was 91.68 wt.% for treated oils obtained by trans-esterification reaction with 10:1 methanol to oil mole ratio, 60 º C reaction temperature, 80 minute reaction time and 0.5 wt.% of NaOH catalyst. The physical properties such as specific gravity, kinematic viscosity, acid number, flash point, pour point, and water content, were measured and compared them with American Standard Test Methods (ASTM D6751. The results of these properties for biodiesel product at (6:1, 8:1, 10:1, and 12:1 of methanol to oil mole ratio were within the range of American Standard Test Methods (ASTM D6751.

  13. Functionalization of Cadmium Selenide Quantum Dots with Poly(ethylene glycol): Ligand Exchange, Surface Coverage, and Dispersion Stability.

    Science.gov (United States)

    Wenger, Whitney Nowak; Bates, Frank S; Aydil, Eray S

    2017-08-22

    Semiconductor quantum dots synthesized using rapid mixing of precursors by injection into a hot solution of solvents and surfactants have surface ligands that sterically stabilize the dispersions in nonpolar solvents. Often, these ligands are exchanged to disperse the quantum dots in polar solvents, but quantitative studies of quantum dot surfaces before and after ligand exchange are scarce. We studied exchanging trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO) ligands on as-synthesized CdSe quantum dots dispersed in hexane with a 2000 g/mol thiolated poly(ethylene glycol) (PEG) polymer. Using infrared spectroscopy we quantify the absolute surface concentration of TOP/TOPO and PEG ligands per unit area before and after ligand exchange. While 50-85% of the TOP/TOPO ligands are removed upon ligand exchange, only a few are replaced with PEG. Surprisingly, the remaining TOP/TOPO ligands outnumber the PEG ligands, but these few PEG ligands are sufficient to disperse the quantum dots in polar solvents such as chloroform, tetrahydrofuran, and water. Moreover, as-synthesized quantum dots once easily dispersed in hexane are no longer dispersible in nonpolar solvents after ligand exchange. A subtle coverage-dependent balance between attractive PEG-solvent interactions and repulsive TOP/TOPO-solvent interactions determines the dispersion stability.

  14. Trans-sphenoidal excision of craniopharyngiomas.

    Directory of Open Access Journals (Sweden)

    Nagpal R

    1991-04-01

    Full Text Available Craniopharyngiomas have been by and large excised by the transcranial route. Since 1982, 11 patients have been operated by the traus-sphensidal route in the department. The clinical features with which they were presented, diagnostic investigations, details of surgical procedures and follow-up analysis is being presented here. A retrospective study of radiological investigation was done to determine the features that help decide the choice of surgical approach to these lesions. Only lesions that were primarily intrasellar, cystic and those that expanded the sella could be treated by the trans-sphenoidal route. Associated suprasellar extensions could also be removed. Predominantly calcified or firm, fleshy tumours lent themselves poorly to removal by the trans-sphenoidal route.

  15. Trans Fat Bans and Human Freedom

    Science.gov (United States)

    Resnik, David

    2014-01-01

    A growing body of evidence has linked consumption of trans fatty acids to cardiovascular disease. To promote public health, numerous state and local governments in the United States have banned the use of artificial trans fats in restaurant foods, and additional bans may follow. Although these policies may have a positive impact on human health, they open the door to excessive government control over food, which could restrict dietary choices, interfere with cultural, ethnic, and religious traditions, and exacerbate socioeconomic inequalities. These slippery slope concerns cannot be dismissed as far-fetched, because the social and political pressures are place to induce additional food regulations. To protect human freedom and other values, policies that significantly restrict food choices, such as bans on types of food, should be adopted only when they are supported by substantial scientific evidence, and when policies that impose fewer restrictions on freedom, such as educational campaigns and product labeling, are likely to be ineffective. PMID:20229412

  16. Introduction to Trans Australia Airlines CRM training

    Science.gov (United States)

    Davidson, Jim

    1987-01-01

    Trans Australia believes that its excellent accident rate record is due to a number of factors. It has a good group of standard operating procedures, and its crews are pretty well self-disciplined and adhere to those procedures. But the other thing that it believes is a factor in its safety record is that perhaps it is also due to its preparedness to be innovative, to keep up with what is going on in the rest of the world and, if it looks to have value, then to be amongst the first to try it out. Trans Australia commenced a program similar to Line Oriented Flight Training (LOFT) fairly early in 1979--that being its first windshear program-- which leads to why they are doing a course of resource management training, which we have chosen to call Aircrew Team Management (ATM). This course is detailed in another presentation.

  17. Siegel discs via trans-quasiconformal surgery

    DEFF Research Database (Denmark)

    Petersen, Carsten Lunde

    2014-01-01

    kompleksstruktur kan integreres, det vil sige definerer en kompleksstruktur. I denne komplekse struktur er den nye afbildning holomorf og har en Siegel disk. Der findes imidlertid masser af tilfælde hvor dette ikke lader sig gøre, men hvor man istedet kan finde en trans-kvasikonform udvidelse til enheds-disken af...... mængde af rotationstal med fuldt mål på cirklen har konjugationen en trans-kvasi-konform udvidelse til disken. Dette er et skridt i beviset for at for næsten alle (i Lebeguemåls forstand) rotations tal, er randen af Siegel-disken for et kvadratisk polynomium med en Siegel disk med et sådant rotationstal...

  18. Analysis of Trans Fat in Edible Oils with Cooking Process

    Science.gov (United States)

    Song, Juhee; Park, Joohyeok; Jung, Jinyeong; Lee, Chankyu; Gim, Seo Yeoung; Ka, HyeJung; Yi, BoRa; Kim, Mi-Ja; Kim, Cho-il

    2015-01-01

    Trans fat is a unsaturated fatty acid with trans configuration and separated double bonds. Analytical methods have been introduced to analyze trans fat content in foods including infrared (IR) spectroscopy, gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, reverses-phase silver ion high performance liquid chromatography, and silver nitrate thin layer chromatography. Currently, FT-IR spectroscopy and GC are mostly used methods. Trans fat content in 6 vegetable oils were analyzed and processing effects including baking, stir-frying, pan-frying, and frying on the formation of trans fat in corn oil was evaluated by GC. Among tested vegetable oils, corn oil has 0.25 g trans fat/100 g, whereas other oils including rapeseed, soybean, olive, perilla, and sesame oils did not have detectable amount of trans fat content. Among cooking methods, stir-frying increased trans fat in corn oil whereas baking, pan-frying, and frying procedures did not make changes in trans fat content compared to untreated corn oils. However, the trans fat content was so low and food label can be declared as ‘0’ trans based on the regulation of Ministry of Food ad Drug Safety (MFDS) (edible oil). PMID:26483890

  19. Trans-triquetral Perilunate fracture dislocation

    OpenAIRE

    John-Henry Rhind; Abhinav Gulihar; Andrew Smith

    2018-01-01

    Perilunate dislocations and perilunate fracture dislocations are rare and serious injuries. Perilunate dislocations represent less than 10% of all carpal injuries of which 61% represent transcaphoid fractures. Because of their rarity, up to 25% of perilunate dislocations are initially missed on first assessment. We present the case of a 66-year-old-gentleman who sustained an isolated trans-triquetral perilunate fracture dislocation while walking his dog. This was diagnosed in the emergency de...

  20. Sneutrino mixing

    International Nuclear Information System (INIS)

    Grossman, Y.

    1997-10-01

    In supersymmetric models with nonvanishing Majorana neutrino masses, the sneutrino and antisneutrino mix. The conditions under which this mixing is experimentally observable are studied, and mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are analyzed

  1. The TransPetro emergency response system

    Energy Technology Data Exchange (ETDEWEB)

    Filho, A.T.F.; Cardoso, V.F.; Carbone, R.; Berardinelli, R.P. [Petrobras-TransPetro, Rio de Janeiro (Brazil); Carvalho, M.T.M.; Casanova, M.A. [Pontificia Univ. Catolica, Rio de Janeiro (Brazil). Dept. de Informatica, TeCGraf

    2004-07-01

    Petrobras-TransPetro developed the TransPetro Emergency Response System in response to emergency situations at large oil pipelines or at terminal facilities located in sea or river harbour areas. The standard of excellence includes full compliance with environmental regulations set by the federal government. A distributed workflow management software called InfoPAE forms the basis of the system in which actions are defined, along with geographic and conventional data. The first prototype of InfoPAE was installed in 1999. Currently it is operational in nearly 80 installations. The basic concepts and functionality of the TransPetro Emergency Response System were outlined in this paper with reference to the mitigative actions that are based on an evaluation of the organization of the emergency teams; the communication procedures; characterization of the installations; definition of accidental scenarios; environmental sensitivity maps; simulation of oil spill trajectories and dispersion behaviour; geographical data of the area surrounding the installations; and, other conventional data related to the installations, including available equipment. The emergency response team can take action as soon as an accident is detected. The action plan involves characterizing several scenarios and delegating mitigative actions to specific sub-teams, each with access to geographic data on the region where the emergency occurred. 13 refs., 3 figs.

  2. Physics of trans-Planckian gravity

    International Nuclear Information System (INIS)

    Dvali, Gia; Folkerts, Sarah; Germani, Cristiano

    2011-01-01

    We study the field theoretical description of a generic theory of gravity flowing to Einstein general relativity in IR. We prove that, if ghost-free, in the weakly-coupled regime such a theory can never become weaker than general relativity. Using this fact, as a by-product, we suggest that in a ghost-free theory of gravity trans-Planckian propagating quantum degrees of freedom cannot exist. The only physical meaning of a trans-Planckian pole is the one of a classical state (black hole) which is described by the light IR quantum degrees of freedom and gives exponentially-suppressed contributions to virtual processes. In this picture Einstein gravity is UV self-complete, although not Wilsonian, and sub-Planckian distances are unobservable in any healthy theory of gravity. We then finally show that this UV/IR correspondence puts a severe constraint on any attempt of conventional Wilsonian UV-completion of trans-Planckian gravity. Specifically, there is no well-defined energy domain in which gravity could become asymptotically weak or safe.

  3. TransAlta 2003 annual report

    International Nuclear Information System (INIS)

    2004-01-01

    This annual report presents financial information from TransAlta Corp., along with a review of its operations throughout 2003 and a summary of the how the electric utility has performed in terms of power generation, independent power producers, transmission and energy marketing. TransAlta is one of the largest non-regulated power generation and wholesale marketing companies in Canada. It's assets include coal-fired, gas-fired, hydro and renewable generation facilities in Canada, the United States, Mexico and Australia. Reported earnings in 2003 were $1.26 per share compared to $1.17 in 2002. The strong first quarter was followed by harsh market conditions, low water levels which affected hydro production, and pricing restrictions in Ontario that reduced contribution from the Sarnia plant. This report outlines the utility's progress in increasing revenue and producing more power. In 2003, unplanned outages were reduced by 7 per cent and injury frequency rate was reduced by 27 per cent. The installation of 114 wind turbines in Fort Macleod, Alberta, increased TransAlta's renewable energy capacity to 3.7 per cent in 2003. The wind farm produces 75 MW of electricity, enough to power more than 32,500 homes annually. This report summarized the company's energy resource activities and presented an operations review as well as consolidated financial statements and common share information. This included the utility's assets, liabilities, revenues, expenses and cash flows. Revenue and expenditure statements were summarized by source. refs., tabs., figs

  4. TransCanada Corporation 2003 annual report

    International Nuclear Information System (INIS)

    2004-01-01

    This annual report presents financial information from TransCanada Corp., along with a review of its operations throughout 2003 and a summary of the how the company performed in terms of providing natural gas transmission and power services in North America. In 2003, TransCanada increased earnings from continuing operations by 7 per cent. It maintained a strong cash flow and continued to strengthen its balance sheet. More than 1.2 billion was invested and dividends were increased by 7 per cent in January 2004, for a total return to shareholders of 27 per cent, including dividends. In 2003, TransCanada also increased its ownership interest in Foothills Pipe Lines Ltd. to 100 per cent from 50 per cent. It secured a position in the Mackenzie Gas Pipeline Project and progressed the development of multiple liquefied natural gas projects in the northeast United States and eastern Canada. The company acquired 31.6 per cent interest in Bruce Power, adding nearly 1,500 megawatts base load generation to its portfolio. Plans are underway for cogeneration plants in Quebec, New Brunswick and Alberta. This report summarized the company's energy resource activities and presented an operations review as well as consolidated financial statements and common share information. This included the utility's assets, liabilities, revenues, expenses and cash flows. Revenue and expenditure statements were summarized by source. tabs., figs

  5. TransCanada Corporation 2004 annual report

    International Nuclear Information System (INIS)

    2005-01-01

    TransCanada is a leading North American energy company dealing with natural gas transmission, power generation and marketing opportunities. Financial information from TransCanada was presented in this annual report along with a review of its operations in 2004 and a summary of how the company performed in terms of providing natural gas transmission and power services in North America. In 2004, TransCanada increased earnings from continuing operations and maintained a strong cash flow and continued to strengthen its balance sheet. Achievements in 2004 included the acquisition of the Gas Transmission Northwest Pipeline System and the North Baja Pipeline System; the purchase of hydroelectric generation assets in New England with a total generating capacity of more than 500 MW; and the completed construction of two new gas-fired cogeneration plants, the 165 MW MacKay River facility in Alberta and the 90 MW Grandview facility in New Brunswick. The challenges in 2004 included the performance of the company's existing asset-based businesses and the new initiatives to produce another year of solid operating and financial results. This report summarized the company's energy resource activities and presented an operations review as well as consolidated financial statements and common share information. This included the utility's assets, liabilities, revenues, expenses and cash flows. Revenue and expenditure statements were summarized by source. tabs., figs

  6. Trans-Cultural, Trans-Language Practices: Potentialities for Rethinking Doctoral Education Pedagogies

    Directory of Open Access Journals (Sweden)

    Sarojni Choy

    2017-01-01

    Full Text Available Over the last decade, there has been a rapid increase in doctoral enrolments of Asian international students in Australian universities. While policies have been developed to meet the needs of these students, there seems to be some confusion around the terms internationalisation, globalisation, bi-cultural, inter-cultural, multi-cultural, and trans-cultural within these policies. In this paper, we define these terms and advocate for a policy position which orients to a futurist definition of culture. We then review the work of Michael Singh and his research team at Western Sydney University who have responded to this rapid increase in Asian international student doctoral enrolments in Australian universities by developing pedagogic principles around notions of trans-language and trans-cultural practices. In the final section of the paper, we then draw on our own experiences of doctoral supervision in Australian universities to reflect on our positioning within the pedagogic principles around trans-language and trans-cultural practices.

  7. Mononuclear, trinuclear, and hetero-trinuclear supramolecular complexes containing a new tri-sulfonate ligand and cobalt(II)/copper(II)-(1,10-phenanthroline) 2 building blocks

    Science.gov (United States)

    Yu, Yunfang; Wei, Yongqin; Broer, Ria; Sa, Rongjian; Wu, Kechen

    2008-03-01

    Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2(H 2O)(HTST)]·2H 2O ( 1), [Co 3(phen) 6(H 2O) 2(TST) 2]·7H 2O ( 2), and [Co 2Cu(phen) 6(H 2O) 2(TST) 2]·10H 2O ( 3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3TST) with the M2+ ( M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). Complex 1 contains a cis-Co(II)(phen) 2 building block and an HTST as monodentate ligand; complex 2 consists of two TST as bidentate ligands connecting one trans- and two cis-Co(II)(phen) 2 building blocks; complex 3 is formed by replacing the trans-Co(II)(phen) 2 in 2 with a trans-Cu(II)(phen) 2, which is the first reported hetero-trinuclear supramolecular complex containing both the Co(II)(phen) 2 and Cu(II)(phen) 2 as building blocks. The study shows the flexible multifunctional self-assembly capability of the H 3TST ligands presenting in these supramolecular complexes through coordinative, H-bonding and even π- π stacking interactions. The photoluminescent optical properties of these complexes are also investigated and discussed as well as the second-order nonlinear optical properties of 1.

  8. Electrochemistry of oxo-technetium(V) complexes containing Schiff base and 8-quinolinol ligands

    International Nuclear Information System (INIS)

    Refosco, F.; Mazzi, U.; Deutsch, E.; Kirchhoff, J.R.; Heineman, W.R.; Seeber, R.

    1988-01-01

    The electrochemistry of six-coordinate, monooxo technetium(V) complexes containing Schiff base ligands has been studied in acetonitrile and N,N'-dimethylformamide solutions. The complexes have the general formula TcOCl(L B ) 2 or TcO(L T )(L B ), where L B represents a bidentate-N,O Schiff base ligand or a bidentate-N,O 8-quinolinol ligand and L T represents a tridentate-O,N,O Schiff base ligand. Cyclic voltammetry at a platinum-disk electrode, controlled-potential coulometry, and thin-layer spectroelectrochemistry were used to probe both the oxidation and the reduction of these complexes. The results of these studies, and previously reported results on the analogous Re(V) complexes, can be understood within a single general reaction scheme. The salient features of this scheme are (i) one-electron reduction of Tc(V) to Tc(IV), (ii) subsequent loss of a ligand situated cis to the Tc≡O linkage, and (iii) subsequent isomerization of this unstable Tc(IV) product to more stable complex in which the site trans to the Tc≡O linkage is vacant. The Tc(IV) complexes can also be reduced to analogous Tc(III) species, which appear to undergo the same ligand loss and isomerization reactions. The technetium complexes are 400-500 mV easier to reduce than are their rhenium analogues. The 8-quinolinol ligands, and especially the 5-nitro derivative, both thermodynamically and kinetically stabilize the Tc(IV) and Tc(III) oxidation states. These electrogenerated species are unusual in that they constitute the bulk of the known examples of monomeric Tc(IV) and Tc(III) complexes containing only N- and O-donating ligands. 34 refs., 9 figs., 1 tab

  9. TransCanada PipeLines Limited 1998 annual report : TransCanada energy solutions

    International Nuclear Information System (INIS)

    1999-01-01

    Financial information from TransCanada PipeLines Limited and a review of the company's 1998 operations was made available for the benefit of shareholders. TransCanada's pipeline system transports natural gas and crude oil from Western Canada Sedimentary Basin to North America's major energy markets. Net earnings from continuing operations for 1998, before unusual charges, were $575 million ($ 355 million after unusual charges) compared to $522 million for 1997. Solid performances from the energy transmission and international business, when compared to 1997, were more than offset by a decreased contribution from energy processing. TransCanada recorded integration costs of $166 million, after tax, related to the merger with NOVA in 1998, which was the major operational accomplishment during the year, creating a seamless economic energy delivery, processing and marketing system from the wellhead to the market. tabs., figs

  10. Sexual desire in trans persons: associations with sex reassignment treatment.

    Science.gov (United States)

    Wierckx, Katrien; Elaut, Els; Van Hoorde, Birgit; Heylens, Gunter; De Cuypere, Griet; Monstrey, Stan; Weyers, Steven; Hoebeke, Piet; T'Sjoen, Guy

    2014-01-01

    Sex steroids and genital surgery are known to affect sexual desire, but little research has focused on the effects of cross-sex hormone therapy and sex reassignment surgery on sexual desire in trans persons. This study aims to explore associations between sex reassignment therapy (SRT) and sexual desire in a large cohort of trans persons. A cross-sectional single specialized center study including 214 trans women (male-to-female trans persons) and 138 trans men (female-to-male trans persons). Questionnaires assessing demographics, medical history, frequency of sexual desire, hypoactive sexual desire disorder (HSDD), and treatment satisfaction. In retrospect, 62.4% of trans women reported a decrease in sexual desire after SRT. Seventy-three percent of trans women never or rarely experienced spontaneous and responsive sexual desire. A third reported associated personal or relational distress resulting in a prevalence of HSDD of 22%. Respondents who had undergone vaginoplasty experienced more spontaneous sexual desire compared with those who planned this surgery but had not yet undergone it (P = 0.03). In retrospect, the majority of trans men (71.0%) reported an increase in sexual desire after SRT. Thirty percent of trans men never or rarely felt sexual desire; 39.7% from time to time, and 30.6% often or always. Five percent of trans men met the criteria for HSDD. Trans men who were less satisfied with the phalloplasty had a higher prevalence of HSDD (P = 0.02). Trans persons who were more satisfied with the hormonal therapy had a lower prevalence of HSDD (P = 0.02). HSDD was more prevalent in trans women compared with trans men. The majority of trans women reported a decrease in sexual desire after SRT, whereas the opposite was observed in trans men. Our results show a significant sexual impact of surgical interventions and both hormonal and surgical treatment satisfaction on the sexual desire in trans persons. © 2013 International Society for Sexual

  11. Ligand-dependent exciton dynamics and photovoltaic properties of PbS quantum dot heterojunction solar cells.

    Science.gov (United States)

    Chang, Jin; Ogomi, Yuhei; Ding, Chao; Zhang, Yao Hong; Toyoda, Taro; Hayase, Shuzi; Katayama, Kenji; Shen, Qing

    2017-03-01

    The surface chemistry of colloidal quantum dots (QDs) plays an important role in determining the photoelectric properties of QD films and the corresponding quantum dot heterojunction solar cells (QDHSCs). To investigate the effects of the ligand structure on the photovoltaic performance and exciton dynamics of QDHSCs, PbS QDHSCs were fabricated by the solid state ligand exchange method with mercaptoalkanoic acid as the cross-linking ligand. Temperature-dependent photoluminescence and ultrafast transient absorption spectra show that the electronic coupling and charge transfer rate within QD ensembles were monotonically enhanced as the ligand length decreased. However, in practical QDHSCs, the second shortest ligand 3-mercaptopropionic acid (MPA) showed higher power conversion efficiency than the shortest ligand thioglycolic acid (TGA). This could be attributed to the difference in their surface trap states, supported by thermally stimulated current measurements. Moreover, compared with the non-conjugated ligand MPA, the conjugated ligand 4-mercaptobenzoic acid (MBA) introduces less trap states and has a similar charge transfer rate in QD ensembles, but has poor photovoltaic properties. This unexpected result could be contributed by the QD-ligand orbital mixing, leading to the charge transfer from QDs to ligands instead of charge transfer between adjacent QDs. This work highlights the significant effects of ligand structures on the photovoltaic properties and exciton dynamics of QDHSCs, which would shed light on the further development of QD-based photoelectric devices.

  12. LigandRFs: random forest ensemble to identify ligand-binding residues from sequence information alone

    KAUST Repository

    Chen, Peng; Huang, Jianhua Z; Gao, Xin

    2014-01-01

    Protein-ligand binding is important for some proteins to perform their functions. Protein-ligand binding sites are the residues of proteins that physically bind to ligands. Despite of the recent advances in computational prediction

  13. Manipulating charge transfer excited state relaxation and spin crossover in iron coordination complexes with ligand substitution

    DEFF Research Database (Denmark)

    Zhang, Wenkai; Kjær, Kasper Skov; Alonso-Mori, Roberto

    2017-01-01

    iron complexes with four cyanide (CN-;) ligands and one 2,2′-bipyridine (bpy) ligand. This enables MLCT excited state and metal-centered excited state energies to be manipulated with partial independence and provides a path to suppressing spin crossover. We have combined X-ray Free-Electron Laser (XFEL...... state lifetime of iron based complexes due to spin crossover-the extremely fast intersystem crossing and internal conversion to high spin metal-centered excited states. We revitalize a 30 year old synthetic strategy for extending the MLCT excited state lifetimes of iron complexes by making mixed ligand...

  14. Zr (IV COMPLEXES OF SOME NITROGEN-OXYGEN DONOR LIGANDS (SEMICARBAZONES & SALICYLALDAZINE

    Directory of Open Access Journals (Sweden)

    Z F DAWOOD

    2002-06-01

    Full Text Available Complexes containing mixed ligands of zirconium (IV have been synthesized by the reaction of zirconium (IV nitrate (Zr(NO34, 5H2O with salicylaldazine (SAH2 and semicarbazone ligands benzaldehyde semicarbazone (BSCH, 4-methoxybenzaldehyde semicarbzone (MBSCH, 2-chlorobenzaldehyde semicrbazone (CISCH and cinnamaldehyde semicarbazone (CinSCH forming complexes of the type [Zr2(SAH2(SCH2](NO38 and [Zr2(SA2 (SC2](NO32 in neutral and basic medium respectively. The ligands and their complexes are characterized physico-chemically.

  15. Ruthenium(II) carbonyl compounds with the 4'-chloro-2,2':6',2''-terpyridine ligand.

    Science.gov (United States)

    Tatikonda, Rajendhraprasad; Haukka, Matti

    2017-04-01

    Two ruthenium carbonyl complexes with the 4'-chloro-2,2':6',2''-terpyridine ligand (tpy-Cl, C 15 H 10 ClN 3 ), i.e. [RuCl(tpy-Cl)(CO) 2 ][RuCl 3 (CO) 3 ] (I) [systematic name: cis -di-carbonyl-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 3 N )ruthenium(II) fac -tricarbonyltri-chlorido-ruthenate(II)], and [RuCl 2 (tpy-Cl)(CO) 2 ] (II) [ cis -dicarbonyl- trans -di-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 2 N 1 , N 1' )ruthenium(II)], were synthesized and characterized by single-crystal X-ray diffraction. The Ru II atoms in both centrosymmetric structures (I) and (II) display similar, slightly distorted octa-hedral coordination spheres. The coordination sphere in the complex cation in compound (I) is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octa-hedral [Ru(CO) 3 Cl 3 ] - counter-anion. In the neutral compound (II), the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the Ru II atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I) and (II), weak C-H⋯Cl inter-actions are observed.

  16. Trans-fatty acids in cooking oils in Bogota, Colombia: changes in the food supply from 2008 to 2013.

    Science.gov (United States)

    Moynihan, Meghan; Villamor, Eduardo; Marin, Constanza; Mora-Plazas, Mercedes; Campos, Hannia; Baylin, Ana

    2015-12-01

    Long-chain n-3 fatty acid intake in Colombia is low because fish consumption is limited. Vegetable oils with high n-3 fatty acid content are recommended, but their concentrations of trans fats were high in previous studies. Thus, regular monitoring of the fatty acid composition of vegetable oils is required. Our objective was to quantify the fatty acid composition in commercially available oils in Bogota, Colombia and determine if composition changed from 2008 to 2013. Cross-sectional study. We obtained samples of all commercially available oils reported in a survey of low- and middle-income families with a child participating in the Bogota School Children Cohort. Bogota, Colombia. Not applicable. Sunflower oil had the highest trans-fatty acid content (2.18%). Canola oil had the lowest proportion of trans-fatty acids (0.40%) and the highest n-3 fatty acid content (9.37%). In terms of percentage reduction from 2008 to 2013 in 18:1 and 18:2 trans-fatty acids, canola oil had 89% and 65% reduction, mixed oils had 44% and 48% reduction, and sunflower oil had 25% and 51 % reduction, respectively. Soyabean oil became widely available in 2013. The content of trans-fatty acids decreased in all oils from 2008 to 2013, suggesting a voluntary reduction by industry. We believe that regular monitoring of the fatty acid composition of oils is warranted.

  17. Rosetta Ligand docking with flexible XML protocols.

    Science.gov (United States)

    Lemmon, Gordon; Meiler, Jens

    2012-01-01

    RosettaLigand is premiere software for predicting how a protein and a small molecule interact. Benchmark studies demonstrate that 70% of the top scoring RosettaLigand predicted interfaces are within 2Å RMSD from the crystal structure [1]. The latest release of Rosetta ligand software includes many new features, such as (1) docking of multiple ligands simultaneously, (2) representing ligands as fragments for greater flexibility, (3) redesign of the interface during docking, and (4) an XML script based interface that gives the user full control of the ligand docking protocol.

  18. Trans fats in New Zealand: time for labelling regulations?

    Science.gov (United States)

    Gladding, Patrick; Benatar, Jocelyne R

    2007-11-09

    Trans fats (trans fatty acids) are commonly used for deep frying in restaurants and in the fast food, snack food, fried food, and baked goods industries, often to extend the shelf life of foods. However they are widely considered to be harmful to health. Trans fats were banned in New York City restaurants from 1 July 2007, and there is growing vocal opposition to trans fats in the European Union. Denmark became the first country, in March 2003, to introduce laws regulating the content of trans fats in food (maximum of 2% of edible fats and oils). What are trans fats, what harm do they cause, and should New Zealand also consider imposing mandatory regulations on their use in food? This article explores the issues.

  19. Nuclear reactions: Science and trans-science

    International Nuclear Information System (INIS)

    Weinberg, A.M.

    1992-01-01

    This book is a collection of essays written by Weinberg over the span of his scientific and administrative career. A sound theorist, he was introduced to nuclear physics as part of the Manhattan project, and assumed administrative responsibilities during that project. His career has allowed him to make valuable contributions in a broad range of fields. These essays touch on topics of interest to him, concern to the country, and of profound import for society as it exists today. They are grouped into five sections: science and trans-science; scientific administration; strategic defense and arms control; time, energy and resources; nuclear energy

  20. TRAN-STAT: statistics for environmental studies

    International Nuclear Information System (INIS)

    Gilbert, R.O.

    1984-09-01

    This issue of TRAN-STAT discusses statistical methods for assessing the uncertainty in predictions of pollutant transport models, particularly for radionuclides. Emphasis is placed on radionuclide transport models but the statistical assessment techniques also apply in general to other types of pollutants. The report begins with an outline of why an assessment of prediction uncertainties is important. This is followed by an introduction to several methods currently used in these assessments. This in turn is followed by more detailed discussion of the methods, including examples. 43 references, 2 figures

  1. Effects of ligand substitution on the excited state dynamics of the Ru(dcbpy)(CO){sub 2}I{sub 2} complex

    Energy Technology Data Exchange (ETDEWEB)

    Lehtovuori, Viivi; Kallioinen, Jani; Myllyperkioe, Pasi; Haukka, Matti; Korppi-Tommola, Jouko

    2003-11-15

    Spectroscopic evidence suggest [PCCP 3 (2001) 1992] that illumination with visible light of the [trans-I-Ru(dcbpy)(CO){sub 2}I{sub 2}] (dcbpy4,4{sup '}-dicarboxy-2,2{sup '}-bipyridine) complex in solution induces dissociation of a CO group followed by reorganization of the ligands and attachment of a solvent molecule. In the present study, we report results on excited state dynamics of this ruthenium complex and its photoproduct. Femtosecond transient absorption measurements reveal dominance of excited state absorption of the reactant and the photoproduct [cis-I-Ru(dcbpy)(CO)(Sol)I{sub 2}] (Sol=ethanol or acetonitrile) in the visible spectral region. The time-resolved measurements for the reactant at 77 K indicate interligand charge transfer from mixed Ru-I states to empty dcbpy orbitals. For the photoproduct, no such transfer was observed. In both complexes recovery from the lowest energy excited triplet state to the ground state occurs via two channels: radiative relaxation and a parallel barrier controlled non-radiative relaxation. The barrier is much higher in the reactant (about 850 cm{sup -1}) than in the product. A combination of DFT and ZINDO/CI calculations was used to estimate excited singlet and triplet spectra of the reactant and the product molecules. Calculated singlet-triplet difference spectra qualitatively match the observed transient spectra 500 fs after excitation supporting the idea that observed excited state relaxation occurs from the triplet states in both complexes.

  2. Structural modification of trans-cinnamic acid using Colletotrichum acutatum

    OpenAIRE

    Velasco B., Rodrigo; Gil G., Jesús H.; García P., Carlos M.; Durango R., Diego L.

    2012-01-01

    The biotransformation of trans-cinnamic acid by whole cells of the Colombian native phytopathogenic fungus Colletotrichum acutatum was studied. Initially, fungitoxicity of this compound against C. acutatum was evaluated; trans-cinnamic acid exhibited a moderate to weak toxicity against the microorganism and apparently a detoxification mechanism was present. Then, in order to study such mechanism and explore the capacity of this fungus to biotransform trans-cinnamic acid into value-added produ...

  3. Trans-nationalisation Processes in the Ukrainian Economy

    OpenAIRE

    Bolharova Natalya K.; Panevnyk Tetyana M.

    2013-01-01

    The article considers main processes of trans-nationalisation of Ukrainian economy, identifies specific features of trans-national production and explains some theoretical aspects of these issues. It provides main stages of theoretical comprehension of activity of trans-national corporations (TNC), specific features of the theory of competitive advantages of TNC and specifies the basic ones of them. The article conducts analysis of flows of direct foreign investments into the Ukrainian econom...

  4. Azido, triazolyl, and alkynyl complexes of gold(I): syntheses, structures, and ligand effects.

    Science.gov (United States)

    Robilotto, Thomas J; Deligonul, Nihal; Updegraff, James B; Gray, Thomas G

    2013-08-19

    Gold(I) triazolyl complexes are prepared in [3 + 2] cycloaddition reactions of (tertiary phosphine)gold(I) azides with terminal alkynes. Seven such triazolyl complexes, not previously prepared, are described. Reducible functional groups are accommodated. In addition, two new (N-heterocyclic carbene)gold(I) azides and two new gold(I) alkynyls are described. Eight complexes are crystallographically authenticated; aurophilic interactions appear in one structure only. The packing diagrams of gold(I) triazolyls all show intermolecular hydrogen bonding between N-1 of one molecule and N-3 of a neighbor. This hydrogen bonding permeates the crystal lattice. Density-functional theory calculations of (triphenylphosphine)gold(I) triazolyls and the corresponding alkynyls indicate that the triazolyl is a stronger trans-influencer than is the alkynyl, but the alkynyl is more electron-releasing. These results suggest that trans-influences in two-coordinate gold(I) complexes can be more than a simple matter of ligand donicity.

  5. Synergistic extraction of manganese(II) with thenoyltrifluoroacetone and neutral unidentate and bidentate ligands

    International Nuclear Information System (INIS)

    Nakamura, S.; Imura, H.; Suzuki, N.

    1984-01-01

    Synergistic effect of neutral bidentate ligands, L, such as 1,10-phenanthroline(phen), 2,9-dimethyl-1,10-phenanthroline(dmp) and 2,2'-bipyridine(bpy) and of neutral unidentate ligands TBP and TOPO have been studied in the extraction of Mn(II) labelled with 54 Mn using 2-thenoyl-trifluoroacetone(HTTA) in various organic solvents. The following factors play important role in the synergistic extraction involving bidentate ligands: a two-phase partition of bidentate ligands, and their protonation and complex formation with Mn(II) in the aqueous phase. The mixed ligand complex, Mn(TTA) 2 L is formed in all bidentate ligand systems. The adduct formation constant (βsub(s,1)) decreases in the following order: phen (lg βsub(s,1)=12.64)>dmp(11.32)>.bpy(8.54) in the cyclohexane system. This order is ascribed to the bacisity and the steric effect of the bidentate ligands. Organic solvents influence both the adduct formation and the partition of the ligands, and βsub(s,1) decreases in the order cyclohexane > carbon tetrachloride > cholrobenzene approx.= benzene > chloroform. (author)

  6. Trans*Forming College Masculinities: Carving out Trans*Masculine Pathways through the Threshold of Dominance

    Science.gov (United States)

    Jourian, T. J.

    2017-01-01

    Men and masculinities studies are gaining prominence in higher education literature, illuminating how cisgender college men understand and grapple with masculinity. Additionally, the increased visibility of trans* students has fueled the expanding scholarship and attention to their experiences, often however centering on white gender-conforming…

  7. Trans advanced surface laser ablation (TransPRK) outcomes using SmartPulseTechnology.

    Science.gov (United States)

    Aslanides, Ioannis M; Kymionis, George D

    2017-02-01

    To evaluate early visual rehabilitation, post-operative pain, epithelial healing and haze after transepithelial photorefractive keratectomy (TransPRK) using the SmartPulseTechnology (SPT) of Schwind Amaris (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany). This was a retrospective comparative evaluation of a cohort of myopic patients undergoing TransPRK with SPT (group 1), with one matched control group that underwent conventional TransPRK (group 2). All cases had a 6-month post-operative follow-up including visual acuity and slit-lamp examination. Subjective evaluation of pain was recorded post-operatively. 49 eyes of 25 patients in group 1 and 40 eyes of 20 patients in group 2 were enrolled. The patients' visual rehabilitation was significantly faster in group 1, one day and one week post-operatively (P0.05). TransPRK using SPT provides promising results in the early post-operative period. Visual rehabilitation, re-epithelialization and pain were faster in the early post-operative period in group 1 in comparison with group 2. Haze formation was not significantly different between the two groups; however, it was consistently less in group 1. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  8. Trans-nationalizing the African Public Sphere: What Role for Trans ...

    African Journals Online (AJOL)

    seriane.camara

    2011-03-09

    Mar 9, 2011 ... At a time when the notion of 'trans-national public spheres' is gaining .... ple refer specifically to the language and its speakers in Senegal and Mauri- .... of the Pulaar language and the improvement of the social and economic.

  9. A trans European Union difference in the decline in trans fatty acids in popular foods

    DEFF Research Database (Denmark)

    Stender, Steen; Astrup, Arne; Dyerberg, Jørn

    2012-01-01

    To minimise the intake of industrial trans fatty acids (I-TFA) some countries have introduced labelling, while others have introduced legislative limits on the content of I-TFA in food. However, most countries still rely on food producers to voluntarily reduce the I-TFA content in food. The objec...

  10. Spectroscopic and density functional theory studies of trans-3-(trans-4-imidazolyl)acrylic acid.

    Science.gov (United States)

    Arjunan, V; Remya, P; Sathish, U; Rani, T; Mohan, S

    2014-08-14

    The structural parameters, thermodynamic properties and vibrational frequencies of the optimised geometry of trans-3-(trans-4-imidazolyl)acrylic acid have been determined from B3LYP methods with 6-311++G(**) and cc-pVTZ basis sets. The effects of substituents (acrylyl group) on the imidazole vibrational frequencies are analysed. The vibrational frequencies of the fundamental modes of trans-3-(trans-4-imidazolyl)acrylic acid have been precisely assigned and analysed and the theoretical results are compared with the experimental vibrations. (1)H and (13)C NMR isotropic chemical shifts are calculated and the assignments made are compared with the experimental values. The energies of important MO's of the compound are also determined from DFT method. The total electron density and electrostatic potential of the compound are determined by natural bond orbital analysis. Various reactivity and selectivity descriptors such as chemical hardness, chemical potential, softness, electrophilicity, nucleophilicity and the appropriate local quantities employing natural population analysis (NPA) are calculated. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. New functionalized β-diketiminate ligands and f elements

    International Nuclear Information System (INIS)

    Dulong, Florian

    2013-01-01

    β-diketiminate ligands have received increased interest in coordination chemistry, especially for homogeneous catalysis. Their successful applications arise from an easy and fine tuning of the ligand electronic and geometric properties. However, these modifications are limited to the introduction of neutral donors (ethers or amines), on the nitrogen substituents of the β-diketiminate skeleton. The main focus of this research project is to overcome this limitation by synthesizing new β-diketiminate ligands functionalized by one or two anionic aryl-oxide groups, and to study their coordination chemistry with lanthanide and actinide ions. Access to these species relies on a fine understanding of the mechanism underlying their formation, and the sensitivity of the β-di-iminium skeleton towards nucleophiles (phenols) has been identified as the limiting side reaction in the synthetic route. Addition of reactants in well defined order allowed the formation of two new N-aryl-oxy-β-diketiminate dianions on a multi-gram scale. The two ligands differ by their steric bulk and exhibit different coordination behaviors towards lanthanides and actinide ions, which were rationalized on geometric considerations. The reactivity of three of these new complexes has been investigated. A Ce(III) N-aryl-oxy-β-diketiminate complex exhibits interesting reduction properties, due to the shift of its oxidation potential to negative values by its coordination environment. A Th(IV) complex presents a vacant coordination site, which has been probed with different Lewis bases, emphasizing two spatial arrangements ruled by inter-ligand repulsion. It has been compared to its U(IV) analogue, which can be oxidized to a rare terminal mono-oxo uranium(VI) species. The latter was reversibly reduced to its U(V) and U(IV) derivatives, creating the first series of terminal mono-oxo uranium complexes with three successive oxidation states. These compounds represent an opportunity to better understand

  12. [CONTENT OF TRANS FATTY ACIDS IN FOOD PRODUCTS IN SPAIN].

    Science.gov (United States)

    Robledo de Dios, Teresa; Dal Re Saavedra, M Ángeles; Villar Villalba, Carmen; Pérez-Farinós, Napoleón

    2015-09-01

    trans fatty acids are associated to several health disorders, as ischemic heart disease or diabetes mellitus. to assess the content of trans fatty acids in products in Spain, and the percentage of trans fatty acids respecting total fatty acids. 443 food products were acquired in Spain, and they were classified into groups. The content in fatty acids was analyzed using gas chromatography. Estimates of central tendency and variability of the content of trans fatty acids in each food group were computed (in g of trans fatty acids/100 g of product). The percentage of trans fatty acids respecting total fatty acids was calculated in each group. 443 products were grouped into 42 groups. Median of trans fatty acids was less than 0.55 g / 100 g of product in all groups except one. 83 % of groups had less than 2 % of trans fatty acids, and 71 % of groups had less than 1 %. the content of trans fatty acids in Spain is low, and it currently doesn't play a public health problem. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  13. Is there such a thing as Tech Trans?

    DEFF Research Database (Denmark)

    Helms, Niels Henrik

    2009-01-01

    This short paper is an attempt to start a discussion on some basic issues within the concept of Tech Trans especially the relationship between flow and structure within the concept. The background to this paper is first of all an academic interest in the relationship between flow and structure...... explores the concept of Tech Trans, show rooms and innovation systems, and it suggests that the notion of Tech Trans should be defined in the fix point of vertical and horizontal innovation. Finally this paper suggests a mathematical formula for evaluating Tech Trans....

  14. Attention modulates trans-saccadic integration.

    Science.gov (United States)

    Stewart, Emma E M; Schütz, Alexander C

    2018-01-01

    With every saccade, humans must reconcile the low resolution peripheral information available before a saccade, with the high resolution foveal information acquired after the saccade. While research has shown that we are able to integrate peripheral and foveal vision in a near-optimal manner, it is still unclear which mechanisms may underpin this important perceptual process. One potential mechanism that may moderate this integration process is visual attention. Pre-saccadic attention is a well documented phenomenon, whereby visual attention shifts to the location of an upcoming saccade before the saccade is executed. While it plays an important role in other peri-saccadic processes such as predictive remapping, the role of attention in the integration process is as yet unknown. This study aimed to determine whether the presentation of an attentional distractor during a saccade impaired trans-saccadic integration, and to measure the time-course of this impairment. Results showed that presenting an attentional distractor impaired integration performance both before saccade onset, and during the saccade, in selected subjects who showed integration in the absence of a distractor. This suggests that visual attention may be a mechanism that facilitates trans-saccadic integration. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  15. Mixing Ventilation

    DEFF Research Database (Denmark)

    Kandzia, Claudia; Kosonen, Risto; Melikov, Arsen Krikor

    In this guidebook most of the known and used in practice methods for achieving mixing air distribution are discussed. Mixing ventilation has been applied to many different spaces providing fresh air and thermal comfort to the occupants. Today, a design engineer can choose from large selection...

  16. Crystallization of protein–ligand complexes

    International Nuclear Information System (INIS)

    Hassell, Anne M.; An, Gang; Bledsoe, Randy K.; Bynum, Jane M.; Carter, H. Luke III; Deng, Su-Jun J.; Gampe, Robert T.; Grisard, Tamara E.; Madauss, Kevin P.; Nolte, Robert T.; Rocque, Warren J.; Wang, Liping; Weaver, Kurt L.; Williams, Shawn P.; Wisely, G. Bruce; Xu, Robert; Shewchuk, Lisa M.

    2007-01-01

    Methods presented for growing protein–ligand complexes fall into the categories of co-expression of the protein with the ligands of interest, use of the ligands during protein purification, cocrystallization and soaking the ligands into existing crystals. Obtaining diffraction-quality crystals has long been a bottleneck in solving the three-dimensional structures of proteins. Often proteins may be stabilized when they are complexed with a substrate, nucleic acid, cofactor or small molecule. These ligands, on the other hand, have the potential to induce significant conformational changes to the protein and ab initio screening may be required to find a new crystal form. This paper presents an overview of strategies in the following areas for obtaining crystals of protein–ligand complexes: (i) co-expression of the protein with the ligands of interest, (ii) use of the ligands during protein purification, (iii) cocrystallization and (iv) soaks

  17. Homologous SV40 RNA trans-splicing: Special case or prime example of viral RNA trans-splicing?

    Directory of Open Access Journals (Sweden)

    Sushmita Poddar

    2014-06-01

    Full Text Available To date the Simian Virus 40 (SV40 is the only proven example of a virus that recruits the mechanism of RNA trans-splicing to diversify its sequences and gene products. Thereby, two identical viral transcripts are efficiently joined by homologous trans-splicing triggering the formation of a highly transforming 100 kDa super T antigen. Sequences of other viruses including HIV-1 and the human adenovirus type 5 were reported to be involved in heterologous trans-splicing towards cellular or viral sequences but the meaning of these events remains unclear. We computationally and experimentally investigated molecular features associated with viral RNA trans-splicing and identified a common pattern: Viral RNA trans-splicing occurs between strong cryptic or regular viral splice sites and strong regular or cryptic splice sites of the trans-splice partner sequences. The majority of these splice sites are supported by exonic splice enhancers. Splice sites that could compete with the trans-splicing sites for cis-splice reactions are weaker or inexistent. Finally, all but one of the trans-splice reactions seem to be facilitated by one or more complementary binding domains of 11 to 16 nucleotides in length which, however occur with a statistical probability close to one for the given length of the involved sequences. The chimeric RNAs generated via heterologous viral RNA trans-splicing either did not lead to fusion proteins or led to proteins of unknown function. Our data suggest that distinct viral RNAs are highly susceptible to trans-splicing and that heterologous viral trans-splicing, unlike homologous SV40 trans-splicing, represents a chance event.

  18. -Pincer Ligand Family through Ligand Post-Modification

    KAUST Repository

    Huang, Mei-Hui; Hu, Jinsong; Huang, Kuo-Wei

    2017-01-01

    A series of air-stable nickel complexes containing triazine-based PN3P-pincer ligands were synthesized and fully characterized. Complex 3 contains a de-aromatized central triazine ring from the deprotonation of one of the N–H arms. With a post-modification strategy, the Me-PN3P*NiCl complex (3) could be converted into a new class of diimine–traizine PN3P-pincer nickel complexes.

  19. -Pincer Ligand Family through Ligand Post-Modification

    KAUST Repository

    Huang, Mei-Hui

    2017-10-02

    A series of air-stable nickel complexes containing triazine-based PN3P-pincer ligands were synthesized and fully characterized. Complex 3 contains a de-aromatized central triazine ring from the deprotonation of one of the N–H arms. With a post-modification strategy, the Me-PN3P*NiCl complex (3) could be converted into a new class of diimine–traizine PN3P-pincer nickel complexes.

  20. Reactivity of halide and pseudohalide ligands

    International Nuclear Information System (INIS)

    Kukushkin, Yu.N.

    1987-01-01

    Reactivity of halide and pseudohalide (cyanide, azide, thiocyanate, cyanate) ligands tending to form bridge bonds in transition metal (Re, Mo, W) complexes is considered. Complexes where transition metal salts are ligands of other, complex-forming ion, are described. Transformation of innerspheric pseudohalide ligands is an important way of directed synthesis of these metal coordination compounds

  1. Adiponectin release and insulin receptor targeting share trans-Golgi-dependent endosomal trafficking routes

    Directory of Open Access Journals (Sweden)

    Maria Rödiger

    2018-02-01

    Full Text Available Objective: Intracellular vesicle trafficking maintains cellular structures and functions. The assembly of cargo-laden vesicles at the trans-Golgi network is initiated by the ARF family of small GTPases. Here, we demonstrate the role of the trans-Golgi localized monomeric GTPase ARFRP1 in endosomal-mediated vesicle trafficking of mature adipocytes. Methods: Control (Arfrp1flox/flox and inducible fat-specific Arfrp1 knockout (Arfrp1iAT−/− mice were metabolically characterized. In vitro experiments on mature 3T3-L1 cells and primary mouse adipocytes were conducted to validate the impact of ARFRP1 on localization of adiponectin and the insulin receptor. Finally, secretion and transferrin-based uptake and recycling assays were performed with HeLa and HeLa M-C1 cells. Results: We identified the ARFRP1-based sorting machinery to be involved in vesicle trafficking relying on the endosomal compartment for cell surface delivery. Secretion of adiponectin from fat depots was selectively reduced in Arfrp1iAT−/− mice, and Arfrp1-depleted 3T3-L1 adipocytes revealed an accumulation of adiponectin in Rab11-positive endosomes. Plasma adiponectin deficiency of Arfrp1iAT−/− mice resulted in deteriorated hepatic insulin sensitivity, increased gluconeogenesis and elevated fasting blood glucose levels. Additionally, the insulin receptor, undergoing endocytic recycling after ligand binding, was less abundant at the plasma membrane of adipocytes lacking Arfrp1. This had detrimental effects on adipose insulin signaling, followed by insufficient suppression of basal lipolytic activity and impaired adipose tissue expansion. Conclusions: Our findings suggest that adiponectin secretion and insulin receptor surface targeting utilize the same post-Golgi trafficking pathways that are essential for an appropriate systemic insulin sensitivity and glucose homeostasis. Keywords: Adiponectin, ARFRP1, Exocytosis, Insulin receptor, trans-Golgi

  2. FROM ADVANCE TO TRANS-PROFESSIONAL EDUCATION

    Directory of Open Access Journals (Sweden)

    A. G. Kislov

    2018-01-01

    Full Text Available Introduction. For several decades, the gap of vocational education with quickly changing realities in labour market, in the field of technologies and socio-economic sphere, and the need for the advancing vocational training, have been considered as the topical and steadily growing problems. Numerous attempts to overcome the presented above problems by means of fundamentalization and predictive methods have not led to anything so far. It is obvious that other education opportunities for in-demand, highly skilled, competitive specialists are needed.The aims of the publication are to discuss the potential of trans-professional education; to come up with arguments in favour of its introduction as the most perspective direction which might allow university and college graduates: to be guided better on labour market; to be more confident in unstable, unpredictable reality; to adapt quickly to dynamically changing situations in the world of professions.Methodology and research methods. The research paper is based on comparative analysis that provided an opportunity to find out the conceptual grounds of traditional mono-professional education and trans-professional education appropriate for challenges of modern Russia.Results and scientific novelty. It is emphasized that mono-professionalism as a paradigm reference point of professional education content is called for global reconsideration; for many years, preservation of traditional forms and methods have prevented mono-professionalism of good intentions to give it the advancing character, especially, at its initial stage.For the first time, trans-professional education has been considered as a result of considerably heterogeneous (as opposed to homogeneous bi- and polyprofessional training; the essence of that training consists in learning not related specialties concerned to one professional group, but professions that are absolutely far apart. Such approach will promote not only expansion of

  3. Two New Families of Lanthanide Mixed-Ligand Complexes, Oxalate-Carbonate and Oxalate-Formate: Synthesis and Structure of [Ce(H 2O)] 2(C 2O 4) 2(CO 3)·2.5 H 2O and Ce(C 2O 4)(HCO 2)

    Science.gov (United States)

    Romero, S.; Mosset, A.; Trombe, J. C.

    1996-12-01

    Two new families of lanthanide complexes associating the ligands oxalate and carbonate or oxalate and formate have been prepared under autogenous pressure at 200°C using a pseudo-hydrothermal method. The two families have been extended to some lanthanides ( Ln): oxalate-carbonate Ln= Ce, Pr, Nd, and Eu; oxalate-formate Ln= La, Ce, and Sm. The starting suspension contains either oxalate or a mixture of oxalate and oxalic acid. The structures have been solved for the element cerium. In both cases, the structure is built up from cerium atoms sharing all their oxygen atoms with oxalate and carbonate or oxalate and formate ligands, thus forming a three-dimensional network. The cerium polyhedra share either faces or edges or corners. The coordination scheme of the oxalate ligands is variable: bischelating, bischelating and monodentate, or bischelating and bismonodentate. The carbonate group acts as a bischelating and bismonodentate ligand while the formate group is chelating and monodentate. The characterization of these two original families by infrared spectra and thermal behavior is presented for some pure phases. A tentative explanation of the synthesis of these two phases will be emphasized.

  4. Ligand-regulated peptide aptamers.

    Science.gov (United States)

    Miller, Russell A

    2009-01-01

    The peptide aptamer approach employs high-throughput selection to identify members of a randomized peptide library displayed from a scaffold protein by virtue of their interaction with a target molecule. Extending this approach, we have developed a peptide aptamer scaffold protein that can impart small-molecule control over the aptamer-target interaction. This ligand-regulated peptide (LiRP) scaffold, consisting of the protein domains FKBP12, FRB, and GST, binds to the cell-permeable small-molecule rapamycin and the binding of this molecule can prevent the interaction of the randomizable linker region connecting FKBP12 with FRB. Here we present a detailed protocol for the creation of a peptide aptamer plasmid library, selection of peptide aptamers using the LiRP scaffold in a yeast two-hybrid system, and the screening of those peptide aptamers for a ligand-regulated interaction.

  5. Sequestering agent for uranyl chelation: a new family of CAMS ligands

    International Nuclear Information System (INIS)

    Leydier, A.; Pellet-Rostaing, S.; Favre-Reguillon, A.; Lemaire, M.; Lecercle, D.; Taran, F.

    2008-01-01

    The synthesis of new dipodal bis-sulfo-catechol-amide uranophiles is presented. Their binding abilities for uranyl cation were determined by UV spectrophotometry in aqueous media under various pH conditions and further studied by 1 H NMR analysis of the resonance signal of both aromatic protons of the sulfo-catechol-amide groups. The results showed that the efficiency of these hydrosoluble chelating agents depends on the nature of the spacers. Each ligand shows a more or less pronounced affinity for uranium. The best receptor is the ligand CYCAMS 5d obtained as a mixture of cis/trans isomers, which achieves the best compromise between rigidity and steric hindrance. (authors)

  6. Repair Activity of trans-Resveratrol toward 2'-Deoxyguanosine Radicals.

    Science.gov (United States)

    Cheng, Xing; An, Ping; Li, Shujin; Zhou, Liping

    2018-04-26

    In the present study, the repair activity of trans-resveratrol toward 2'-deoxyguanosine (dGuo) radicals in polar and nonpolar solvents was studied using density functional theory. The hydrogen transfer/proton coupled electron transfer and single electron transfer (SET) mechanisms between trans-resveratrol and dGuo-radicals were considered. Taking into consideration the molar fraction of neutral trans-resveratrol (ROH) and anionic trans-resveratrol (RO - ), the overall rate constants for repairing dGuo-radicals by trans-resveratrol are 9.94 × 10 8 and 2.01 × 10 9 dm 3 mol -1 s -1 in polar and nonpolar solvents, respectively, and the overall rate constant of repairing cation radical (dGuo •+ ) by trans-resveratrol via an SET mechanism is 7.17 × 10 9 dm 3 mol -1 s -1 . The repair activity of RO - toward dGuo-radicals is better than that of ROH, but the repair activity of ROH toward dGuo •+ is better than that of RO - . Unfortunately, neither ROH nor RO - can repair the 2'-deoxyribose radicals of dGuo. It can therefore be concluded that trans-resveratrol is an effective antioxidant for repairing base radicals of dGuo and dGuo •+ . The study can help us understand the repair activity of trans-resveratrol toward dGuo radicals.

  7. Shifting Paradigms: Moving beyond "Trans 101" in Sexuality Education

    Science.gov (United States)

    Green, Eli R.

    2010-01-01

    Trans-inclusive sexuality education can be complex, confusing, and outright intimidating for even the most seasoned sexuality educator to teach. Historically, standalone "Trans 101" sessions have successfully raised awareness about the highly marginalized transgender community. However, their potential success has been limited by being taught in…

  8. Illela border market: origin and contributions to trans-border ...

    African Journals Online (AJOL)

    Illela border market: origin and contributions to trans-border relations between Nigeria and Niger republic. ... cordial relations between her and her immediate neighbours and thus stem the scourge of smuggling and other trans-border crimes which have negatively affected the Nigerian economy and her international image.

  9. TransPlanckian Particles and the Quantization of Time

    NARCIS (Netherlands)

    Hooft, G. 't

    1999-01-01

    Trans-Planckian particles are elementary particles accelerated such that their energies surpass the Planck value. There are several reasons to believe that trans-Planckian particles do not represent independent degrees of freedom in Hilbert space, but they are controlled by the cis-Planckian

  10. Relative Stability of cis- and trans-Hydrindanones

    Directory of Open Access Journals (Sweden)

    Motoo Tori

    2015-01-01

    Full Text Available The relative stabilities of several cis- and trans-hydrindanones were compared using both isomerization experiments and MM2 calculations. The generally believed rule that cis-hydrindanones are more stable than trans-isomers is applicable, but is not always true. This review introduces examples, mainly from studies in our laboratory, to explain these facts.

  11. Ligand binding by PDZ domains

    DEFF Research Database (Denmark)

    Chi, Celestine N.; Bach, Anders; Strømgaard, Kristian

    2012-01-01

    , for example, are particularly rich in these domains. The general function of PDZ domains is to bring proteins together within the appropriate cellular compartment, thereby facilitating scaffolding, signaling, and trafficking events. The many functions of PDZ domains under normal physiological as well...... as pathological conditions have been reviewed recently. In this review, we focus on the molecular details of how PDZ domains bind their protein ligands and their potential as drug targets in this context....

  12. Survey of the trans-resveratrol and trans-piceid content of cocoa-containing and chocolate products.

    Science.gov (United States)

    Hurst, W Jeffrey; Glinski, Jan A; Miller, Kenneth B; Apgar, Joan; Davey, Matthew H; Stuart, David A

    2008-09-24

    Dietary resveratrol (3,4',5-trihydroxystilbene) has been implicated in the health benefits associated with grapes and red wine, more specifically with potential benefits for metabolic syndrome, energy use, and increased endurance. Levels of trans-resveratrol and its glucoside, trans-piceid, were determined in 19 top selling commercially available cocoa-containing and chocolate products from the U.S. market. Amounts of trans-resveratrol and trans-piceid were closely correlated with the amount of nonfat cocoa solids (NFCS) in the cocoa-containing products. Among these products, trans-resveratrol levels were highest in cocoa powders (1.85 +/- 0.43 microg/g), followed by unsweetened baking chocolates (1.24 +/- 0.22), semisweet chocolate baking chips (0.52 +/- 0.14), dark chocolates (0.35 +/- 0.08), milk chocolates (0.10 +/- 0.05), and chocolate syrups (0.09 +/- 0.02). These cocoa-containing and chocolate products have about 3-5 times more trans-piceid than trans-resveratrol. Levels of trans-piceid were highest in the cocoa powders (7.14 +/- 0.80 microg/g), followed by unsweetened baking chocolates (4.04 +/- 0.14), semisweet chocolate baking chips (2.01 +/- 0.18), dark chocolates (1.82 +/- 0.36), milk chocolates (0.44 +/- 0.06), and chocolate syrups (0.35 +/- 0.06). On an equal weight basis, cocoa powder had about half as much trans-resveratrol as the average California red wine. On a per serving basis, cocoa-containing and chocolate products had less trans-resveratrol than red wine and grape juice but more than roasted peanuts. Overall, these cocoa-containing and chocolate products rank second after red wines and grape juice in foods with the highest levels of total trans-resveratrol in the diet.

  13. Bitopic Ligands and Metastable Binding Sites

    DEFF Research Database (Denmark)

    Fronik, Philipp; Gaiser, Birgit I; Sejer Pedersen, Daniel

    2017-01-01

    of orthosteric binding sites. Bitopic ligands have been employed to address the selectivity problem by combining (linking) an orthosteric ligand with an allosteric modulator, theoretically leading to high-affinity subtype selective ligands. However, it remains a challenge to identify suitable allosteric binding...... that have been reported to date, this type of bitopic ligands would be composed of two identical pharmacophores. Herein, we outline the concept of bitopic ligands, review metastable binding sites, and discuss their potential as a new source of allosteric binding sites....

  14. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  15. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  16. Trans Ocean Gas CNG transportation development plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-11-01

    Liquefied natural gas (LNG) transportation is on the rise due to increased global demand for natural gas. However, the challenge of transporting LNG lies in finding suitable locations for import terminals. Compressed natural gas (CNG) transportation offers an alternative method for transporting stranded natural gas to existing markets and for creating new natural gas markets not practical for LNG or pipelines. The founder of Trans Ocean Gas Inc. (TOG) modified an existing fibre reinforced plastic (FRP) pressure vessel technology to safely store CNG on a ship. The newly developed containment system has proven to overcome all the deficiencies of steel-based systems. TOG patented the containment system and will license its use to owners of stranded gas and shipping service providers around the world. Financial support is needed to perform verification testing and for regulatory approval. The CNG systems will be built and assembled throughout facilities in Atlantic Canada. 2 tabs., 3 figs.

  17. Exploring the Trans-Neptunian Solar System

    Science.gov (United States)

    1998-01-01

    A profound question for scientists, philosophers and, indeed, all humans concerns how the solar system originated and subsequently evolved. To understand the solar system's formation, it is necessary to document fully the chemical and physical makeup of its components today, particularly those parts thought to retain clues about primordial conditions and processes.] In the past decade, our knowledge of the outermost, or trans-neptunian, region of the solar system has been transformed as a result of Earth-based observations of the Pluto-Charon system, Voyager 2's encounter with Neptune and its satellite Triton, and recent discoveries of dozens of bodies near to or beyond the orbit of Neptune. As a class, these newly detected objects, along with Pluto, Charon, and Triton, occupy the inner region of a hitherto unexplored component of the solar system, the Kuiper Belt. The Kuiper Belt is believed to be a reservoir of primordial objects of the type that formed in the solar nebula and eventually accreted to form the major planets. The Kuiper Belt is also thought to be the source of short-period comets and a population of icy bodies, the Centaurs, with orbits among the giant planets. Additional components of the distant outer solar system, such as dust and the Oort comet cloud, as well as the planet Neptune itself, are not discussed in this report. Our increasing knowledge of the trans-neptunian solar system has been matched by a corresponding increase in our capabilities for remote and in situ observation of these distant regions. Over the next 10 to 15 years, a new generation of ground- and space-based instruments, including the Keck and Gemini telescopes and the Space Infrared Telescope Facility, will greatly expand our ability to search for and conduct physical and chemical studies on these distant bodies. Over the same time span, a new generation of lightweight spacecraft should become available and enable the first missions designed specifically to explore the icy

  18. Neurologic condition of healthy term infants at 18 months : Positive association with venous umbilical DHA status and negative association with umbilical trans-fatty acids

    NARCIS (Netherlands)

    Bouwstra, Hylco; Dijck-Brouwer, Janneke; Decsi, Tamas; Boehm, Guenther; Boersma, E. Rudy; Muskiet, Frits A. J.; Hadders-Algra, Mijna

    Prenatal long-chain polyunsaturated fatty acids (LCPUFAs) and trans-fatty acids may affect neurodevelopment. In healthy term children, we determined relationships between relative fatty acid contents of umbilical arteries and veins and neurodevelopment at 18 mo. The study comprised a mixed group of

  19. A feasibility study of unconventional planar ligand spacers in chalcogenide nanocrystals.

    Science.gov (United States)

    Lukose, Binit; Clancy, Paulette

    2016-05-18

    The solar cell efficiency of chalcogenide nanocrystals (quantum dots) has been limited in the past by the insulation between neighboring quantum dots caused by intervening, often long-chain, aliphatic ligands. We have conducted a computationally based feasibility study to investigate the use of ultra-thin, planar, charge-conducting ligands as an alternative to traditional long passive ligands. Not only might these radically unconventional ligands decrease the mean distance between adjacent quantum dots, but, since they are charge-conducting, they have the potential to actively enhance charge migration. Our ab initio studies compare the binding energies, electronic energy gaps, and absorption characteristics for both conventional and unconventional ligands, such as phthalocyanines, porphyrins and coronene. This comparison identified these unconventional ligands with the exception of titanyl phthalocyanine, that bind to themselves more strongly than to the surface of the quantum dot, which is likely to be less desirable for enhancing charge transport. The distribution of finite energy levels of the bound system is sensitive to the ligand's binding site and the levels correspond to delocalized states. We also observed a trap state localized on a single Pb atom when a sulfur-containing phenyldithiocarbamate (PTC) ligand is attached to a slightly off-stoichiometric dot in a manner that the sulfur of the ligand completes stoichiometry of the bound system. Hence, this is indicative of the source of trap state when thio-based ligands are bound to chalcogenide nanocrystals. We also predict that titanyl phthalocyanine in a mix with chalcogenide dots of diameter ∼1.5 Å can form a donor-acceptor system.

  20. Becoming lesbian: Monique Wittig's queer-trans-feminism.

    Science.gov (United States)

    Henderson, Kevin

    2018-04-03

    Inspired by Lynne Huffer's queer feminist genealogy, this article explores queer-trans-feminism as a project that would bring together queer, feminist, and transgender theory and politics into a shared critical lineage. I suggest that Monique Wittig is a neglected thinker who could re-enliven connections and debates within queer, feminist, and trans theory and politics. Utilizing recent historiographies of queer and feminist theory, I imagine what it would mean to hold on to the figure of the lesbian as a figure for queer-trans-feminist politics rather than render the lesbian anachronistic. I then explore the implications of Wittig's notion that "lesbians are not women" for a queer-trans-feminism. I argue that Wittig's critique of the language of the social sciences offers queer-trans-feminist scholars a source for contemporary self-critique and coalition.

  1. Differential Effects of Munc18s on Multiple Degranulation-Relevant Trans-SNARE Complexes.

    Directory of Open Access Journals (Sweden)

    Hao Xu

    Full Text Available Mast cell exocytosis, which includes compound degranulation and vesicle-associated piecemeal degranulation, requires multiple Q- and R- SNAREs. It is not clear how these SNAREs pair to form functional trans-SNARE complexes and how these trans-SNARE complexes are selectively regulated for fusion. Here we undertake a comprehensive examination of the capacity of two Q-SNARE subcomplexes (syntaxin3/SNAP-23 and syntaxin4/SNAP-23 to form fusogenic trans-SNARE complexes with each of the four granule-borne R-SNAREs (VAMP2, 3, 7, 8. We report the identification of at least six distinct trans-SNARE complexes under enhanced tethering conditions: i VAMP2/syntaxin3/SNAP-23, ii VAMP2/syntaxin4/SNAP-23, iii VAMP3/syntaxin3/SNAP-23, iv VAMP3/syntaxin4/SNAP-23, v VAMP8/syntaxin3/SNAP-23, and vi VAMP8/syntaxin4/SNAP-23. We show for the first time that Munc18a operates synergistically with SNAP-23-based non-neuronal SNARE complexes (i to iv in lipid mixing, in contrast to Munc18b and c, which exhibit no positive effect on any SNARE combination tested. Pre-incubation with Munc18a renders the SNARE-dependent fusion reactions insensitive to the otherwise inhibitory R-SNARE cytoplasmic domains, suggesting a protective role of Munc18a for its cognate SNAREs. Our findings substantiate the recently discovered but unexpected requirement for Munc18a in mast cell exocytosis, and implicate post-translational modifications in Munc18b/c activation.

  2. Strong ligand field effects of blue phosphorescent mono-cyclometalated iridium(III) complexes

    International Nuclear Information System (INIS)

    Ham, Ho Wan; Jung, Kyung Yoon; Kim, Young Sik

    2010-01-01

    A series of mono-cyclometalated blue phosphorescent iridium(III) complexes with two phosphines trans to each other and two cis-ancillary ligands, such as Ir(F 2 Meppy)(PPhMe 2 ) 2 (H)(Cl), [Ir(F 2 Meppy)(PPhMe 2 ) 2 (H)(NCMe)] + and Ir(F 2 Meppy)(PPhMe 2 ) 2 -(H)(CN), [F 2 Meppy = 2-(2',4'-difluorophenyl)-4-methyl-pyridine] were synthesized and studied to tune the phosphorescence wavelength to the deep blue region and to enhance the luminescence efficiencies. We investigate the electron-withdrawing capabilities of ancillary ligands using the DFT and TD-DFT calculations on the ground and excited states of the three complexes to gain insight into the factors responsible for the emission color change and the different luminescence efficiency. Reducing the molecular weight of phosphine ligand with PPhMe 2 leads to a strategy of the efficient deep blue organic light-emitting devices (OLED) by thermal processing instead of the solution processing. The electron-withdrawing difluoro group substituted on the phenyl ring and the cyano strong field ancillary ligand in the trans position to the carbon atom of phenyl ring increased HOMO-LUMO gap and achieved the hypsochromic shift in emission color. As a result, the maximum emission spectra of Ir(F 2 Meppy)(PPhMe 2 ) 2 (H)(Cl), [Ir(F 2 Meppy)(PPhMe 2 ) 2 (H)-(NCMe)] + and Ir(F 2 Meppy)(PPh-Me 2 ) 2 (H)(CN) were in the ranges of 446, 440, 439 nm, respectively.

  3. Strong ligand field effects of blue phosphorescent mono-cyclometalated iridium(III) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Ho Wan [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Jung, Kyung Yoon [International Design School for Advanced Studies, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Young Sik, E-mail: youngkim@hongik.ac.k [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of)

    2010-09-01

    A series of mono-cyclometalated blue phosphorescent iridium(III) complexes with two phosphines trans to each other and two cis-ancillary ligands, such as Ir(F{sub 2}Meppy)(PPhMe{sub 2}){sub 2}(H)(Cl), [Ir(F{sub 2}Meppy)(PPhMe{sub 2}){sub 2}(H)(NCMe)]{sup +} and Ir(F{sub 2}Meppy)(PPhMe{sub 2}){sub 2}-(H)(CN), [F{sub 2}Meppy = 2-(2',4'-difluorophenyl)-4-methyl-pyridine] were synthesized and studied to tune the phosphorescence wavelength to the deep blue region and to enhance the luminescence efficiencies. We investigate the electron-withdrawing capabilities of ancillary ligands using the DFT and TD-DFT calculations on the ground and excited states of the three complexes to gain insight into the factors responsible for the emission color change and the different luminescence efficiency. Reducing the molecular weight of phosphine ligand with PPhMe{sub 2} leads to a strategy of the efficient deep blue organic light-emitting devices (OLED) by thermal processing instead of the solution processing. The electron-withdrawing difluoro group substituted on the phenyl ring and the cyano strong field ancillary ligand in the trans position to the carbon atom of phenyl ring increased HOMO-LUMO gap and achieved the hypsochromic shift in emission color. As a result, the maximum emission spectra of Ir(F{sub 2}Meppy)(PPhMe{sub 2}){sub 2}(H)(Cl), [Ir(F{sub 2}Meppy)(PPhMe{sub 2}){sub 2}(H)-(NCMe)]{sup +} and Ir(F{sub 2}Meppy)(PPh-Me{sub 2}){sub 2} (H)(CN) were in the ranges of 446, 440, 439 nm, respectively.

  4. Acetylcholinesterase Inhibition and Antioxidant Activity of N-trans-Caffeoyldopamine and N-trans-Feruloyldopamine

    Directory of Open Access Journals (Sweden)

    Muamer Dizdar

    2018-04-01

    Full Text Available Phenolic acids and their derivatives found in nature are well-known for their potential biological activity. In this study, two amides derived from trans-caffeic/ferulic acid and dopamine were synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR, mass spectrometry, proton and carbon-13 nuclear magnetic resonance spectroscopy. The compounds were tested for the inhibition of acetylcholinesterase (AChE from Electrophorus electricus and for antioxidant activity by scavenging 2,2-diphenyl-1-pycrylhydrazyl free radical (DPPH• and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS•+, reducing ferric ions, and ferrous ions chelation. N-trans-Feruloyldopamine displayed the highest inhibitory effect on AChE with half-maximal inhibitory concentration (IC50 values of 8.52 μM. In addition, an in silico study was done to determine the most favorable AChE cluster with the synthesized compounds. Further, these clusters were investigated for binding positions at the lowest free binding energy. Both synthesized hydroxycinnamates were found to be better antioxidants than the parent acids in in vitro tests applied. N-trans-Caffeoyldopamine showed the best antioxidant activity in the three tested methods—against non-biological stable free radicals IC50 5.95 μM for DPPH•, 0.24 μM for the ABTS•+ method, and for reducing power (ascorbic acid equivalent (AAE 822.45 μmol/mmol—while for chelation activity against Fe2+ ions N-trans-feruloyldopamine had slightly better antioxidant activity (IC50 3.17 mM.

  5. Understanding the complexity of trans fatty acid reduction in the American diet: American Heart Association Trans Fat Conference 2006: report of the Trans Fat Conference Planning Group.

    Science.gov (United States)

    Eckel, Robert H; Borra, Susan; Lichtenstein, Alice H; Yin-Piazza, Shirley Y

    2007-04-24

    A 2-day forum was convened to discuss the current status and future implications of reducing trans fatty acids without increasing saturated fats in the food supply while maintaining functionality and consumer acceptance of packaged, processed, and prepared foods. Attendees represented the agriculture and oilseed industry and oil processing, food manufacturing, food service, government, food technology, and health and nutrition disciplines. Presentations included food science behind fatty acid technology, the health science of dietary fatty acids, alternatives to trans fatty acids, and the use of alternatives in food manufacturing and food service. The reduction of trans fatty acids in the food supply is a complex issue involving interdependent and interrelated stakeholders. Actions to reduce trans fatty acids need to carefully consider both intended and unintended consequences related to nutrition and public health. The unintended consequence of greatest concern is that fats and oils high in saturated fats, instead of the healthier unsaturated fats, might be used to replace fats and oils with trans fatty acids. Many different options of alternative oils and fats to replace trans fatty acids are available or in development. Decisions on the use of these alternatives need to consider availability, health effects, research and development investments, reformulated food quality and taste, supply-chain management, operational modifications, consumer acceptance, and cost. The conference demonstrated the value of collaboration between the food industry and health and nutrition professionals, and this conference model should be used to address other food development, processing, and/or technology issues.

  6. Micro-Sugar-Snap and -Wire-Cut Cookie Baking with Trans- and Zero-Trans-Fat Shortenings

    Science.gov (United States)

    The effect of trans- and zero-trans-fat shortenings on cookie-baking performance was evaluated, using the two AACC micro-cookie-baking methods. Regardless of fat type, sugar-snap cookies made with a given flour were larger in diameter, smaller in height, and greater in weight loss during baking tha...

  7. Study of substitution reactions of ligands in VO2+ complexes in toluene solutions by ESR method

    International Nuclear Information System (INIS)

    Lundkvist, R.; Panfilov, A.T.; Kalinichenko, N.B.; Marov, I.N.; AN SSSR, Moscow. Inst. Geokhimii i Analiticheskoj Khimii)

    1976-01-01

    Kinetics and equilibrium of stepwise substitution of ligands have been investigated at different temperatures for the complexes of oxovanadium (4) with salicylaldoxime, 8-oxyquinoline, acetylacetone, benzoylacetone, and tenoyltrifluoroacetone. The relative complexability of these ligands in toluene has been studied. The parameters of spin-Hamiltonian of EPR spectra of the VO 2+ complexes have been determined. The equilibrium constants, the rate constants, and activation energy have been found for the substitution reactions of ligands in the complexes VOA 2 : VOA 2 +HB=VOAB+HA; VOAB+HB=VOB 2 +HA, where HA and HB are the ligands with different donor atoms. The mixed complexes have been detected of the general formula VOAB, where HA is salicylaldoxime or 8-oxyquinoline and HB is β-diketone

  8. Protonation of Ferrous Dinitrogen Complexes Containing a Diphosphine Ligand with a Pendant Amine

    Energy Technology Data Exchange (ETDEWEB)

    Heiden, Zachariah M.; Chen, Shentan; Mock, Michael T.; Dougherty, William G.; Kassel, W. S.; Rousseau, Roger J.; Bullock, R. Morris

    2013-04-01

    The addition of protons to pendant amine containing ferrous dinitrogen complexes, of the type [FeX(N2)(PEtNMePEt)(dmpm)]+ (X = H, Cl, or Br; PEtNMePEt = Et2PCH2N(Me)CH2PEt2 and dmpm = Me2PCH2PMe2), was found to protonate at the pendant amine as opposed to the dinitrogen ligand. This protonation increased the νN2 of the complex by about 25 cm-1, shifting the Fe(II/I) couple 330 mV to a more positive potential. A similar shift was observed in the case of [FeX(CO)(PEtNMePEt)(dmpm)]+ (X = H, Cl, or Br). Computational analysis verified these experimental results and showed the coordination of N2 to Fe(II) centers increases the basicity of N2 (vs. free N2) by 13 and 20 pKa units for the trans halides and hydrides, respectively. Although the iron center was found to increase the basicity of the bound N2 ligand, coordinated N2 is not sufficiently basic to be protonated. In the case of ferrous dinitrogen complexes containing a basic pendant methylamine, the amine site was determined to be the most basic site by 30 pKa units compared to protonation at the N2 ligand. To increase the basicity of the N2 ligand in order to promote proton transfer from the pendant amine to the N2 ligand, chemical reduction of these ferrous dinitrogen complexes was performed and found to result in oxidative addition of the methylene C-H bond of the PEtNMePEt ligand to Fe, preventing isolation of a reduced Fe(0) N2 complex. This work was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences.

  9. Phosphatidylinositol 3-kinase is essential for kit ligand-mediated survival, whereas interleukin-3 and flt3 ligand induce expression of antiapoptotic Bcl-2 family genes

    DEFF Research Database (Denmark)

    Karlsson, Richard; Engström, Maria; Jönsson, Maria

    2003-01-01

    Cytokines such as interleukin 3 (IL-3), kit ligand (KL), and flt3 ligand (FL) promote survival of hematopoietic stem cells and myeloid progenitor cells. In many cell types, members of the Bcl-2 gene family are major regulators of survival, but the mediating mechanisms are not fully understood....... Using two myeloid progenitor cell lines, FDCP-mix and FDC-P1, as well as primary mouse bone marrow progenitors, we demonstrate that KL-mediated survival is dependent on the activation of phosphatidylinositol-3 (PI-3) kinase. The inhibitor LY294002 was able to completely abolish survival mediated by KL...

  10. The met axial ligand determines the redox potential in Cu-A sites

    DEFF Research Database (Denmark)

    Ledesma, G.N.; Murgida, D.H.; Ly, H.K.

    2007-01-01

    The replacement of the axial methionine ligand in a native Cu-A protein rendered a series of stable mutants with spectroscopic features of a mixed valence center. The mutations resulted in minor perturbations of the electronic structure of this site but led to significant changes in the redox pot...

  11. Assessment of biofuels supporting policies using the BioTrans model

    International Nuclear Information System (INIS)

    Lensink, Sander; Londo, Marc

    2010-01-01

    The introduction of advanced, 2nd generation biofuels is a difficult to forecast process. Policies may impact the timing of their introduction and the future biofuels mix. The least-cost optimization model BioTrans supports policy analyses on these issues. It includes costs for all parts of the supply chain, and endogenous learning for all biofuels technologies, including cost reductions through scale. BioTrans shows that there are significant lock-in effects favouring traditional biofuels, and that the optimal biofuels mix by 2030 is path dependent. The model captures important barriers for the introduction of emerging technologies, thereby providing valuable quantitative information that can be used in analyses of biofuels supporting policies. It is shown that biodiesel from oil crops will remain a cost effective way of producing biofuels in the medium term at moderate target levels. Aiming solely at least-cost biofuel production is in conflict with a longer term portfolio approach on biofuels, and the desire to come to biofuels with the lowest greenhouse gas emissions. Lowering the targets because of environmental constraints delays the development of 2nd generation biofuels, unless additional policy measures (such as specific sub targets for these fuels) are implemented.

  12. Mixed parentage

    DEFF Research Database (Denmark)

    Bang Appel, Helene; Singla, Rashmi

    2016-01-01

    Despite an increase in cross border intimate relationships and children of mixed parentage, there is little mention or scholarship about them in the area of childhood and migrancy in the Nordic countries. The international literature implies historical pathologisation, contestation and current...... of identity formation in the . They position themselves as having an “in-between” identity or “ just Danes” in their every day lives among friends, family, and during leisure activities. Thus a new paradigm is evolving away- from the pathologisation of mixed children, simplified one-sided categories...

  13. Ruthenium chalcogenonitrosyl and bridged nitrido complexes containing chelating sulfur and oxygen ligands.

    Science.gov (United States)

    Ng, Ho-Yuen; Cheung, Wai-Man; Kwan Huang, Enrique; Wong, Kang-Long; Sung, Herman H-Y; Williams, Ian D; Leung, Wa-Hung

    2015-11-14

    Ruthenium thio- and seleno-nitrosyl complexes containing chelating sulfur and oxygen ligands have been synthesised and their de-chalcogenation reactions have been studied. The reaction of mer-[Ru(N)Cl3(AsPh3)2] with elemental sulfur and selenium in tetrahydrofuran at reflux afforded the chalcogenonitrosyl complexes mer-[Ru(NX)Cl3(AsPh3)2] [X = S (1), Se (2)]. Treatment of 1 with KN(R2PS)2 afforded trans-[Ru(NS)Cl{N(R2PS)2}2] [R = Ph (3), Pr(i) (4), Bu(t) (5)]. Alternatively, the thionitrosyl complex 5 was obtained from [Bu(n)4N][Ru(N)Cl4] and KN(Bu(t)2PS)2, presumably via sulfur atom transfer from [N(Bu(t)2PS)2](-) to the nitride. Reactions of 1 and 2 with NaLOEt (LOEt(-) = [Co(η(5)-C5H5){P(O)(LOEt)2}3](-)) gave [Ru(NX)LOEtCl2] (X = S (8), Se (9)). Treatment of [Bu(n)4N][Ru(N)Cl4] with KN(R2PS)2 produced Ru(IV)-Ru(IV)μ-nitrido complexes [Ru2(μ-N){N(R2PS)2}4Cl] [R = Ph (6), Pr(i) (7)]. Reactions of 3 and 9 with PPh3 afforded 6 and [Ru(NPPh3)LOEtCl2], respectively. The desulfurisation of 5 with [Ni(cod)2] (cod = 1,5-cyclooctadiene) gave the mixed valance Ru(III)-Ru(IV)μ-nitrido complex [Ru2(μ-N){N(Bu(t)2PS)2}4] (10) that was oxidised by [Cp2Fe](PF6) to give the Ru(IV)-Ru(IV) complex [Ru2(μ-N){N(Bu(t)2PS)2}4](PF6) ([10]PF6). The crystal structures of 1, 2, 3, 7, 9 and 10 have been determined.

  14. Structural modification of trans-cinnamic acid using Colletotrichum acutatum

    OpenAIRE

    Rodrigo Velasco B.; Jesús H. Gil G.; Carlos M. García P.; Diego L. Durango R.

    2012-01-01

    Se estudió la biotransformación de ácido trans-cinámico mediante células completas del hongo fitopatógeno nativo colombiano Colletotrichum acutatum. Inicialmente, se evaluó la fungitoxicidad de este compuesto contraC. acutatum; el ácido trans-cinámico exhibió una toxicidad moderada a débil contra el microorganismo y aparentemente se presentó un mecanismo de detoxificación. Luego, para estudiar tal mecanismo y explorar la capacidad de este hongo para biotransformar el ácido trans-cinámico en ...

  15. Study on the interactions of trans-resveratrol and curcumin with bovine α-lactalbumin by spectroscopic analysis and molecular docking

    International Nuclear Information System (INIS)

    Mohammadi, Fakhrossadat; Moeeni, Marzieh

    2015-01-01

    The ability of bovine α-lactalbumin (BLA) as a whey protein to carry curcumin and trans-resveratrol as two natural polyphenolic compounds was investigated by fluorescence quenching measurements and docking studies. Curcumin is the bioactive component of turmeric and trans-resveratrol is abundant in different types of fruits and vegetables. The binding parameters such as binding constants and the number of substantive binding sites have been estimated from the analysis of fluorescence quenching measurements. The differences in affinities of curcumin and trans-resveratrol for BLA were compared. The short Förster's distance (r) between donor (BLA) and acceptor (curcumin and trans-resveratrol) and also the binding constant values demonstrated the strong interaction between these two polyphenolic compounds and BLA. The thermodynamic parameters were obtained from the fluorescence quenching measurements in different temperatures. It can be concluded from the sign and magnitude of ∆H and ∆S that the final ligand–protein complexes were stabilized by hydrogen bonds. The considerable change in microregion of the Trp residues in BLA is observed upon the binding of the trans-resveratrol to BLA by synchronous fluorescence while this conformation alteration was not observed upon interaction with curcumin. It was indicated by docking studies that curcumin come closer to the Trp-118 than to other tryptophans and trans-resveratrol binds in the vicinity of Trp-60 and Trp-104. Docking studies indicated that these two compounds bind to BLA by two hydrogen bonds. The calculated distances between bound ligands and tryptophans obtained by docking studies were in agreement with fluorescence resonance energy transfer results. Therefore, the strong interaction of curcumin and trans-resveratrol with BLA was confirmed by theoretical and experimental studies. These achieved results may be applicable in the milk industry and drug formulation. - Highlights: • The binding parameters

  16. Study on the interactions of trans-resveratrol and curcumin with bovine α-lactalbumin by spectroscopic analysis and molecular docking

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Fakhrossadat, E-mail: fmohammadi@iasbs.ac.ir; Moeeni, Marzieh

    2015-05-01

    The ability of bovine α-lactalbumin (BLA) as a whey protein to carry curcumin and trans-resveratrol as two natural polyphenolic compounds was investigated by fluorescence quenching measurements and docking studies. Curcumin is the bioactive component of turmeric and trans-resveratrol is abundant in different types of fruits and vegetables. The binding parameters such as binding constants and the number of substantive binding sites have been estimated from the analysis of fluorescence quenching measurements. The differences in affinities of curcumin and trans-resveratrol for BLA were compared. The short Förster's distance (r) between donor (BLA) and acceptor (curcumin and trans-resveratrol) and also the binding constant values demonstrated the strong interaction between these two polyphenolic compounds and BLA. The thermodynamic parameters were obtained from the fluorescence quenching measurements in different temperatures. It can be concluded from the sign and magnitude of ∆H and ∆S that the final ligand–protein complexes were stabilized by hydrogen bonds. The considerable change in microregion of the Trp residues in BLA is observed upon the binding of the trans-resveratrol to BLA by synchronous fluorescence while this conformation alteration was not observed upon interaction with curcumin. It was indicated by docking studies that curcumin come closer to the Trp-118 than to other tryptophans and trans-resveratrol binds in the vicinity of Trp-60 and Trp-104. Docking studies indicated that these two compounds bind to BLA by two hydrogen bonds. The calculated distances between bound ligands and tryptophans obtained by docking studies were in agreement with fluorescence resonance energy transfer results. Therefore, the strong interaction of curcumin and trans-resveratrol with BLA was confirmed by theoretical and experimental studies. These achieved results may be applicable in the milk industry and drug formulation. - Highlights: • The binding parameters

  17. Insights into an original pocket-ligand pair classification: a promising tool for ligand profile prediction.

    Directory of Open Access Journals (Sweden)

    Stéphanie Pérot

    Full Text Available Pockets are today at the cornerstones of modern drug discovery projects and at the crossroad of several research fields, from structural biology to mathematical modeling. Being able to predict if a small molecule could bind to one or more protein targets or if a protein could bind to some given ligands is very useful for drug discovery endeavors, anticipation of binding to off- and anti-targets. To date, several studies explore such questions from chemogenomic approach to reverse docking methods. Most of these studies have been performed either from the viewpoint of ligands or targets. However it seems valuable to use information from both ligands and target binding pockets. Hence, we present a multivariate approach relating ligand properties with protein pocket properties from the analysis of known ligand-protein interactions. We explored and optimized the pocket-ligand pair space by combining pocket and ligand descriptors using Principal Component Analysis and developed a classification engine on this paired space, revealing five main clusters of pocket-ligand pairs sharing specific and similar structural or physico-chemical properties. These pocket-ligand pair clusters highlight correspondences between pocket and ligand topological and physico-chemical properties and capture relevant information with respect to protein-ligand interactions. Based on these pocket-ligand correspondences, a protocol of prediction of clusters sharing similarity in terms of recognition characteristics is developed for a given pocket-ligand complex and gives high performances. It is then extended to cluster prediction for a given pocket in order to acquire knowledge about its expected ligand profile or to cluster prediction for a given ligand in order to acquire knowledge about its expected pocket profile. This prediction approach shows promising results and could contribute to predict some ligand properties critical for binding to a given pocket, and conversely

  18. Insights into an original pocket-ligand pair classification: a promising tool for ligand profile prediction.

    Science.gov (United States)

    Pérot, Stéphanie; Regad, Leslie; Reynès, Christelle; Spérandio, Olivier; Miteva, Maria A; Villoutreix, Bruno O; Camproux, Anne-Claude

    2013-01-01

    Pockets are today at the cornerstones of modern drug discovery projects and at the crossroad of several research fields, from structural biology to mathematical modeling. Being able to predict if a small molecule could bind to one or more protein targets or if a protein could bind to some given ligands is very useful for drug discovery endeavors, anticipation of binding to off- and anti-targets. To date, several studies explore such questions from chemogenomic approach to reverse docking methods. Most of these studies have been performed either from the viewpoint of ligands or targets. However it seems valuable to use information from both ligands and target binding pockets. Hence, we present a multivariate approach relating ligand properties with protein pocket properties from the analysis of known ligand-protein interactions. We explored and optimized the pocket-ligand pair space by combining pocket and ligand descriptors using Principal Component Analysis and developed a classification engine on this paired space, revealing five main clusters of pocket-ligand pairs sharing specific and similar structural or physico-chemical properties. These pocket-ligand pair clusters highlight correspondences between pocket and ligand topological and physico-chemical properties and capture relevant information with respect to protein-ligand interactions. Based on these pocket-ligand correspondences, a protocol of prediction of clusters sharing similarity in terms of recognition characteristics is developed for a given pocket-ligand complex and gives high performances. It is then extended to cluster prediction for a given pocket in order to acquire knowledge about its expected ligand profile or to cluster prediction for a given ligand in order to acquire knowledge about its expected pocket profile. This prediction approach shows promising results and could contribute to predict some ligand properties critical for binding to a given pocket, and conversely, some key pocket

  19. Ligand photo-isomerization triggers conformational changes in iGluR2 ligand binding domain.

    Directory of Open Access Journals (Sweden)

    Tino Wolter

    Full Text Available Neurological glutamate receptors bind a variety of artificial ligands, both agonistic and antagonistic, in addition to glutamate. Studying their small molecule binding properties increases our understanding of the central nervous system and a variety of associated pathologies. The large, oligomeric multidomain membrane protein contains a large and flexible ligand binding domains which undergoes large conformational changes upon binding different ligands. A recent application of glutamate receptors is their activation or inhibition via photo-switchable ligands, making them key systems in the emerging field of optochemical genetics. In this work, we present a theoretical study on the binding mode and complex stability of a novel photo-switchable ligand, ATA-3, which reversibly binds to glutamate receptors ligand binding domains (LBDs. We propose two possible binding modes for this ligand based on flexible ligand docking calculations and show one of them to be analogues to the binding mode of a similar ligand, 2-BnTetAMPA. In long MD simulations, it was observed that transitions between both binding poses involve breaking and reforming the T686-E402 protein hydrogen bond. Simulating the ligand photo-isomerization process shows that the two possible configurations of the ligand azo-group have markedly different complex stabilities and equilibrium binding modes. A strong but slow protein response is observed after ligand configuration changes. This provides a microscopic foundation for the observed difference in ligand activity upon light-switching.

  20. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear...... as possible operational moves....

  1. Lateral Mixing

    Science.gov (United States)

    2014-09-30

    negative (right panel c) and the kinetic energy dissipation is larger than that expected from meterological forcing alone (right panel a). This is...10.1002/grl.50919. Shcherbina, A. et al., 2014, The LatMix Summer Campaign: Submesoscale Stirring in the Upper Ocean., Bull. American Meterological

  2. Ionising radiation and trans-generational instability

    International Nuclear Information System (INIS)

    Vrhovac, I.; Niksic, G.

    2007-01-01

    Indirect monitoring of the impact posed by ionising radiation to the genome instability of the descendants, consequent to the irradiation of one of their parents, boils down to the investigation of changes occurring exclusively in the mini-satellite loci of the cells constituting the gametal developmental line. The resultant mini-satellite mutations are expressed in their percentages, and equal to the ratio of the number of mutated alleles in that particular generation over the total number of alleles present. The impact of ionising radiation to the irradiated parent's offspring was first noticed on haematopoietic mouse stem-cells. Even though an irradiated cell of a female parent lacks any mutations whatsoever, daughter cells present with the increased mutation rates. The observed phenomenon of the so called trans-generational instability has been defined as the occurrence of mutations in the genome of individuals originating from the irradiated ancestors. Due to the aforementioned, one can conclude that these mutations need not be present in the irradiated parental cells, and do not necessarily vanish in the next few generations, but may result in the increase in mutation rates observed in the latter. The results of the investigations performed on the animal model, as well as of those carried out in human population, point to the occurrence of significant changes to be found on mini-satellite loci of the descending generation, while the mechanism underlying those changes hasn't been completely clarified yet, and, therefore, calls for the further investigation. (author)

  3. Synthesis and characterization of technetium(III) complexes containing 2,2'-bipyridine and 1,10-phenanthroline. X-ray crystal structures of cis (Cl),trans(P)-[TcCl2(P(CH3)2C6H5)2(bpy)]B(C6H5)4, cis (Cl),trans(P)-[TcCl2(P(CH3)2C6H5)2(phen)]B(C6H5)4, and cis (Cl),trans(P)-[TcCl2(P(CH3CH2)(C6H5)2)2(bpy)]SO3CF3

    International Nuclear Information System (INIS)

    Wilcox, B.E.; Ho, D.M.; Deutsch, E.

    1989-01-01

    Technetium(III) complexes of the general formula cis(Cl),trans(P)-[TcCl 2 (P) 2 L] + , where (P) is dimethylphenylphosphine (PMe 2 Ph) or ethyldiphenylphosphine (PEtPh 2 ) and L is 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (Me 2 bpy), or 1,10-phenanthroline (phen), have been synthesized and characterized. They are prepared by L substitution onto, with concomitant displacement of one chloride and one phosphine ligand from, the mer-TcCl 3 (P) 3 starting material in refluxing ethanol. Analysis of these complexes by fast atom bombardment mass spectrometry (in the positive ion mode) provides fingerprint mass spectra that exhibit peaks assigned to the molecular ion M + as well as peaks assigned to M + minus one or more monodentate ligands. Results of single-crystal x-ray structure determinations of cis(Cl),trans(P)-[TcCl 2 (PMe 2 Ph) 2 (bpy)]BPh 4 (A), cis(Cl),trans(P)-[TcCl 2- (PMe 2 Ph) 2 (phen)]BPh 4 (B), and cis(Cl),trans(P)-[TcCl 2 (PEtPh 2 ) 2 (bpy)]SO 3 CF 3 (C), with formula weights of 921.62, 945.64, and 903.65, respectively are reported. 26 refs., 5 figs., 5 tabs

  4. Crystallinity and the effect of ionizing radiation in polyethylene. V. Distribution of trans-vinylene and trans, trans conjugated double bonds in linear polyethylene

    International Nuclear Information System (INIS)

    Patel, G.N.

    1975-01-01

    Freeze-dried chain folded single crystals and the single crystals without amorphous surface layers (crystalline cores) of different thicknesses of linear polyethylene were irradiated with 60 Co γ-rays up to 600 Mrad. Concentration of trans-vinylene double bonds and conjugated diene produced during irradiation of the crystals was measured by infrared. Concentrations of trans-vinylene and of the conjugated diene were independent of thickness of crystalline core which suggest that the double bonds were randomly distributed in the crystalline parts of the crystals. Concentrations of trans-vinylene and of conjugated double bonds were lower in chain-folded crystals than in the crystalline cores and this suggests that the folds (amorphous surface layers) are less preferential sites for formation of the double bonds. The zero-order growth and first-order decay kinetics of trans-vinylene double bonds was studied by the equation derived by Dole et al. The equation is strictly obeyed up to 300 Mrad and the results then deviate. Since there is the decay of trans-vinylene double bonds and though there are no crosslinks in the crystalline cores, it has been suggested that the decay of the double bond does not result in the crosslinks

  5. Development of immobilized ligands for actinide separations

    International Nuclear Information System (INIS)

    Paine, R.T.

    1994-01-01

    Primary goals during this grant period were to (1) synthesize new bifunctional chelating ligands, (2) characterize the structural features of the Ln and An coordination complexes formed by these ligands, (3) use structural data to iteratively design new classes of multifunctional ligands, and (4) explore additional routes for attachment of key ligands to solid supports that could be useful for chromatographic separations. Some highlights of recently published work as well as a summary of submitted, unpublished and/or still in progress research are outlined

  6. DESENVOLVIMENTO, LIBERDADE E GÊNERO: EXPERIÊNCIAS TRANS / DEVELOPMENT, FREEDOM AND GENDER: TRANS EXPERIENCES

    Directory of Open Access Journals (Sweden)

    Tuanny Soeiro Sousa

    2017-04-01

    Full Text Available This essay seeks to make an examination on how the gender category influences in the development process, based on the concept of development as freedom by Amartya Sen. In view of this purpose, we analyze the main human rights violations suffered by travesties and transsexuals due to the female and male identity construction in contrast to social norms establishing hierarchical positions of men and women as constituents of male and female categories. In other words, conflicts made in the wake of gender relations. This study is the result of a literature review and analysis of data on homophobic violence against trans experience.

  7. Finding a Trans-Affirmative Provider: Challenges Faced by Trans and Gender Diverse Psychologists and Psychology Trainees.

    Science.gov (United States)

    Dickey, Lore M; Singh, Anneliese A

    2017-08-01

    This article explores some of the challenges faced by trans and gender diverse (TGD) individuals who not only are attempting to access trans-affirmative care, but who are also members of the very profession from which they are seeking services. The authors explore challenges related to finding supervision, accessing care for assessment services, and finding a provider for personal counseling. With each example, the authors unpack the challenges and also address the implications for training for all involved. Based on these challenges that TGD psychologists and trainees face in attempting to access care, the authors provide recommendations related to trans-affirmative training for psychologists. © 2017 Wiley Periodicals, Inc.

  8. Synthesis, solvatochromism and crystal structure of trans-[Cu(Et2NCH2CH2NH2)2.H2O](NO3)2 complex: Experimental with DFT combination

    Science.gov (United States)

    Warad, Ismail; Musameh, Sharif; Badran, Ismail; Nassar, Nashaat N.; Brandao, Paula; Tavares, Carlos Jose; Barakat, Assem

    2017-11-01

    In this study, two dicationic asymmetrical diamine/copper(II) nitrate salt complexes of the general formula trans-[CuII(NN‧)2.H2O](NO3)2 were successfully synthesized using N,N-dimethylethylenediamine and N,N-diethylethylenediamine as asymmetrical diamine ligands. The structure of complex 2 was identified by X-ray single crystal diffraction analysis confirming that the bidentate ligand N,N-dimethylethylenediamine forms a penta-coordinated complex with an H2O molecule located around the copper(II) ion in a trans configuration. It was found that the metal centre is coordinated in a distorted square pyramidal fashion with a τ value of 0.274. The desired complexes were fully characterized using, MS, UV-Vis, CV, FTIR, TG/DTA, and Hirshfeld surface computational analysis. High level theoretical calculations were also performed in order to investigate the complexes structure, conformers, vibrational frequencies, and their excited states.

  9. Naturally occurring and process-induced trans fatty acids and ...

    African Journals Online (AJOL)

    CHOKRI

    2013-05-22

    May 22, 2013 ... Key words: Trans-fatty acids, conjugated linoleic acid, butter oil. INTRODUCTION ... important role in determining risk of coronary heart diseases (CHD) than ... performance liquid chromatography (HPLC) grade, supplied by.

  10. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.

    2012-01-01

    Transformer based Z-source (trans-Z-source) inverters are recently proposed by extending the traditional Z-source inverter with higher buck-boost capability as well as reducing the passive components at the same time. Multi-Level Z-source inverters are single-stage topological solutions used...... for buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...... modulation scheme, the three-level trans-Z-source inverter can function with minimum of six device commutations per half carrier cycle (same as the traditional buck NPC inverter), while maintaining to produce the designed volt-sec average and inductive voltage boosting at ac output terminals. The designed...

  11. READING COLONIZATION IN CONRAD'S TRANS-RACIAL LOVE PLOTS

    Directory of Open Access Journals (Sweden)

    Sandra Lilyana

    2017-07-01

    Full Text Available The study is about a close look at Conrad's trans-racial romance related to the Victorian period. Trans-racial love between white men and non-white women becomes a popular theme in the early works of Josep Conrad, a famous writer of the late Victorian period. Using a closely technical reading in the three of Conrad's works Lord Jim, Almayer's Folly, and An Outcast of the Island, we can show that such a trans-racial romance is not merely meant for appreciating equivalence. In turn, the trans-racial romance of Conrad's can be understood as the reflection of the Western colonization on the East where the white men take a role as subjects who had dominately explored while the non-white women as objects who are passively being explored. Key words: colonization, race, romance plot, subject, object, and dominance

  12. Mapping Discrimination Experienced by Indonesian Trans* FtM Persons.

    Science.gov (United States)

    Gordon, Danny; Pratama, Mario Prajna

    2017-01-01

    This work sought to document how Indonesian trans* FtM persons experienced discrimination across the interlinked domains of social networks, religious and educational institutions, employment and the workplace, and health care institutions. Objectives were (1) to map the discrimination experienced by trans* FtM individuals in Indonesia, and (2) to establish the specific priorities of the Indonesian trans* FtM community. In-depth interviews, focus groups, and participant observation was used involving 14 respondents. Findings revealed that respondents experienced othering through rejection, misidentification, harassment, "correction," and bureaucratic discrimination across the five preestablished domains. Health care and a lack of information emerged as areas of particular concern for respondents. This work calls for health care that is sensitive to the needs of trans* FtM people coupled with high-quality information to alleviate the cycles through which discrimination is sustained.

  13. TRANS-NEPTUNIAN OBJECT LIGHTCURVES V1.1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes a collection of published lightcurves of trans-Neptunian objects published through December 2002. The collection includes lightcurves of 18...

  14. Redox-induced spin-state switching and mixed valency in quinonoid-bridged dicobalt complexes

    Czech Academy of Sciences Publication Activity Database

    Schweinfurth, D.; Rechkemmer, Y.; Hohloch, S.; Deibel, N.; Peremykin, I.; Fiedler, Jan; Marx, R.; Neugebauer, P.; van Slageren, J.; Sarkar, B.

    2014-01-01

    Roč. 20, č. 12 (2014), s. 3475-3486 ISSN 0947-6539 R&D Projects: GA ČR GA203/09/0705 Institutional support: RVO:61388955 Keywords : bridging ligand s * mixed -valent compounds * non-innocent ligand s Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.731, year: 2014

  15. Polarization in high Psub(trans) and cumulative hadron production

    International Nuclear Information System (INIS)

    Efremov, A.V.

    1978-01-01

    The final hadron polarization in the high Psub(trans) processes is analyzed in the parton hard scattering picture. Scaling assumption allows a correct qualitative description to be given for the Psub(trans)-behaviour of polarization or escape angle behaviour in cumulative production. The energy scaling and weak dependence on the beam and target type is predicted. A method is proposed for measuring the polarization of hadron jets

  16. Bioavailability of trans-resveratrol from red wine in humans.

    Science.gov (United States)

    Vitaglione, Paola; Sforza, Stefano; Galaverna, Gianni; Ghidini, Cristiana; Caporaso, Nicola; Vescovi, Pier Paolo; Fogliano, Vincenzo; Marchelli, Rosangela

    2005-05-01

    Many in vitro studies demonstrated significant biological effects of trans-resveratrol. Thus, understanding the rate of intestinal absorption and metabolization in vivo of trans-resveratrol is the prerequisite to evaluate its potential health impact. Bioavailability studies mainly in animals or in humans using the pure compound at very high doses were performed. In this work, trans-resveratrol bioavailability from a moderate consumption of red wine in 25 healthy humans has been studied by three different experiments. The wine ingestion was associated to three different dietary approaches: fasting, a standard meal, a meal with high and low amount of lipids. Trans-resveratrol 3- and 4'-glucuronides were synthesized, purified, and characterized as pure standards. Bioavailability data were obtained by measuring the concentration of free, 3-glucuronide and 4'-glucuronide trans-resveratrol by high-performance liquid chromatography (HPLC), both with ultraviolet (UV) and mass spectrometry (MS) detection, in serum samples taken at different times after red wine administration. Free trans-resveratrol was found, in trace amounts, only in some serum samples collected 30 min after red wine ingestion while after longer times resveratrol glucuronides predominated. Trans-resveratrol bioavailability was shown to be independent from the meal or its lipid content. The finding in human serum of trans-resveratrol glucuronides, rather than the free form of the compound, with a high interindividual variability, raises some doubts about the health effects of dietary resveratrol consumption and suggests that the benefits associated to red wine consumption could be probably due to the whole antioxidant pool present in red wine.

  17. The importance of trans-generational effects in Lepidoptera

    OpenAIRE

    Woestmann, Luisa; Saastamoinen, Marjo

    2016-01-01

    The importance of trans-generational effects in shaping an individuals' phenotype and fitness, and consequently even impacting population dynamics is increasingly apparent. Most of the research on trans-generational effects still focuses on plants, mammals, and birds. In the past few years, however, increasing number of studies, especially on maternal effects, have highlighted their importance also in many insect systems. Lepidoptera, specifically butterflies, have been used as model systems ...

  18. Ligand-induced internalization of neurotensin in transfected COS-7 cells: differential intracellular trafficking of ligand and receptor.

    Science.gov (United States)

    Vandenbulcke, F; Nouel, D; Vincent, J P; Mazella, J; Beaudet, A

    2000-09-01

    The neuropeptide neurotensin (NT) is known to be internalized in a receptor-mediated fashion into its target cells. To gain insight into the mechanisms underlying this process, we monitored in parallel the migration of the NT1 neurotensin receptor subtype and a fluorescent analog of NT (fluo-NT) in COS-7 cells transfected with a tagged NT1 construct. Fluo-NT internalization was prevented by hypertonic sucrose, potassium depletion and cytosol acidification, demonstrating that it proceeded via clathrin-coated pits. Within 0-30 minutes, fluo-NT accumulated together with its receptor in Acridine Orange-positive, acidic organelles. These organelles concentrated transferrin and immunostained positively for rab 5A, therefore they were early endosomes. After 30-45 minutes, the ligand and its receptor no longer colocalized. Fluo-NT was first found in rab 7-positive late endosomes and later in a nonacidic juxtanuclear compartment identified as the Trans-Golgi Network (TGN) by virtue of its staining for syntaxin 6. This juxtanuclear compartment also stained positively for rab 7 and for the TGN/pericentriolar recycling endosome marker rab 11, suggesting that the ligand could have been recruited to the TGN from either late or recycling endosomes. By that time, internalized receptors were detected in Lamp-1-immunoreactive lysosomes. These results demonstrate that neurotensin/NT1 receptor complexes follow a recycling cycle that is unique among the G protein-coupled receptors studied to date, and provide the first evidence for the targeting of a nonendogenous protein from endosomes to the TGN.

  19. Parity mixing

    International Nuclear Information System (INIS)

    Adelberger, E.G.

    1975-01-01

    The field of parity mixing in light nuclei bears upon one of the exciting and active problems of physics--the nature of the fundamental weak interaction. It is also a subject where polarization techniques play a very important role. Weak interaction theory is first reviewed to motivate the parity mixing experiments. Two very attractive systems are discussed where the nuclear physics is so beautifully simple that the experimental observation of tiny effects directly measures parity violating (PV) nuclear matrix elements which are quite sensitive to the form of the basic weak interaction. Since the measurement of very small analyzing powers and polarizations may be of general interest to this conference, some discussion is devoted to experimental techniques

  20. Crystal structure of {2,2′-[N,N′-bis(pyridin-2-ylmethylcyclohexane-trans-1,2-diyldi(nitrilo]diacetato}cobalt(III hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    Craig C. McLauchlan

    2015-04-01

    Full Text Available The title compound [Co(C22H26N4O4]PF6, commonly known as [Co(bpcd]PF6, where bpcd2− is derived from the historical ligand name N,N′-bis(2-pyridylmethyl-trans-1,2-diaminocyclohexane-N,N′-diacetate, crystallized by slow evaporation of a saturated acetonitrile solution in air. The cation of the hexafluoridophosphate salt has the CoIII atom in a distorted octahedral coordination geometry provided by an N4O2 donor atom set. The acetate groups, which are oriented trans with respect to each other, exhibit monodentate coordination whereas the pyridyl N atoms are coordinating in a cis configuration. The geometry of the cation is compared to the geometries of other diamino diacetate complexes with CoIII.

  1. Crystal structure of trans-dichloridobis[N-(5,5-dimethyl-4,5-dihydro-3H-pyrrol-2-yl-κNacetamide]palladium(II dihydrate

    Directory of Open Access Journals (Sweden)

    Jamal Lasri

    2017-04-01

    Full Text Available The title complex, [PdCl2(C8H14N2O2]·2H2O, was obtained by N–O bond cleavage of the oxadiazoline rings of the trans-[dichlorido-bis(2,5,5-trimethyl-5,6,7,7a-tetrahydropyrrolo[1,2-b][1,2,4]oxadiazole-N1]palladium(II complex. The palladium(II atom exhibits an almost square-planar coordination provided by two trans-arranged chloride anions and a nitrogen atom from each of the two neutral organic ligands. In the crystal, N—H...O, O—H...O and O—H...Cl hydrogen bonds link complex molecules into double layers parallel to the bc plane.

  2. A comparison of trans-cranial and trans-sphenoidal approaches for vision improvement due to pitutary adenomas

    Directory of Open Access Journals (Sweden)

    Fakhr Tabatabai SA

    1997-07-01

    Full Text Available To improve visual disturbance, optic nerve decompression can be performed via transcranial or tran-sphenoidal approaches. Although the surgical exposure in transcranial approach is favourable, yet the optic nerve's presence in the field may make it vulnerable to damage. Of fighty patients with different types of pituitary adenomas, 35 cases with medium-sized (1-3 cm tumors have been studied in a randomized clinical trial during a three year period, to compare the applicability of these approaches. While short hospital stay with better visual outcome was observed in fifteen trans-sphenoidal cases, in comparison to 20 trans-cranial cases, however the preoperative visual status and underlying disorders were similar in both groups. Decompressing the optic apparatus, trans-sphenoidally, seems beneficial, where there are no contraindications for the procedure in medium-sized pituitary adenomas

  3. Macrocyclic ligands for uranium complexation

    International Nuclear Information System (INIS)

    Potts, K.T.

    1991-04-01

    A highly preorganized 24-macrocycle containing biuret, thiobiuret and pyridine subunits has been prepared by high dilution ring-closure procedures. Intermediate products to this macrocycle have been utilized to extend this synthetic route to include further representatives where solubility and stability will be influenced by substituent variation. A 1:1 complex has been formed from uranyl acetate and a quinquepyridine derivative, this representing a new type of ligand for the uranyl ion. A very convenient synthetic procedure that will allow the incorporation of these macrocycles into polymeric systems has been developed for the introduction of a vinyl substituent into the 4-position of the pyridine ring. Using triflate, vinyltributyltin and Pd 0 chemistry, this procedure should make a variety of substituted 4-vinylpyridines available for the first time. 3 refs

  4. Effect of silage type and concentrate level on conjugated linoleic acids, trans-C18 : 1 isomers and fat content in milk from dairy cows

    DEFF Research Database (Denmark)

    Nielsen, Torben Skov; Straarup, Ellen Marie; Jungersen, Mogens Vestergaard

    2006-01-01

    to one of four diets in a 2 x 2 factorial arrangement of treatments and a six week experimental period. Treatments were total mixed rations with maize (M) or grass (G) silage differing in polyunsaturated fatty acid (PUFA) profile and starch content, combined with a high (H) or a low (L) level......:1 and reduced cis9, trans11-CLA and trans11-C18:1 when maize but not grass silage was provided. The results suggest that high levels of concentrate (grain) do not significantly alter the pattern of PUFA biohydrogenation in the rumen, the concentration of CLA and trans-C18:1 isomers in milk or cause milk fat...

  5. Integration of a semi-rigid proline ligand and 4,4'-bipyridine in the synthesis of homochiral metal-organic frameworks with helices.

    Science.gov (United States)

    Xu, Zhong-Xuan; Kang, Yao; Han, Min-Le; Li, Dong-Sheng; Zhang, Jian

    2015-06-28

    A pair of 3-D homochiral metal-organic frameworks (HMOFs) based on a mixed semi-rigid 5-(2-carboxypyrrolidine-1-carbonyl)isophthalate (PIA) ligand and rigid 4,4'-bipyridine (bipy), [Co3((R)-PIA)2(bipy)3]·6H2O (1-D) and [Co3((S)-PIA)2(bipy)3]·6H2O (1-L) are synthesized and structurally characterized. They are enantiomers and exhibit three-dimensional open frameworks. In each structure, the PIA ligands link the Co centers into homochiral frameworks with large open channels that are occupied by the bipy ligands. Interesting helical chains built from the connectivity between PIA ligands and Co centers are presented. Antiferromagnetic coupling is observed in 1-D. These results demonstrated that the mixed ligand approach is successful for the construction of HMOFs.

  6. PUTAS Y TRANS. ¿ESTÁN LAS MUJERES TRANS EN LAS NARRATIVAS SOBRE LA PROSTITUCIÓN?

    Directory of Open Access Journals (Sweden)

    Liza García Reyes

    2015-06-01

    Full Text Available Este artículo evidencia los principales resultados de la investigación cualitativa titulada: Putas y trans. Narrativas sobre mujeres trans en España –desarrollada en 2010–, la cual estudió su presencia en textos académicos sobre prostitución en España, producidos entre los años 2000-2009. El análisis de contenido de 34 narrativas evidenció que las referencias a mujeres trans resulta escasa en ellas, aun siendo ellas quienes tienen mayor presencia en la prostitución, en proporción con las mujeres biológicas. Solo nueve textos mencionan la experiencia trans al interior de la prostitución y, entre estos, el asunto solo aparece asertivamente descrito cuando son las propias mujeres trans quienes escriben. AbstractThis paper shows the results of a qualitative research entitled: Hookers and Trans Women: Narratives about trans women in Spain. This study was developed in 2010 and it is based on presence of trans women in the academic texts of prostitution in Spain produced between 2000 and 2009. The content analysis of thirty four narratives showed that the references to in transsexual women in these texts were few, although they have more presence into prostitution, in relation to the biological women. Only nine texts show an experience of prostitution and among these, transexperience only is described assertively when transsexual women write the texts themselves.

  7. Biscoitos recheados: quanto mais baratos maior teor de gordura trans? = Filled cookies: the cheaper the higher trans fat content?

    Directory of Open Access Journals (Sweden)

    Galdino, Tatiana Pizzato

    2010-01-01

    Conclusões: quanto maior a quantidade de gorduras trans, menor a quantidade de gordura saturada e menor preço. Sugere-se uma revisão na legislação quanto à inserção da quantidade exata de gorduras trans no rótulo, uma vez que o consumo elevado dessas gorduras está associado a dislipidemias, um fator de risco para doença cardiovascular

  8. Synthesis and characterization of the Bis- Cyclometalating Ligand 3,3',5,5'-tetrakis[(dimethylamino)methyl]biphenyl and its use in the preparation of bimetallic M(II), M(IV) (M = Pt, Pd) and mixed-valence Pt(II)-Pt(IV) complexes via a dilithio-derivative. Crystal structure of the Pd dimer [ClPd{2,6-(Me2NCH2)2C6H2}]2,

    NARCIS (Netherlands)

    Koten, G. van; Lagunas, M.C.; Gossage, R.A.; Spek, A.L.

    1998-01-01

    The potentially bis-cyclometalating ligand 3,3',5,5'-tetrakis[(dimethylamino)methyl]biphenyl, was prepared from 3,5-(Me2NCH2)2C6H3Br in a one-pot synthesis involving lithium-halogen exchange, transmetalation, and reductive-elimination reactions. This ligand undergoes selective dilithiation in the 4

  9. CXCR4 Ligands : The Next Big Hit?

    NARCIS (Netherlands)

    Walenkamp, Annemiek M. E.; Lapa, Constantin; Herrmann, Ken; Wester, Hans-Juergen

    2017-01-01

    The G protein-coupled protein receptor C-X-C chemokine receptor 4 (CXCR4) is an attractive target for cancer diagnosis and treatment, as it is overexpressed in many solid and hematologic cancers. Binding of its ligand, C-X-C chemokine ligand 12 (CXCL12), results in receptor internalization and

  10. Ligand-receptor Interactions by NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Novak. P.

    2008-04-01

    Full Text Available Today NMR spectroscopy is a method of choice for elucidation of interactions between biomolecules and the potential ligands. Knowledge on these interactions is an essential prerequisite for the rational drug design. The most important contribution of NMR to drug design a few years ago was the 3D structure determination of proteins. Besides delivering the 3D structures of the free proteins as a raw material for the modeling studies on ligand binding, NMR can directly yield valuable experimental data on the biologically important protein-ligand complexes. In addition to X-ray diffraction, NMR spectroscopy can provide information on the internal protein dynamics ordynamics of intermolecular interactions. Changes in NMR parameters allow us to detect ("SAR by NMR" and quantitatively determine binding affinities (titration, diffusion NMR experiments, etc. of potential ligands. Also, it is possible to determine the binding site and conformations of ligands, receptors and receptor-ligand complexes with the help of NMR methods such as tr-NOESY. Epitopes or functional groups responsible for binding of ligands to the receptor can be identified by employing STD or WaterLOGSY experiments. In this review are described some of the most frequent NMR methods for the characterization of the interactions between biomolecules and ligands, together with their advantages and disadvantages.

  11. Autocrine signal transmission with extracellular ligand degradation

    Science.gov (United States)

    Muratov, C B; Posta, F; Shvartsman, S Y

    2009-03-01

    Traveling waves of cell signaling in epithelial layers orchestrate a number of important processes in developing and adult tissues. These waves can be mediated by positive feedback autocrine loops, a mode of cell signaling where binding of a diffusible extracellular ligand to a cell surface receptor can lead to further ligand release. We formulate and analyze a biophysical model that accounts for ligand-induced ligand release, extracellular ligand diffusion and ligand-receptor interaction. We focus on the case when the main mode for ligand degradation is extracellular and analyze the problem with the sharp threshold positive feedback nonlinearity. We derive expressions that link the speed of propagation and other characteristics of traveling waves to the parameters of the biophysical processes, such as diffusion rates, receptor expression level, etc. Analyzing the derived expressions we found that traveling waves in such systems can exhibit a number of unusual properties, e.g. non-monotonic dependence of the speed of propagation on ligand diffusivity. Our results for the fully developed traveling fronts can be used to analyze wave initiation from localized perturbations, a scenario that frequently arises in the in vitro models of epithelial wound healing, and guide future modeling studies of cell communication in epithelial layers.

  12. Organotellurium ligands – designing and complexation reactions

    Indian Academy of Sciences (India)

    Unknown

    membered rings it is negative and ~30 ppm only. Keywords. Organotellurium ligands; hybrid telluroether; platinum metal complexes; tellurium-125 NMR. 1. Introduction. Tellurium is the noblest metalloid which may act as a Lewis acid as well as Lewis base. The ligand chemistry of tellurium, which acts as a 'soft' donor, was ...

  13. Reasons for decision in the matter of Trans Mountain Pipeline Inc. (formerly Terasen Pipelines (Trans Mountain) Inc.) : tariffs

    International Nuclear Information System (INIS)

    2007-01-01

    In 2006 and 2007 Terasen Pipelines (Trans Mountain) Inc. (now Trans Mountain Pipeline Inc.) submitted a series of applications to the National Energy Board for revisions to the Trans Mountain Tariffs. They were filed in response to apportionment concerns on the Trans Mountain pipeline. Four of the applications involved pronounced and contentious changes to the capacity allocation procedures on the pipeline system. For ease of reference, the Board amalgamated its 4 decisions on these applications into a single document. A map of the Trans Mountain pipeline system as a whole was presented along with a detailed map indicating the delivery locations served by the system in the lower mainland of British Columbia and the state of Washington. The issues considered by the Board in each of these decisions included capacity allocation for Westridge Dock; capacity allocations to export destinations; common carriage requirements; and the need for creating a new barge subcategory. Relevant sections of the National Energy Board Act referred to in the decisions were highlighted. This document also listed the Trans Mountain Tariffs that have introduced notable revisions to the capacity allocation procedures on the system since September 2003. 16 refs., 2 figs., 3 appendices

  14. Dysprosium complexes with the tetraphenylporphyrin macrocyclic ligand

    International Nuclear Information System (INIS)

    Martinez M, V.; Padilla, J.; Ramirez, F.M.

    1992-04-01

    In this report, the results obtained on the synthesis, characterization and study of the chemical behavior of dysprosium complex with the acetylacetone chelating agent (Hacac) and the tetraphenylporphyrin macrocyclic ligand (H 2 TFP) are given. Based on the literature but according to our necessities and interest, the appropriate methodology settled down from the synthesis of prime matters until the obtaining and characterization of the products. The acetyl acetonate complex was obtained of mono hydrated dysprosium [Dy(acac) 3 . H 2 0] and trihydrated [Dy(acac) 3 .3 H 2 0], the mono tetra phenyl porphyrinate [Dy(TFP)(acac). 2 ac] the double sandwich of the dysprosium porphyrinate [Dy(TFP) 2 ] and the triple sandwich of the dysprosium porphyrinate [Dy(TFP) 3 . 2 TCB] (TCB = trichlorobenzene). Its were characterized by their melting points, solubility, IR, UV, TGA and DTA both first and besides the techniques already mentioned for NMR'H, RPE and Magnetic susceptibility the three last complexes. From the spectroscopic point of view, IR and RPE its suggested the existence of a complex of inverse mixed valence [Dy(TFP) 2- (TFP) 1- ] for the Dy(TFP) 2 as a result of the existence of the free radical (TFP' 1- and that it was not in none of the other porphyrin compounds. In the NMR'H spectra of the compounds were not observed signals in the region from 0 to 10 ppm that which shows that the dysprosium complexes in special those of the porphyrin type are highly paramagnetic and its could be used as displacement reagents, creators of images and contrast agents of great utility in these days in studies of NMR, technique today by today used in medical diagnoses. (Author)

  15. A directed approach for the identification of transcripts harbouring the spliced leader sequence and the effect of trans-splicing knockdown in Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Marina de Moraes Mourao

    2013-09-01

    Full Text Available Schistosomiasis is a major neglected tropical disease caused by trematodes from the genus Schistosoma. Because schistosomes exhibit a complex life cycle and numerous mechanisms for regulating gene expression, it is believed that spliced leader (SL trans-splicing could play an important role in the biology of these parasites. The purpose of this study was to investigate the function of trans-splicing in Schistosoma mansoni through analysis of genes that may be regulated by this mechanism and via silencing SL-containing transcripts through RNA interference. Here, we report our analysis of SL transcript-enriched cDNA libraries from different S. mansoni life stages. Our results show that the trans-splicing mechanism is apparently not associated with specific genes, subcellular localisations or life stages. In cross-species comparisons, even though the sets of genes that are subject to SL trans-splicing regulation appear to differ between organisms, several commonly shared orthologues were observed. Knockdown of trans-spliced transcripts in sporocysts resulted in a systemic reduction of the expression levels of all tested trans-spliced transcripts; however, the only phenotypic effect observed was diminished larval size. Further studies involving the findings from this work will provide new insights into the role of trans-splicing in the biology of S. mansoni and other organisms. All Expressed Sequence Tags generated in this study were submitted to dbEST as five different libraries. The accessions for each library and for the individual sequences are as follows: (i adult worms of mixed sexes (LIBEST_027999: JZ139310 - JZ139779, (ii female adult worms (LIBEST_028000: JZ139780 - JZ140379, (iii male adult worms (LIBEST_028001: JZ140380 - JZ141002, (iv eggs (LIBEST_028002: JZ141003 - JZ141497 and (v schistosomula (LIBEST_028003: JZ141498 - JZ141974.

  16. 'Homens trans': novos matizes na aquarela das masculinidades? 'Trans men': new colours in the masculinities picture?

    Directory of Open Access Journals (Sweden)

    Guilherme Almeida

    2012-08-01

    Full Text Available O artigo discute de forma exploratória a emergência de uma nova categoria identitária no Brasil, a de 'homem trans'. Essa se constrói diferenciando-se da identidade lésbica e, também, de expressões de gênero de outros grupos que tiveram seus corpos assignados como femininos ao nascimento, mas que contestam essa assignação sem, contudo, se afirmarem 'homens' de forma constante. Afirma-se que a emergência dos 'homens trans' tem sido potencializada pelo estabelecimento do processo transexualizador no SUS. Discutem-se o uso do termo "homem trans" e algumas características comuns a tais sujeitos. Problematizam-se a complexidade de seus processos de autorreconhecimento e construção de masculinidades, sua rápida capacidade de indiferenciação a partir de modificações corporais e, alguns dos efeitos políticos e subjetivos, da visibilidade e da indiferenciação.The article discusses in an exploratory form the emergence of a new identity category in Brazil, namely "transmen". This identity is constructed as a differentiation from the lesbian identity and also from gender expressions of other groups that had their bodies assigned as female upon birth, but that later refuted this assignment without, however, affirming themselves as "men" on a permanent way. The article claims that the emergence of "transmen" has been made possible by the establishment of the transexualization process in the Public Health Care System. Furthermore, the article discusses the use of the term "transman" and some common characteristics related to those persons. The author critiques their complex processes of self-knowledge and construction of masculinities, as well as their quick capacity for non-differentiation from the stand-point of bodily modifications. Finally, the author discusses the political and subjective consequences of their visibility and non-differentiation.

  17. Mechanistic Insights into Solvent and Ligand Dependency in Cu(I)-Catalyzed Allylic Alkylation with gem-Diborylalkanes.

    Science.gov (United States)

    Zhang, Qi; Wang, Bing; Liu, Jia-Qin; Fu, Yao; Wu, Yu-Cheng

    2018-01-19

    The recent Cu-catalyzed allylic substitution reaction between gem-diboryalkane and allyl electrophiles shows intriguing solvent and ligand-controlled regioselectivity. The α-alkylation product was obtained in DMF solvent, while γ-alkylation product was obtained in dioxane solvent and the dioxane and NHC ligand situation. In the present study, density functional theory calculations have been used to investigate the reaction mechanism and origin of the regioselectivity. For both dioxane and DMF, γ-alkylation undergoes successive oxidative addition (CH 2 Bpin trans to leaving group) and direct Cγ-C reductive elimination. The α-alkylation is found to undergo oxidative addition (CH 2 Bpin trans to leaving group), isomerization, and Cα-C reductive elimination rather than the previously proposed oxidative addition (-CH 2 Bpin cis to the leaving group) and Cα-C reductive elimination. The γ-alkylation and α-alkylation is, respectively, favorable for dioxane and DMF solvent, which is consistent with the γ- and α-selectivity in experiment. The solvent interferes the isomerization step, thereby affects the relative facility of the α- and γ-alkylation. Further investigation shows that η 1 -intermediate formation promoted by solvent is the rate-determining step of the isomerization. The stronger electron-donating ability of DMF than dioxane facilitates the η 1 -intermediate formation and finally results in the easier isomerization in DMF. For dioxane and NHC situation, in the presence of neutral NHC ligand, the -PO 4 Et 2 group tightly coordinates with the Cu center after the oxidative addition, preventing the isomerization process. The regioselectivity is determined by the relative facility of the oxidative addition step. Therefore, the favorable oxidative addition (in which -CH 2 Bpin trans to the leaving group) results in the facility of γ-alkylation.

  18. Metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, in mouse liver by alcohol dehydrogenase Adh1 and aldehyde reductase AKR1A4

    International Nuclear Information System (INIS)

    Short, Duncan M.; Lyon, Robert; Watson, David G.; Barski, Oleg A.; McGarvie, Gail; Ellis, Elizabeth M.

    2006-01-01

    The reductive metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, was studied in mouse liver. Using an HPLC-based stopped assay, the primary reduced metabolite was identified as 6-hydroxy-trans, trans-2,4-hexadienal (OH/CHO) and the secondary metabolite as 1,6-dihydroxy-trans, trans-2,4-hexadiene (OH/OH). The main enzymes responsible for the highest levels of reductase activity towards trans, trans-muconaldehyde were purified from mouse liver soluble fraction first by Q-sepharose chromatography followed by either blue or red dye affinity chromatography. In mouse liver, trans, trans-muconaldehyde is predominantly reduced by an NADH-dependent enzyme, which was identified as alcohol dehydrogenase (Adh1). Kinetic constants obtained for trans, trans-muconaldehyde with the native Adh1 enzyme showed a V max of 2141 ± 500 nmol/min/mg and a K m of 11 ± 4 μM. This enzyme was inhibited by pyrazole with a K I of 3.1 ± 0.57 μM. Other fractions were found to contain muconaldehyde reductase activity independent of Adh1, and one enzyme was identified as the NADPH-dependent aldehyde reductase AKR1A4. This showed a V max of 115 nmol/min/mg and a K m of 15 ± 2 μM and was not inhibited by pyrazole

  19. Trans, Switzerland: new drinking-water hydropower station; Gemeinde Trans (GR) - Neubau Trinkwasserkraftwerk - Bauprojekt

    Energy Technology Data Exchange (ETDEWEB)

    Gadient, N.; Scherrer, I.

    2008-10-15

    This report for the Swiss Federal Office of Energy (SFOE) presents the construction project for the realisation of a hydropower installation that uses the water of the drinking-water mains in Trans, Grisons, Switzerland, to generate electricity. Figures are presented on the head of water available, the proposed electrical power to be installed as well as the annual production and the financing of the project. The latter has been assured by the Swiss scheme for the cost-covering remuneration of electrical energy generated using renewable resources. The construction project agreed on is described and discussed. The project is to be realised together with the refurbishment of the existing drinking-water supply system. The installations necessary and the proposed electromechanical equipment are described and discussed. Also, the supply of increased amounts of water for fire-fighting purposes are noted.

  20. Correcting ligands, metabolites, and pathways

    Directory of Open Access Journals (Sweden)

    Vriend Gert

    2006-11-01

    Full Text Available Abstract Background A wide range of research areas in bioinformatics, molecular biology and medicinal chemistry require precise chemical structure information about molecules and reactions, e.g. drug design, ligand docking, metabolic network reconstruction, and systems biology. Most available databases, however, treat chemical structures more as illustrations than as a datafield in its own right. Lack of chemical accuracy impedes progress in the areas mentioned above. We present a database of metabolites called BioMeta that augments the existing pathway databases by explicitly assessing the validity, correctness, and completeness of chemical structure and reaction information. Description The main bulk of the data in BioMeta were obtained from the KEGG Ligand database. We developed a tool for chemical structure validation which assesses the chemical validity and stereochemical completeness of a molecule description. The validation tool was used to examine the compounds in BioMeta, showing that a relatively small number of compounds had an incorrect constitution (connectivity only, not considering stereochemistry and that a considerable number (about one third had incomplete or even incorrect stereochemistry. We made a large effort to correct the errors and to complete the structural descriptions. A total of 1468 structures were corrected and/or completed. We also established the reaction balance of the reactions in BioMeta and corrected 55% of the unbalanced (stoichiometrically incorrect reactions in an automatic procedure. The BioMeta database was implemented in PostgreSQL and provided with a web-based interface. Conclusion We demonstrate that the validation of metabolite structures and reactions is a feasible and worthwhile undertaking, and that the validation results can be used to trigger corrections and improvements to BioMeta, our metabolite database. BioMeta provides some tools for rational drug design, reaction searches, and

  1. Reference values of urinary trans,trans-muconic acid: Italian Multicentric Study.

    Science.gov (United States)

    Aprea, C; Sciarra, G; Bozzi, N; Pagliantini, M; Perico, A; Bavazzano, P; Leandri, A; Carrieri, M; Scapellato, M L; Bettinelli, M; Bartolucci, G B

    2008-08-01

    This article reports the results of a study, conducted in the framework of the scientific activities of the Italian Society for Reference Values, aimed at defining reference values of urinary trans,trans-muconic acid (t,t-MA) in the general population not occupationally exposed to benzene. t,t-MA concentrations detected in 376 subjects of the resident population in three areas of Italy, two in central (Florence and southern Tuscany) and one in northern Italy (Padua), by three laboratories, compared by repeated interlaboratory controls, showed an interval of 14.4-225.0 microg/L (5th-95th percentile) and a geometric mean of 52.5 microg/L. The concentrations measured were influenced by tobacco smoking in a statistically significant way: Geometric mean concentrations were 44.8 microg/L and 76.1 microg/Ll in nonsmokers (264 subjects) and smokers (112 subjects), respectively. In the nonsmoking population, a significant influence of gender was found when concentrations were corrected for urinary creatinine, geometric mean concentrations being 36.7 microg/g creatinine in males (128 subjects) and 44.7 microg/g creatinine in females (136 subjects). The place of residence of subjects did not seem to influence urinary excretion of the metabolite, although personal inhalation exposure to benzene over a 24-h period showed slightly higher concentrations in Padua and Florence (geometric means of 6.5 microg/m(3) and 6.6 microg/m(3), respectively) than in southern Tuscany (geometric mean of 3.9 microg/m(3)). Concentration of t,t-MA in urine samples collected at the end of personal air sampling showed little relationship to personal inhalation exposure to benzene, confirming the importance of other factors in determining excretion of t,t-MA when concentrations in personal air samples are very low.

  2. trans-Diaquabis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole]cobalt(II bis(tetrafluoridoborate

    Directory of Open Access Journals (Sweden)

    Fouad Bentiss

    2011-07-01

    Full Text Available The bidentate 1,3,4-thiadiazole ligand substituted by two 2-pyridyl rings (denoted L has been found to produce the new monomeric title complex, [Co(C12H8N4S2(H2O2](BF42. The thiadiazole and pyridyl rings surrounding the Co atom are almost coplanar [dihedral angle = 4.35 (7°]. The mean plane defined by these heterocyclic moieties makes a dihedral angle of 18.72 (6° with the non-coordinated pyridyl ring. The Co2+ cation, located at a crystallographic center of symmetry, is bonded to two ligands and two water molecules in a trans configuration in an octahedral environment. The tetrafluoridoborate ions can be regarded as free anions in the crystal lattice. Nevertheless, they are involved in an infinite two-dimensional network along the [010] and [101] directions of O—H...F hydrogen bonds.

  3. Autocrine signal transmission with extracellular ligand degradation

    International Nuclear Information System (INIS)

    Muratov, C B; Posta, F; Shvartsman, S Y

    2009-01-01

    Traveling waves of cell signaling in epithelial layers orchestrate a number of important processes in developing and adult tissues. These waves can be mediated by positive feedback autocrine loops, a mode of cell signaling where binding of a diffusible extracellular ligand to a cell surface receptor can lead to further ligand release. We formulate and analyze a biophysical model that accounts for ligand-induced ligand release, extracellular ligand diffusion and ligand–receptor interaction. We focus on the case when the main mode for ligand degradation is extracellular and analyze the problem with the sharp threshold positive feedback nonlinearity. We derive expressions that link the speed of propagation and other characteristics of traveling waves to the parameters of the biophysical processes, such as diffusion rates, receptor expression level, etc. Analyzing the derived expressions we found that traveling waves in such systems can exhibit a number of unusual properties, e.g. non-monotonic dependence of the speed of propagation on ligand diffusivity. Our results for the fully developed traveling fronts can be used to analyze wave initiation from localized perturbations, a scenario that frequently arises in the in vitro models of epithelial wound healing, and guide future modeling studies of cell communication in epithelial layers

  4. Disintegration of aerobic granules induced by trans-2-decenoic acid.

    Science.gov (United States)

    Cai, Pei-Jie; Xiao, Xiang; He, Yan-Rong; Li, Wen-Wei; Yu, Lei; Yu, Han-Qing

    2013-01-01

    One current major hurdle to practical implementation of aerobic granule technology is the frequent occurrence of granule disintegration during long-term operation. However, the mechanism behind this is largely unclear today. Here, 2-decenoic acid, which has been previously demonstrated to be released by Pseudomonas aeruginosa and disperse biofilms, was found to also induce the disintegration of aerobic granules. A comparison of the solution compositions from samples of only trans-2-decenoic acid, only aerobic granules, and granules added with trans-2-decenoic acid shows that bacteria and extracellular polymeric substances (EPS) were stripped from granule surface upon trans-2-decenoic acid dosing. Due to the possible toxicity of trans-2-decenoic acid at a saturation concentration, the disintegrated granules and the milky suspension in the disintegration test showed a significantly lower oxygen uptake rate than the un-integrated granules. This work suggests that trans-2-decenoic acid released by microbes might play a critical role in regulating the disintegration of aerobic granules. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. The importance of trans-generational effects in Lepidoptera.

    Science.gov (United States)

    Woestmann, Luisa; Saastamoinen, Marjo

    2016-10-01

    The importance of trans-generational effects in shaping an individuals' phenotype and fitness, and consequently even impacting population dynamics is increasingly apparent. Most of the research on trans-generational effects still focuses on plants, mammals, and birds. In the past few years, however, increasing number of studies, especially on maternal effects, have highlighted their importance also in many insect systems. Lepidoptera, specifically butterflies, have been used as model systems for studying the role of phenotypic plasticity within generations. As ectotherms, they are highly sensitive to environmental variation, and indeed many butterflies show adaptive phenotypic plasticity in response to environmental conditions. Here, we synthesize what is known about trans-generational effects in Lepidoptera, compile evidence for different environmental cues that are important drivers of trans-generational effects, and point out which offspring traits are mainly impacted. Finally, we emphasize directions for future research that are needed for better understanding of the adaptive nature of trans-generational effects in Lepidoptera in particular, but potentially also in other organisms.

  6. A simplified study of trans-mitral Doppler patterns

    Directory of Open Access Journals (Sweden)

    Thomas George

    2008-11-01

    Full Text Available Abstract Background Trans-mitral Doppler produces complex patterns with a great deal of variability. There are several confusing numerical measures and indices to study these patterns. However trans-mitral Doppler produces readymade data visualization by pattern generation which could be interpreted by pattern analysis. By following a systematic approach we could create an order and use this tool to study cardiac function. Presentation of the hypothesis In this new approach we eliminate the variables and apply pattern recognition as the main criterion of study. Proper terminologies are also devised to avoid confusion. In this way we can get some meaningful information. Testing the hypothesis Trans-mitral Doppler should be seen as patterns rather than the amplitude. The hypothesis can be proven by logical deduction, extrapolation and elimination of variables. Trans-mitral flow is also analyzed vis-à-vis the Starling's Law applied to the left atrium. Implications of the hypothesis Trans-mitral Doppler patterns are not just useful for evaluating diastolic function. They are also useful to evaluate systolic function. By following this schema we could get useful diagnostic information and therapeutic options using simple pattern recognition with minimal measurements. This simplified but practical approach will be useful in day to day clinical practice and help in understanding cardiac function better. This will also standardize research and improve communication.

  7. Trans-nationalisation Processes in the Ukrainian Economy

    Directory of Open Access Journals (Sweden)

    Bolharova Natalya K.

    2013-12-01

    Full Text Available The article considers main processes of trans-nationalisation of Ukrainian economy, identifies specific features of trans-national production and explains some theoretical aspects of these issues. It provides main stages of theoretical comprehension of activity of trans-national corporations (TNC, specific features of the theory of competitive advantages of TNC and specifies the basic ones of them. The article conducts analysis of flows of direct foreign investments into the Ukrainian economy. It shows distribution of direct foreign investments into Ukraine by main countries-investors, regions-recipients and types of economic activity. It conducts review and analysis of the modern state of trans-national corporations of foreign origin in the Ukrainian market. It considers functioning of domestic TNC in Ukraine and main tendencies of entering of Ukrainian companies into the world environment and also identifies directions of further development of these phenomena. Prospects of further studies in this direction are identification of the degree of trans-nationalisation processes in the Ukrainian economy and identification of the positive effect, in particular, synergy from integration and globalisation.

  8. Mutagenesis Analysis Reveals Distinct Amino Acids of the Human Serotonin 5-HT2C Receptor Underlying the Pharmacology of Distinct Ligands.

    Science.gov (United States)

    Liu, Yue; Canal, Clinton E; Cordova-Sintjago, Tania C; Zhu, Wanying; Booth, Raymond G

    2017-01-18

    While exploring the structure-activity relationship of 4-phenyl-2-dimethylaminotetralins (PATs) at serotonin 5-HT 2C receptors, we discovered that relatively minor modification of PAT chemistry impacts function at 5-HT 2C receptors. In HEK293 cells expressing human 5-HT 2C-INI receptors, for example, (-)-trans-3'-Br-PAT and (-)-trans-3'-Cl-PAT are agonists regarding Gα q -inositol phosphate signaling, whereas (-)-trans-3'-CF 3 -PAT is an inverse agonist. To investigate the ligand-receptor interactions that govern this change in function, we performed site-directed mutagenesis of 14 amino acids of the 5-HT 2C receptor based on molecular modeling and reported G protein-coupled receptor crystal structures, followed by molecular pharmacology studies. We found that S3.36, T3.37, and F5.47 in the orthosteric binding pocket are critical for affinity (K i ) of all PATs tested, we also found that F6.44, M6.47, C7.45, and S7.46 are primarily involved in regulating EC/IC 50 functional potencies of PATs. We discovered that when residue S5.43, N6.55, or both are mutated to alanine, (-)-trans-3'-CF 3 -PAT switches from inverse agonist to agonist function, and when N6.55 is mutated to leucine, (-)-trans-3'-Br-PAT switches from agonist to inverse agonist function. Notably, most point-mutations that affected PAT pharmacology did not significantly alter affinity (K D ) of the antagonist radioligand [ 3 H]mesulergine, but every mutation tested negatively impacted serotonin binding. Also, amino acid mutations differentially affected the pharmacology of other commercially available 5-HT 2C ligands tested. Collectively, the data show that functional outcomes shared by different ligands are mediated by different amino acids and that some 5-HT 2C receptor residues important for pharmacology of one ligand are not necessarily important for another ligand.

  9. Radiation induced ligand loss from cobalt complexes

    International Nuclear Information System (INIS)

    Funston, A. M.; McFadyen, W.D.; Tregloan, P.A.

    2000-01-01

    Full text: Due to the rapid nature of ligand dissociation from cobalt(II) complexes the study of the rate of ligand dissociation necessitates the use of a technique such as pulse radiolysis. This allows the rapid reduction of the corresponding cobalt(III) complex by a reducing radical, such as the aquated electron, to form the cobalt(II) complex. However, to date, no systematic study of either the mechanism of reduction or the influence of the electronic structure on the rate of ligand dissociation has been carried out. In order to understand these processes more fully the mechanism of reduction of a range of related cobalt(III) complexes by the aquated electron and the subsequent rate of ligand dissociation from the resulting cobalt(II) complexes is being investigated. It has been found that a number of processes are observed following the initial rapid reaction of the cobalt(III) complex with the aquated electron. Ultimately ligand loss is observed. Depending upon the complex, the initial processes observed may include the formation of coordinated radicals and electron transfer within the complex. For complexes containing aromatic ligands such as 2,2'-bipyridine, 1,10-phenanthroline and dipyrido[3,2-a:2',3'-c]phenazine the formation of a coordinated radical is observed as the initial reduction step. The kinetics of ligand dissociation of these complexes has been determined. The loss of monodentate ligands is fast and has been indistinguishable from the reduction processes when aromatic ligands are also present in the complex. However, for diamine chelates and diimine chelates spectra of the transient species can be resolved

  10. Labeled receptor ligands for spect

    International Nuclear Information System (INIS)

    Kung, H.F.

    1989-01-01

    Receptor specific imaging agents for single photon emission computed tomography (SPECT) can potentially be useful in the understanding of basic biochemistry and pharmacology of receptors. SPECT images may also provide tools for evaluation of density and binding kinetics of a specific receptor, information important for diagnosis and patient management. Basic requirements for receptor imaging agents are: (a) they are labeled with short-lived isotopes, (b) they show high selectivity and specific uptake, (c) they exhibit high target/background ratio, and (d) they can be modeled to obtain quantitative information. Several good examples of CNS receptor specific ligands labeled with I-123 have been developed, including iodoQNB, iodoestrogen iodobenzadiazepine, iodobenazepine, iodobenzamides for muscarinic, estrogen benzadiazepine, D-1 and D-2 dopamine receptors. With the advent of newer and faster SPECT imaging devices, it may be feasible to quantitate the receptor density by in vivo imaging techniques. These new brain imaging agents can provide unique diagnostic information, which may not be available through other imaging modalities, such as CT and MRI

  11. Sub-20 nm Stable Micelles Based on a Mixture of Coiled-Coils: A Platform for Controlled Ligand Presentation.

    Science.gov (United States)

    Ang, JooChuan; Ma, Dan; Jung, Benson T; Keten, Sinan; Xu, Ting

    2017-11-13

    Ligand-functionalized, multivalent nanoparticles have been extensively studied for biomedical applications from imaging agents to drug delivery vehicles. However, the ligand cluster size is usually heterogeneous and the local valency is ill-defined. Here, we present a mixed micelle platform hierarchically self-assembled from a mixture of two amphiphilic 3-helix and 4-helix peptide-polyethylene glycol (PEG)-lipid hybrid conjugates. We demonstrate that the local multivalent ligand cluster size on the micelle surface can be controlled based on the coiled-coil oligomeric state. The oligomeric states of mixed peptide bundles were found to be in their individual native states. Similarly, mixed micelles indicate the orthogonal self-association of coiled-coil amphiphiles. Using differential scanning calorimetry, fluorescence recovery spectroscopy, and coarse-grained molecular dynamics simulation, we studied the distribution of coiled-coil bundles within the mixed micelles and observed migration of coiled-coils into nanodomains within the sub-20 nm mixed micelle. This report provides important insights into the assembly and formation of nanophase-separated micelles with precise control over the local multivalent state of ligands on the micelle surface.

  12. A Versatile Dinucleating Ligand Containing Sulfonamide Groups

    DEFF Research Database (Denmark)

    Sundberg, Jonas; Witt, Hannes; Cameron, Lisa

    2014-01-01

    ligand can be prepared in aqueous solutions using only divalent metal ions. Two of the copper(II) complexes, [Cu2(psmp)(OH)] and [Cu2(psmp)(OAc)2]-, demonstrate the anticipated 1:2 ligand/metal stoichiometry and show that the dimetallic binding site created for exogenous ligands possesses high inherent...... of antiferromagnetic coupling. This is corroborated computationally by broken-symmetry density functional theory, which for isotropic modeling of the coupling predicts an antiferromagnetic coupling strength of J = 70.5 cm-1....

  13. Mononuclear, trinuclear, and hetero-trinuclear supramolecular complexes containing a new tri-sulfonate ligand and cobalt(II)/copper(II)-(1,10-phenanthroline)2 building blocks

    International Nuclear Information System (INIS)

    Yu Yunfang; Wei Yongqin; Broer, Ria; Sa Rongjian; Wu Kechen

    2008-01-01

    Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2 (H 2 O)(HTST)].2H 2 O (1), [Co 3 (phen) 6 (H 2 O) 2 (TST) 2 ].7H 2 O (2), and [Co 2 Cu(phen) 6 (H 2 O) 2 (TST) 2 ].10H 2 O (3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3 TST) with the M 2+ (M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). Complex 1 contains a cis-Co(II)(phen) 2 building block and an HTST as monodentate ligand; complex 2 consists of two TST as bidentate ligands connecting one trans- and two cis-Co(II)(phen) 2 building blocks; complex 3 is formed by replacing the trans-Co(II)(phen) 2 in 2 with a trans-Cu(II)(phen) 2 , which is the first reported hetero-trinuclear supramolecular complex containing both the Co(II)(phen) 2 and Cu(II)(phen) 2 as building blocks. The study shows the flexible multifunctional self-assembly capability of the H 3 TST ligands presenting in these supramolecular complexes through coordinative, H-bonding and even π-π stacking interactions. The photoluminescent optical properties of these complexes are also investigated and discussed as well as the second-order nonlinear optical properties of 1. - Graphical abstract: Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2 (H 2 O)(HTST)].2H 2 O (1), [Co 3 (phen) 6 (H 2 O) 2 (TST) 2 ].7H 2 O (2), and [Co 2 Cu(phen) 6 (H 2 O) 2 (TST) 2 ].10H 2 O (3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3 TST) with the M 2+ (M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). The study shows the flexible multifunctional self-assembly capability of H 3 TST ligand presenting in these supramolecular complexes

  14. 1,2-Ferrocenediylazaphosphinines 3: a new class of planar chiral ligands for Cu-catalyzed cyclopropanation

    Energy Technology Data Exchange (ETDEWEB)

    Paek, Seung Hwan; Co, Thanh Thien; Lee, Dong Ho; Park, Yu Chul; Kim, Tae Jeong [Kyungpook National Univ., Daegu (Korea, Republic of)

    2002-12-01

    The synthesis and catalytic application of a new class of planar chiral ferrocenes, 1,2-ferrocenediylazaphos-phinines (1 and 2) are described. They are powerful ligands for the copper(I)-catalyzed asymmetric cyclopropanation of a range of alkenes with diazo esters to exhibit an exceptionally high degree of diastereoselectivity ({approx}100%) in favor of trans isomers, regardless the structure of the olefins and the diazo compounds. Comparative studies between 1 and 2 reveal that the former works better in terms of diastereocontrol. In contrast, however, enantioselectivity is low with both 1 and 2 as a whole although, in certain cases with a proper combination of the olefin and the diazo ester, high optical yields (up to 100% ee) can be achieved. Other reaction parameters such as the reaction temperature and the structure of the ligand do exhibit some influence, although infinitesimal, on both chemical and optical yields.

  15. 1,2-Ferrocenediylazaphosphinines 3: a new class of planar chiral ligands for Cu-catalyzed cyclopropanation

    International Nuclear Information System (INIS)

    Paek, Seung Hwan; Co, Thanh Thien; Lee, Dong Ho; Park, Yu Chul; Kim, Tae Jeong

    2002-01-01

    The synthesis and catalytic application of a new class of planar chiral ferrocenes, 1,2-ferrocenediylazaphos-phinines (1 and 2) are described. They are powerful ligands for the copper(I)-catalyzed asymmetric cyclopropanation of a range of alkenes with diazo esters to exhibit an exceptionally high degree of diastereoselectivity (∼100%) in favor of trans isomers, regardless the structure of the olefins and the diazo compounds. Comparative studies between 1 and 2 reveal that the former works better in terms of diastereocontrol. In contrast, however, enantioselectivity is low with both 1 and 2 as a whole although, in certain cases with a proper combination of the olefin and the diazo ester, high optical yields (up to 100% ee) can be achieved. Other reaction parameters such as the reaction temperature and the structure of the ligand do exhibit some influence, although infinitesimal, on both chemical and optical yields

  16. Regional Cooperation Towards Trans-country Natural Gas Market

    DEFF Research Database (Denmark)

    Shukla, P.R.; Dhar, Subash

    2009-01-01

    India began gas imports since 2004 through liquified natural gas (LNG) route. Imports through trans-country gas pipelines could help in bringing gas directly into the densely populated Northern part of India, which are far from domestic gas resources as well as coastal LNG terminals. The purpose ...... of this paper is to report scenarios, which quantify the impacts for India of regional cooperation to materialize trans-country pipelines. The analysis covers time period from 2005 to 2030.......India began gas imports since 2004 through liquified natural gas (LNG) route. Imports through trans-country gas pipelines could help in bringing gas directly into the densely populated Northern part of India, which are far from domestic gas resources as well as coastal LNG terminals. The purpose...

  17. In Search of a Trans-national Climate Change Law

    International Nuclear Information System (INIS)

    Lassus Saint-Genies, Geraud de

    2016-01-01

    Private entities engagement in the battle against climate change is a well-established fact, and a source of intense and diversified normative activity. A certain type of climate rules has thus arisen, with a private origin and an international scope, as they transcend the borders of existing territories. In this context, one could wonder about the possible existence of a trans-national climate change law, as a relatively autonomous body of law, which would exist at the margins of international and national climate change law. Building on the discussions that have been conducted about the trans-national law in other areas of regulations, this study intends to provide answers about the possible existence of a trans-national climate change law

  18. Mechanically induced cis to trans reisomerization of azobenzene

    Science.gov (United States)

    Turansky, Robert; Konopka, Martin; Stich, Ivan; Marx, Dominik

    2007-03-01

    Using density functional techniques we study mechanochemistry of the azobenzene molecule. Azobenzene is an optically switchable molecule. Laser light is normally used to achieve molecular switching between the cis and trans isomers. We use mechanochemistry to achieve the switching. Thiolate-gold bond can used to exert mechanical energy on the molecule bonded between two gold electrodes in static AFM apparatus. Our model consists of two realistic gold electrodes bridged by dithioazobenzene. We find that pulling the transisomer leads just to formation of gold nanowires and mechanical breakage of the electrodes. However, mechanochemistry with modest applied forces leads to cis trans reisomerization via rotation mechanism. Contrary, use of simple constraints instead of realistic gold electrodes, leads to cis trans reisomerization, albeit with significantly larger applied forces and via inversion mechanism. Important experimental and theoretical ramifications of these simulations will be discussed.

  19. Asymmetrically doped one-dimensional trans-polymers

    International Nuclear Information System (INIS)

    Caldas, Heron

    2009-01-01

    More than 30 years ago [H. Shirakawa, E.J. Louis, A.G. MacDiarmid, C.K. Chiang, A.J. Heeger, J. Chem. Soc. Chem. Comm. 578 (1977); S. Etemad, A.J. Heeger, Ann. Rev. Phys. Chem. 33 (1982) 443] it was discovered that doped trans-polyacetylene (CH) x , a one-dimensional (1D) conjugated polymer, exhibits electrical conductivity. In this work we show that an asymmetrically doped 1D trans-polymer has non-conventional properties, as compared to symmetrically doped systems. Depending on the level of asymmetry between the chemical potentials of the two involved fermionic species, the polymer can be in a partially or fully spin polarized state. Some possible experimental consequences of doped 1D trans-polymers used as 1D organic polarized conductors are discussed.

  20. Letter to the editor: healthy alternatives to trans fats

    Directory of Open Access Journals (Sweden)

    Moulin Julie

    2007-04-01

    Full Text Available Abstract Consumption of trans fats is associated with an increase of cardiovascular disease (CVD risk. To comply with regulatory policies and public health authorities recommendations, trans fats should be replaced in food products. The study by Sundram et al. (Nutrition & Metabolism 2007, 4:3 reporting the effect on CVD risk factors of interesterified fat (IE and partially hydrogenated soybean oil (PHSO compared to palm olein (POL has been critically analyzed. The study design and in particular the composition of the tested fats was not suitable to properly answer the question raised regarding the effect of alternative ingredients to trans fats on plasma lipids. The observed effects are divergent with predicted data derived from the literature model consolidated using the individual results of 60 randomized clinical trials. The results of the study published by Sundram and co-workers have to be considered with awareness.

  1. Concentration Effect on Quenching of Chlorophyll a Fluorescence by All-Trans-β-Carotene in Photosynthesis

    Directory of Open Access Journals (Sweden)

    Chen Chen

    2017-09-01

    Full Text Available Absorption, fluorescence spectra of chlorophyll a (Chl-a and all-trans-β-carotene (β-Car mixing solution are investigated in different polarity and polarizability solvents. The carotenoids regulate the energy flow in photosynthesis by interaction with chlorophyll, leading to an observable reduction of Chl-a fluorescence. The fluorescence red shifts with the increasing solvent polarizability. The energy transfer in the Chl-a and β-Car system is proposed. The electron transfer should be dominant in quenching Chl-a fluorescence rather than the energy transfer in this system. Polar solvent with large polarizability shows high quenching efficiency. When dissolved in carbon tetrachloride, Chl-a presents red shift of absorption and blue shift of fluorescence spectra with increasing β-Car concentration, which implies a Chl-a conformational change.

  2. Evolution of cichlid vision via trans-regulatory divergence

    Directory of Open Access Journals (Sweden)

    O’Quin Kelly E

    2012-12-01

    Full Text Available Abstract Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory “hotspots” associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73% occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the

  3. Peel Region TransHelp's experience

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-09-15

    TransHelp was founded in the Peel Region of Ontario in 1981 to provide paratransit service to individuals unable to use conventional transit. The TransHelp vehicle fleet consists of 40 buses that make over 220,000 one way trips annually. Each vehicle has a typical life span of between 375,000 and 425,000 km. TransHelp vehicles spend much of their time idling in emissions-sensitive areas, such as outside hospitals. In order to reduce fuel costs, TransHelp adopted the use of propane to fuel its vehicles. However, difficulties were experienced with this technology, particularly on V-10 engines where increased maintenance was a problem. SFI Technologies Inc. provided a solution with their SEQUIN System which allows seamless transitioning between gasoline and propane under all conditions without any operator involvement in fuel selection. The technology favours propane as the fuel of choice and automatically switches between propane and gasoline based on the ideal conditions at the time of operation. The technology has received certification from the Environmental Protection Agency in the United States and the Canadian Standards Association. The use of the SEQUIN System has proven to successful for TransHelp. It has allowed the use of propane to be continued, meaning that vehicle emissions are greatly reduced relative to gasoline or diesel fuelled vehicles. TransHelp has realized a fuel savings of 15-20 per cent over gasoline and receives an additional federal transit rebate of 15 per cent for the conversion cost.

  4. Use of Trans Fat Information on Food Labels and Its Determinants in a Multiethnic College Student Population

    Science.gov (United States)

    Jasti, Sunitha; Kovacs, Szilvia

    2010-01-01

    Objectives: To examine the correlates of trans fat knowledge and trans fat label use; to examine the influence of trans fat knowledge, trans fat label use, and dietary attitudes on intake of high trans fat food. Design: Cross-sectional survey. Setting: An urban commuter college. Subjects: Two hundred twenty-two college students. Variables…

  5. Ligand based pharmacophore modelling of anticancer histone ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... The study was carried out using the software Ligand Scout (version .... Computer Science, for his great help and support. We are also grateful to Faculty of Engineering and applied. Sciences, Mohammad .... Aided Mol. Design ...

  6. Synthesis and characterization β-ketoamine ligands

    Science.gov (United States)

    Zaid, Nurzati Amani Mohamed; Hassan, Nur Hasyareeda; Karim, Nurul Huda Abd

    2018-04-01

    β-ketoamine ligands are important members of heterodonor ligand because of their ease of preparation and modification of both steric and/or electronic effects. Complexes with β-ketoamine has received much less attention and there has been no study about this complex with β-ketoamine in ionic liquid reported. Two type of β-ketoamine ligands which are 4-amino-3-pentene-2-onato (A) and 3-amino-2-butenoic acid methyl ester (B) have been synthesized in this work. The resulting compound formed was characterized using standard spectroscopic and structural techniques which includes 1H and 13C, NMR spectroscopy and FTIR spectroscopy. The 1H and 13C NMR spectrum displayed all the expected signals with correct integration and multiplicity. And it is proved that there are some differences between two ligands as observed in NMR and FTIR spectrum.

  7. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Clouse, Katherine N; Goodrich, Jennifer S

    2006-01-01

    ...) activity has been associated with an increased prognosis of breast cancer. During cogenesis in Drosophila melanogaster local Egfr activation by the spatially-restricted TGFalpha-like ligand Gurken (Grk...

  8. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Goodrich, Jennifer S

    2005-01-01

    ...) activity has been associated with an increased prognosis of breast cancer. During oogenesis in Drosophila melanogaster, local EGFR activation by the spatially restricted TGF alpha-like ligand, Gurken (Grk...

  9. A double salt of iodobismuthate: cis-aquaiodidobis(1,10-phenanthrolinecobalt(II tris(1,10-phenanthrolinecobalt(II trans-hexa-μ2-iodido-hexaiodidotribismuthate(III

    Directory of Open Access Journals (Sweden)

    Jiongke Chen

    2011-09-01

    Full Text Available In the title complex, [Co(C12H8N23][CoI(C12H8N22(H2O][Bi3I12], conventionally abbreviated [Co(phen3][CoI(phen2(H2O][Bi3I12], where phen is 1,10-phenanthroline, the CoII atom in one cation is coordinated by six N atoms from three phen ligands in an octahedral coordination while the CoII atom in the other cation is coordinated octahedrally by four N atoms from two phen ligands, one water O atom and one I atom. In the anion, three BiIII ions adopt an octahedral coordination constructed by six I− ligands. The three BiI6 octahedra are fused together through trans face-sharing.

  10. After runaway: The trans-Hill stage of planetesimal growth

    International Nuclear Information System (INIS)

    Lithwick, Yoram

    2014-01-01

    When planetesimals begin to grow by coagulation, they first enter an epoch of runaway, during which the biggest bodies grow faster than all the others. The questions of how runaway ends and what comes next have not been answered satisfactorily. We show that runaway is followed by a new stage—the 'trans-Hill stage'—that commences when the bodies that dominate viscous stirring ('big bodies') become trans-Hill, i.e., when their Hill velocity matches the random speed of the small bodies they accrete. Subsequently, the small bodies' random speed grows in lockstep with the big bodies' sizes, such that the system remains in the trans-Hill state. Trans-Hill growth is crucial for determining the efficiency of growing big bodies, as well as their growth timescale and size spectrum. Trans-Hill growth has two sub-stages. In the earlier one, which occurs while the stirring bodies remain sufficiently small, the evolution is collisionless, i.e., collisional cooling among all bodies is irrelevant. The efficiency of forming big bodies in this collisionless sub-stage is very low, ∼10α << 1, where α ∼ 0.005(a/AU) –1 is the ratio between the physical size of a body and its Hill radius. Furthermore, the size spectrum is flat (equal mass per size decade, i.e., q = 4). This collisionless trans-Hill solution explains results from previous coagulation simulations for both the Kuiper Belt and the asteroid belt. The second trans-Hill sub-stage commences once the stirring bodies grow big enough (>α –1 × the size of the accreted small bodies). After that time, collisional cooling among small bodies controls the evolution. The efficiency of forming big bodies rises and the size spectrum becomes more top heavy. Trans-Hill growth can terminate in one of two ways, depending on the sizes of the small bodies. First, mutual accretion of big bodies can become significant and conglomeration proceeds until half of the total mass is converted into big bodies

  11. Science and trans-science in standard setting

    International Nuclear Information System (INIS)

    Majone, G.

    1984-01-01

    Standard-setting is a blending of scientific, trans-scientific, and political elements which result in a number of consequences. Health standards, for example, are influenced by biological and philosophical assumptions and scientific traditions, with the dose-response function treated as a trans-scientific question because of scientific uncertainties. Costs and benefits and other values besides health, safety, or environment also enter into the balancing of regulatory decisions and keep regulations from a purely scientific knowledge is desirable. Recommendations that industry be self-regulatory reflect a shift in emphasis from legal enforcement to information-based compliance

  12. cis–trans Isomerization of silybins A and B

    Directory of Open Access Journals (Sweden)

    Michaela Novotná

    2014-05-01

    Full Text Available Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3∙OEt2 isomerization of silybins A (1a and B (1b (trans-isomers. The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis–trans-isomerization of silybin are proposed and supported by quantum mechanical calculations.

  13. Trans women and Michfest: An ethnophenomenology of attendees' experiences.

    Science.gov (United States)

    McConnell, Elizabeth A; Odahl-Ruan, Charlynn A; Kozlowski, Christine; Shattell, Mona; Todd, Nathan R

    2016-01-01

    The rise of queer and transgender studies has greatly contributed to feminist and lesbian understandings of sex, gender, and sexuality and also has resulted in rifts, tensions, and border wars. One such tension is around the inclusion of trans women in women-only space, such as the Michigan Womyn's Music Festival (Michfest). In this ethnophenomenological study, we interviewed and surveyed 43 cisgender women who attended Michfest in 2013. Participants had a variety of perspectives on trans inclusion and on the dialogue surrounding it, and these paralleled intersections, frictions, and tensions between feminism, queer theory, and transgender studies.

  14. Selective amygdalohippocampectomy via trans-superior temporal gyrus keyhole approach.

    Science.gov (United States)

    Mathon, Bertrand; Clemenceau, Stéphane

    2016-04-01

    Hippocampal sclerosis is the most common cause of drug-resistant epilepsy amenable for surgical treatment and seizure control. The rationale of the selective amygdalohippocampectomy is to spare cerebral tissue not included in the seizure generator. Describe the selective amygdalohippocampectomy through the trans-superior temporal gyrus keyhole approach. Selective amygdalohippocampectomy for temporal lobe epilepsy is performed when the data (semiology, neuroimaging, electroencephalography) point to the mesial temporal structures. The trans-superior temporal gyrus keyhole approach is a minimally invasive and safe technique that allows disconnection of the temporal stem and resection of temporomesial structures.

  15. A "Trans-Dyadic" Perspective on the Goldwater Rule.

    Science.gov (United States)

    Plakun, Eric M

    2017-11-01

    The Goldwater Rule has been debated, redefined, and debated further since the election of Donald Trump as President of the United States. This column offers a perspective on the Goldwater Rule that moves beyond psychiatry's current preoccupation with precision DSM-5 diagnosis of individuals, which ethically requires consent or other legal authorization for release of diagnostic information to others, and into the realm of leadership as seen through the "trans-dyadic" lens of psychoanalytic understanding of large group processes on a societal level. Concepts from large group psychology are introduced to illustrate "trans-dyadic" perspectives on leadership that do not challenge the Goldwater Rule.

  16. Trans-dinitroglycoluril isomers-A DFT treatment

    Directory of Open Access Journals (Sweden)

    Lemi Türker

    2017-02-01

    Full Text Available Isomers of trans-1,4-Dinitroglycoluril (trans-DINGU and their 1,3-tautomers are considered within the constraints of B3LYP/6-31++G (d,p and B3LYP/CC-PVTZ levels of DFT calculations. Additionally, the interactions of these isomers and proton in vacuum are investigated. The data have revealed that two of the three isomers undergo CH bond cleavage as the result of interaction with proton in vacuum. The total energies, some structural properties, the calculated IR and UV spectra are discussed.

  17. Trans- and cis-2-phenylindole platinum(II) complexes as cytotoxic agents against human breast adenocarcinoma cell lines

    Science.gov (United States)

    Tomé, Maria; López, Concepción; González, Asensio; Ozay, Bahadir; Quirante, Josefina; Font-Bardía, Mercè; Calvet, Teresa; Calvis, Carme; Messeguer, Ramon; Baldomá, Laura; Badía, Josefa

    2013-09-01

    The synthesis and characterization of the new 2-phenylindole derivative: C8H3N-2-C6H5-3NOMe-5OMe (3c) and the trans- and cis-isomers of [Pt(3c)Cl2(DMSO)] complexes (4c and 5c, respectively) are described. The crystal structures of 4c·CH2Cl2 and 5c confirm: (a) the existence of a Pt-Nindole bond, (b) the relative arrangement of the Cl- ligands [trans- (in 4c) or cis- (in 5c)] and (c) the anti-(E) configuration of the oxime. The cytotoxic assessment of C8H3N-2-(C6H4-4‧R1)-3NOMe-5R2 [with R1 = R2 = H (3a); R1 = Cl, R2 = H (3b) and R1 = H, R2 = OMe (3c)] and the geometrical isomers of [Pt(L)Cl2(DMSO)] with L = 3a-3c [trans- (4a-4c) and cis- (5a-5c), respectively] against human breast adenocarcinoma cell lines (MDA-MB231 and MCF-7) is also reported and reveals that all the platinum(II) complexes (except 4a) are more cytotoxic than cisplatin in front of the MCF7 cell line. Electrophoretic DNA migration studies of the synthesized compounds in the absence and in the presence of topoisomerase-I have been performed, in order to get further insights into their mechanism of action.

  18. Cell-specific targeting by heterobivalent ligands.

    Science.gov (United States)

    Josan, Jatinder S; Handl, Heather L; Sankaranarayanan, Rajesh; Xu, Liping; Lynch, Ronald M; Vagner, Josef; Mash, Eugene A; Hruby, Victor J; Gillies, Robert J

    2011-07-20

    Current cancer therapies exploit either differential metabolism or targeting to specific individual gene products that are overexpressed in aberrant cells. The work described herein proposes an alternative approach--to specifically target combinations of cell-surface receptors using heteromultivalent ligands ("receptor combination approach"). As a proof-of-concept that functionally unrelated receptors can be noncovalently cross-linked with high avidity and specificity, a series of heterobivalent ligands (htBVLs) were constructed from analogues of the melanocortin peptide ligand ([Nle(4), dPhe(7)]-α-MSH) and the cholecystokinin peptide ligand (CCK-8). Binding of these ligands to cells expressing the human Melanocortin-4 receptor and the Cholecystokinin-2 receptor was analyzed. The MSH(7) and CCK(6) were tethered with linkers of varying rigidity and length, constructed from natural and/or synthetic building blocks. Modeling data suggest that a linker length of 20-50 Å is needed to simultaneously bind these two different G-protein coupled receptors (GPCRs). These ligands exhibited up to 24-fold enhancement in binding affinity to cells that expressed both (bivalent binding), compared to cells with only one (monovalent binding) of the cognate receptors. The htBVLs had up to 50-fold higher affinity than that of a monomeric CCK ligand, i.e., Ac-CCK(6)-NH(2). Cell-surface targeting of these two cell types with labeled heteromultivalent ligand demonstrated high avidity and specificity, thereby validating the receptor combination approach. This ability to noncovalently cross-link heterologous receptors and target individual cells using a receptor combination approach opens up new possibilities for specific cell targeting in vivo for therapy or imaging.

  19. High-pressure phase equilibrium data for systems with carbon dioxide, α-humulene and trans-caryophyllene

    International Nuclear Information System (INIS)

    Michielin, Eliane M.Z.; Rosso, Sibele R.; Franceschi, Elton; Borges, Gustavo R.; Corazza, Marcos L.; Oliveira, J. Vladimir; Ferreira, Sandra R.S.

    2009-01-01

    The aim of this work is to report phase equilibrium data for the binary systems (CO 2 + α-humulene) and (CO 2 + trans-caryophyllene), and for the ternary system (CO 2 + α-humulene + trans-caryophyllene). Results from literature show that α-humulene and trans-caryophyllene are the main compounds responsible for the anti-inflammatory and anti-allergic characteristics attributed to the medicinal plant Cordia verbenacea D.C., hence giving importance to the phase behaviour investigation performed in this work. Phase equilibrium experiments were performed in a high-pressure, variable-volume view cell over the temperature range of T = (303 to 343) K and pressures up to 20 MPa. (Liquid + liquid) and (vapour + liquid + liquid) equilibrium were observed at T = 303 K, while (vapour + liquid) phase transitions were verified to occur from T = (313 to 343) K, for all systems studied. Thermodynamic modelling was performed using the Peng-Robinson equation of state and the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values

  20. High-pressure phase equilibrium data for systems with carbon dioxide, {alpha}-humulene and trans-caryophyllene

    Energy Technology Data Exchange (ETDEWEB)

    Michielin, Eliane M.Z.; Rosso, Sibele R [EQA/UFSC, Chemical and Food Engineering Department, Federal University of Santa Catarina, C.P. 476, CEP 88040-900, Florianopolis, SC (Brazil); Franceschi, Elton; Borges, Gustavo R; Corazza, Marcos L; Oliveira, J Vladimir [Department of Food Engineering, URI - Campus de Erechim, Av. Sete de Setembro, 1621, Erechim, RS, 99700-000 (Brazil); Ferreira, Sandra R.S. [EQA/UFSC, Chemical and Food Engineering Department, Federal University of Santa Catarina, C.P. 476, CEP 88040-900, Florianopolis, SC (Brazil)], E-mail: sandra@enq.ufsc.br

    2009-01-15

    The aim of this work is to report phase equilibrium data for the binary systems (CO{sub 2} + {alpha}-humulene) and (CO{sub 2} + trans-caryophyllene), and for the ternary system (CO{sub 2} + {alpha}-humulene + trans-caryophyllene). Results from literature show that {alpha}-humulene and trans-caryophyllene are the main compounds responsible for the anti-inflammatory and anti-allergic characteristics attributed to the medicinal plant Cordia verbenacea D.C., hence giving importance to the phase behaviour investigation performed in this work. Phase equilibrium experiments were performed in a high-pressure, variable-volume view cell over the temperature range of T = (303 to 343) K and pressures up to 20 MPa. (Liquid + liquid) and (vapour + liquid + liquid) equilibrium were observed at T = 303 K, while (vapour + liquid) phase transitions were verified to occur from T = (313 to 343) K, for all systems studied. Thermodynamic modelling was performed using the Peng-Robinson equation of state and the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values.

  1. DETERMINATION OF MIXED STABILITY CONSTANTS OF LEAD(II ...

    African Journals Online (AJOL)

    A method involving the use of paper ionophoresis is described for the study of equilibria in mixedligand complex systems in solution. The technique is based on the movement of a spot of metal ion under an electric field with the complexants added to the background electrolyte at pH 8.5. The stability constants of the ...

  2. Complexation of biological ligands with lanthanides(III) for MRI: Structure, thermodynamic and methods; Complexation des cations lanthanides trivalents par des ligands d'origine biologique pour l'IRM: Structure, thermodynamique et methodes

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C

    2006-07-15

    New cyclic ligands derived from sugars and amino-acids form a scaffold carrying a coordination sphere of oxygen atoms suitable to complex Ln(III) ions. In spite of their rather low molecular weights, the complexes display surprisingly high relaxivity values, especially at high field. The ACX and BCX ligands, which are acidic derivatives of modified and cyclo-dextrins, form mono and bimetallic complexes with Ln(III). The LnACX and LnBCX complexes show affinities towards Ln(III) similar to those of tri-acidic ligands. In the bimetallic Lu2ACX complex, the cations are deeply embedded in the cavity of the ligand, as shown by the X-ray structure. In aqueous solution, the number of water molecules coordinated to the cation in the LnACX complex depends on the nature and concentration of the alkali ions of the supporting electrolyte, as shown by luminescence and relaxometric measurements. There is only one water molecule coordinated in the LnBCX complex, which enables us to highlight an important second sphere contribution to relaxivity. The NMR study of the RAFT peptidic ligand shows the complexation of Ln(III), with an affinity similar to those of natural ligands derived from calmodulin. The relaxometric study also shows an important second sphere contribution to relaxivity. To better understand the intricate molecular factors affecting relaxivity, we developed new relaxometric methods based on probe solutes. These methods allow us to determine the charge of the complex, weak affinity constants, trans-metallation constants, and the electronic relaxation rate. (author)

  3. Complexation of biological ligands with lanthanides(III) for MRI: Structure, thermodynamic and methods; Complexation des cations lanthanides trivalents par des ligands d'origine biologique pour l'IRM: Structure, thermodynamique et methodes

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C

    2006-07-15

    New cyclic ligands derived from sugars and amino-acids form a scaffold carrying a coordination sphere of oxygen atoms suitable to complex Ln(III) ions. In spite of their rather low molecular weights, the complexes display surprisingly high relaxivity values, especially at high field. The ACX and BCX ligands, which are acidic derivatives of modified and cyclo-dextrins, form mono and bimetallic complexes with Ln(III). The LnACX and LnBCX complexes show affinities towards Ln(III) similar to those of tri-acidic ligands. In the bimetallic Lu2ACX complex, the cations are deeply embedded in the cavity of the ligand, as shown by the X-ray structure. In aqueous solution, the number of water molecules coordinated to the cation in the LnACX complex depends on the nature and concentration of the alkali ions of the supporting electrolyte, as shown by luminescence and relaxometric measurements. There is only one water molecule coordinated in the LnBCX complex, which enables us to highlight an important second sphere contribution to relaxivity. The NMR study of the RAFT peptidic ligand shows the complexation of Ln(III), with an affinity similar to those of natural ligands derived from calmodulin. The relaxometric study also shows an important second sphere contribution to relaxivity. To better understand the intricate molecular factors affecting relaxivity, we developed new relaxometric methods based on probe solutes. These methods allow us to determine the charge of the complex, weak affinity constants, trans-metallation constants, and the electronic relaxation rate. (author)

  4. Semiconductor Quantum Dots with Photoresponsive Ligands.

    Science.gov (United States)

    Sansalone, Lorenzo; Tang, Sicheng; Zhang, Yang; Thapaliya, Ek Raj; Raymo, Françisco M; Garcia-Amorós, Jaume

    2016-10-01

    Photochromic or photocaged ligands can be anchored to the outer shell of semiconductor quantum dots in order to control the photophysical properties of these inorganic nanocrystals with optical stimulations. One of the two interconvertible states of the photoresponsive ligands can be designed to accept either an electron or energy from the excited quantum dots and quench their luminescence. Under these conditions, the reversible transformations of photochromic ligands or the irreversible cleavage of photocaged counterparts translates into the possibility to switch luminescence with external control. As an alternative to regulating the photophysics of a quantum dot via the photochemistry of its ligands, the photochemistry of the latter can be controlled by relying on the photophysics of the former. The transfer of excitation energy from a quantum dot to a photocaged ligand populates the excited state of the species adsorbed on the nanocrystal to induce a photochemical reaction. This mechanism, in conjunction with the large two-photon absorption cross section of quantum dots, can be exploited to release nitric oxide or to generate singlet oxygen under near-infrared irradiation. Thus, the combination of semiconductor quantum dots and photoresponsive ligands offers the opportunity to assemble nanostructured constructs with specific functions on the basis of electron or energy transfer processes. The photoswitchable luminescence and ability to photoinduce the release of reactive chemicals, associated with the resulting systems, can be particularly valuable in biomedical research and can, ultimately, lead to the realization of imaging probes for diagnostic applications as well as to therapeutic agents for the treatment of cancer.

  5. Designer TGFβ superfamily ligands with diversified functionality.

    Directory of Open Access Journals (Sweden)

    George P Allendorph

    Full Text Available Transforming Growth Factor--beta (TGFβ superfamily ligands, including Activins, Growth and Differentiation Factors (GDFs, and Bone Morphogenetic Proteins (BMPs, are excellent targets for protein-based therapeutics because of their pervasiveness in numerous developmental and cellular processes. We developed a strategy termed RASCH (Random Assembly of Segmental Chimera and Heteromer, to engineer chemically-refoldable TGFβ superfamily ligands with unique signaling properties. One of these engineered ligands, AB208, created from Activin-βA and BMP-2 sequences, exhibits the refolding characteristics of BMP-2 while possessing Activin-like signaling attributes. Further, we find several additional ligands, AB204, AB211, and AB215, which initiate the intracellular Smad1-mediated signaling pathways more strongly than BMP-2 but show no sensitivity to the natural BMP antagonist Noggin unlike natural BMP-2. In another design, incorporation of a short N-terminal segment from BMP-2 was sufficient to enable chemical refolding of BMP-9, without which was never produced nor refolded. Our studies show that the RASCH strategy enables us to expand the functional repertoire of TGFβ superfamily ligands through development of novel chimeric TGFβ ligands with diverse biological and clinical values.

  6. LigandRFs: random forest ensemble to identify ligand-binding residues from sequence information alone

    KAUST Repository

    Chen, Peng

    2014-12-03

    Background Protein-ligand binding is important for some proteins to perform their functions. Protein-ligand binding sites are the residues of proteins that physically bind to ligands. Despite of the recent advances in computational prediction for protein-ligand binding sites, the state-of-the-art methods search for similar, known structures of the query and predict the binding sites based on the solved structures. However, such structural information is not commonly available. Results In this paper, we propose a sequence-based approach to identify protein-ligand binding residues. We propose a combination technique to reduce the effects of different sliding residue windows in the process of encoding input feature vectors. Moreover, due to the highly imbalanced samples between the ligand-binding sites and non ligand-binding sites, we construct several balanced data sets, for each of which a random forest (RF)-based classifier is trained. The ensemble of these RF classifiers forms a sequence-based protein-ligand binding site predictor. Conclusions Experimental results on CASP9 and CASP8 data sets demonstrate that our method compares favorably with the state-of-the-art protein-ligand binding site prediction methods.

  7. Trans people's experiences with assisted reproduction services: a qualitative study.

    Science.gov (United States)

    James-Abra, S; Tarasoff, L A; Green, D; Epstein, R; Anderson, S; Marvel, S; Steele, L S; Ross, L E

    2015-06-01

    What are the experiences of trans persons (i.e. those whose gender identity does not match the gender assigned to them at birth) who sought or accessed assisted reproduction (AR) services in Ontario, Canada, between 2007 and 2010? The majority of trans persons report negative experiences with AR service providers. Apart from research examining desire to have children among trans people, most of the literature on this topic has debated the ethics of assisting trans persons to become parents. To-date, all of the published research concerning trans persons' experiences with AR services is solely from the perspective of service providers; no studies have examined the experiences of trans people themselves. Secondary qualitative research study of data from nine trans-identified people and their partners (total n = 11) collected as part of a community-based study of access to AR services for sexual and gender minority people between 2010 and 2012. Trans-identified volunteers (and their partners, when applicable) who had used or attempted to access AR services since 2007 from across Ontario, Canada, participated in a 60-90 minute, semi-structured qualitative interview. Qualitative analysis was performed using a descriptive phenomenological approach. Emerging themes were continually checked against the data as part of an iterative process. The data highlight barriers to accessing AR services for trans people. Participant recommendations for improving AR service provision to better meet the needs of this population are presented. These recommendations address the following areas: (i) AR service provider education and training; (ii) service provider and clinic practices and (iii) clinic environment. The majority of study participants were trans people who identified as men and who resided in major urban areas; those living in smaller communities may have different experiences that were not adequately captured in this analysis. While existing literature debates the ethics of

  8. trans-Bis(methanol-κObis(quinoline-2-carboxylato-κ2N,Omanganese(II

    Directory of Open Access Journals (Sweden)

    Lucjan B. Jerzykiewicz

    2008-11-01

    Full Text Available The title compound, [Mn(C10H6NO22(CH4O2], was obtained unintentionally as the product of an attempt to synthesize a polynuclear carboxylate bridged manganese(III/IV complex, using methanol to reduce the permanganate ion. The molecule is centrosymmetric; the pairs of equivalent ligands coordinate trans to each other in a distorted octahedral geometry. Intramolecular C—H...O bonds lying in the equatorial plane stabilize the molecule. In the crystal, molecules are linked by O—H...O and C—H...O hydrogen bonds, creating a three-dimensional supramolecular structure. π–π and C—H...π interactions are also observed. The dihedral angle and centroid-to-centroid distance between the pyridine ring (A and the benzene ring (Bi of a symmetrically related molecule [symmetry code: (i −1 − x, −y, −z] are 1.27 (11° and 3.974 (2 Å, respectively. For the C—H...π interactions, the relevant distances and angles are: C...Cg[Aii] = 3.643 (2 Å, H...Cg[Aii] = 2.750 (2 Å and C—H...Cg[Aii] = 155 (1° [symmetry code: (ii x, −1 + y, z].

  9. Parameters and characteristics governing cellular internalization and trans-barrier trafficking of nanostructures

    Directory of Open Access Journals (Sweden)

    Murugan K

    2015-03-01

    Full Text Available Karmani Murugan, Yahya E Choonara, Pradeep Kumar, Divya Bijukumar, Lisa C du Toit, Viness Pillay Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa Abstract: Cellular internalization and trans-barrier transport of nanoparticles can be manipulated on the basis of the physicochemical and mechanical characteristics of nanoparticles. Research has shown that these factors significantly influence the uptake of nanoparticles. Dictating these characteristics allows for the control of the rate and extent of cellular uptake, as well as delivering the drug-loaded nanosystem intra-cellularly, which is imperative for drugs that require a specific cellular level to exert their effects. Additionally, physicochemical characteristics of the nanoparticles should be optimal for the nanosystem to bypass the natural restricting phenomena of the body and act therapeutically at the targeted site. The factors at the focal point of emerging smart nanomedicines include nanoparticle size, surface charge, shape, hydrophobicity, surface chemistry, and even protein and ligand conjugates. Hence, this review discusses the mechanism of internalization of nanoparticles and ideal nanoparticle characteristics that allow them to evade the biological barriers in order to achieve optimal cellular uptake in different organ systems. Identifying these parameters assists with the progression of nanomedicine as an outstanding vector of pharmaceuticals. Keywords: nanoparticles, transport mechanisms, cellular uptake, size, shape, charge

  10. Racemic cobalt phosphonates incorporating flexible bis(imidazole) co-ligands.

    Science.gov (United States)

    Feng, Jian-Shen; Cai, Zhong-Sheng; Ren, Min; Bao, Song-Song; Zheng, Li-Min

    2015-11-07

    By incorporating flexible bis(imidazol-1-ylmethyl)benzene (bix) co-ligands, four new racemic cobalt phosphonates with formulae Co3(3-ppap)2(1,4-bix)2(H2O)4·4H2O (1), Co3(3-ppap)2(1,3-bix)2(H2O)4·5H2O (2), Co3(3-ppap)2(1,2-bix)2(H2O)4·4H2O (3) and Co3(ppa)2(1,2-bix)2·4H2O (4) are isolated, where 3-ppapH3 represents 3-phenyl-3-((phosphonomethyl)amino)propanoic acid and ppaH3 is 2-phenyl-2-(phosphonomethylamino)acetic acid. Compounds 1-3 crystallize in the monoclinic space group P21/c and show two-dimensional structures in which the Co3(3-ppap)2 chains are bridged by 1,4-bix, 1,3-bix and 1,2-bix ligands in trans-modes, respectively. Within the chain, a racemic dimer of Co2(3-ppap)2(2-) is found, where the Co atoms are doubly bridged by O-P-O units from the (S)- and (R)-3-ppap(3-) ligands. The dimers are connected by another crystallographically independent Co atom through O-P-O linkages to form an infinite racemic chain. The packing modes of the layers in 1-3 are quite different, however, which are ABAB in the cases of 1 and 3 while ABCDABCD in the case of 2, attributed to the positional isomerism of the bix co-ligands. Compound 4 displays a chain structure in which the 1,2-bix bridges the Co atoms in cis-mode within the chain. Magnetic properties are investigated for all compounds.

  11. Context-Dependent Functional Divergence of the Notch Ligands DLL1 and DLL4 In Vivo.

    Directory of Open Access Journals (Sweden)

    Kristina Preuße

    2015-06-01

    Full Text Available Notch signalling is a fundamental pathway that shapes the developing embryo and sustains adult tissues by direct communication between ligand and receptor molecules on adjacent cells. Among the ligands are two Delta paralogues, DLL1 and DLL4, that are conserved in mammals and share a similar structure and sequence. They activate the Notch receptor partly in overlapping expression domains where they fulfil redundant functions in some processes (e.g. maintenance of the crypt cell progenitor pool. In other processes, however, they appear to act differently (e.g. maintenance of foetal arterial identity raising the questions of how similar DLL1 and DLL4 really are and which mechanism causes the apparent context-dependent divergence. By analysing mice that conditionally overexpress DLL1 or DLL4 from the same genomic locus (Hprt and mice that express DLL4 instead of DLL1 from the endogenous Dll1 locus (Dll1Dll4ki, we found functional differences that are tissue-specific: while DLL1 and DLL4 act redundantly during the maintenance of retinal progenitors, their function varies in the presomitic mesoderm (PSM where somites form in a Notch-dependent process. In the anterior PSM, every cell expresses both Notch receptors and ligands, and DLL1 is the only activator of Notch while DLL4 is not endogenously expressed. Transgenic DLL4 cannot replace DLL1 during somitogenesis and in heterozygous Dll1Dll4ki/+ mice, the Dll1Dll4ki allele causes a dominant segmentation phenotype. Testing several aspects of the complex Notch signalling system in vitro, we found that both ligands have a similar trans-activation potential but that only DLL4 is an efficient cis-inhibitor of Notch signalling, causing a reduced net activation of Notch. These differential cis-inhibitory properties are likely to contribute to the functional divergence of DLL1 and DLL4.

  12. Biscoitos recheados: quanto mais baratos maior teor de gordura trans? = Filled cookies: the cheaper the higher trans fat content?

    OpenAIRE

    Galdino, Tatiana Pizzato

    2010-01-01

    Objetivos: identificar a quantidade de gorduras totais, saturadas e trans descritas nos rótulos de biscoitos recheados e verificar se existe associação entre o preço e a quantidade de gorduras trans Métodos: a amostra foi composta por 25 pacotes de biscoitos recheados de diferentes tipos e marcas, copiando-se de cada rótulo as informações necessárias. Para análise dos resultados foram efetuados cálculos de estatística descritiva, análise de variância e correlação de Spearmann Resultados...

  13. Exploración estocástica de las superficies de energía potencial de dímeros cis-trans y trans-trans del ácido fórmico

    Directory of Open Access Journals (Sweden)

    Said F. Figueredo

    2014-01-01

    Full Text Available Potential energy surface (PES of cis-trans and trans-trans formic acid dimers were sampled using a stochastic method, and the geometries, energies, and vibrational frequencies were computed at B3LYP/6-311++G(3df,2p level of theory. The results show that molar free energy of dimerization deviated up to 108.4% when basis set superposition error (BSSE and zero-point energy (ZPE were not considered. For cis-trans dimers, C=O and O - H bond weakened, whereas C - O bonds strengthened due to dimerization. Also, trans-trans FA dimers did not show a trend regarding strengthening or weakening of the C=O, O - H and C - O bonds.

  14. Trans-sinusoidal maxillary distraction in three cleft patients.

    NARCIS (Netherlands)

    Wenghoefer, M.H.; Martini, M.; Nadjmi, N.; Schutyser, F.A.C.; Jagtman, A.K.; Bergé, S.J.

    2006-01-01

    The trans-sinusoidal maxillary distractor (TS-MD) was used to achieve maxillary advancement in three patients with repaired cleft lip and palate. After preoperative computer-aided planning of the distraction vectors, each TS-MD was bent on a stereolithographic model of the maxilla of the patient.

  15. Transient nerve damage following intubation for trans-sphenoidal hypophysectomy

    NARCIS (Netherlands)

    Evers, KA; Eindhoven, GB; Wierda, JMKH

    1999-01-01

    Purpose: To describe a case of transient lingual and hypoglossal nerve damage following intubation for a transsphenoidal hypophysectomy. Clinical features: A 56-yr-old acromegalic man was scheduled for trans-sphenoidal hypophysectomy. He had been treated with octreotide six months previously which

  16. transPLANT Resources for Triticeae Genomic Data

    Directory of Open Access Journals (Sweden)

    Manuel Spannagl

    2016-03-01

    Full Text Available The genome sequences of many important Triticeae species, including bread wheat ( L. and barley ( L., remained uncharacterized for a long time because their high repeat content, large sizes, and polyploidy. As a result of improvements in sequencing technologies and novel analyses strategies, several of these have recently been deciphered. These efforts have generated new insights into Triticeae biology and genome organization and have important implications for downstream usage by breeders, experimental biologists, and comparative genomicists. transPLANT ( is an EU-funded project aimed at constructing hardware, software, and data infrastructure for genome-scale research in the life sciences. Since the Triticeae data are intrinsically complex, heterogenous, and distributed, the transPLANT consortium has undertaken efforts to develop common data formats and tools that enable the exchange and integration of data from distributed resources. Here we present an overview of the individual Triticeae genome resources hosted by transPLANT partners, introduce the objectives of transPLANT, and outline common developments and interfaces supporting integrated data access.

  17. FDA Developments: Food Code 2013 and Proposed Trans Fat Determination

    NARCIS (Netherlands)

    Grossman, M.R.

    2014-01-01

    268 Reports EFFL 4|2014 USA FDA Developments: Food Code 2013 and Proposed Trans Fat Determination Margaret Rosso Grossman* I. Food Code 2013 and Food Code Reference System Since 1993, the US Food and Drug Administration has published a Food Code, now updated every four years. In November 2013, the

  18. Triplet State Resonance Raman Spectrum of all-trans-diphenylbutadiene

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Grossman, W.E.L.; Killough, P.M

    1984-01-01

    The resonance Raman spectrum of all-trans-diphenylbutadiene (DPB) in its ground state and the resonance Raman spectrum (RRS) of DPB in its short-lived electronically excited triplet state are reported. Transient spectra were obtained by a pump-probe technique using two pulsed lasers...

  19. Endoscopic trans-sphenoidal drainage of petrous apex cholesterol ...

    African Journals Online (AJOL)

    Cholesterol granulomas of the petrous apex are rare lesions that pose challenging surgical decisions and approaches when attempting surgical drainage. In this article we present 2 cases of successful surgical management using an endoscopic trans-sphenoidal approach and review the requirements and considerations ...

  20. Trans-umbilical Laparoscopic Appendectomy for Acute Appendicitis ...

    African Journals Online (AJOL)

    Trans-umbilical Laparoscopic Appendectomy for Acute Appendicitis without Raising Skin-flaps: An Easy-to-use Modification Applied to the Series of 164 Patients from a Rural Institute of Central India. Priyadarshan Anand Jategaonkar, Sudeep Pradeep Yadav1. INTRODUCTION. Laparoscopic appendectomy (LA) is widely ...