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Sample records for donor semicarbazone ligand

  1. Expanding the family of heteroleptic oxidovanadium(IV) compounds with salicylaldehyde semicarbazones and polypyridyl ligands showing anti-Trypanosoma cruzi activity.

    Science.gov (United States)

    Scalese, Gonzalo; Benítez, Julio; Rostán, Santiago; Correia, Isabel; Bradford, Lara; Vieites, Marisol; Minini, Lucía; Merlino, Alicia; Coitiño, E Laura; Birriel, Estefania; Varela, Javier; Cerecetto, Hugo; González, Mercedes; Pessoa, João Costa; Gambino, Dinorah

    2015-06-01

    Searching for prospective vanadium-based drugs for the treatment of Chagas disease, a new series of heteroleptic [V(IV)O(L-2H)(NN)] compounds was developed by including the lipophilic 3,4,7,8-tetramethyl-1,10-phenanthroline (tmp) NN ligand and seven tridentate salicylaldehyde semicarbazone derivatives (L1-L7). The compounds were characterized in the solid state and in solution. EPR spectroscopy suggests that the NN ligand is bidentate bound through both nitrogen donor atoms in an axial-equatorial mode. The EPR and (51)V-NMR spectra of aerated solutions at room temperature indicate that the compounds are stable to hydrolysis and that no significant oxidation of V(IV) to V(V) takes place at least in 24h. The complexes are more active in vitro against Trypanosoma cruzi, the parasite responsible for Chagas disease, than the reference drug Nifurtimox and most of them are more active than previously reported [V(IV)O(L-2H)(NN)] complexes of other NN co-ligands. Selectivity towards the parasite was analyzed using J-774 murine macrophages as mammalian cell model. Due to both, high activity and high selectivity, L2, L4, L5 and L7 complexes could be considered new hits for further drug development. Lipophilicity probably plays a relevant role in the bioactivity of the new compounds. The [V(IV)O(L-2H)(NN)] compounds were designed aiming DNA as potential molecular target. Therefore, the novel L1-L7 tmp complexes were screened by computational modeling, comparing their DNA-binding features with those of previously reported [V(IV)O(L-2H)(NN)] compounds with different NN co-ligands. Whereas all the complexes interact well with DNA, with binding modes and strength tuned in different extents by the NN and semicarbazone co-ligands, molecular docking suggests that the observed anti-T. cruzi activity cannot be explained upon DNA intercalation as the sole mechanism of action. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Template synthesis of two new supramolecular zinc(II) complexes containing pentadentate N3O2 semicarbazone ligand: Nanostructure synthesis, Hirshfeld surface analysis, and DFT studies

    Science.gov (United States)

    Tyula, Yunes Abbasi; Zabardasti, Abedien; Goudarziafshar, Hamid; Roudsari, Majid Sadeghi; Dusek, Michal; Eigner, Vaclav

    2017-12-01

    Two new zinc(II) complexes, [Zn(H2dapsc) (CH3OH)2][ZnBr2Cl2] (1) and [Zn(H2dapsc) (CH3OH)Br]Br.(CH3OH) (2), where H2dapsc is 2,6-diacetylpyridine bis(semicarbazone), were synthesized using a template method in which the pentadentate N3O2 semicarbazone ligand derived from [1 + 2] condensation of 2,6-diacetylpyridine and semicarbazide in the presence of zinc(II) ion as template agent. These compounds were characterized by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. Their single crystal X-ray structures showed that in both complex cations, the metal center has a distorted pentagonal-bipyramidal geometry in which the semicarbazone (H2dapsc) ligand occupies the equatorial plane, while the axial positions occupy by two methanol ligands in (1) and two bromo and methanol ligands in (2). Furthermore, the impact of the close intermolecular contacts on the crystal packing of (1) and (2) have been further studied using Hirshfeld surface analysis. Density Functional Theory (DFT) method was applied for the calculation of HOMO-LUMO energy gap, atomic charges and vibrational frequencies of title complexes. Moreover, the nanostructure of zinc complex was synthesized by a sonochemical method and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy, and elemental analysis.

  3. Ni(II, Pd(II and Pt(II complexes with ligand containing thiosemicarbazone and semicarbazone moiety: synthesis, characterization and biological investigation

    Directory of Open Access Journals (Sweden)

    SULEKH CHANDRA

    2008-07-01

    Full Text Available The synthesis of nickel(II, palladium(II and platinum(II complexes with thiosemicarbazone and semicarbazone of p-tolualdehyde are reported. All the new compounds were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, 1H-NMR, IR and electronic spectral studies. Based on the molar conductance measurements in DMSO, the complexes may be formulated as [Ni(L2Cl2] and [M(L2]Cl2 (where M = Pd(II and Pt(II due to their non-electrolytic and 1:2 electrolytic nature, respectively. The spectral data are consistent with an octahedral geometry around Ni(II and a square planar geometry for Pd(II and Pt(II, in which the ligands act as bidentate chelating agents, coordinated through the nitrogen and sulphur/oxygen atoms. The ligands and their metal complexes were screened in vitro against fungal species Alternaria alternata, Aspergillus niger and Fusarium odum, using the food poison technique.

  4. Lanthanide(III) complexes of bis-semicarbazone and bis-imine-substituted phenanthroline ligands: solid-state structures, photophysical properties, and anion sensing.

    Science.gov (United States)

    Nadella, Sandeep; Selvakumar, Paulraj M; Suresh, Eringathodi; Subramanian, Palani S; Albrecht, Markus; Giese, Michael; Fröhlich, Roland

    2012-12-21

    Phenanthroline-based hexadentate ligands L(1) and L(2) bearing two achiral semicarbazone or two chiral imine moieties as well as the respective mononuclear complexes incorporating various lanthanide ions, such as La(III), Eu(III), Tb(III), Lu(III), and Y(III) metal ions, were synthesized, and the crystal structures of [ML(1)Cl(3)] (M=La(III), Eu(III), Tb(III), Lu(III), or Y(III)) complexes were determined. Solvent or water molecules act as coligands for the rare-earth metals in addition to halide anions. The big Ln(III) ion exhibits a coordination number (CN) of 10, whereas the corresponding Eu(III), Tb(III), Lu(III), and Y(III) centers with smaller ionic radii show CN=9. Complexes of L(2), namely [ML(2)Cl(3)] (M=Eu(III), Tb(III), Lu(III), or Y(III)) ions could also be prepared. Only the complex of Eu(III) showed red luminescence, whereas all the others were nonluminescent. The emission properties of the Eu derivative can be applied as a photophysical signal for sensing various anions. The addition of phosphate anions leads to a unique change in the luminescence behavior. As a case study, the quenching behavior of adenosine-5'-triphosphate (ATP) was investigated at physiological pH value in an aqueous solvent. A specificity of the sensor for ATP relative to adenosine-5'-diphosphate (ADP) and adenosine-5'-monophosphate (AMP) was found. (31)P NMR spectroscopic studies revealed the formation of a [EuL(2)(ATP)] coordination species. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Syntheses, crystal structures and antimicrobial activities of 6-coordinate antimony(III) complexes with tridentate 2-acetylpyridine thiosemicarbazone, bis(thiosemicarbazone) and semicarbazone ligands.

    Science.gov (United States)

    Kasuga, Noriko Chikaraishi; Onodera, Kuniaki; Nakano, Saori; Hayashi, Kunihiko; Nomiya, Kenji

    2006-07-01

    Five novel antimony(III) complexes with the mono- and bis(thiosemicarbazone) ligands of 2N1S or 4N2S donor atoms, N'-[1-(2-pyridyl)ethylidene]morpholine-4-carbothiohydrazide (Hmtsc, L1) and bis[N'-[1-(2-pyridyl)ethylidene

  6. and Tetradentate N,O-donor Ligands

    African Journals Online (AJOL)

    NICO

    )], derived from the oxidation reactions (by O2) of trans-[ReCl3(MeCN)(PPh3)2] with the tridentate N2O-donor chelate 2-[((2-pyridinylmethyl)amino)methyl]phenol (Hham) and the N2O2-donor N,N-bis(2-hydroxybenzyl)-aminomethyl- pyridine ...

  7. (E-1-Phenylethanone semicarbazone

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2009-08-01

    Full Text Available In the title compound, C9H11N3O, the benzene ring is disordered over two positions with refined occupancies of 0.922 (5 and 0.078 (5. The program PLATON [Spek (2009. Acta Cryst. D65, 148–155] recommends the solution in the space group C2/m with a = 7.3050 (3, b = 6.6745 (2, c = 18.3853 (6 Å and β = 96.986 (2°. However, the large number of non-extinct reflections needed to be ignored if C2/m is chosen suggested that the space group is incorrect, even though the R values are lower than that for P21/c. The semicarbazone group is essentially planar, with a maximum deviation of 0.046 (1 Å for one of the N atoms. The mean plane of the semicarbazone group forms dihedral angles of 33.61 (8 and 39.1 (9° with the benzene ring of the major and minor components, respectively. In the crystal structure, molecules are linked by intermolecular N—H...O hydrogen bonds into extended chains along the c axis. The crystal structure is further stabilized by weak intermolucular C—H...π interactions.

  8. Synthesis, spectral characterization and structural studies of a novel O, N, O donor semicarbazone and its binuclear copper complex with hydrogen bond stabilized lattice

    Science.gov (United States)

    Layana, S. R.; Saritha, S. R.; Anitha, L.; Sithambaresan, M.; Sudarsanakumar, M. R.; Suma, S.

    2018-04-01

    A novel O,N,O donor salicylaldehyde-N4-phenylsemicarbazone, (H2L) has been synthesized and physicochemically characterized. Detailed structural studies of H2L using single crystal X-ray diffraction technique reveals the existence of intra and inter molecular hydrogen bonding interactions, which provide extra stability to the molecule. We have successfully synthesized a binuclear copper(II) complex, [Cu2(HL)2(NO3)(H2O)2]NO3 with phenoxy bridging between the two copper centers. The complex was characterized by elemental analysis, magnetic susceptibility and conductivity measurements, FT-IR, UV-Visible, mass and EPR spectral methods. The grown crystals of the copper complex were employed for the single crystal X-ray diffraction studies. The complex possesses geometrically different metal centers, in which the ligand coordinates through ketoamide oxygen, azomethine nitrogen and deprotonated phenoxy oxygen. The extensive intermolecular hydrogen bonding interactions of the coordinated and the lattice nitrate groups interconnect the complex units to form a 2D supramolecular assembly. The ESI mass spectrum substantiates the existence of 1:1 complex. The g values obtained from the EPR spectrum in frozen DMF suggest dx2 -y2 ground state for the unpaired electron.

  9. Synthesis, crystal structure, antimicrobial activity and electrochemistry study of chromium(III) and copper(II) complexes based on semicarbazone Schiff base and azide ligands

    Czech Academy of Sciences Publication Activity Database

    Shaabani, B.; Khandar, A.A.; Dušek, Michal; Pojarová, Michaela; Mahmoudi, F.

    2013-01-01

    Roč. 394, JAN (2013), s. 563-568 ISSN 0020-1693 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378271 Keywords : antimicrobial activity * azide ligand * metal complex * Schiff base ligand * X-ray structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.041, year: 2013

  10. Stereochemistry of lead(II) complexes with oxygen donor ligands.

    Energy Technology Data Exchange (ETDEWEB)

    Stavilla, Vitalie; Davidovich, Ruven L.; Whitmire, Kenton Herbert (Rice University); Voit, Elena I.; Marinin, Dmitry V.

    2008-10-01

    This review discusses the coordination number (CN) and the coordination geometry of the first coordination sphere of Pb(II) atoms in crystal structures of 98 lead(II) complexes with O-donor ligands and the stereochemically active lone pair of electrons (LP, E) in the terms of the valence shell electron-pair repulsion (VSEPR) model. The CN of Pb(II) atoms of the first coordination sphere has values falling into the range (3 + E) to (6 + E). The following coordination polyhedra-{psi}-tetrahedron (I), {psi}-trigonal bipyramid (II), {psi}-octahedron (III), {psi}-pentagonal bipyramid with an axial (IV) or equatorial (V) vacant position are formed. For the investigated structures of the Pb(II) complexes, the formula of each compound, the overall CN of the Pb(II) atom considered as the sum of the CN in the first coordination sphere and the number of secondary bonds, the polyhedron shape, the Pb-O bond lengths, and O-Pb-O bond angles in the first coordination sphere, secondary bond lengths, references and REFCODEs are presented in the comprehensive Tables. The quantum chemical investigations performed using density functional theory (DFT) method have confirmed the stereochemical activity of the LP of Pb(II) atoms in the studied structures of lead(II) complexes with O-donor ligands.

  11. Template synthesis of two new supramolecular zinc(II) complexes containing pentadentate N.sub.3./sub.O.sub.2./sub. semicarbazone ligand: Nanostructure synthesis, Hirshfeld surface analysis, and DFT studies

    Czech Academy of Sciences Publication Activity Database

    Tyula, Y.A.; Zabardasti, A.; Goudarziafshar, H.; Roudsari, M.S.; Dušek, Michal; Eigner, Václav

    2017-01-01

    Roč. 1150, Dec (2017), s. 383-394 ISSN 0022-2860 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : sonochemical synthesis * Hirshfeld surface analysis * DFT calculations * bis(semicarbazone) * pentagonal-bipyramidal Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.753, year: 2016

  12. 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

  13. Entangled zinc-ditetrazolate frameworks involving in situ ligand synthesis and topological modulation by various secondary N-donor ligands

    International Nuclear Information System (INIS)

    Li Yunwu; Chen Weilin; Wang Yonghui; Li Yangguang; Wang Enbo

    2009-01-01

    The introduction of various secondary N-donor ligands into an in situ ditetrazolate-ligand synthesis system of terephthalonitrile, NaN 3 and ZnCl 2 led to the formation of three new entangled frameworks Zn(pdtz)(4,4'-bipy).3H 2 O (1), [Zn(pdtz)(bpp)] 2 .3H 2 O (2) and Zn(pdtz) 0.5 (N 3 )(2,2'-bipy) (3) (4,4'-bipy=4,4'-bipyridine; bpp=1,3-bis(4-pyridyl)propane; 2,2'-bipy=2,2'-bipyridine; H 2 pdtz=5,5'-1,4-phenylene-ditetrazole). The formation of pdtz 2- ligand involves the Sharpless [2+3] cycloaddition reaction between terephthalonitrile and NaN 3 in the presence of Zn 2+ ion as a Lewis-acid catalyst under hydrothermal conditions. Compound 1 exhibits a fivefold interpenetrating 3D framework based on the diamondoid topology. Compound 2 displays a twofold parallel interpenetrating framework based on the wavelike individual network. Compound 3 possesses a 2D puckered network. These new Zn-ditetrazolate frameworks are highly dependent on the modulation of different secondary N-donor ligands. Their luminescent properties were investigated. - Graphical abstract: Three new entangled frameworks were prepared by an in situ ditetrazolate-ligand synthesis system assisted with various auxiliary N-donor ligands. The entangled structures can be modulated by different secondary ligands.

  14. Metallo-supramolecular Architectures based on Multifunctional N-Donor Ligands

    OpenAIRE

    Tanh Jeazet, Harold Brice

    2010-01-01

    Self-assembly processes were used to construct supramolecular architectures based on metal-ligand interactions. The structures formed strongly depend on the used metal ion, the ligand type, the chosen counter ion and solvent as well as on the experimental conditions. The focus of the studies was the design of multifunctional N-donor ligands and the characterization of their complexing and structural properties. This work was divided into three distinct main parts: The bis(2-pyridylimine), the...

  15. Nickel (II) complexes containing ONS donor ligands: Synthesis ...

    Indian Academy of Sciences (India)

    The analysis revealed that the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative tridentate ONS fashion. The catalytic activity of complexes towards some C–C coupling reactions (viz., Kumada-Corriu, Suzuki-Miyaura and Sonogashira) has been examined. The complexes ...

  16. Nickel(II) complexes of N2S2 donor set ligand and halide ...

    Indian Academy of Sciences (India)

    Nickel(II) complexes of N2S2 donor set ligand and halide/pseudohalides: Synthesis, crystal structure, DNA and bovine/human serum albumin interaction. ANIMESH PATRAa ..... sitive to the length changes of nucleic acids, and so a classical intercalation mode should be indicated by a lengthening of the DNA double chain, ...

  17. Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

    Science.gov (United States)

    Brahma, Sanjaya; Shivashankar, S. A.

    2015-12-01

    We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.

  18. Spectroscopic studies on Isatin-3-Semicarbazone and Isatin-3 ...

    African Journals Online (AJOL)

    ... bombardment (FAB) and negative ion chemical ionization (NICI) mass spectra are also reported. Fragmentation of molecular and pseudomolecular ions are tabulated and rationalized. KEY WORDS: IH NMR, 13C NMR, Semicarbazone thiosemicarbazone, mass spectra, negative ion chemical ionization, fragmentation.

  19. A Protein Data Bank survey reveals shortening of intermolecular hydrogen bonds in ligand-protein complexes when a halogenated ligand is an H-bond donor.

    Directory of Open Access Journals (Sweden)

    Jarosław Poznański

    Full Text Available Halogen bonding in ligand-protein complexes is currently widely exploited, e.g. in drug design or supramolecular chemistry. But little attention has been directed to other effects that may result from replacement of a hydrogen by a strongly electronegative halogen. Analysis of almost 30000 hydrogen bonds between protein and ligand demonstrates that the length of a hydrogen bond depends on the type of donor-acceptor pair. Interestingly, lengths of hydrogen bonds between a protein and a halogenated ligand are visibly shorter than those estimated for the same family of proteins in complexes with non-halogenated ligands. Taking into account the effect of halogenation on hydrogen bonding is thus important when evaluating structural and/or energetic parameters of ligand-protein complexes. All these observations are consistent with the concept that halogenation increases the acidity of the proximal amino/imino/hydroxyl groups and thus makes them better, i.e. stronger, H-bond donors.

  20. A Protein Data Bank survey reveals shortening of intermolecular hydrogen bonds in ligand-protein complexes when a halogenated ligand is an H-bond donor.

    Science.gov (United States)

    Poznański, Jarosław; Poznańska, Anna; Shugar, David

    2014-01-01

    Halogen bonding in ligand-protein complexes is currently widely exploited, e.g. in drug design or supramolecular chemistry. But little attention has been directed to other effects that may result from replacement of a hydrogen by a strongly electronegative halogen. Analysis of almost 30000 hydrogen bonds between protein and ligand demonstrates that the length of a hydrogen bond depends on the type of donor-acceptor pair. Interestingly, lengths of hydrogen bonds between a protein and a halogenated ligand are visibly shorter than those estimated for the same family of proteins in complexes with non-halogenated ligands. Taking into account the effect of halogenation on hydrogen bonding is thus important when evaluating structural and/or energetic parameters of ligand-protein complexes. All these observations are consistent with the concept that halogenation increases the acidity of the proximal amino/imino/hydroxyl groups and thus makes them better, i.e. stronger, H-bond donors.

  1. 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

  2. Activation of the Hg-C Bond of Methylmercury by [S2]-Donor Ligands.

    Science.gov (United States)

    Karri, Ramesh; Banerjee, Mainak; Chalana, Ashish; Jha, Kunal Kumar; Roy, Gouriprasanna

    2017-10-16

    Here we report that [S 2 ]-donor ligands Bmm OH , Bmm Me , and Bme Me bind rapidly and reversibly to the mercury centers of organomercurials, RHgX, and facilitate the cleavage of Hg-C bonds of RHgX to produce stable tetracoordinated Hg(II) complexes and R 2 Hg. Significantly, the rate of cleavage of Hg-C bonds depends critically on the X group of RHgX (X = BF 4 - , Cl - , I - ) and the [S 2 ]-donor ligands used to induce the Hg-C bonds. For instance, the initial rate of cleavage of the Hg-C bond of MeHgI induced by Bme Me is almost 2-fold higher than the initial rate obtained by Bmm OH or Bmm Me , indicating that the spacer between the two imidazole rings of [S 2 ]-donor ligands plays a significant role here in the cleavage of Hg-C bonds. Surprisingly, we noticed that the initial rate of cleavage of the Hg-C bond of MeHgI induced by Bme Me (or Bmm Me ) is almost 10-fold and 100-fold faster than the cleavage of Hg-C bonds of MeHgCl and [MeHg]BF 4 respectively, under identical reaction conditions, suggesting that the Hg-C bond of [MeHg]BF 4 is highly inert at room temperature (21 °C). We also show here that the nature of the final stable cleaved products, i.e. Hg(II) complexes, depends on the X group of RHgX and the [S 2 ]-donor ligands. For instance, the reaction of Bmm Me with MeHgCl (1:1 molar ratio) afforded the formation of the 16-membered metallacyclic dinuclear mercury compound (Bmm Me ) 2 Hg 2 Cl 4 , in which the two Cl atoms are located inside the ring, whereas due to the large size of the I atom, a similar reaction with MeHgI yielded polymeric [(Bmm Me ) 2 HgI 2 ] m ·(MeHgI) n . However, the treatment of Bmm Me with ionic [RHg]BF 4 led to the formation of the tetrathione-coordinated mononuclear mercury compound [(Bmm Me ) 2 Hg](BF 4 ) 2 , where BF 4 - serves as a counteranion.

  3. Probing the influence of N-donor capping ligands on supramolecular assembly in molecular uranyl materials

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Korey P.; Kalaj, Mark; Cahill, Christopher L. [Department of Chemistry, The George Washington University, Washington, DC (United States)

    2016-01-15

    The syntheses and crystal structures of six new compounds containing the UO{sub 2}{sup 2+} cation, 3,5-dichlorobenzoic acid, and a chelating N-donor [2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 4,7-dimethyl-1,10-phenanthroline (dimethylphen), 2,2{sup '}:6{sup '},2''-terpyridine (terpy), 4{sup '}-chloro-2,2{sup '}:6{sup '},2''-terpyridine (Cl-terpy), or 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ)] are reported. Single-crystal X-ray diffraction analysis of these materials enabled the exploration of the structural relationship between the benzoic acids and the chelating N-donor as well as providing a platform to evaluate the effects of ligand choice on uranyl hydrolysis and subsequent oligomerization. At an unadjusted pH (ca. 3), a mix of uranyl monomers and dimers are observed, dimer formation resulting from both bridging carboxylate linkers and hydroxo bridges. Assembly by halogen- and hydrogen-bonding interactions as well as π-π interactions was observed depending on the experimental conditions utilized. Further, spectroscopic characterization (both vibrational and luminescence) of complexes 1, 4, and 5 to explore the effects of the electron-donating ability of the capping ligand on the corresponding uranyl luminescence and vibrational spectra suggests that there is a relationship between the observed bathochromic shifts and the electron-donating ability of the capping ligands. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Probing the influence of N-donor capping ligands on supramolecular assembly in molecular uranyl materials

    International Nuclear Information System (INIS)

    Carter, Korey P.; Kalaj, Mark; Cahill, Christopher L.

    2016-01-01

    The syntheses and crystal structures of six new compounds containing the UO 2 2+ cation, 3,5-dichlorobenzoic acid, and a chelating N-donor [2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 4,7-dimethyl-1,10-phenanthroline (dimethylphen), 2,2 ' :6 ' ,2''-terpyridine (terpy), 4 ' -chloro-2,2 ' :6 ' ,2''-terpyridine (Cl-terpy), or 2,4,6-tris(2-pyridyl)-s-triazine (TPTZ)] are reported. Single-crystal X-ray diffraction analysis of these materials enabled the exploration of the structural relationship between the benzoic acids and the chelating N-donor as well as providing a platform to evaluate the effects of ligand choice on uranyl hydrolysis and subsequent oligomerization. At an unadjusted pH (ca. 3), a mix of uranyl monomers and dimers are observed, dimer formation resulting from both bridging carboxylate linkers and hydroxo bridges. Assembly by halogen- and hydrogen-bonding interactions as well as π-π interactions was observed depending on the experimental conditions utilized. Further, spectroscopic characterization (both vibrational and luminescence) of complexes 1, 4, and 5 to explore the effects of the electron-donating ability of the capping ligand on the corresponding uranyl luminescence and vibrational spectra suggests that there is a relationship between the observed bathochromic shifts and the electron-donating ability of the capping ligands. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Eight-Electron Silver and Mixed Gold/Silver Nanoclusters Stabilized by Selenium Donor Ligands.

    Science.gov (United States)

    Chang, Wan-Ting; Lee, Po-Yi; Liao, Jian-Hong; Chakrahari, Kiran Kumarvarma; Kahlal, Samia; Liu, Yu-Chiao; Chiang, Ming-Hsi; Saillard, Jean-Yves; Liu, C W

    2017-08-14

    The first atomically and structurally precise silver-nanoclusters stabilized by Se-donor ligands, [Ag 20 {Se 2 P(O i Pr) 2 } 12 ] (3) and [Ag 21 {Se 2 P(OEt) 2 } 12 ] + (4), were isolated by ligand replacement reaction of [Ag 20 {S 2 P(O i Pr) 2 } 12 ] (1) and [Ag 21 {S 2 P(O i Pr) 2 } 12 ] + (2), respectively. Furthermore, doping reactions of 4 with Au(PPh 3 )Cl resulted in the formation of [AuAg 20 {Se 2 P(OEt) 2 } 12 ] + (5). Structures of 3, 4, and 5 were determined by single-crystal X-ray diffraction. The anatomy of cluster 3 with an Ag 20 core having C 3 symmetry is very similar to that of its dithiophosphate analogue 1. Clusters 4 and 5 exhibit an Ag 21 and Au@Ag 20 core of O h symmetry composed of eight silver capping atoms in a cubic arrangement and encapsulating an Ag 13 and Au@Ag 12 centered icosahedron, respectively. Both ligand exchange and heteroatom doping result in significant changes in optical and emissive properties for chalcogen-passivated silver nanoparticles, which have been theoretically confirmed as 8-electron superatoms. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Recipient-donor KIR ligand matching prevents CMV reactivation post-haploidentical T cell-replete transplantation.

    Science.gov (United States)

    Zhao, Xiang-Yu; Luo, Xue-Yi; Yu, Xing-Xing; Zhao, Xiao-Su; Han, Ting-Ting; Chang, Ying-Jun; Huo, Ming-Rui; Xu, Lan-Ping; Zhang, Xiao-Hui; Liu, Kai-Yan; Li, Dan; Jiang, Zheng-Fan; Huang, Xiao-Jun

    2017-06-01

    Licensed natural killer (NK) cells have been demonstrated to have anti-cytomegalovirus (CMV) activity. We prospectively analysed the human leucocyte antigen typing of donor-recipient pairs and the killer cell immunoglobulin-like receptor (KIR) typing of donors for 180 leukaemia patients to assess the predictive roles of licensed NK cells on CMV reactivation post-T-cell-replete haploidentical stem cell transplantation. Multivariate analysis showed that donor-recipient KIR ligand graft-versus-host or host-versus-graft direction mismatch was associated with increased refractory CMV infection (Hazard ratio = 2·556, 95% confidence interval, 1·377-4·744, P = 0·003) post-transplantation. Donor-recipient KIR ligand matching decreased CMV reactivation [51·65% (46·67, 56·62%) vs. 75·28% (70·87, 79·69%), P = 0·012], refractory CMV infection [17·58% (13·77, 21·40%) vs. 35·96% (31·09, 40·82%), P = 0·004] and CMV disease [3·30% (1·51, 5·08%) vs. 11·24% (8·04, 14·43%), P = 0·024] by day 100 post-transplantation. In addition, the percentage of γ-interferon expression on donor-derived NK cells was significantly higher in the recipients among the recipient-donor pairs with a KIR ligand match compared with that in the recipients among the pairs with a KIR ligand graft-versus-host or host-versus-graft direction mismatch on days 30 and 100 post-transplantation (P = 0·036 and 0·047, respectively). These findings have suggested that donor-recipient KIR ligand matching might promote the NK cell licensing process, thereby increasing NK cell-mediated protection against CMV reactivation. © 2017 John Wiley & Sons Ltd.

  7. Role of Killer Immunoglobulin-Like Receptor and Ligand Matching in Donor Selection

    Directory of Open Access Journals (Sweden)

    Meral Beksaç

    2012-01-01

    Full Text Available Despite all efforts to improve HLA typing and immunosuppression, it is still impossible to prevent severe graft versus host disease (GVHD which can be fatal. GVHD is not always associated with graft versus malignancy and can prevent stem cell transplantation from reaching its goals. Overall T-cell alloreactivity is not the sole mechanism modulating the immune defense. Innate immune system has its own antigens, ligands, and mediators. The bridge between HLA and natural killer (NK cell-mediated reactions is becoming better understood in the context of stem cell transplantation. Killer immunoglobulin-like receptors (KIRs constitute a wide range of alleles/antigens segregated independently from the HLA alleles and classified into two major haplotypes which imprints the person's ability to suppress or to amplify T-cell alloreactivity. This paper will summarize the impact of both activating and inhibitory KIRs and their ligands on stem cell transplantation outcome. The ultimate goal is to develop algorithms based on KIR profiles to select donors with maximum antileukemic and minimum antihost effects.

  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. Structure and properties of silver sulfate complexes derived from dipyridyl methylthio ligands with secondary donor site

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Hua; Yan, Hao-Jie; Chen, Hui; Liu, Rui-Heng; Li, Ai-Min; Wang, Guo [Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048 (China); Wan, Chong-Qing, E-mail: wancq@cnu.edu.cn [Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048 (China); State Key Laboratory of Structural Chemistry in China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2017-06-15

    Dipyridyl sulphide ligands 4-(pyridin-4-ylmethylthio)pyridine (abbreviated as L1) and 3-(pyridin-4-ylmethylthio)pyridine (abbreviated as L2) have been designed and used as μ-{sub N},{sub N}-bridging linkages to construct coordination polymers with free –S–CH{sub 2}– groups as secondary donor sites. By use solvent control method, coordination polymers ([Ag{sub 3}SO{sub 4}(L1){sub 3}](Cl)·4.5H{sub 2}O){sub ∞}(1), ([Ag{sub 2}SO{sub 4}(L1){sub 2}]·6H{sub 2}O·2CH{sub 3}OH){sub ∞}(2), ([Ag{sub 2}SO{sub 4}(L2){sub 2}]·H{sub 2}O){sub ∞}(3) and ([Ag{sub 4}(SO{sub 4}){sub 2}(L2){sub 4}]·5H{sub 2}O){sub ∞}(4) with different architectures were obtained. Complexes 1, 3 and 4 feature 1D channel with different sizes and structures. Complex 1 exhibits guest exchange by THF and 1,4-dioxane, and Hg{sup 2+} sorption ability from solution due to its relative larger channel and available bonding sites of –S– exposed to the channel region. All complexes have been characterized through single-crystal and powder X-ray diffraction (PXRD), FT-IR spectra, X-ray photoelectron spectroscopy (XPS), elemental and thermogravimetric analyses. The guest exchange and Hg{sup 2+} sorption were monitored and identified, and the structure-property relationship of coordination polymers 1–4 are discussed. - Graphical abstract: Coordination polymers of silver(I) sulfate with secondary donor sites are shown guest exchange property and Hg{sup 2+} absorb ability from solution. This work provides a new method to construct functional materials with potential application. - Highlights: • New example of constructing functional coordination polymer with secondary donor methylthio group. • Guest exchange and interesting Hg(II) absorb ability from solution are investigated. • New method to construct functional materials with potential application.

  10. Application of X-ray single crystal diffractometry to investigation of Np(5) complexes with n-donor ligands

    International Nuclear Information System (INIS)

    Andreev, G.

    2007-01-01

    Full text of publication follows. We present here some results of application of conventional X-ray single crystal diffractometry to the research on the interaction of Np(V) with N-donor ligands. Compounds that can coordinate to actinides through one or several nitrogen atoms are of a great variety and occur widely in the biosphere. For example, imidazole, pyridine and their derivatives are the building blocks of many biologically important molecules; triazines are known to occur in some aquatic plants. The presence of anthropogenic organic agents like amine-N-carboxylic acids in surface waters has the potential to re-mobilize metals from sediments and aquifers and to influence their bioavailability. The interaction of radionuclides with such ligands needs to be studied in detail to give fundamental understanding the conditions of the incorporation of long lived a-emitters (Np and Pu primarily) into the food chain. Another aspect of the same problem is the design of new chelating ligands for selective co-ordination of actinide ions as an alternative to the traditional sequestering agents. The problem of the separation of long-lived minor actinides and their transmutation also calls for design of new highly selective ligands for solvent extraction. Polydentate N-donor ligands are now considered to be very promising. A detailed study of structural chemistry is crucial for understanding the relationship between the architecture of the ligands and their binding affinity for actinides. The X-ray single crystal diffractometry became conventional technique as applied to the investigation of actinides in spite of difficulties regarding safe handling of radionuclides. This technique provides unambiguous information about modes of the ligand co-ordination to the metal ion and geometrical parameters of complexes. Moreover, the employment of a synchrotron radiation shows considerable promise for determination of solid state structures as well as obtaining structural

  11. Pincer ligands with an all-phosphorus donor set: subtle differences between rhodium and palladium

    NARCIS (Netherlands)

    Bauer, R.C.; Gloaguen, Y.; Lutz, M.; Reek, J.N.H.; de Bruin, B.; van der Vlugt, J.I.

    2011-01-01

    The synthesis of a new, all-phosphorus pincer PPNEt2P ligand L3NEt2, which is derived from 2-indolylphosphine and features a central N2P(NEt2) core, is described. This ‘PPP’ species shows coordination toward Rh as a neutral trisphosphine ligand. Tridentate diphenylphosphine-derived PPHP ligands L1H

  12. Weakening of Carbide–Platinum Bonds as a Probe for Ligand Donor Strengths

    DEFF Research Database (Denmark)

    Reinholdt, Anders; Bendix, Jesper

    2017-01-01

    Functionalization of the terminal ruthenium carbide ligand in (Cy3P)2Cl2Ru≡C: with platinum and a range of ligands provides {Ru≡C−Pt−L} fragments with trans geometries. The bridging carbide exhibits chemical shifts and coupling constants to platinum, which are highly responsive to the degree of w...... of weakening of the RuC−Pt linkage induced by the trans ligands, making the terminal ruthenium carbide complex a sensitive probe for the electron donating abilities of other ligands.......Functionalization of the terminal ruthenium carbide ligand in (Cy3P)2Cl2Ru≡C: with platinum and a range of ligands provides {Ru≡C−Pt−L} fragments with trans geometries. The bridging carbide exhibits chemical shifts and coupling constants to platinum, which are highly responsive to the degree...

  13. CO2 activation through silylimido and silylamido zirconium hydrides supported on N-donor chelating SBA15 surface ligand

    KAUST Repository

    Pasha, Fahran Ahmad

    2016-01-04

    Density functional theory calculations and 2D 1H-13C HETCOR solid state NMR spectroscopy prove that CO2 can probe, by its own reactivity, different types of N-donor surface ligands on SBA15-supported ZrIV hydrides: [(≡Si-O-)(≡Si-N=)[Zr]H] and [(≡Si-NH-)(≡Si-X-)[Zr]H2] (X = O or NH). Moreover, [(≡Si-O-)(≡Si-N=)[Zr]H] activates CO2 more efficiently than the other complexes and leads to a carbimato Zr formate.

  14. Impact of Donor Activating KIR Genes on HSCT Outcome in C1-Ligand Negative Myeloid Disease Patients Transplanted with Unrelated Donors-A Retrospective Study.

    Directory of Open Access Journals (Sweden)

    Christine Neuchel

    Full Text Available Natural Killer cells (NK are lymphocytes with the potential to recognize and lyse cells which escaped T-cell mediated lysis due to their aberrant HLA expression profiles. Killer cell immunoglobulin-like receptors (KIR influence NK-cell activity by mediation of activating or inhibitory signals upon interaction with HLA-C (C1, C2 ligands. Therefore, absence of ligands for donor inhibitory KIRs following hematopoietic stem cell transplantation (HSCT may have an influence on its outcome. Previous studies showed that C1 negative patients have a decreased HSCT outcome. Our study, based on a cohort of 200 C1-negative patients, confirmed these findings for the endpoints: overall survival (OS: HR = 1.41, CI = 1.14-1.74, p = 0.0012, disease free survival (DFS: HR = 1.27, CI = 1.05-1.53, p = 0.015, treatment related mortality (TRM: HR = 1.41, CI = 1.01-1.96, p = 0.04, and relapse incidence (RI: HR = 1.33, CI = 1.01-1.75, p = 0.04 all being inferior when compared to C1-positive patients (n = 1246. Subsequent analysis showed that these findings applied for patients with myeloid malignancies but not for patients with lymphoproliferative diseases (OS: myeloid: HR = 1.51, CI = 1.15-1.99, p = 0.003; lymphoblastic: HR = 1.26, CI = 0.91-1.75, p = 0.16; DFS: myeloid: HR = 1.31, CI = 1.01-1.70, p = 0.04; lymphoblastic: HR = 1.21, CI = 0.90-1.61, p = 0.21; RI: myeloid: HR = 1.31, CI = 1.01-1.70, p = 0.04; lymphoblastic: HR = 1.21, CI = 0.90-1.61, p = 0.21. Interestingly, within the C1-negative patient group, transplantation with KIR2DS2 resulted in better OS (9/10 matched: HR = 0.24, CI = 0.08-0.67, p = 0.007 as well as DFS (9/10 matched: HR = 0,26, CI = 0.11-0.60, p = 0.002, and transplantation with KIR2DS1 positive donors was associated with a decreased RI (HR = 0.30, CI = 0.13-0.69, p = 0.005. TRM was increased when the donor was positive for KIR2DS1 (HR = 2.61, CI = 1.26-5.41, p = 0.001. Our findings suggest that inclusion of KIR2DS1/2/5 and KIR3DS1-genotyping in

  15. Protein-ligand interfaces are polarized: discovery of a strong trend for intermolecular hydrogen bonds to favor donors on the protein side with implications for predicting and designing ligand complexes

    Science.gov (United States)

    Raschka, Sebastian; Wolf, Alex J.; Bemister-Buffington, Joseph; Kuhn, Leslie A.

    2018-02-01

    Understanding how proteins encode ligand specificity is fascinating and similar in importance to deciphering the genetic code. For protein-ligand recognition, the combination of an almost infinite variety of interfacial shapes and patterns of chemical groups makes the problem especially challenging. Here we analyze data across non-homologous proteins in complex with small biological ligands to address observations made in our inhibitor discovery projects: that proteins favor donating H-bonds to ligands and avoid using groups with both H-bond donor and acceptor capacity. The resulting clear and significant chemical group matching preferences elucidate the code for protein-native ligand binding, similar to the dominant patterns found in nucleic acid base-pairing. On average, 90% of the keto and carboxylate oxygens occurring in the biological ligands formed direct H-bonds to the protein. A two-fold preference was found for protein atoms to act as H-bond donors and ligand atoms to act as acceptors, and 76% of all intermolecular H-bonds involved an amine donor. Together, the tight chemical and geometric constraints associated with satisfying donor groups generate a hydrogen-bonding lock that can be matched only by ligands bearing the right acceptor-rich key. Measuring an index of H-bond preference based on the observed chemical trends proved sufficient to predict other protein-ligand complexes and can be used to guide molecular design. The resulting Hbind and Protein Recognition Index software packages are being made available for rigorously defining intermolecular H-bonds and measuring the extent to which H-bonding patterns in a given complex match the preference key.

  16. Synthesis and evaluation of 4-substituted semicarbazones of levulinic acid for anticonvulsant activity

    Science.gov (United States)

    Aggarwal, Navneet; Mishra, Pradeep

    2005-01-01

    Objective: A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity. Methods: All the compounds were evaluated for anticonvulsant activity. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) and subcutaneous metrazol (ScMet) induced seizure methods and minimal motor impairment was determined by rotorod test. Results: A majority of the compounds exhibited significant anticonvulsant activity after intraperitoneal administration. In the present study 4-(4′-fluoro phenyl) levulinic acid semicarbazone emerged as the most active molecule, showing broad spectrum of activity with low neurotoxicity. Unsubstituted levulinic acid semicarbazone was found to be inactive in all the screens. Conclusion: The results obtained validate the hypothesis that presence of an aryl group near the semicarbazone moiety is essential for anticonvulsant activity. The results also indicate that the hydrophilic-hydrophobic site can accommodate hydrophilic groups. PMID:15973761

  17. Copper(I) Chelation by Tetradentate NSSN Donor Ligands: Reversible Oxidation but no Oxygenation

    Czech Academy of Sciences Publication Activity Database

    Schnödt, J.; Sieger, M.; Sarkar, B.; Fiedler, Jan; Manzur, J.; Su, Ch. Y.; Kaim, W.

    2011-01-01

    Roč. 637, 7-8 (2011), s. 930-934 ISSN 0044-2313 R&D Projects: GA ČR GA203/09/0705 Institutional research plan: CEZ:AV0Z40400503 Keywords : benzimidazole ligands * coordination geometry * copper Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.249, year: 2011

  18. Nickel (II) complexes of N 2 S 2 donor set ligand and halide ...

    Indian Academy of Sciences (India)

    The complexes were characterized by physicochemical and spectroscopic methods along with detailed structural characterization of 1,2 and 3 by single crystal X-ray diffraction analyses. The structural study showed that the nickel(II) ion has a distorted octahedral geometry being chelated by the tetradentate N2S2 ligand ...

  19. Circularly Polarized Luminescence in Enantiopure Europium and Terbium Complexes with Modular, All-Oxygen Donor Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Michael; Do, King; Ingram, Andrew; Moore, Evan; Muller, Gilles; Raymond, Kenneth

    2009-06-04

    The modular syntheses of three new octadentate, enantiopure ligands are reported, one with the bidentate chelating unit 2-hydroxyisophthalamide (IAM) and two with bidentate 1-hydroxy-2-pyridinone (1,2-HOPO) units. A new design principle is introduced for the chiral, non-racemic hexamines which constitute the central backbones for the presented class of ligands. The terbium(III) complex of the IAM ligand, as well as the europium(III) complexes of the 1,2-HOPO ligands, are synthesized and characterized by various techniques (NMR, UV, CD, luminescence spectroscopy). All species exhibit excellent stability and moderate to high luminescence efficiency (quantum yields {phi}{sub Eu} = 0.05-0.08 and {phi}{sub Tb} = 0.30-0.57) in aqueous solution at physiological pH. Special focus is put onto the properties of the complexes in regard to circularly polarized luminescence (CPL). The maximum luminescence dissymmetry factors (glum) in aqueous solution are high with |glum|max = 0.08-0.40. Together with the very favorable general properties (good stability, high quantum yields, long lifetimes), the presented lanthanide complexes can be considered as good candidates for analytical probes based on CPL in biologically relevant environments.

  20. Synergistic effect of KIR ligands missing and cytomegalovirus reactivation in improving outcomes of haematopoietic stem cell transplantation from HLA-matched sibling donor for treatment of myeloid malignancies.

    Science.gov (United States)

    Cardozo, Daniela Maira; Marangon, Amanda Vansan; da Silva, Rodrigo Fernandes; Aranha, Francisco José Penteado; Visentainer, Jeane Eliete Laguila; Bonon, Sandra Helena Alves; Costa, Sandra Cecília Botelho; Miranda, Eliana Cristina Martins; de Souza, Carmino Antonio; Guimarães, Fernando

    2016-10-01

    The goal of this study was to evaluate the influence of KIR-HLA genotypes on the outcome of patients undergoing treatment for haematological malignancies by non-T-depleted lymphocyte haematopoietic stem cell transplantation (HSCT) from HLA-matched sibling donors. The prospective study was conducted at the Center of Hematology, University of Campinas, and 50 patients and their donors were followed up from 2008 to 2014. KIR and HLA class I genes were genotyped and patients grouped based on the presence of KIR ligands combined with KIR genotype of their respective donors. Patients with all KIR ligands present (n=13) had a significantly higher (p=0.04) incidence of acute graft-versus-host-disease (GVHD) than patients with one or more KIR ligands missing (n=37). The overall survival following transplantation of patients with myeloid malignancies (n=27) was significantly higher (p=0.035) in the group with one or more KIR ligands missing (n=18) than in the group with all ligands present (n=9). Presence of KIR2DS2 was associated with a worsening of HSCT outcome while reactivation of cytomegalovirus (CMV) infection improved the outcome of patients with one or more KIR ligands missing. Our results indicate that KIR-HLA interactions affect the outcome of the HLA-matched transplantation, particularly in patients with myeloid malignancies. Copyright © 2016. Published by Elsevier Inc.

  1. Chemokine (C-X-C Ligand 12 Facilitates Trafficking of Donor Spermatogonial Stem Cells

    Directory of Open Access Journals (Sweden)

    Zhiyv Niu

    2016-01-01

    Full Text Available The chemokine (C-X-C receptor type 4 (CXCR4 is an early marker of primordial germ cells (PGCs essential for their migration and colonization of the gonads. In spermatogonial stem cells (SSCs, the expression of CXCR4 is promoted by the self-renewal factor, glial cell line-derived neurotrophic factor (GDNF. Here, we demonstrate an important role of CXCR4 during donor mouse SSCs reoccupation of the endogenous niche in recipient testis. Silencing of CXCR4 expression in mouse SSCs dramatically reduced the number of donor stem cell-derived colonies, whereas colony morphology and spermatogenesis were comparable to controls. Inhibition of CXCR4 signaling using a small molecule inhibitor (AMD3100 during the critical window of homing also significantly lowered the efficiency of donor-derived SSCs to establish spermatogenic colonies in recipient mice; however, the self-renewal of SSCs was not affected by exposure to AMD3100. Rather, in vitro migration assays demonstrate the influence of CXCR4-CXCL12 signaling in promoting germ cell migration. Together, these studies suggest that CXCR4-CXCL12 signaling functions to promote homing of SSCs towards the stem cell niche and plays a critical role in reestablishing spermatogenesis.

  2. Transition metal complexes with oxygen donor ligands: a synthesis, spectral, thermal and antimicrobial study

    Directory of Open Access Journals (Sweden)

    VAIBHAV N. PATANGE

    2008-10-01

    Full Text Available Transition metal complexes of chalcones derived from the conden¬sation of 3-acetyl-6-methyl-2H-pyran-2,4(3H-dione (dehydroacetic acid and p-methoxybenzaldehyde (HL1 or p-nitrobenzaldehyde (HL2 were synthesized and characterized by elemental analysis, conductometry, thermal analysis, magnetic measurements, IR, 1H-NMR, UV–Vis spectroscopy and a microbial study. From the analytical and thermal data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand. The molar conductance data revealed that all the metal chelates were non-electrolytes. The thermal stability of the complexes was studied by thermogravimetry and the decomposition schemes of the complexes are given. The ligands and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli, and fungicidal activity against Aspergillus flavus, Curvularia lunata and Penicillium notatum.

  3. Complexation Studies of Bidentate Heterocyclic N-Donor Ligands with Nd(III) and Am(III)

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, Mark; Hoch, Courtney L.; Sinkov, Sergey I.; Meier, Patrick; Lumetta, Gregg J.; Nash, Kenneth L.

    2011-11-28

    A new bidentate nitrogen donor complexing agent that combines pyridine and triazole functional groups, 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridine (PTMP), has been synthesized. The strength of its complexes with trivalent americium (Am3+) and neodymium (Nd3+) in anhydrous methanol has been evaluated using spectrophotometric techniques. The purpose of this investigation is to assess this ligand (as representative of a class of similarly structured species) as a possible model compound for the challenging separation of trivalent actinides from lanthanides. This separation, important in the development of advanced nuclear fuel cycles, is best achieved through the agency of multidentate chelating agents containing some number of nitrogen or sulfur donor groups. To evaluate the relative strength of the bidentate complexes, the derived constants are compared to those of the same metal ions with 2,2*-bipyridyl (bipy), 1,10-phenanthroline (phen), and 2-pyridin-2-yl-1H-benzimidazole (PBIm). At issue is the relative affinity of the triazole moiety for trivalent f element ions. For all ligands, the derived stability constants are higher for Am3+ than Nd3+. In the case of Am3+ complexes with phen and PBIm, the presence of 1:2 (AmL2) species is indicated. Possible separations are suggested based on the relative stability and stoichiometry of the Am3+ and Nd3+ complexes. It can be noted that the 1,2,3-triazolyl group imparts a potentially useful selectivity for trivalent actinides (An(III)) over trivalent lanthanides (Ln(III)), though the attainment of higher complex stoichiometries in actinide compared with lanthanide complexes may be an important driver for developing successful separations.

  4. Complexation Studies of Bidentate Heterocyclic N-Donor Ligands with Nd(III) and Am(III)

    International Nuclear Information System (INIS)

    Ogden, Mark; Hoch, Courtney L.; Sinkov, Sergey I.; Meier, Patrick; Lumetta, Gregg J.; Nash, Kenneth L.

    2011-01-01

    A new bidentate nitrogen donor complexing agent that combines pyridine and triazole functional groups, 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridine (PTMP), has been synthesized. The strength of its complexes with trivalent americium (Am3+) and neodymium (Nd3+) in anhydrous methanol has been evaluated using spectrophotometric techniques. The purpose of this investigation is to assess this ligand (as representative of a class of similarly structured species) as a possible model compound for the challenging separation of trivalent actinides from lanthanides. This separation, important in the development of advanced nuclear fuel cycles, is best achieved through the agency of multidentate chelating agents containing some number of nitrogen or sulfur donor groups. To evaluate the relative strength of the bidentate complexes, the derived constants are compared to those of the same metal ions with 2,2*-bipyridyl (bipy), 1,10-phenanthroline (phen), and 2-pyridin-2-yl-1H-benzimidazole (PBIm). At issue is the relative affinity of the triazole moiety for trivalent f element ions. For all ligands, the derived stability constants are higher for Am3+ than Nd3+. In the case of Am3+ complexes with phen and PBIm, the presence of 1:2 (AmL2) species is indicated. Possible separations are suggested based on the relative stability and stoichiometry of the Am3+ and Nd3+ complexes. It can be noted that the 1,2,3-triazolyl group imparts a potentially useful selectivity for trivalent actinides (An(III)) over trivalent lanthanides (Ln(III)), though the attainment of higher complex stoichiometries in actinide compared with lanthanide complexes may be an important driver for developing successful separations.

  5. 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.

  6. Probing the difference in covalence by enthalpy measurements: a new heterocyclic N-donor ligand for actinide/lanthanide separation.

    Science.gov (United States)

    Yang, Yanqiu; Liu, Jun; Yang, Liang; Li, Kun; Zhang, Huabei; Luo, Shunzhong; Rao, Linfeng

    2015-05-21

    Complexation of Am(III), Nd(III), and Eu(III) with a new heterocyclic nitrogen-donor ligand, 2,9-di(quinazolin-2-yl)-1,10-phenanthroline (denoted as BQPhen in this paper), was studied by thermodynamic measurements and theoretical computations. The stability constants of two successive complexes in dimethylformamide, ML(3+) and ML2(3+) where M stands for Nd, Eu, or Am while L stands for the BQPhen ligand, were determined by absorption spectrophotometry. The enthalpy of complexation was determined by microcalorimetry. Results show that BQPhen forms ten times stronger complexes with Am(III) than Eu(III) or Nd(III) under identical conditions, suggesting that BQPhen could be used as an efficient extractant for the separations of trivalent actinides from lanthanides. The higher binding strength of BQPhen towards Am(III) than Nd(III) or Eu(III) is mainly due to the more favourable enthalpy of complexation for Am(III)/BQPhen complexes, implying a higher degree of covalence in the Am(III)/BQPhen complexes than the lanthanide(III)/BQPhen complexes. The thermodynamic trend was corroborated with computational results and validated by solvent extraction experiments that demonstrated BQPhen preferably extracted Am(III) more than Eu(III), with a separation factor of about 10. Discussions have been made to compare BQPhen with other phenanthroline derivatives such as CyMe4-BTPhen, a bis-triazine-phenanthroline derivative that was reported in the literature. Data suggest that, under identical conditions, BQPhen would form stronger complexes with Am(III), Eu(III), and Nd(III) than CyMe4-BTPhen.

  7. Complexation of trivalent cationic lanthanides by N.O donor ligands: physico-chemical studies of the association and selectivity in solution

    International Nuclear Information System (INIS)

    Bravard, F.

    2004-01-01

    The aim of this work is to study the complexation of f-elements in solution by ligands incorporating N-heterocyclic donors. These ligands display interesting properties for the selective separation of An(III)/Ln(III) have been studied to obtain a better understanding of the coordination properties with f-elements and to develop more selective extractants. The hepta-dentate ligand tpaam shows an affinity for Ln(III) similar to the tetradentate ligand tpa in water even when the three additional amide groups are bonded to the metal. Even though the complexation with tpa is exothermic, that with tpaam is endothermic with a more positive entropy. The dehydration of the cation disfavours the formation of Ln(III) complexes with ligands containing weak donors. The analysis of the solution paramagnetic relaxation times of the tpaam complexes is in agreement with data in the solid-state. There is little difference between the formation constants of the Ln 3+ complexes with different ligands (tpaam, tpzen, tpa and tpza) as determined by UV-vis spectrophotometry in anhydrous acetonitrile. The limitations encountered during this study are intrinsic to the ligands studied. The preliminary study of two tetrapodal ligands containing acid and pyridine groups (L py )or pyrazine (L pz ) show the formation of 1:1 complexes in water. Analysis of the formation constants of the corresponding Gd(III) complexes shows that replacement of a pyridine group by pyrazine result in a loss of stability of 1.6 logarithmic units. (author) [fr

  8. Zinc Bioavailability from Phytate-Rich Foods and Zinc Supplements. Modeling the Effects of Food Components with Oxygen, Nitrogen, and Sulfur Donor Ligands.

    Science.gov (United States)

    Tang, Ning; Skibsted, Leif H

    2017-10-04

    Aqueous solubility of zinc phytate (K sp = (2.6 ± 0.2) × 10 -47 mol 7 /L 7 ), essential for zinc bioavailability from plant foods, was found to decrease with increasing temperature corresponding to ΔH dis of -301 ± 22 kJ/mol and ΔS dis of -1901 ± 72 J/(mol K). Binding of zinc to phytate was found to be exothermic for the stronger binding site and endothermic for the weaker binding site. The solubility of the slightly soluble zinc citrate and insoluble zinc phytate was found to be considerably enhanced by the food components with oxygen donor, nitrogen donor, and sulfur donor ligands. The driving force for the enhanced solubility is mainly due to the complex formation between zinc and the investigated food components rather than ligand exchange and ternary complex formation as revealed by quantum mechanical calculations and isothermal titration calorimetry. Histidine and citrate are promising ligands for improving zinc absorption from phytate-rich foods.

  9. Synthesis and photoluminescence properties of silver(I) complexes based on N-benzoyl-L-glutamic acid and N-donor ligands with different flexibility

    Science.gov (United States)

    Yan, Ming-Jie; Feng, Qi; Song, Hui-Hua

    2016-05-01

    By changing the N-donor ancillary ligand, three novel silver (I) complexes {[Ag(HbzgluO) (4,4‧-bipy)]·H2O}n (1), {[Ag2(HbzgluO)2 (bpe)2]·2H2O}n (2) and {[Ag(HbzgluO)(bpp)]·2H2O}n (3) (H2bzgluO = N-benzoyl-L-glutamic acid, 4,4‧-bipy = 4,4ˊ-bipyridine, bpe = 1,2-di(4-pyridyl)ethane, bpp = 1,3-di(4-pyridyl)propane) were synthesized. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). In this study, the N-donor ligands are changed from rigidity (4,4‧-bipy), quasi-flexibility (bpe) to flexibility (bpp), the structures of complexes also change. Complex 1 features a 1D chain structure which is further linked together to construct a 2D supramolecular structure through hydrogen bonds. Complex 2 is a 1D double-chains configuration which eventually forms a 3D supramolecular network via hydrogen bonding interactions. Whereas, complex 3 exhibits a 2D pleated grid structure which is linked by hydrogen bonding interactions into a 3D supramolecular network. The present observations demonstrate that the modulation of coordination polymers with different structures can accomplish by changing the spacer length of N-donor ligands. In addition, the solid-state circular dichroism (CD) spectra indicated that compound 2 exhibited negative cotton effect which originated from the chiral ligands H2bzgluO and the solid-state fluorescence spectra of the three complexes demonstrated the auxiliary ligands have influence on the photoluminescence properties of the complexes.

  10. 3,4-Dimethyl diphenyldithiophosphate of mononuclear cobalt(II) with N-donor ligands: Synthesis, structural characterization, DFT and antibacterial studies

    Science.gov (United States)

    Kumar, Sandeep; Kour, Gurpreet; Schreckenbach, Georg; Andotra, Savit; Hundal, Geeta; Sharma, Vishal; Jaglan, Sundeep; Pandey, Sushil K.

    2017-08-01

    3,4-Dimethyl diphenyldithiophosphate of cobalt(II) with N-donor ligands [{(ArO)2PS2}2CoL2] [Ar = 3,4-(CH3)2C6H3 (1-3); L = C5H5N (1), 3,4-(CH3)2C5H3N (2) and 4-(C2H5)C5H4N (3)] have been synthesized and characterized by elemental analyses, infrared spectroscopy (IR), powder X-ray diffraction (PXRD) and single crystal X-ray analysis. Complex 1 crystallizes in the monoclinic space group P21/n whereas complexes 2 and 3 crystallize in the triclinic space group Pbar1. The crystal structures of complexes 1-3 reveal mononuclear units with the Co(II) center chelated in bidentate fashion by four S atoms of the two diphenyldithiophosphate ligands. The N atoms from two donor ligands are axially coordinated, leading to distorted octahedral geometry around Co(II). The complexes have been optimized using density functional theory (DFT), structural parameters have been calculated, and the energy gaps of the frontier orbitals (HOMO-LUMO) have been predicted. Mayer bond orders have also been calculated. Structural parameters from the crystallographic and DFT studies are in good agreement with each other. To explore the biological potential, complexes were evaluated for their antibacterial activity against three bacterial strains. The bacterial growth inhibition capacity of the ligand and complexes followed the order of 3 > 2 > 1 > L1.

  11. Bonding Study on the Chemical Separation of Am(III) from Eu(III) by S-, N-, and O-Donor Ligands by Means of All-Electron ZORA-DFT Calculation.

    Science.gov (United States)

    Kaneko, Masashi; Miyashita, Sunao; Nakashima, Satoru

    2015-07-20

    We performed a theoretical investigation for the selectivity of Eu(III)/Am(III) ions depending on the donor atoms by means of all-electron ZORA-DFT calculation. We estimated their selectivity as the relative stability in the complex formation reaction. The B2PLYP functional reproduced the experimental selectivity in which S- and N-donor ligands favor Am(III) ion, but O-donor ligand favors Eu(III) ion. Mulliken's bond overlap population analysis revealed that the contribution of the f orbital to the bonding was small or zero for Eu complex, whereas it was large for Am complex. The bonding nature of the f orbital for Am ion was the bonding type to S- and N-donor ligands, while it was the antibonding type to O-donor ligand. It was suggested that the difference in the bonding nature between the f orbital in the metal and the donor atoms determines the selectivity of Eu(III)/Am(III) by donor ligands.

  12. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives.

    Science.gov (United States)

    Souza, Marina Azevêdo; Johann, Susana; Lima, Luciana Alves Rodrigues dos Santos; Campos, Fernanda Fraga; Mendes, Isolda Castro; Beraldo, Heloisa; Souza-Fagundes, Elaine Maria de; Cisalpino, Patrícia Silva; Rosa, Carlos Augusto; Alves, Tânia Maria de Almeida; de Sá, Nívea Pereira; Zani, Carlos Leomar

    2013-05-01

    Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.

  13. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

    Directory of Open Access Journals (Sweden)

    Marina Azevedo Souza

    2013-05-01

    Full Text Available Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively. In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.

  14. 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.

  15. Synthesis, Characterization, and Antimicrobial and Antispermatogenic Activity of Bismuth(III and Arsenic(III Derivatives of Biologically Potent Nitrogen and Sulfur Donor Ligands

    Directory of Open Access Journals (Sweden)

    Latika Dawara

    2012-01-01

    Full Text Available A series of Bi(III and As(III complexes with two N∩S donor ligands, 1-(4-chloro-2-oxo-2H-chromen-3-yl-methylene-thiosemicarbazide (L1H and N′-[1-(2-oxo-2H-chrome-3yl-ethylidene]-hydrazinecarbodithionic acid benzyl ester (L2H have been synthesized by the reaction of BiCl3 and Ph3As with ligands in 1 : 1 and 1 : 2 molar ratios. All the synthesized compounds were characterized by elemental analyses, melting point determinations, and a combination of electronic, IR, 1H NMR, 13C NMR spectroscopic techniques, and X-ray diffraction for structure elucidation. In order to evaluate the effect of metal ions upon chelation, both the ligands and their complexes have been screened for their antimicrobial activity against the various pathogenic bacterial and fungal strains. The metal complexes have shown to be more antimicrobial against the microbial species as compared to free ligands. Both the ligands and their corresponding metal complexes have been tested for their antifertility activity in male albino rats. The marked reduction in sperm motility and density resulted in infertility. Significant alterations were found in biochemical parameters of reproductive organs in treated animals as compared to control group. It is concluded that all these effects may finally impair the fertility of male rats.

  16. Donor-Recipient Matching for KIR Genotypes Reduces Chronic GVHD and Missing Inhibitory KIR Ligands Protect against Relapse after Myeloablative, HLA Matched Hematopoietic Cell Transplantation.

    Directory of Open Access Journals (Sweden)

    Rehan Mujeeb Faridi

    Full Text Available Allogeneic hematopoietic cell transplantation (HCT can be curative for many hematologic diseases. However, complications such as graft-versus-host disease (GVHD and relapse of primary malignancy remain significant and are the leading causes of morbidity and mortality. Effects of killer Ig-like receptors (KIR-influenced NK cells on HCT outcomes have been extensively pursued over the last decade. However, the relevance of the reported algorithms on HLA matched myeloablative HCT with rabbit antithymocyte globulin (ATG is used for GVHD prophylaxis remains elusive. Here we examined the role of KIR and KIR-ligands of donor-recipient pairs in modifying the outcomes of ATG conditioned HLA matched sibling and unrelated donor HCT.The study cohort consisted of 281 HLA matched sibling and unrelated donor-recipient pairs of first allogeneic marrow or blood stem cell transplantation allocated into 'discovery' (135 pairs and 'validation' (146 pairs cohorts. High resolution HLA typing was obtained from the medical charts and KIR gene repertoires were obtained by a Luminex® based SSO method. All surviving patients were followed-up for a minimum of two years. KIR and HLA class I distributions of HCT pairs were stratified as per applicable definitions and were tested for their association with cause specific outcomes [acute GVHD grade II-IV (aGVHD, chronic GVHD needing systemic therapy (cGVHD and relapse] using a multivariate competing risks regression model as well as with survival outcomes [relapse-free survival (RFS, cGVHD & relapse free survival (cGRFS and overall survival (OS] by multivariate Cox proportional hazards regression model. A significant association between KIR genotype mismatching (KIR-B/x donor into KIR-AA recipient or vice versa and cGVHD was found in both discovery (p = 0.001; SHR = 2.78; 95%CI: 1.50-5.17 and validation cohorts (p = 0.005; SHR = 2.61; 95%CI: 1.33-5.11. High incidence of cGVHD associated with KIR genotype mismatching was

  17. Donor-Recipient Matching for KIR Genotypes Reduces Chronic GVHD and Missing Inhibitory KIR Ligands Protect against Relapse after Myeloablative, HLA Matched Hematopoietic Cell Transplantation.

    Science.gov (United States)

    Faridi, Rehan Mujeeb; Kemp, Taylor J; Dharmani-Khan, Poonam; Lewis, Victor; Tripathi, Gaurav; Rajalingam, Raja; Daly, Andrew; Berka, Noureddine; Storek, Jan; Masood Khan, Faisal

    2016-01-01

    Allogeneic hematopoietic cell transplantation (HCT) can be curative for many hematologic diseases. However, complications such as graft-versus-host disease (GVHD) and relapse of primary malignancy remain significant and are the leading causes of morbidity and mortality. Effects of killer Ig-like receptors (KIR)-influenced NK cells on HCT outcomes have been extensively pursued over the last decade. However, the relevance of the reported algorithms on HLA matched myeloablative HCT with rabbit antithymocyte globulin (ATG) is used for GVHD prophylaxis remains elusive. Here we examined the role of KIR and KIR-ligands of donor-recipient pairs in modifying the outcomes of ATG conditioned HLA matched sibling and unrelated donor HCT. The study cohort consisted of 281 HLA matched sibling and unrelated donor-recipient pairs of first allogeneic marrow or blood stem cell transplantation allocated into 'discovery' (135 pairs) and 'validation' (146 pairs) cohorts. High resolution HLA typing was obtained from the medical charts and KIR gene repertoires were obtained by a Luminex® based SSO method. All surviving patients were followed-up for a minimum of two years. KIR and HLA class I distributions of HCT pairs were stratified as per applicable definitions and were tested for their association with cause specific outcomes [acute GVHD grade II-IV (aGVHD), chronic GVHD needing systemic therapy (cGVHD) and relapse] using a multivariate competing risks regression model as well as with survival outcomes [relapse-free survival (RFS), cGVHD & relapse free survival (cGRFS) and overall survival (OS)] by multivariate Cox proportional hazards regression model. A significant association between KIR genotype mismatching (KIR-B/x donor into KIR-AA recipient or vice versa) and cGVHD was found in both discovery (p = 0.001; SHR = 2.78; 95%CI: 1.50-5.17) and validation cohorts (p = 0.005; SHR = 2.61; 95%CI: 1.33-5.11). High incidence of cGVHD associated with KIR genotype mismatching was applicable

  18. Anti-Inflammatory Oxicams as Multi-donor Ligand Systems: pH- and Solvent-Dependent Coordination Modes of Meloxicam and Piroxicam to Ru and Os.

    Science.gov (United States)

    Aman, Farhana; Hanif, Muhammad; Kubanik, Mario; Ashraf, Adnan; Söhnel, Tilo; Jamieson, Stephen M F; Siddiqui, Waseeq Ahmad; Hartinger, Christian G

    2017-04-06

    The nitrogen- and sulfur-containing 1,2-benzothiazines meloxicam and piroxicam are widely used as nonsteroidal anti-inflammatory drugs. Intrigued by the presence of multiple donor atoms and therefore potentially rich coordination chemistry, we prepared a series of organometallic Ru and Os compounds with meloxicam and piroxicam featuring either as mono- or bidentate ligand systems. The choice of the solvent and the pH value was identified as the critical parameter to achieve selectively mono- or bidentate coordination. The coordination modes were confirmed experimentally by NMR spectroscopy and single crystal X-ray diffraction analysis. Using DFT calculations, it was established that complexes in which meloxicam acts as a bidentate N,O donor are energetically more favorable than coordination as O,O and S,O donor systems. Since meloxicam and piroxicam derivatives have shown anticancer activity in the past, we aimed to compare the complexes with mono- and bidentate ligands on their in vitro anticancer activity. However, stability studies revealed that only the latter complexes were stable in [D 6 ]DMSO/D 2 O (5:95) and therefore no direct comparisons could be made. The meloxicam complexes 1 and 2 showed moderate cytotoxicity, whereas the piroxicam derivatives 5 and 6 were hardly active against the utilized cell lines. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Synthesis, spectroscopic characterization, electrochemistry and biological evaluation of some binuclear transition metal complexes of bicompartmental ONO donor ligands containing benzo[b]thiophene moiety

    Science.gov (United States)

    Mahendra Raj, K.; Vivekanand, B.; Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2014-02-01

    A series of new binucleating Cu(II), Co(II), Ni(II) and Zn(II) complexes of bicompartmental ligands with ONO donor were synthesized. The ligands were obtained by the condensation of 3-chloro-6-substituted benzo[b]thiophene-2-carbohydrazides and 4,6-diacetylresorcinol. The synthesized ligands and their complexes were characterized by elemental analysis and various spectroscopic techniques. Elemental analysis, IR, 1H NMR, ESI-mass, UV-Visible, TG-DTA, magnetic measurements, molar conductance and powder-XRD data has been used to elucidate their structures. The bonding sites are the oxygen atom of amide carbonyl, azomethine nitrogen and phenolic oxygen for ligands 1 and 2. The binuclear nature of the complexes was confirmed by ESR spectral data. TG-DTA studies for some complexes showed the presence of coordinated water molecules and the final product is the metal oxide. All the complexes were investigated for their electrochemical activity, only the Cu(II) complexes showed the redox property. Cu(II) complexes were square planar, whereas Co(II), Ni(II) and Zn(II) complexes were octahedral. Powder-XRD pattern have been studied in order to test the degree of crystallinity of the complexes and unit cell calculations were made. In order to evaluate the effect of antimicrobial activity of metal ions upon chelation, both the ligands and their metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The results showed that the metal complexes were found to be more active than free ligands. The DNA cleaving capacities of all the complexes were analyzed by agarose gel electrophoresis method against supercoiled plasmid DNA. Among the compounds tested for antioxidant capacity, ligand 1 displayed excellent activity than its metal complexes.

  20. A novel phosphorescent iridium(iii) complex bearing a donor-acceptor-type o-carboranylated ligand for endocellular hypoxia imaging.

    Science.gov (United States)

    Li, Xiang; Yin, Yongheng; Gao, Pengli; Li, Weijie; Yan, Hong; Lu, Changsheng; Zhao, Qiang

    2017-10-17

    The structure-property relationship of carborane-embedded cationic iridium(iii) complexes was investigated in this work, especially with donor-acceptor-type ligands. Firstly, an efficient synthetic approach for the new donor-acceptor-type ligands (2 and 4) was developed. By using these ligands, novel iridium(iii) complexes II and IV were prepared. Complex IV shows about a 92 nm red-shift in solution (Φ P = 0.13 in ethanol), and the emission color has an obvious change from green to red when compared with the Model complex. In addition, the photophysical characteristics of complex IV are quite sensitive to the oxygen level in living cells, based on which endocellular hypoxia imaging of complex IV has been realized by the phosphorescence lifetime imaging microscopy (PLIM) technology. Besides the experimental studies, density functional theory (DFT) and time dependent DFT (TD-DFT) calculations have been successfully applied to investigate the excited-state electronic structures of carborane-modified iridium complexes.

  1. Separation of americium(III) and europium(III) from nitrate medium using a binary mixture of Cyanex-301 with neutral donor ligands

    International Nuclear Information System (INIS)

    Bhattacharyya, A.; Mohapatra, P.K.; Manchanda, V.K.

    2005-01-01

    Separation behaviour of Am 3+ and Eu 3+ was investigated from aqueous nitrate medium using a binary mixture of Cyanex-301 (bis(2,4,4- trimethylpentyl) dithiophosphinic acid) and several N, O or S donor ligands such as 1,10-phenanthroline (phen), TPTZ (2,4,6- tri(2-pyridyl)- 1,3,5- triazine), 2,2'-bipyridyl(bipy), hexa thia 18 crown 6 (S 6 18C6), TBP (tri-n-butyl phosphate), TBTP (tri-n-butyl thiophosphate) in toluene. The S.F. values of >40,000 obtained with bipy and phen are the highest reported to date. (author)

  2. Conformational supramolecular isomerism in one-dimensional silver(I) coordination polymer of a flexible bis(bidentate) N,N-donor ligand with p-xylyl spacer.

    Science.gov (United States)

    Chakraborty, Biswarup; Halder, Partha; Paine, Tapan Kanti

    2011-04-14

    The isolation and structural characterisation of three isomeric silver(I) complexes, 1a, 1b and 2 with the general formula {[AgL(1)]ClO(4)}(n) (where L(1) is a bis(bidentate) N,N-donor ligand derived from the Schiff-base condensation of α,α'-diamino-p-xylene and pyridine-2-carboxaldehyde) are discussed. Single-crystal X-ray structures reveal the polymeric nature for the complexes where all the silver ions are in pseudotetrahedral geometry with the AgN(4) coordination environment. Isomers 1a (Pc space group) and 1b (Cc space group) were crystallised from acetonitrile whereas 2 (C2/c space group) was crystallised during the synthesis from a solvent mixture of dicholormethane and methanol. The flexible ligand (L(1)) adopts only an anti conformation in 1b and the presence of two different anti conformations in the repeating unit results in the formation of a trapezoidal wave polymeric chain. However, both gauche and anti conformations of the ligand are found to be present in the polymeric chains of 1a. In the polymeric chain of 2, only one anti isomer of the ligand is present in the repeating unit resulting in a triangular wave chain. The structure of isomer 1a is solvent induced and solvent plays a major role in the crystal packing of this isomer. One-dimensional coordination polymers 1a, 1b and 2 are related to each other as conformational supramolecular isomers. Additionally, two independent polymeric chains parallel to each other: one triangular wave consisting of only an anti conformation and a trapezoidal wave chain consisting of alternate gauche and anti conformations of the ligand are observed in 1a. This is a rare example of two supramolecular isomers present in the same crystal. Six different conformers of the flexible ligand are observed in the crystals of coordination polymers. © The Royal Society of Chemistry 2011

  3. Synthesis, crystal structures, and properties of two novel cadmium(II)-organic frameworks based on asymmetric dicarboxylate and N-donor ligands

    Science.gov (United States)

    Chen, Xiaoli; Gao, Loujun; Zhang, Xiaoge; Han, Xuhua; Wang, Yao; Sun, Rong

    2014-08-01

    Two novel cadmium(II)-organic frameworks with asymmetric dicarboxylate and N-donor ligands, namely [Cd(cpa)(phen)]n (1) and {[Cd2(cpa)2(bpy)1.5]·0.5H2O}n (2) (H2cpa = 3-(4-benzoic)propionic acid, phen = 1,10-phenanthroline, bpy = 4,4";-bipyridine) have been hydrothermally synthesized and characterized by elemental analyses, FT-IR spectra, single-crystal X-ray diffraction analyses, TGA, powder XRD and fluorescent measurements. 1 displays a double zigzag chain structure containing 8-number and 22-number circles. 2 Shows a 6-connected 3D polymer network based on tetranuclear cadmium cluster units. The most striking feature of 2 is that a pair of identical 3D networks are interlocked with each other to the form a 2-fold interpenetrated 3D α-Po structural topology. The diverse structures of two complexes indicate that the skeleton of N-donor ligands plays a great role in the assembly of such different frameworks. In addition, the thermal stabilities, XRD and photoluminescence properties of 1-2 were also studied.

  4. Synthesis of mononuclear copper(II) complexes of N3O2 and N4O2 donors containing Schiff base ligands: Theoretical and biological observations

    Science.gov (United States)

    Mancha Madha, K.; Gurumoorthy, P.; Arul Antony, S.; Ramalakshmi, N.

    2017-09-01

    A new series of six mononuclear copper(II) complexes were synthesized from N3O2 and N4O2 donors containing Schiff base ligands, and characterized by various spectral methods. The geometry of the complexes was determined using UV-Vis, EPR and DFT calculations. The complexes of N3O2 donors (1-3) adopted square pyramidal geometry and the remaining complexes of N4O2 donors (4-6) show distorted octahedral geometry around copper(II) nuclei. Redox properties of the complexes show a one-electron irreversible reduction process in the cathodic potential (Epc) region from -0.74 to -0.98 V. The complexes show potent antioxidant activity against DPPH radicals. Molecular docking studies of complexes showed σ-π interaction, hydrogen bonding, electrostatic and van der Waals interactions with VEGFR2 kinase receptor. In vitro cytotoxicity of the complexes was tested against human breast cancer (MDA-MB-231) cell lines and one normal human dermal fibroblasts (NHDF) cell line through MTT assay. The morphological assessment data obtained by Hoechst 33258 and AO/EB staining revealed that the complexes induce apoptosis pathway of cell death.

  5. Attachment of Luminescent Neutral “Pt(pq(C≡CtBu” Units to Di and Tri N-Donor Connecting Ligands: Solution Behavior and Photophysical Properties

    Directory of Open Access Journals (Sweden)

    Elena Lalinde

    2014-10-01

    Full Text Available Binuclear derivatives [{Pt(pq(C≡CtBu}2(μ-L] (1a–5a, containing a series of dinitrogen linker ligands and the trinuclear [{Pt(pq(C≡CtBu}3(μ-L] (6a [L = μ-1,3,5-tris(pyridine-4-ylethynylbenzene], formed by bridge-splitting reactions with [Pt(pq(μ-κCα:η2-C≡CtBu]2 (Pt-1, are reported. The complexes are characterized by a combination of 1H NMR spectroscopy, mass spectrometry and X-ray crystallography (2a and 4a. 1H NMR proves the existence of a dynamic equilibrium in solution between the diplatinum complexes (species a, the corresponding mononuclear complex with terminal N-donor ligands (species b, the starting material (Pt-1 and the free ligand (L. The effects of concentration, temperature and solvent properties on the equilibrium have been studied. The optical properties of these systems have been investigated by UV-visible absorption and emission spectroscopies in solid state and in solution, and the nature of the transitions and the excited state analyzed by theoretical calculations on 2a.

  6. Thio- and Semicarbazones: Hope in the Search for Treatment of Leishmaniasis and Chagas Disease.

    Science.gov (United States)

    Silva, Barbara V; Silva, Bianca N M

    2017-01-01

    Trypanosomiasis and leishmaniasis cause severe infections in humans and domestic animals in the tropics. Although typical diseases in Latin America, globalization and the migration of infected people has spread these diseases to countries in North America, Asia and Europe. Currently available drugs are not effective in the chronic phase, as well as cause side effects and develop resistance. Among the chemical groups studied as potential anti-T. cruzi and anti-Leishmania are the thio-and semicarbazones, which are easy to obtain, possess structural versatility and can sequester metal. In this article, we present an overview of thio-and semicarbazones associated with heterocycles, indanones, and styryl and aryl skeletons, including their metal complexes with antimony, platinum, palladium, copper, ruthenium, rhenium, manganese and vanadium. Because of the efficiency and selectivity that some of these derivatives have shown, it can be concluded that thio-and semicarbazones constitute promising chemical scaffolds in the search for new anti-parasitic agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. 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.

  8. Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua, E-mail: songhuihua@mail.hebtu.edu.cn; Yu, Hai-Tao, E-mail: haitaoyu@mail.hebtu.edu.cn

    2016-01-15

    Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H{sub 2}bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H{sub 2}O)]{sub n} (1), [Cd(bzgluO)(2,4′-bipy){sub 2}(H{sub 2}O)·3H{sub 2}O]{sub n} (2), [Cd(bzgluO)(phen)·H{sub 2}O]{sub n} (3), [Cd(bzgluO)(4,4′-bipy)(H{sub 2}O)]{sub n} (4), [Cd(bzgluO)(bpp)(H{sub 2}O)·2H{sub 2}O]{sub n} (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H{sub 2}bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H{sub 2}bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H{sub 2}bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid

  9. Synthetic routes to mixed-ligand cobalt(III) dithiocarbamato complexes containing imidazole, amine and pyridine donors and the X-ray crystal structure of a cobalt(III) bis(dithiocarbamato) histamine complex.

    Science.gov (United States)

    Hodgson, Michael C; Brothers, Penelope J; Clark, George R; Ware, David C

    2008-04-01

    The binuclear cobalt complex [Co(2)(Me(2)dtc)(5)](+) reacts with a range of nitrogen donor ligands L' or L'' to form an equimolar mixture of Co(Me(2)dtc)(3) and the mixed-ligand complexes [Co(Me(2)dtc)(2)(L')(2)](+) or [Co(Me(2)dtc)(2)(L'')](+), where (L')(2) is two monodentate ligands and (L'') is one bidentate ligand. The complexes prepared by this route contain the monodentate ligands L'=1-methyl-imidazole, 1-methyl-5-nitro-imidazole and benzimidazole, all of which coordinate to cobalt through an imidazole nitrogen atom. Symmetrical bidentate ligand complexes contain the bisimidazole L''=2,2'-bis(4,5-dimethylimidazole), the diamine L''=1,2-diaminobenzene and the pyridine donors L''=2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine and 1,10-phenanthroline. Two examples of complexes with unsymmetrical bidentate imidazole-amine donors were prepared in which L''=4-(2-aminoethyl)imidazole (histamine) and 2-aminomethylbenzimidazole. All new complexes were fully characterised, and the X-ray crystal structure of the histamine complex [Co(Me(2)dtc)(2)(hist)]ClO(4) is also reported.

  10. Cytotoxic, antibacterial, DNA interaction and superoxide dismutase like activities of sparfloxacin drug based copper(II) complexes with nitrogen donor ligands.

    Science.gov (United States)

    Patel, Mohan N; Joshi, Hardik N; Patel, Chintan R

    2013-03-01

    The novel neutral mononuclear copper(II) complexes with fluoroquinolone antibacterial drug, sparfloxacin and nitrogen donor heterocyclic ligand have been synthesized and characterized. An antimicrobial efficiency of the complexes has been tested against five different microorganisms and showed diverse biological activity. The interaction of complex with Herring sperm (HS) DNA was investigated using viscosity titration and absorption titration techniques. The results indicate that the complexes bind to DNA by intercalative mode and have rather high DNA-binding constants. DNA cleavage study showed better cleaving ability of the complexes compare to metal salt and standard drug. All the complexes showed good cytotoxic activity with LC(50) values ranging from 4.89 to 11.94 μg mL(-1). Complexes also exhibit SOD-like activity with their IC(50) values ranging from 0.717 to 1.848 μM. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Studies on coordination chemistry and bioactivity of some nitrogen-sulfur donor ligands with some heavy metal ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Zakaria, C.M.; Wan bin Abdullah; Grouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-08-01

    A bidentate NS ligand, hydraziniumdithiocarbazate (HzDTC), was prepared. The reaction of HzDTC with benzoin (HzDTCl) yielded a new Schiff base. Some complexes of cadmium(II), tin(II) and antimony(III) containing HzDTC and S-picolyldithiocarbazate (SPDTC) were prepared and characterized by a variety of physico-chemical techniques. The structure of the Schiff base, bis(methylphenyl)methylene (N-phenylmethylene-N'-phenylmethine)hydrazine, was solved by X-ray crystallography. The HzDTC and SPDTC behaved as uninegatively charged bidentate ligands. The antibacterial and anti-fungal properties of ligands and their metal complexes were evaluated against four pathogenic bacteria and fungi. HzDTC was very effective against all the microbes while the complexes of HzDTC were antibacterial. The complexes of SPDTC were effective against fungi. [Cd(HzDTC)Br. H 2 O], in particular, was moderately active against CEM-SS (human cell T-lymphoblastic leukemia) cells. (author)

  12. Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

    Science.gov (United States)

    Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

    2016-01-01

    Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2‧-bipy)(H2O)]n (1), [Cd(bzgluO)(2,4‧-bipy)2(H2O)·3H2O]n (2), [Cd(bzgluO)(phen)·H2O]n (3), [Cd(bzgluO)(4,4‧-bipy)(H2O)]n (4), [Cd(bzgluO)(bpp)(H2O)·2H2O]n (5) were synthesized (2,2‧-bipy=2,2‧-bipyridine, 2,4‧-bipy=2,4‧-bipyridine, phen=1,10-phenanthroline, 4,4‧-bipy=4,4‧-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1-2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π-π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π-π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H2bzgluO. Luminescent properties of 1-5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated.

  13. Synthesis, spectral and thermal studies of some dioxouranium(VI) coordination compounds of 4[N -( 4- hydroxy -3- methoxybenzalidene ) amino] antipyrine semicarbazone and 4[N-(3,4,5- trimethoxybenzalidene) amino] antipyrine semicarbazone

    International Nuclear Information System (INIS)

    Singh, Lakshman; Singh, U.P.; Chakraborti, Indranil

    2001-01-01

    In view of high coordination compounds formed by actinide metal ions, the present work describes the 8, 9 and 10-coordinated compounds of dioxouranium(IV) with 4[N-(4-hydroxy-3-methoxy-benzalidene) amino] antipyrine semicarbazone (HMBAAPS) and 4[N-(3,4,5-trimethoxybenzalidene) amino] antipyrine semicarbazone (TMBAAPS) with the general composition UO 2 X 2 .L (X = Br - , I - , NCS - or ClO 4 ) and UO 2 X 2 .L (X = NO 3 - or CH 3 COO - , and L HMBAAPS or TMBAAPS). All these complexes were characterized through elemental, spectral and thermal studies. (author)

  14. New mixed ligand cobalt(II/III) complexes based on the drug sodium valproate and bioactive nitrogen-donor ligands. Synthesis, structure and biological properties

    Science.gov (United States)

    Abu Ali, Hijazi; Abu Shamma, Amani; Kamel, Shayma

    2017-08-01

    New cobalt valproate complexes with different nitrogen based ligands were synthesized and characterized using various techniques such as IR, UV-Vis, single crystal X-ray diffraction as well as other physical properties. The general formula of the prepared complexes is [Con(valp)m(L)z], (n = 1, 2 …; m = 1, 2, …; Z = 1, 2 …). The complexes [Co2(valp)4] (1), [Co(valp)2(2-ampy)2] (2) and [Co2(valp)4(quin)2] (3) showed different carboxylate coordination modes. The crystal structures of the complexes 2 and 3 were determined using single crystal X-ray diffraction. Kinetic studies of hydrolysis reactions of BNPP [bis-(p-nitrophenyl)phosphate] with complexes 2 and 3 were performed. The hydrolysis rate of BNPP was studied at different temperatures, pH and concentrations by UV-Vis spectrophotometric method. The results showed that the hydrolysis rate of BNPP was 7.70 × 102 L mol-1 s-1 for (3) and 2.60 × 10-1 L mol-1 s-1 for (2).

  15. 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.

  16. Improving the Response of Copper(II) Selective PVC Membrane Electrode by Modification of N2S2 Donor Ligand.

    Science.gov (United States)

    Brinić, Slobodan; Buzuk, Marijo; Generalić, Eni; Bralić, Marija

    2010-06-01

    S,S'-bis(2-aminophenyl)ethanebis(thioate), (APhET), is reported as N2S2 ligand which form chelate with copper of high stability as compared to the other metals. Two modification of APhET, simpler 1,2-di-(o-aminophenylthio)ethane (DAPhTE), and the complex one 1,2-di-(o-salicylaldiminophenylthio)ethane (SAPhTE), were examined as the active material for copper(II) ion selective PVC membrane electrodes, and observed results are correlated. The obtained results with DAPhTE based electrodes show that only coordination abilities of ligand are insufficient for preparing the efficient membrane material. On the other hand, the results that are achieved with electrodes based on SAPhTE actuate interaction of ligand with polymer membrane matrix and necessity of ionophore immobilization in membrane. Optimized SAPhTE based membrane electrode has a linear range down to 10-6 mol L-1, with slope of 27.0 mV per decade, very rapid response time (under 5 seconds) and detection limit of 5.1 × 10-7 mol L-1. Such electrode is suitable for determination of copper(II) in analytical measurements by direct potentiometry and in potentiometric titrations, within pH between 2 and 7. The electrode is selective for copper(II) ions over a large number of metal ions, with the exception on Hg2+ ion when is present in concentrations above 2 × 10-5 mol L-1.

  17. Ab initio and density functional theoretical design and screening of model crown ether based ligand (host) for extraction of lithium metal ion (guest): effect of donor and electronic induction.

    Science.gov (United States)

    Boda, Anil; Ali, Sk Musharaf; Rao, Hanmanth; Ghosh, Sandip K

    2012-08-01

    The structures, energetic and thermodynamic parameters of model crown ethers with different donor, cavity and electron donating/ withdrawing functional group have been determined with ab initio MP2 and density functional theory in gas and solvent phase. The calculated values of binding energy/ enthalpy for lithium ion complexation are marginally higher for hard donor based aza and oxa crown compared to soft donor based thia and phospha crown. The calculated values of binding enthalpy for lithium metal ion with 12C4 at MP2 level of theory is in good agreement with the available experimental result. The binding energy is altered due to the inductive effect imparted by the electron donating/ withdrawing group in crown ether, which is well correlated with the values of electron transfer. The role of entropy for extraction of hydrated lithium metal ion by different donor and functional group based ligand has been demonstrated. The HOMO-LUMO gap is decreased and dipole moment of the ligand is increased from gas phase to organic phase because of the dielectric constant of the solvent. The gas phase binding energy is reduced in solvent phase as the solvent molecules weaken the metal-ligand binding. The theoretical values of extraction energy for LiCl salt from aqueous solution in different organic solvent is validated by the experimental trend. The study presented here should contribute to the design of model host ligand and screening of solvent for metal ion recognition and thus can contribute in planning the experiments.

  18. [Bis(TrimethylsilylMethyl]Lithium and -Sodium: Solubility in Alkanes and Complexes with O- and N- Donor Ligands

    Directory of Open Access Journals (Sweden)

    Markus von Pilgrim

    2017-06-01

    Full Text Available In contrast to alkyl compounds of lithium, which play an important role in organometallic chemistry, the corresponding heavier alkali metal compounds are less investigated. These compounds are mostly insoluble in inert solvents or undergo solvolysis in coordinating solvents due to their high reactivity. An exception from this typical behavior is demonstrated by bis(trimethylsilylmethylsodium. This study examines alkane solutions of bis(trimethylsilylmethyllithium and -sodium by NMR spectroscopic and cryoscopic methods. In addition, structural studies by X-ray crystallography of the corresponding compounds coordinated by O- and N- ligands (tetrahydrofuran and tetramethylethylenediamine present possible structural motifs of the uncoordinated compounds in solution.

  19. Inspection of the duality of a verdazyl-based radical in transition metal complexes: a pi* donor ligand and a magnetic partner.

    Science.gov (United States)

    Rota, Jean-Baptiste; Norel, Lucie; Train, Cyrille; Ben Amor, Nadia; Maynau, Daniel; Robert, Vincent

    2008-08-06

    The behavior of a verdazyl-based radical bound to open-shell transition metal ions in the structurally and magnetically characterized [M(hfac)2imvd(o)] (M = Mn, Ni; hfac = (1,1,1,5,5,5)hexafluoroacetylacetonate; imvd(o) = 3-(2'-imidazolyl)-1,5-dimethyl-6-oxoverdazyl) complexes is rationalized using ab initio wave-function-based calculations analysis. The calculated exchange coupling constants J (H = -J(s(M) x s(imvd(o)); J(Mn)(calcd) = -63 cm(-1), J(Ni)(calcd) = 205 cm(-1)) are in excellent agreement with the experimental ones (J(Mn)(exp) = -63 cm(-1), J(Ni)(exp) = 193 cm(-1)). Even though both rings are involved through the binding mode of the imvd(o) radical, the spin density remains essentially localized on the nitrogen-rich ring. The singularity stems from its bidentate coordinating character. The analysis of the correlated wave function suggests that the verdazyl-based radical acts as a pi* donor ligand which allows ligand-to-metal charge transfer and excludes metal-to-ligand charge transfer. This reflects the weak covalent character of the M-imvd(o) pi coordination bond. From a magnetic point of view, the through-space exchange governs the ferromagnetic character in the Ni derivative up to 153 cm(-1) as expected from a description limited to the magnetic orbitals. Nevertheless, the CI expansion displays the participation of excited doublet and quartet states (spin polarization) on the verdazyl moiety which leads to a significant additional ferromagnetic contribution (52 cm(-1)). In the [Mn(hfac)2imvd(o)] analogue, the antiferromagnetic contribution arising from kinetic exchange is only one-third of the observed exchange coupling constant. It is necessary to introduce dynamical correlation effects to quantitatively recover the exchange interaction in this compound. Since the pi* donor and spin-polarized characters of the verdazyl moiety dominate over the negligible polarizability of the imidazole part, it is concluded that the noninnocent nature of the imvd

  20. Impact of Donor Activating KIR Genes on HSCT Outcome in C1-Ligand Negative Myeloid Disease Patients Transplanted with Unrelated Donors—A Retrospective Study

    Science.gov (United States)

    Neuchel, Christine; Fürst, Daniel; Niederwieser, Dietger; Tsamadou, Chrysanthi; Wulf, Gerald; Pfreundschuh, Michael; Wagner, Eva; Stuhler, Gernot; Einsele, Hermann; Schrezenmeier, Hubert; Mytilineos, Joannis

    2017-01-01

    Natural Killer cells (NK) are lymphocytes with the potential to recognize and lyse cells which escaped T-cell mediated lysis due to their aberrant HLA expression profiles. Killer cell immunoglobulin-like receptors (KIR) influence NK-cell activity by mediation of activating or inhibitory signals upon interaction with HLA-C (C1, C2) ligands. Therefore, absence of ligands for donor inhibitory KIRs following hematopoietic stem cell transplantation (HSCT) may have an influence on its outcome. Previous studies showed that C1 negative patients have a decreased HSCT outcome. Our study, based on a cohort of 200 C1-negative patients, confirmed these findings for the endpoints: overall survival (OS: HR = 1.41, CI = 1.14–1.74, p = 0.0012), disease free survival (DFS: HR = 1.27, CI = 1.05–1.53, p = 0.015), treatment related mortality (TRM: HR = 1.41, CI = 1.01–1.96, p = 0.04), and relapse incidence (RI: HR = 1.33, CI = 1.01–1.75, p = 0.04) all being inferior when compared to C1-positive patients (n = 1246). Subsequent analysis showed that these findings applied for patients with myeloid malignancies but not for patients with lymphoproliferative diseases (OS: myeloid: HR = 1.51, CI = 1.15–1.99, p = 0.003; lymphoblastic: HR = 1.26, CI = 0.91–1.75, p = 0.16; DFS: myeloid: HR = 1.31, CI = 1.01–1.70, p = 0.04; lymphoblastic: HR = 1.21, CI = 0.90–1.61, p = 0.21; RI: myeloid: HR = 1.31, CI = 1.01–1.70, p = 0.04; lymphoblastic: HR = 1.21, CI = 0.90–1.61, p = 0.21). Interestingly, within the C1-negative patient group, transplantation with KIR2DS2 resulted in better OS (9/10 matched: HR = 0.24, CI = 0.08–0.67, p = 0.007) as well as DFS (9/10 matched: HR = 0,26, CI = 0.11–0.60, p = 0.002), and transplantation with KIR2DS1 positive donors was associated with a decreased RI (HR = 0.30, CI = 0.13–0.69, p = 0.005). TRM was increased when the donor was positive for KIR2DS1 (HR = 2.61, CI = 1.26–5.41, p = 0.001). Our findings suggest that inclusion of KIR2DS1/2/5 and

  1. Synthesis, spectral characterization, computational calculations and biological activity of complexes designed from NNO donor Schiff-base ligand

    Science.gov (United States)

    El-Gammal, Ola A.; El-Reash, G. M. Abu; Yousef, T. A.; Mefreh, M.

    2015-07-01

    A new series of Co(II), Ni(II) and Cu(II) complexes of (Z)-2-oxo-2-(phenylamino)-N‧-(1-(pyridin-2-yl)ethylidene)acetohydrazide (H2OPPAH) have been prepared and characterized by conventional techniques. The spectral data indicated that the ligand acts as neutral or mononegative NNO tridentate. On the basis of magnetic and electronic spectral data an octahedral geometry for Ni(II) and Cu(II) complexes and a tetrahedral geometry for Co(II) complex have been proposed. The molecular modeling using DFT method are drawn showing the bond length, bond angle, chemical reactivity, energy components (kcal/mol) and binding energy (kcal/mol) for all title compounds. The Kinetic parameters were determined for each thermal degradation stages of the ligand and its complexes using Coats-Redfern and Horowitz-Metzger methods. Also, the compounds were screened for antioxidant activity using ABTS free radical, anti-hemolytic, and in vitro cytotoxic assay. H2OPPAH showed the potent antioxidant activity followed by Co(II) and Cu(II) complexes. On the other hand Ni(II) complex exhibited weak antioxidant activity using ABTS free radical and Erlich and strong erythrocyte hemolysis activity.

  2. Spectroscopic studies of transition metal complexes with a N-donor tetradentate(N 4) 12-membered macrocylic ligand

    Science.gov (United States)

    Chandra, Sulekh; Verma, Shweta

    2008-11-01

    Chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), ruthenium(III), iridium(III), palladium(II) and platinum(II) complexes were synthesized with a 12-membered 1,4,7,10-tetraazadodeca-5,6,11,12-tetraene macrocylic ligand (L) and characterized by elemental analysis, molar conductance, magnetic susceptibility, IR, electronic, EPR and Mössbauer [Fe(III)] spectral studies. The molar conductance measurements of all the complexes in DMF solution correspond to non-electrolytic nature for M(L)Cl 2 complexes [where M = Mn(II), Co(II), Ni(II), Cu(II)], 1:1 electrolytes for M'(L)Cl 3 complexes [where M' = Cr(III), Fe(III), Ru(III) and Ir(III)] and 1:2 electrolytes for M″(L)Cl 2 complexes [where M″ = Pd(II) and Pt(II)]. Thus, the complexes may be formulated as [M(L)C1 2], [M'(L)C1 2]C1 and [M″(L)]C1 2, respectively [where L = ligand]. All complexes were of the high-spin type and found to have six-coordinate octahedral geometry except the Pd(II) and Pt(II) complexes which were four coordinate, square planar and diamagnetic.

  3. Studies on coordination chemistry and biological activities of a nitrogen-sulfur donor ligand with lighter and heavier metal ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Asmadi, A.; Talib, S.M.S.; Ali, A.M.; Crouse, K.A.

    1999-05-01

    Complexes of S-benzyldithiocarbazate (SBDTC) with lighter and heavier metals, viz., Cr(III), Fe(III), Sb(III), Zr(IV), Th(IV), and U(VI) have been prepared and characterized by elemental analyses, conductivity measurements, and spectral studies. The complexes were all prepared in alkaline media with the compositions of [Cr(SBDTCA) 3 ], [Fe(SBDTCA) 3 ], [Sb(SBDTCA) 3 ], [Sb(SBDTCA) 2 CI.H 2 O], [Zr(O)(SBDTCA) 2 .H 2 O], [Th(SBDTCA)(NO 3 ) 3 .H 2 O)], and [U(O) 2 (SBDTCA) 2 ]. The complexes were all hexa-coordinated with bidentate, uninegative chelation of the ligand. [Fe(SBDTCA) 3 ], [Sb(SBDTCA) 3 ] and [Sb(SBDTCA) 2 CI.H 2 O] were strongly effective against bacteria, Pseudomonas aeruginosa and Bacillus cereus giving clear inhibition zones. The compounds were poor antifungal. (author)

  4. Two coordination polymers based on semicarbazone Schiff base and azide: synthesis, crystal structure, electrochemistry, magnetic properties and biological activity

    Czech Academy of Sciences Publication Activity Database

    Shaabani, B.; Khandar, A.A.; Dušek, Michal; Pojarová, Michaela; Mahmoudi, F.; Feher, A.; Kajňaková, M.

    2013-01-01

    Roč. 66, č. 5 (2013), s. 748-762 ISSN 0095-8972 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378271 Keywords : Schiff bases * semicarbazone * coordination polymer * structure analyses Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.224, year: 2013

  5. A series of Cadmium(II) complexes with 2-substituted terephthalate building block and N-Donor co-ligands: Structural diversity and fluorescence properties

    Science.gov (United States)

    Ren, Yixia; Zhou, Shanhong; Wang, Zhixiang; Zhang, Meili; Wang, Jijiang; Cao, Jia

    2017-11-01

    Four new Cd(II) complexes have been prepared based on 1,2,4-trimellitic acid (H3tma) and monosodium 2-sulfoterephthalate (2-NaH2stp), formulated as [Cd2(Htma)2 (dpp)2(H2O)] (1), [Cd3 (tma)2 (2,4-bipy)4(H2O)2] (2), [Cd (2-Hstp) (2,2'-bipy)2]·2H2O (3) and [Cd (2-Hstp) (2,4-bipy) (H2O)2] (4) (dpp = dipyrido [3,2-a:2‧,3'-c] phenazine, 2,4-bipy = 2,4-bipyridine, 2,2'-bipy = 2,2'- bipyridine) by hydrothermal method. X-ray diffraction structural analyses show all these complexes crystallized in triclinic crystal system of Pī space group, but their structures are diverse. Complex 1 exhibits an infinite one-dimensional chain featuring the left- and right-handed stranded chains interweaved each other. For 2, the two-dimensional network is constructed by one-dimensional ladder-like chain linked by Cd2 ions. In complex 3, the cadmium ion is surrounded with one 2-Hstp2- anion and two 2,2'-bipy molecules. Complex 4 is also a discrete structure based on a metallic dimer unit. In all these complexes, the N-donor co-ligands take the important roles in the assembly of three-dimensional supramolecular structures. The fluorescence properties of complexes 1-4 could be assigned to the π - π* transition of organic ligands.

  6. Thermodynamic study on the complexation of Trivalent actinide and lanthanide cation by N-donor ligands in homogeneous conditions; Etude thermodynamique de la complexation des ions actinide (III) et lanthanide (III) par des ligands polyazotes en milieu homogene

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M

    2004-07-01

    Polydentate N-donor ligands, alone or combined with a synergic acid, may selectively extract minor actinides(III) from lanthanide(III) ions, allowing to develop separation processes of long-live radioelements. The aim of the researches carried out during this thesis was to better understand the chemical mechanisms of the complexation of f-elements by Adptz, a tridentate N-donor ligand, in homogeneous conditions. A thermodynamic approach was retained in order to estimate, from an energetic point of view, the influence of the different contributions to the reaction, and to acquire a complete set of thermodynamic data on this reaction. First, the influence of the nature of the cation on the thermodynamics was considered. The stability constants of the 1/1 complexes were systematically determined by UV-visible spectrophotometry for every lanthanide ion (except promethium) and for yttrium in a mixed solvent methanol/water in volume proportions 75/25%. The thermodynamic parameters ({delta}H{sup 0} {delta}{sup S}) of complexation were estimated by the van't Hoff method and by micro-calorimetry. The trends of the variations across the lanthanide series are compared with similar studies. The same methods were applied to the study of three actinide(III) cations: plutonium, americium and curium. The comparison of these values with those obtained for the lanthanides highlights the increase of stability of these complexes by a factor of 20 in favor of the actinide cations. This gap is explained by a more exothermic reaction and is associated, in the data interpretation, to a higher covalency of the actinide(III)-nitrogen bond. Then, the influence of the change of solvent composition on the thermodynamic of complexation was studied. The thermodynamic parameters of the complexation of europium(III) by Adptz were determined for several fractions of methanol. The stability of the complex formed increases with the percentage of methanol in the mixed solvent, owing to an

  7. 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.

  8. Synthesis, characterization, crystal structure, superoxide dismutase and biological activities of nickel (II) complexes with bidentate ligands possessing N and O donor atoms

    Science.gov (United States)

    Sangeeta, S.; Ahmad, K.; Noorussabah, N.; Bharti, S.; Mishra, M. K.; Sharma, S. R.; Choudhary, M.

    2017-12-01

    Two new Schiff bases 2-((E)-(4-bromo-2-chlorophenylimino)methyl)-4-bromophenol(HL1) and1-((E)-(4-bromo-2-chlorophenylimino)methyl)naphthalene-2-ol (HL2) and their new nickel (II) complexes [Ni(L1)2]·DMF(1) and [Ni(L2)2] (2) have been synthesized and characterized by various physico- chemical and spectroscopic methods. The solid-state structures of synthesized compounds were determined by single crystal X-ray crystallography, which revealed square planar geometry around Ni (II) ion. Infrared spectra, UV-Vis, thermal analysis and magnetic susceptibility measurements agreed with the observed crystal structures. The ligand (HL1) crystallized in the Orthorhombic system of the space group Pbca,a = 7.5485(4)Å, b = 11.5514(5) Å, c = 30.1370(14)Å, α = 90°, β = 90°, γ = 90°and Z = 8. Complex[Ni(L1)2]·DMF(1) crystallized in the Triclinic system of the space group P-1, a = 8.9954(3) Å, b = 9.4593(4) Å, c = 13.2657(5) Å, α = 101.478°, β = 99.595°, γ = 117.651°and Z = 2, whereas complex [Ni(L2)2]·(2) crystallized in the Monoclinic system of the space group P21/c, a = 9.301(9)Å, b = 12.149(8)Å, c = 13.792(10)Å, α = 90°, β = 106.35(4).°, γ = 90°and Z = 2. The Schiff bases (HL1and HL2) behaved as monobasic bidentate ligands possessing N and O donor atoms. The SOD activities of HL1 and its Ni (II) complex[Ni(L1)2]·DMF(1) have been measured using xanthine-xanthine oxidase as a source of superoxide radical and NBT assay as O2- scavenger. In vitro antimicrobial activities of the Ni(II) complexes (1) and (2)against Bacillus cereus and Staphylococcus aureus as Gram + ve and Salmonella typhi, Klebsiella pneumonia and Escherichia coli as Gram-ve species have been investigated comparing with the Schiff base ligands (HL1and HL2).

  9. Synthesis and coordination chemistry of two N2-donor chelating di(indazolyl)methane ligands: structural characterization and comparison of their metal chelation aptitudes.

    Science.gov (United States)

    Pettinari, Claudio; Marinelli, Alessandro; Marchetti, Fabio; Ngoune, Jean; Galindo, Agustín; Álvarez, Eleuterio; Gómez, Margarita

    2010-11-15

    The N(2)-donor bidentate ligands di(1H-indazol-1-yl)methane (L(1)) and di(2H-indazol-2-yl)methane (L(2)) (L in general) have been synthesized, and their coordination behavior toward Zn(II), Cd(II), and Hg(II) salts has been studied. Reaction of L(1) and L(2) with ZnX(2) (X = Cl, Br, or I) yields [ZnX(2)L] species (1-6), that, in the solid state, show a tetrahedral structure with dihapto ligand coordination via the pyrazolyl arms. The reaction of L(1) and L(2) with Zn(NO(3))(2)·6H(2)O is strongly dependent on the reaction conditions and on the ligand employed. Reaction of L(1) with equimolar quantities of Zn(NO(3))(2)·6H(2)O yields the neutral six-coordinate species [Zn(NO(3))(2)(L(1))], 7. On the other hand the use of L(1) excess gives the 2:1 adduct [Zn(NO(3))(2)(L(1))(2)], 8 where both nitrates act as a unidentate coordinating ligand. Analogous stoichiometry is found in the compound obtained from the reaction of L(2) with Zn(NO(3))(2)·6H(2)O which gives the ionic [Zn(NO(3))(L(2))(2)](NO(3)), 10. Complete displacement of both nitrates from the zinc coordination sphere is observed when the reaction between L(1) excess and the zinc salt was carried out in hydrothermal conditions. The metal ion type is also determining structure and stoichiometry: the reaction of L(2) with CdCl(2) gave the 2:1 adduct [CdCl(2)(L(2))(2)] 11 where both chlorides complete the coordination sphere of the six-coordinate cadmium center; on the other hand from the reaction of L(1) with CdBr(2) the polynuclear [CdBr(2)(L(1))](n) 12 is obtained, the Br(-) anion acting as bridging ligands in a six-coordinate cadmium coordination environment. The reaction of L(1) and L(2) with HgX(2) (X = Cl, I, SCN) is also dependent on the reaction conditions and the nature of X, two different types of adducts being formed [HgX(L)] (14: L = L(1), 16, 17: L = L(1) or L(2), X = I, 19: L = L(2), X = SCN) and [HgX(L)(2)] (15: L = L(2), X = Cl, 18: L = L(1), X = SCN). The X-ray diffraction analyses of compounds 1

  10. Synthetic aspects, spectral, thermal studies and antimicrobial screening on bis(N,N-dimethyldithiocarbamato-S,S‧)antimony(III) complexes with oxo or thio donor ligands

    Science.gov (United States)

    Chauhan, H. P. S.; Carpenter, Jaswant; Joshi, Sapana

    2014-09-01

    The bis(N,N-dimethyldithiocarbamato-S,S‧)antimony(III) complexes have been obtained by the reaction of chloro bis(N,N-dimethyldithiocarbamato-S,S‧)antimony(III) with corresponding oxo or thio donor ligands such as sodium benzoate 1, sodium thioglycolate 2, phenol 3, sodium 1-propanethiolate 4, potassium thioacetate 5, sodium salicylate 6, ethane-1,2-dithiolate 7 and disodium oxalate 8. These complexes have been characterized by the physicochemical [melting point, molecular weight determination and elemental analysis (C, H, N, S and Sb)], spectral [UV-Visible, FT-IR, far IR, NMR (1H and 13C)], thermogravimetric (TG & DTA) analysis, ESI-Mass and powder X-ray diffraction studies. Thermogravimetric analysis of the complexes confirmed the final decomposition product as highly pure antimony sulfide (Sb2S3) and powder X-ray diffraction studies show that the complexes are in lower symmetry with monoclinic crystal lattice and nano-ranged particle size (11.51-20.82 nm). The complexes have also been screened against some bacterial and fungal strains for their antibacterial and antifungal activities and compared with standard drugs. These show that the complexes have greater activities against some human pathogenic bacteria and fungi than the activities of standard drugs.

  11. Synthetic aspects, spectral, thermal studies and antimicrobial screening on bis(N,N-dimethyldithiocarbamato-S,S')antimony(III) complexes with oxo or thio donor ligands.

    Science.gov (United States)

    Chauhan, H P S; Carpenter, Jaswant; Joshi, Sapana

    2014-09-15

    The bis(N,N-dimethyldithiocarbamato-S,S')antimony(III) complexes have been obtained by the reaction of chloro bis(N,N-dimethyldithiocarbamato-S,S')antimony(III) with corresponding oxo or thio donor ligands such as sodium benzoate 1, sodium thioglycolate 2, phenol 3, sodium 1-propanethiolate 4, potassium thioacetate 5, sodium salicylate 6, ethane-1,2-dithiolate 7 and disodium oxalate 8. These complexes have been characterized by the physicochemical [melting point, molecular weight determination and elemental analysis (C, H, N, S and Sb)], spectral [UV-Visible, FT-IR, far IR, NMR (1H and 13C)], thermogravimetric (TG & DTA) analysis, ESI-Mass and powder X-ray diffraction studies. Thermogravimetric analysis of the complexes confirmed the final decomposition product as highly pure antimony sulfide (Sb2S3) and powder X-ray diffraction studies show that the complexes are in lower symmetry with monoclinic crystal lattice and nano-ranged particle size (11.51-20.82 nm). The complexes have also been screened against some bacterial and fungal strains for their antibacterial and antifungal activities and compared with standard drugs. These show that the complexes have greater activities against some human pathogenic bacteria and fungi than the activities of standard drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Synthesis and characterization of toluene-3,4-dithiolatoantimony(III) derivatives with some oxygen and/or sulphur donor ligands.

    Science.gov (United States)

    Chauhan, H P S; Bhatiya, Sumit; Bakshi, Abhilasha

    2009-09-15

    Replacement reactions of toluene-3,4-dithiolatoantimony(III) chloride with oxygen and/or sulphur donor ligands like benzoic acid, thiobenzoic acid, thioacetic acid, phenol, thiophenol, sodium salicylate and thio glycolic acid in 1:1 molar ratio as well as disodium oxalate in 2:1 molar ratio in refluxing anhydrous benzene yielded toluene-3,4-dithiolatoantimony(III) mono oxo and/or thio carboxylic or phenolic derivatives of the general formula {R=OOCC(6)H(5), SOCC(6)H(5), SOCCH(3), OC(6)H(5), SC(6)H(5), OOCC(6)H(4)(OH) and SCH(2)COOH} and These newly synthesized derivatives are yellow and brown solids/liquids and are soluble in common organic solvents like benzene, chloroform, dichloromethane, etc. These derivatives have been characterized by melting point determination, molecular weight determination, elemental analysis (C, H, S and Sb), spectral {UV, IR and NMR ((1)H and (13)C)} and thermal (TGA, DTA and DSC) studies.

  13. Synthesis, spectroscopic, thermal and antimicrobial studies of toluene-3,4-dithiolatoarsenic(III) derivatives with some oxygen and sulphur donor ligands

    Science.gov (United States)

    Chauhan, H. P. S.; Bhatiya, Sumit

    2012-11-01

    Replacement reactions of toluene-3,4-dithiolatoarsenic(III) chloride with oxygen and sulphur donor ligands like benzoic acid, thiobenzoic acid, anhydrous sodium acetate, thioacetic acid, phenol, thiophenol, sodium salicylate and thio glycolic acid in 1:1 molar ratio as well as disodium oxalate in 2:1 molar ratio in refluxing anhydrous benzene yielded toluene-3,4-dithiolatoarsenic(III) mono oxo or thio carboxylic or phenolic derivatives of the general formula SC6H3(CH3)SAsR {where R = OOCC6H5, SOCC6H5, OOCCH3, SOCCH3, OC6H5, SC6H5, OOCC6H4(OH), SCH2COOH} and SC6H3(CH3)SAsOOC-COOAsS(CH3)C6H3S. These synthesized derivatives are yellow, yellow-brown solids/ liquids and are soluble in common organic solvents like benzene, chloroform, dichloromethane, dimethyl formamide, dimethyl sulphoxide etc. These derivatives have been characterized by melting point determination, molecular weight determination, elemental analysis (C, H, S and As), spectral {UV, IR, NMR (1H and 13C), ESI-Mass, SEM and powder X-ray diffraction} and thermal (TGA, DTA and DSC) studies. Some of these compounds have been screened for their antimicrobial activities using the disc diffusion method. These derivatives have shown good activity as antibacterial and antifungal agents on some selected bacterial and fungal strains, which increased on increasing the concentration. Chloroamphenicol and terbinafin were used as standards for the comparison.

  14. Electronic transitions and bonding properties in a series of five-coordinate "16-electron" complexes [Mn(CO)3(L2)]- (L2 = chelating redox-active .pi.-donor ligand)

    Czech Academy of Sciences Publication Activity Database

    Hartl, F.; Rosa, P.; Ricard, L.; Le Floch, P.; Záliš, Stanislav

    2007-01-01

    Roč. 251, 3-4 (2007), s. 557-576 ISSN 0010-8545 R&D Projects: GA MŠk 1P05OC068; GA AV ČR 1ET400400413 Institutional research plan: CEZ:AV0Z40400503 Keywords : manganese carbonyl * .pi.-donor ligand * electronic delocalization * Five-coordinate complex Subject RIV: CG - Electrochemistry Impact factor: 8.568, year: 2007

  15. Binuclear and tetranuclear Mn(II) clusters in coordination polymers derived from semirigid tetracarboxylate and N‑donor ligands: syntheses, new topology structures and magnetism

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiao-Ling [College of Chemistry and Chemical Engineering, and Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934 (China); Liu, Guang-Zhen, E-mail: gzliuly@126.com [College of Chemistry and Chemical Engineering, and Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934 (China); Xin, Ling-Yun [College of Chemistry and Chemical Engineering, and Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934 (China); Wang, Li-Ya [College of Chemistry and Chemical Engineering, and Henan Key Laboratory of Function-Oriented Porous Materials, Luoyang Normal University, Luoyang 471934 (China); College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang, Henan 473061 (China)

    2017-02-15

    Two topologically new Mn(II) coordination polymers, namely ([Mn{sub 2}(H{sub 4}ipca)(4,4′-bpy){sub 1.5}(CH{sub 3}CH{sub 2}OH){sub 0.5}(H{sub 2}O){sub 1.5}]·0.5CH{sub 3}CH{sub 2}OH·2.5H{sub 2}O){sub n} (1) and (Mn{sub 4}(H{sub 4}ipca){sub 2}(bze)(H{sub 2}O){sub 4}){sub n} (2) were prepared by the solvothermal reactions of Mn(II) acetate with 5-(2’,3’-dicarboxylphenoxy)isophthalic acid (H{sub 4}ipca) in the presence of different N-donor coligands (4,4′-bpy=4,4′-bipyridyl and bze=1, 4-bis(1-imidazoly)benzene). The single crystal X-ray diffractions reveal that two complexes display 3D metal-organic frameworks with binuclear and tetranuclear Mn(II) units, respectively. Complex 1 features a (3,4,6)-connected porous framework based on dinuclear Mn(II) unit with the (4.5{sup 2}){sub 2}(4{sup 2}.6{sup 8}.8{sup 3}.9{sup 2})(5{sup 2}.8.9{sup 2}.10) new topology, and complex 2 possesses a (3,8)-connected network based on tetranuclear Mn(II) unit with the (4{sup 2}.6){sub 2}(4{sup 4}.6{sup 14}.7{sup 7}.8{sup 2}.9) new topology. Magnetic analyses indicate that both two compounds show weak antiferromagnetic interactions within binuclear and tetranuclear Mn(II) units. - Graphical abstract: Two topologically new Mn(II) metal-organic frameworks with dinuclear and tetranuclear Mn(II) units respectively were assembled by using 5-(2′,3′-Dicarboxylphenoxy)isophthalic acid and N-donor ancillary coligands. Magnetic analysis revealed the existence of dominant antiferromagnetic interactions within the polynuclear Mn(II) units. - Highlights: • Mixed ligand strategy produces two topologically new MOFs with dinuclear and tetranuclear Mn(II) respectively. • Magnetic fitting gives weak antiferromagnetic interactions within the polynuclear Mn(II) units.

  16. A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Bai, Chao [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China); Yuan, Fei; Xue, Gang-Lin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710127 (China)

    2017-05-15

    Eight Zn(II)-based coordination polymers, namely, [Zn{sub 2}L{sub 2}(2,2’-bipy)]{sub n}·nH{sub 2}O (1), [Zn{sub 2}L{sub 2}(phen)]{sub n}·nH{sub 2}O (2), [ZnL(phen)(H{sub 2}O)]{sub n} (3), [Zn{sub 3}L{sub 3}(4,4’-bipy)]{sub n} (4), [Zn{sub 2}L{sub 2}(4,4’-bipy){sub 2}]{sub n} [Zn{sub 2}L{sub 2}(H{sub 2}O){sub 2}]{sub n}·2nH{sub 2}O (5), [Zn{sub 4}L{sub 4}(bpp){sub 2}]{sub n} (6), [ZnL(bbi){sub 0.5}]{sub n} (7), [ZnL(bpz)]{sub n} (8) (H{sub 2}L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2

  17. Thiosemicarbazones, semicarbazones, dithiocarbazates and hydrazide/hydrazones: anti-Mycobacterium tuberculosis activity and cytotoxicity.

    Science.gov (United States)

    Pavan, Fernando R; da S Maia, Pedro I; Leite, Sergio R A; Deflon, Victor M; Batista, Alzir A; Sato, Daisy N; Franzblau, Scott G; Leite, Clarice Q F

    2010-05-01

    The aim of this study was to identify a candidate drug for the development of anti-tuberculosis therapy from previously synthesized compounds based on the thiosemicarbazones, semicarbazones, dithiocarbazates and hydrazide/hydrazones compounds. The minimal inhibitory concentration (MIC) of these compounds against Mycobacterium tuberculosis was determined. Their in vitro cytotoxicity to J774 cells (IC50) was determined to establish a selectivity index (SI) (SI=IC50/MIC). The best compounds were the thiosemicarbazones (2, 3 and 4) and the hydrazide/hydrazones (14, 15, 16 and 18). The results are comparable to or better than those of "first line" or "second line" drugs commonly used to treat TB, suggesting these compounds as anti-TB drug candidates. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  18. FT-IR, FT-Raman and Computational Study of Ethyl Methyl Ketone Semicarbazone

    Directory of Open Access Journals (Sweden)

    P. S. Binil

    2011-01-01

    Full Text Available FT-IR and FT-Raman spectra of ethyl methyl ketone semicarbazone were recorded and analyzed. The vibrational wavenumbers were computed using HF/6-31G*, B3PW91/6-31G* and B3LYP/6-31G* basis and compared with experimental data. The first hyperpolarizability, infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non-linear optics. The extended π-electron delocalization over the carbazone moiety is responsible for the nonlinearity of the molecule. The geometrical parameters of the title compound are in agreement with that of similar derivatives. The red shift of the NH stretching wavenumber in the infrared spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom.

  19. Synthesis, spectroscopic (FT-IR, FT-Raman, UV and NMR) and computational studies on 3t-pentyl-2r,6c-diphenylpiperidin-4-one semicarbazone.

    Science.gov (United States)

    Arockia doss, M; Savithiri, S; Rajarajan, G; Thanikachalam, V; Saleem, H

    2015-09-05

    The structural and spectroscopic studies of 3t-pentyl-2r,6c-diphenylpiperidin-4-one semicarbazone (PDPOSC) were made by adopting B3LYP/HF levels theory using 6-311++G(d,p) basis set. The FT-IR and Raman spectra were recorded in solid phase, the fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. DFT method indicates that B3LYP is superior to HF method for molecular vibrational analysis. UV-vis spectrum of the compound was recorded in different solvents in the region of 200-800 nm and the electronic properties such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies were evaluated by time-dependent DFT (TD-DFT) approach. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. The hyperconjugative interaction energy (E((2))) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. In addition, MEP and atomic charges of carbon, nitrogen and oxygen were calculated using B3LYP/6-311++G(d,p) level theory. Moreover, thermodynamic properties of the title compound were calculated by B3LYP/HF, levels using 6-311++G(d,p) basis set. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Reversible CO2Addition to a Si=O Bond and Synthesis of a Persistent SiO2-CO2Cycloadduct Stabilized by a Lewis Donor-Acceptor Ligand.

    Science.gov (United States)

    Rodriguez, Ricardo; Alvarado-Beltran, Isabel; Saouli, Jérémy; Saffon-Merceron, Nathalie; Baceiredo, Antoine; Branchadell, Vicenç; Kato, Tsuyoshi

    2018-03-01

    The donor-stabilized sila-β-lactone 1 reacts with CO 2 via a remarkable reversible [2+2]-cycloaddition reaction to form the spiro-cyclic silicon carbonate derivative 2. Furthermore, photolysis of 2 under pressure of CO 2 affords the first persistent SiO 2 -CO 2 cycloadduct 3, presenting a Si 2 O 4 -like structure, which is stabilized by a Lewis donor-acceptor type ligand. As predicted by theoretical calculations, in marked contrast to the thermodynamically stable SiO 2 dimer, the SiO 2 -CO 2 mixed cycloadduct 3 is labile and readily releases CO 2 . © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Influence of bidentate ligand donor types on the formation and stability in 2 + 1 fac-[MI(CO)3]+ (M = Re, 99mTc) complexes.

    Science.gov (United States)

    Hayes, Thomas R; Bottorff, Shalina C; Slocumb, Winston S; Barnes, Charles L; Clark, Aurora E; Benny, Paul D

    2017-01-24

    In the last two decades, a number of chelate strategies have been proposed for the fac-[M I (CO) 3 ] + (M = Re, 99m Tc) core in radiopharmaceutical applications. However, the development of new ligands/complexes with improved function and in vivo performance has been limited in recent years. Expanding on our previous studies using the 2 + 1 labeling strategy, a series of bidentate ligands (neutral vs. anionic) containing an aromatic amine in combination with monodentate pyridine analogs or imidazole were explored to determine the influence of the bidentate and monodentate ligands on the formation and stability of the respective complexes. The 2 + 1 complexes with Re and 99m Tc were synthesized in two steps and characterized by standard radio/chemical methods. X-ray characterization and density functional theory analysis of the Re 2 + 1 complexes with the complete bidentate series with 4-dimethylaminopyridine were conducted, indicating enhanced ligand binding energies of the neutral over anionic ligands. In the 99m Tc studies, anionic bidentate ligands had significantly higher formation yields of the 2 + 1 product, but neutral ligands appear to have increased stability in an amino acid challenge assay. Both bidentate series exhibited improved stability by increasing the basicity of the pyridine ligands.

  2. Studies on coordination chemistry and bioactivity of complexes of a bidentate oxygen-oxygen donor ligand, 1,2-dibenzoylhydrazine, with Cr3+, Co2+, Ni2+, Cu2+ and Zn2+ Ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Lai Wee Wong; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-08-01

    A new bidentate ligand, 1,2-dibenzoylhydrazine (DBHz), with OO donor sequences, was prepared. Several complexes of DBHz containing Cr(JJI), Fe(UI), Co(U), Ni(JJ), Cu(II) and Zn(TJ) ions have been synthesized and characterized by CHN analyses, IR, molar conductivity and UV/Visible spectroscopic studies. All of the compounds were tested for their antibacterial, antifungal and anticancer properties. DBHz was very effective against Pseudomonas aeruginosa, Bacillus subtilis mutant and Bacillus subtilis wild type bacteria. It was also effective against Saccaromyces cereiviceae, Candida albicans, Candida albicans lypolytica and Aspergillus ochraceous fungi. The free ligand, DBHz, in particular, was strongly active against colon cancer cell lines (HT-29), with a CD 50 value of 2.5 /μg/ml. (author)

  3. Synthesis, characterization and antibacterial investigation of divalent metal complexes of NO-donor ligand: {5-chloro-2-[(4-chlorobenzylidene-amino]phenyl}(phenylmethanone

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam

    2015-05-01

    Full Text Available A ligand L has been synthesized by the condensation of 4-chlorobenzaldehyde and 2-amino-5-chlorobenzophenone. The complexes 1–5 of Pb+2, Ni+2, Co+2, Cu+2 and Cd+2 with ligand were prepared. The newly synthesized ligand L and its complexes 1–5 were characterized on the basis of elemental analyses, molar conductance, 1H NMR, IR and MS spectral data. The ligand was also characterized by X-ray crystallography. By electronic spectra and magnetic moment data, the square planar geometry for complex 1 and the octahedral geometry for complexes 2–5 were proposed. The conductivity data suggests non-electrolytic nature of the complexes 1–5. The complexes have higher antibacterial activity than the parent ligand L.

  4. Synthesis and characterization of fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] complexes (M = Re, (99m)Tc) with acetylacetone and curcumin as OO donor bidentate ligands.

    Science.gov (United States)

    Triantis, Charalampos; Tsotakos, Theodoros; Tsoukalas, Charalampos; Sagnou, Marina; Raptopoulou, Catherine; Terzis, Aris; Psycharis, Vassilis; Pelecanou, Maria; Pirmettis, Ioannis; Papadopoulos, Minas

    2013-11-18

    The synthesis and characterization of neutral mixed ligand complexes fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] (M = Re, (99m)Tc), with deprotonated acetylacetone or curcumin as the OO donor bidentate ligands and a phosphine (triphenylphosphine or methyldiphenylphosphine) as the monodentate P ligand, is described. The complexes were synthesized through the corresponding fac-[M(CO)3(H2O)(OO)] (M = Re, (99m)Tc) intermediate aqua complex. In the presence of phosphine, replacement of the H2O molecule of the intermediate complex at room temperature generates the neutral tricarbonyl monophosphine fac-[Re(CO)3(P)(OO)] complex, while under reflux conditions further replacement of the trans to the phosphine carbonyl generates the new stable dicarbonyl bisphosphine complex cis-trans-[Re(CO)2(P)2(OO)]. The Re complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray crystallography showing a distorted octahedral geometry around Re. Both the monophosphine and the bisphosphine complexes of curcumin show selective binding to β-amyloid plaques of Alzheimer's disease. At the (99m)Tc tracer level, the same type of complexes, fac-[(99m)Tc(CO)3(P)(OO)] and cis-trans-[(99m)Tc(CO)2(P)2(OO)], are formed introducing new donor combinations for (99m)Tc(I). Overall, β-diketonate and phosphine constitute a versatile ligand combination for Re(I) and (99m)Tc(I), and the successful employment of the multipotent curcumin as β-diketone provides a solid example of the pharmacological potential of this system.

  5. Spectroscopic characterization of chromium(III), manganese(II) and nickel(II) complexes with a nitrogen donor tetradentate, 12-membered azamacrocyclic ligand

    Science.gov (United States)

    Chandra, Sulekh; Pundir, Meenakshi

    2008-01-01

    The complexes of Cr(III), Mn(II) and Ni(II) were synthesized with macrocyclic ligand i.e. 5,11-dimethyl-6,12-diethyl-dione-1,2,4,7,9,10-hexazacyclododeca -1,4,6,10-tetraene. The ligand (L) was prepared by [2 + 2] condensation reaction of 2,3-pentanedione and semicarbazide hydrochloride. These complexes were found to have the general composition [Cr(L)X 2]X and [M(L)X 2] (where M = Mn(II) and Ni(II); X = Cl -, NO 3-, (1/2)SO 42-, NCS - and L = ligand [N 6]). The ligand and its transition metal complexes were characterized by the elemental analysis, molar conductance, magnetic susceptibility, mass, IR, electronic and EPR spectral studies. On the basis of IR, electronic and EPR spectral studies, an octahedral geometry has been assigned for these complexes except sulphato complexes which are of five coordinated geometry.

  6. Synthesis, Characterization and Antimicrobial Evaluation of some Thiazole-Derived Carbamates, Semicarbazones, Amides and Carboxamide

    International Nuclear Information System (INIS)

    Balawi, N.A.A.; ALShaikh, M.A.A.; Alafeefy, A.M.; Khan, K.M.

    2016-01-01

    This study comprises the synthesis and characterization of twenty thiazole-derived carbamates (3a-e), N-substituted amides (8a-h) and carboxamide (10) from 2-aminothiazoles (1a, b) via nucleophilic substitution reactions with activated carbonyl compounds including, chloroformates (2a-d), acid chlorides (7a-e) and glutaric anhydride (9), respectively. Sequential hydrazinolysis of carbamate (3e) and condensation with a variety of aldehydes and ketones (5a d) afforded the corresponding semicarbazones (6a-d). Some selected synthesized compounds were subjected to in vitro antimicrobial evaluation against common pathogens including, Gram+ve bacteria Bacillus subtilis (NRRL B-543) and Staphylococcus aureus, Gram-ve bacteria Escherichia coli (NRRLB-21), yeasts-Candida albicans (NRRLY-477) and Saccharomyces cercvisiae (NRRL Y-567) and fungs Asperigillus niger (NRRL 599). Screening results revealed that most of the tested compounds possess good antimicrobial activity compared to standard drugs. The highest inhibitory effects against Gram-ve Escherichia coli, Gram+ve Staphylococcus aureus, yeast Candida albicans and fungus Aspergillus niger was displayed by amide (8g) bearing the thiophene moiety. (author)

  7. Mg(II Selective PVC Membrane Electrode Based on Methyl Phenyl Semicarbazone as an Ionophore

    Directory of Open Access Journals (Sweden)

    Sulekh Chandra

    2013-01-01

    Full Text Available A PVC-membrane-based Mg(II selective electrode was constructed using methyl phenyl semicarbazone (MPS as a neutral carrier. The sensor exhibits a Nernstian response for Mg(II ion over a wide concentration range 1.0×10-8  to  1.0×10-1 M with the slope of 28.4 mV/per decade having detection limit 1.7×10-9 M. It was relatively a fast response time (<10 s for concentration ≥1.0×10-3 and <15 s for concentration of ≥1.0×10-6 M and can be used for 8 months without any considerable divergence in potentials. The proposed sensor revealed relatively good selectivity and high sensitivity for Mg(II over a mono-, di-, and trivalent cation and can be used in a pH range of 1.0–9.5. It was also successfully used as an indicator electrode in potentiometer titration and in the analysis of concentration of magnesium in various real samples.

  8. 14-Membered cyclic bis-semicarbazones: Stereoselective synthesis and structural features

    Science.gov (United States)

    Shutalev, Anatoly D.; Fesenko, Anastasia A.; Yankov, Alexander N.; Tafeenko, Victor A.; Chernyshev, Vladimir V.

    2017-12-01

    Stereoselectivity of acid-catalyzed cyclization of 4-(1-aryl-3-oxobutyl)semicarbazide hydrazones into mixtures of trans- and cis-isomers of 14-membered cyclic bis-semicarbazones has been studied. The isomer ratio is dependent on solvent, catalyst acidity, substrate structure and concentration, reaction temperature and time, catalyst loading. The experimental data show that the macrocyclization of acyclic precursors initially formed from two molecules of substrates proceeds with low diastereoselectivity to give mixtures of trans- and cis-macrocycles followed by slow transformation of cis-isomers into trans-isomers via ring opening by a retro-aza-Michael reaction resulting in high trans-selectivity. The driving force of this isomerization is shown to be a lower solubility of trans-isomers compared with cis-isomers. Some mechanistical aspects of the macrocycle formation were confirmed by calculations performed at the DFT B3LYP/6-311++G(d,p) level of theory. Molecular structure of the obtained hexaaza macrocycles was established using single crystal and powder X-ray diffraction, IR, UV-Vis, 1H and 13C NMR spectroscopy, and DFT calculations.

  9. New Ruthenium complexes containing N, P and S-donor type of ligands: coordination chemistry, characterization and application to asymetric and non-asymetric catalysis

    OpenAIRE

    Sala Román, Xavier

    2007-01-01

    Synthesis, spectroscopic characterization and redox properties of a new Ru-H2O complex containing 1,10-phenantroline and the soft [9]aneS3 ligand. Substitution pathways of a new Ru-py complex [Ru(phen)(py)([9]aneS3)]2+ to form the corresponding Ru-MeCN complex through kinetic analysis. Kinetic establishment of a reaction intermediate. Synthesis of new Ru(II) complexes containing the chiral 1,2-bis(oxazolinyl) benzene ligand. Rotationally restricted isomers were produced upon coordination to a...

  10. Spectroscopic approach in characterization of chromium(III), manganese(II), iron(III) and copper(II) complexes with a nitrogen donor tetradentate, 14-membered azamacrocyclic ligand

    Science.gov (United States)

    Chandra, Sulekh; Gupta, Lokesh Kumar

    2005-07-01

    The complexes of Cr(III), Mn(II), Fe(III) and Cu(II) were synthesized with the macrocyclic ligand i.e. 2,3,9,10-tetraketo-1,4,8,11-tetraazacyclotetradecane. The ligand was prepared by the [2 + 2] condensation reaction of diethyloxalate and 1,3-diamino propane. These complexes were found to have the general composition M(L)X 3 and M'(L)X 2 [where M = Mn(II) and Cu(II), M' = Cr(III) and Fe(III), L = ligand (N 4) and X = Cl -, NO 3-, 1/2SO 42- and [CH 3COO -]. The ligand and its transition metal complexes were characterized by the elemental analyses, molar conductance, magnetic susceptibility, mass, IR, electronic, and EPR spectral studies. On the basis of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Cr(III), Mn(II) and Fe(III) and a tetragonal geometry for Cu(II) complexes.

  11. Palladium(II) and zinc(II) complexes of neutral [N2O2] donor Schiff bases derived from furfuraldehyde: synthesis, characterization, fluorescence and corrosion inhibitors of ligands.

    Science.gov (United States)

    Ali, Omyma A M

    2014-11-11

    Metal complexes of Schiff bases derived from furfuraldehyde and 4,5-dimethyl-1,2-phenylendiamine (L1) or 4,5-dichloro-1,2-phenylendiamine (L2) have been reported and characterized based on elemental analyses, IR, 1H NMR, UV-Vis, magnetic moment, molar conductance and thermal analysis. The complexes are found to have the formulae [PdL1-2]Cl2 and [ZnL1-2](AcO)2·H2O. The molar conductance data reveal that Pd(II) and Zn(II) chelates are ionic in nature and are of the type 2:1 electrolytes. The spectral data are consistent with a square planar and tetrahedral geometry around Pd(II) and Zn(II), respectively, in which the ligands act as tetradentate ligands. The thermal behavior of some chelates is studied and the activation thermodynamic parameters are calculated using Coats-Redfern method. The corrosion inhibition of stainless steel types 410 and 304 in 1 M HCl using the synthesized Schiff bases as inhibitors have been studied by weight loss method. The obtained data considered these ligands as efficient corrosion inhibitors. The ligands and their metal complexes exhibited considerable antibacterial activity against Staphylococcusaureus, and Escherichiacoli and antifungal activity against Candida albicans. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Synthesis, characterization and biological relevance of some metal (II) complexes with oxygen, nitrogen and oxygen (ONO) donor Schiff base ligand derived from thiazole and 2-hydroxy-1-naphthaldehyde

    Science.gov (United States)

    Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2015-04-01

    The novel Schiff base ligand 2-((2-hydroxynaphthalen-1-yl)methylene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-hydroxy-1-naphthaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), Zn(II) and Cd(II) complexes have been characterized by microanalysis, molar conductance, IR, 1H NMR, ESI-mass, UV-Visible, TGA/DTA, ESR and powder X-ray diffraction data to explicate their structures. The IR results confirmed the tridentate binding of the ligand involving oxygen atom of amide carbonyl, azomethine nitrogen and naphthol oxygen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. Thermogravimetric studies for Cu(II) and Ni(II) complexes indicated the presence of coordinated water molecules and the final product is the metal oxide. In order to appraise the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antimicrobial activity by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 (Bangal re Genei, Bengaluru, Cat. No 105850) as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties against Artemia salina. Furthermore, the antioxidant activity were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH). The ligand exhibited better in vitro-antioxidant activity than its metal complexes.

  13. Mononuclear late first row transition metal complexes of ONO donor hydrazone ligand: Synthesis, characterization, crystallographic insight, in vivo and in vitro anti-inflammatory activity

    Science.gov (United States)

    Kendur, Umashri; Chimmalagi, Geeta H.; Patil, Sunil M.; Gudasi, Kalagouda B.; Frampton, Christopher S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.

    2018-02-01

    Air and moisture stable coordination compounds of late first row transition metal ions, viz., Co(II), Ni(II), Cu(II) and Zn(II) with a newly designed ligand, (E)-2-amino-N'-(1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl)ethylidene)benzohydrazide (H2L) were prepared and extensively characterized using various spectro-analytical techniques. The ligand acts both in mono as well as doubly deprotonated manner. The ligand to metal stoichiometry was found to be 1:2 in case of complexes using chloride salts, whereas 1:1 in case of copper (II) complex using its acetate salt. The molecular structures of H2L, nickel and copper complexes were unambiguously determined by single-crystal X-ray diffraction studies reveal that H2L exists in a zwitterionic form while copper complex has copper centre in a distorted square planar environment. On the other hand, cobalt, nickel and zinc complexes display distorted octahedral coordination around the metal ion. In case of [Ni(HL)2].H2O, intramolecular Csbnd H⋯π stacking interaction were observed between the centroid of five membered chelate ring and phenyl proton C5sbnd H5 and intermolecular Csbnd H⋯π stacking interaction between the centroid of phenyl ring, dehydroacetic acid (DHA) ring and phenyl protons. The [Cu(L)DMF] complex is stabilized by intramolecular hydrogen bonding N1H⋯N2 and by intermolecular hydrogen bonding N1H⋯O4. Intermolecular interactions were investigated by Hirshfeld surfaces. Further, H2L and its metal complexes were screened for their in vivo and in vitro anti-inflammatory activities. The activity of the ligand has enhanced on coordination with transition metals. The tested compounds have shown excellent activity, which is almost equipotent to the standard used in the study.

  14. Ruthenium nitrosyls derived from tetradentate ligands containing carboxamido-N and phenolato-o donors: syntheses, structures, photolability, and time dependent density functional theory studies.

    Science.gov (United States)

    Fry, Nicole L; Rose, Michael J; Rogow, David L; Nyitray, Crystal; Kaur, Manpreet; Mascharak, Pradip K

    2010-02-15

    In order to examine the role(s) of designed ligands on the NO photolability of {Ru-NO}(6) nitrosyls, a set of three nitrosyls with ligands containing two carboxamide groups along with a varying number of phenolates have been synthesized. The nitrosyls namely, (NEt(4))(2)[(hybeb)Ru(NO)(OEt)] (1), (PPh(4))[(hypyb)Ru(NO)(OEt)] (2), and [(bpb)Ru(NO)(OEt)] (3) have been characterized by X-ray crystallography. Complexes 1-3 are diamagnetic, exhibit nu(NO) in the range 1780-1840 cm(-1) and rapidly release NO in solution upon exposure to low power UV light (7 mW/cm(2)). Density Functional Theory (DFT) and Time Dependent DFT (TDDFT) calculations on 1-3 indicate considerable contribution of ligand orbitals in the MOs involved in transitions leading to NO photolability. The results of the theoretical studies match well with the experimental absorption spectra as well as the parameters for NO photorelease and provide insight into the transition(s) associated with loss of NO.

  15. Synthesis, spectroscopic characterization and DNA nuclease activity of Cu(II) complexes derived from pyrazolone based NSO-donor Schiff base ligands

    Science.gov (United States)

    Vyas, Komal M.; Joshi, Rushikesh G.; Jadeja, R. N.; Ratna Prabha, C.; Gupta, Vivek K.

    2011-12-01

    Two neutral mononuclear Cu(II) complexes have been prepared in EtOH using Schiff bases derived from 4-toluoyl pyrazolone and thiosemicarbazide. Both the ligands have been characterized on the basis of elemental analysis, IR, 1H NMR, 13C NMR and mass spectral data. The molecular geometry of one of these ligands has been determined by single crystal X-ray study. It reveals that these ligands exist in amine-one tautomeric form in the solid state. Microanalytical data, Cu-estimation, molar conductivity, magnetic measurements, IR, UV-Visible, FAB-Mass, TG-DTA data and ESR spectral studies were used to confirm the structures of the complexes. Electronic absorption and IR spectra of the complexes suggest a square-planar geometry around the central metal ion. The interaction of complexes with pET30a plasmid DNA was investigated by spectroscopic measurements. Results suggest that the copper complexes bind to DNA via an intercalative mode and can quench the fluorescence intensity of EB bound to DNA. The interaction between the complexes and DNA has also been investigated by agarose gel electrophoresis, interestingly, we found that the copper(II) complexes can cleave circular plasmid DNA to nicked and linear forms.

  16. Studies on coordination chemistry and bioactivity of metal complexes of some nitrogen-sulfur donor ligands: Section A: hydraziniumdithiocarbazate and its complexes. Section B: complexes of Ni2+ and Cu2+ ions with s-picolyldithiocarbazate

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Liza bt Abdullah; Crouse, Karen A.; Ali, A.M.

    2003-08-01

    Two new nitrogen - sulphur donor ligands, hydraziniumdithiocarbazate(HzDTC) and S-picolyldithiocarbazate(SPDTC), along with three novel Schiff bases were prepared. Complexes of some of HzDTC with nickel(II), zinc(II), and those of SPDTC with nickel(II) and copper(II) were prepared and characterized by a variety of physico- chemical techniques. The ligand, HzDTC, was a potential bidentate and uninegatively charged providing terminal amino and thiolate bindings with the metal ions, while SPDTC coordinates via the pyridine nitrogen and the thiolate anion. All of the compounds were tested against four pathogenic bacteria and fungi. HzDTC was found to be very effective antimicrobial than its complexes. The complexes of SPDTC and the Schiff bases of HzDTC were more antifungal. None of the compounds were effective anti- cancer agents except for [Ni(HzDTCA)Cl.H 2 O], which was moderately active against CEM- SS (Human cell T- lymphoblastic) leukemic cells. (author)

  17. Rhodium complexes of a chelating ligand with imidazol-2-ylidene and pyridin-2-ylidene donors: the effect of C-metalation of nicotinamide groups on uptake of hydride ion.

    Science.gov (United States)

    McSkimming, Alex; Ball, Graham E; Bhadbhade, Mohan M; Colbran, Stephen B

    2012-02-20

    Rhodium complexes of the imidazolylidene (C-im) N-heterocyclic carbene (NHC) ligand, C-im-pyH(+), bearing a nicotinamide cation substituent (pyH(+)) have been targeted for ligand-centered uptake and delivery of hydride ion. This work reveals that rhodium(I) complexes such as [Rh(C-im-pyH(+))(COD)X][PF(6)] (1, a: X = Cl, b: X = I) undergo facile C-metalation of the nicotinamide ring to afford rhodium complexes of a novel chelate ligand, C,C'-im-py, with coordinated imidazolylidene (C(im)) and pyridylidene (C(py)) NHC-donors. Seven examples were characterized and include rhodium(III) monomers of the general formula [Rh(C,C'-im-py)L(x)I(2)](z+) (2: z = 1, L = H(2)O or solvent, x = 2; 3, 5, 7: z = 0, L = carboxylate, x = 1) and novel rhodium(II) dimers, the anti/syn-isomers of [Rh(2)(C,C'-im-py)(2)(μOAc)(2)I(2)] (4-anti/syn). The NMR data, backed by DFT calculations, is consistent with attribution of the C,C'-im-py ligand as a bis(carbene) donor. Single crystal X-ray diffraction studies are reported for 2, 3, 4-anti, 4-syn and 7. Consistently, within the each complex, the Rh-C(im) bond length is shorter than the Rh-C(py) bond length, which is the opposite trend to that expected based on simple electronic considerations. It is proposed that intramolecular steric interactions imposed by different rings in the rigid C,C'-im-py chelate ligand dictate the observed Rh-C(NHC) bond lengths. Attempts to add hydride to the C-metalated nicotinamide ring in 3 were unsuccessful. The redox behavior of 3 and 4 and, for comparison, an analogous bis(imidazolylidene)rhodium(III) monomer (8), were characterized by cyclic voltammetry, electron paramagnetic resonance (EPR), and UV-vis spectroelectrochemistry. In 3 and 4, the C-metalated nicotinamide ring is found to exhibit a one-electron reduction process at far lower potential (-2.34 V vs. Fc(+)/Fc in acetonitrile) than the two-electron nicotinamide cation-dihydronicotinamide couple found for the corresponding nonmetalated ring (-1.24 V

  18. Coupling of metal-based light-harvesting antennas and electron-donor subunits: Trinuclear Ruthenium(II) complexes containing tetrathiafulvalene-substituted polypyridine ligands

    DEFF Research Database (Denmark)

    Campagna, Sebastiano; Serroni, Scolastica; Puntoriero, Fausto

    2002-01-01

    as light-harvesting antennas and the tetrathiafulvalene electron donors can induce charge separation. The absorption spectra, redox behavior, and luminescence properties (both at room temperature in acetonitrile and at 77 K in a rigid matrix of butyronitrile) of the trinuclear metal complexes have been......+) (4,4'-Mebpy = 4,4'-dimethyl-2,2'-bipyridine) and [{(bpy)(2)Ru(mu-2,3-dpp)}(2)Ru(bpy)](6+). The absorption spectra and redox behavior of all the new metal compounds can be interpreted by a multicomponent approach, in which specific absorption features and redox processes can be assigned to specific...... subunits of the structures. The luminescence properties of the complexes in rigid matrices at 77 K are very similar to those of the corresponding model compounds without TTF moieties, whereas the new species are nonluminescent, or exhibit very weak emissions relative to those of the model compounds...

  19. A series of coordination polymers constructed from R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands: Syntheses, structures and fluorescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yong-Hong, E-mail: zhou21921@sina.com [School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000 (China); Zhou, Xu-Wan; Zhou, Su-Rong [School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000 (China); Tian, Yu-Peng; Wu, Jie-Ying [Department of Chemistry and Chemical Technology, Anhui University, Hefei 230039 (China)

    2017-01-15

    Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn{sub 2}Na(sip){sub 2}(bpp){sub 3}(Hbpp)(H{sub 2}O){sub 2}]·8H{sub 2}O (1), [Cd{sub 3}(sip){sub 2}(nbi){sub 6}(H{sub 2}O){sub 2}]·7H{sub 2}O (2), [Zn(sip)(nbi){sub 2}(H{sub 2}O)]·Hnbi·3H{sub 2}O (3), [Cd(hip)(nbi){sub 2}(H{sub 2}O)]·nbi·5H{sub 2}O (4), [Cd{sub 2}(nip){sub 2}(nbi){sub 2}(H{sub 2}O){sub 2}]·DMF (5), and [Cu(nip)(nbi)(H{sub 2}O){sub 2}]·H{sub 2}O (6) (H{sub 3}sip=5-sulfoisophthalic acid, H{sub 2}hip=5-hydroxylisophthalic acid, H{sub 2}nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through O atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip{sup 3−} anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3–5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip{sup 2−} ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied. - Graphical abstract: A series of Cd(II)/Zn(II)/ Cu(II) coordination polymers based on R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands have been synthesized under hydrothermal conditions and structurally characterized. Photoluminescent properties

  20. Fluorescence and electron paramagnetic resonance studies of norfloxacin and N-donor mixed-ligand ternary copper(II) complexes: Stability and interaction with SDS micelles

    Science.gov (United States)

    Vignoli Muniz, Gabriel S.; Incio, Jimmy Llontop; Alves, Odivaldo C.; Krambrock, Klaus; Teixeira, Letícia R.; Louro, Sonia R. W.

    2018-01-01

    The stability of ternary copper(II) complexes of a heterocyclic ligand, L (L being 2,2‧-bipyridine (bipy) or 1,10-phenanthroline (phen)) and the fluorescent antibacterial agent norfloxacin (NFX) as the second ligand was studied at pH 7.4 and different ionic strengths. Fluorescence quenching upon titration of NFX with the binary complexes allowed to obtain stability constants for NFX binding, Kb, as a function of ionic strength. The Kb values vary by more than two orders of magnitude when buffer concentration varies from 0.5 to 100 mM. It was observed that previously synthesized ternary complexes dissociate in buffer according with the obtained stability constants. This shows that equimolar solutions of NFX and binary complexes are equivalent to solutions of synthesized ternary complexes. The interaction of the ternary copper complexes with anionic SDS (sodium dodecyl sulfate) micelles was studied by fluorescence and electron paramagnetic resonance (EPR). Titration of NFX-loaded SDS micelles with the complexes Cu:L allowed to determine the stability constants inside the micelles. Fluorescence quenching demonstrated that SDS micelles increase the stability constants by factors around 50. EPR spectra gave details of the copper(II) local environment, and demonstrated that the structure of the ternary complexes inside SDS micelles is different from that in buffer. Mononuclear ternary complexes formed inside the micelles, while in buffer most ternary complexes are binuclear. The results show that anionic membrane interfaces increase formation of copper fluoroquinolone complexes, which can influence bioavailability, membrane diffusion, and mechanism of action of the antibiotics.

  1. Iron coordination chemistry with new ligands containing triazole and pyridine moieties. Comparison of the coordination ability of the N-donors.

    Science.gov (United States)

    Ségaud, Nathalie; Rebilly, Jean-Noël; Sénéchal-David, Katell; Guillot, Régis; Billon, Laurianne; Baltaze, Jean-Pierre; Farjon, Jonathan; Reinaud, Olivia; Banse, Frédéric

    2013-01-18

    We report the synthesis, characterization, and solution chemistry of a series of new Fe(II) complexes based on the tetradentate ligand N-methyl-N,N'-bis(2-pyridyl-methyl)-1,2-diaminoethane or the pentadentate ones N,N',N'-tris(2-pyridyl-methyl)-1,2-diaminoethane and N,N',N'-tris(2-pyridyl-methyl)-1,3-diaminopropane, modified by propynyl or methoxyphenyltriazolyl groups on the amino functions. Six of these complexes are characterized by X-ray crystallography. In particular, two of them exhibit an hexadentate coordination environment around Fe(II) with two amino, three pyridyl, and one triazolyl groups. UV-visible and cyclic voltammetry experiments of acetonitrile solutions of the complexes allow to deduce accurately the structure of all Fe(II) species in equilibrium. The stability of the complexes could be ranked as follows: [L(5)Fe(II)-py](2+) > [L(5)Fe(II)-Cl](+) > [L(5)Fe(II)-triazolyl](2+) > [L(5)Fe(II)-(NCMe)](2+), where L(5) designates a pentadentate coordination sphere composed of the two amines of ethanediamine and three pyridines. For complexes based on propanediamine, the hierarchy determined is [L(5)Fe(II)-Cl](+) > [L(5)Fe(II)(OTf)](+) > [L(5)Fe(II)-(NCMe)](2+), and no ligand exchange could be evidenced for [L(5)Fe(II)-triazolyl](2+). Reactivity of the [L(5)Fe(II)-triazolyl](2+) complexes with hydrogen peroxide and PhIO is similar to the one of the parent complexes that lack this peculiar group, that is, generation of Fe(III)(OOH) and Fe(IV)(O), respectively. Accordingly, the ability of these complexes at catalyzing the oxidation of small organic molecules by these oxidants follows the tendencies of their previously reported counterparts. Noteworthy is the remarkable cyclooctene epoxidation activity by these complexes in the presence of PhIO.

  2. Characterization of Water Coordination to Ferrous Nitrosyl Complexes with fac-N2O, cis-N2O2, and N2O3 Donor Ligands.

    Science.gov (United States)

    McCracken, John; Cappillino, Patrick J; McNally, Joshua S; Krzyaniak, Matthew D; Howart, Michael; Tarves, Paul C; Caradonna, John P

    2015-07-06

    Electron paramagnetic resonance (EPR) experiments were done on a series of S = (3)/2 ferrous nitrosyl model complexes prepared with chelating ligands that mimic the 2-His-1-carboxylate facial triad iron binding motif of the mononuclear nonheme iron oxidases. These complexes formed a comparative family, {FeNO}(7)(N2Ox)(H2O)3-x with x = 1-3, where the labile coordination sites for the binding of NO and solvent water were fac for x = 1 and cis for x = 2. The continuous-wave EPR spectra of these three complexes were typical of high-spin S = (3)/2 transition-metal ions with resonances near g = 4 and 2. Orientation-selective hyperfine sublevel correlation (HYSCORE) spectra revealed cross peaks arising from the protons of coordinated water in a clean spectral window from g = 3.0 to 2.3. These cross peaks were absent for the {FeNO}(7)(N2O3) complex. HYSCORE spectra were analyzed using a straightforward model for defining the spin Hamiltonian parameters of bound water and showed that, for the {FeNO}(7)(N2O2)(H2O) complex, a single water conformer with an isotropic hyperfine coupling, Aiso = 0.0 ± 0.3 MHz, and a dipolar coupling of T = 4.8 ± 0.2 MHz could account for the data. For the {FeNO}(7)(N2O)(H2O)2 complex, the HYSCORE cross peaks assigned to coordinated water showed more frequency dispersion and were analyzed with discrete orientations and hyperfine couplings for the two water molecules that accounted for the observed orientation-selective contour shapes. The use of three-pulse electron spin echo envelope modulation (ESEEM) data to quantify the number of water ligands coordinated to the {FeNO}(7) centers was explored. For this aspect of the study, HYSCORE spectra were important for defining a spectral window where empirical integration of ESEEM spectra would be the most accurate.

  3. 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.

  4. Synthesis and physicochemical characterization of two lead(II) complexes with O-, N-donor ligands. Lone pair functionality and crystal structure

    Science.gov (United States)

    Masternak, Joanna; Barszcz, Barbara; Hodorowicz, Maciej; Khavryuchenko, Oleksiy V.; Majka, Alina

    2015-02-01

    A dinuclear [Pb2(4-CHO-5-MeIm)6(NO3)2](NO3)2 (1) and a polynuclear [Pb(2-pzc)2(H2O)]n (2) complexes (where 5(4)-carbaldehyde-4(5)-methylimidazole (5(4)-CHO-4(5)-MeIm) and pyrazine-2-carboxylic acid (2-pzcH)) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. Structural determination for complex 1 reveals a cationic species [Pb(4-CHO-5-MeIm)3]2+ connected through bridging nitrate(V) ions. There are also an uncoordinated nitrate ions as counterions. Complex 2 is a three-dimensional architecture consisting of Pb6O12 building units. The pyrazine-2-carboxylato ligand behaves as a chelating agent and a bi-connective bridge. The coordination polyhedra around lead(II) ion could be described as a distorted docecahedron (1) or monocapped trigonal prism (2). The luminescent properties of 1 and 2 investigated in the solid state at room temperature indicate structure-dependent photoluminescent properties. The DFT calculations and the X-ray structural data point on rather hemidirected type of coordination around Pb(II) ions of 1 and 2.

  5. Correlation between DNA interactions and cytotoxic activity of four new ternary compounds of copper(II) with N-donor heterocyclic ligands.

    Science.gov (United States)

    Silva, Priscila P; Guerra, Wendell; Dos Santos, Geandson Coelho; Fernandes, Nelson G; Silveira, Josiane N; da Costa Ferreira, Ana M; Bortolotto, Tiago; Terenzi, Hernán; Bortoluzzi, Adailton João; Neves, Ademir; Pereira-Maia, Elene C

    2014-03-01

    Four new ternary complexes of copper(II) were synthesized and characterized: [Cu(hyd)(bpy)(acn)(ClO4)](ClO4)] (1), [Cu(hyd)(phen)(acn)(ClO4)](ClO4)] (2), [Cu(Shyd)(bpy)(acn)(ClO4)](ClO4)] (3) and [Cu(Shyd)(phen)(acn)(ClO4)](ClO4)] (4), in which acn=acetonitrile; hyd=2-furoic acid hydrazide, bpy=2,2-bipyridine; phen=1,10-phenanthroline and Shyd=2-thiophenecarboxylic acid hydrazide. The cytotoxic activity of the complexes in a chronic myelogenous leukemia cell line was investigated. All complexes are able to enter cells and inhibit cellular growth in a concentration-dependent manner, with an activity higher than that of the corresponding free ligands. The substitution of Shyd for hyd increases the activity, while the substitution of bpy for phen renders the complex less active. Therefore, the most potent complex is 4 with an IC50 value of 1.5±0.2μM. The intracellular copper concentration needed to inhibit 50% of cell growth is approximately 7×10(-15)mol/cell. It is worth notifying that a correlation between cytotoxic activity, DNA binding affinity and DNA cleavage was found: 1<3<2<4. © 2013.

  6. Tungsten(VI) Carbyne/Bis(carbene) Tautomerization Enabled by N-Donor SBA15 Surface Ligands: A Solid-State NMR and DFT Study

    KAUST Repository

    Bendjeriou-Sedjerari, Anissa

    2016-08-11

    Designing supported well-defined bis(carbene) complexes remains a key challenge in heterogeneous catalysis. The reaction of W(CtBu)(CH(2)tBu)(3) with amine-modified mesoporous SBA15 silica, which has vicinal silanol/silylamine pairs [(SiOH)(SiNH2)], leads to [(SiNH2-)(SiO-)W(CHtBu)(CH(2)tBu)(2)] and [(SiNH2-)(SiO-)W(=CHtBu)(2)(CH(2)tBu). Variable temperature, H-1-H-1 2D double-quantum, H-1-C-13 HETCOR, and HETCOR with spin diffusion solid-state NMR spectroscopy demonstrate tautomerization between the alkyl alkylidyne and the bis(alkylidene) on the SBA15 surface. Such equilibrium is possible through the coordination of W to the surface [(Si-OH)(Si-NH2)] groups, which act as a [N,O] pincer ligand. DFT calculations provide a rationalization for the surface-complex tautomerization and support the experimental results. This direct observation of such a process shows the strong similarity between molecular mechanisms in homogeneous and heterogeneous catalysis. In propane metathesis (at 150 degrees C), the tungsten bis(carbene) tautomer is favorable, with a turnover number (TON) of 262. It is the highest TON among all the tungsten alkyl-supported catalysts.

  7. Synthesis, X-ray crystal structure, photo luminescent property, antimicrobial activities and DFT computational study of Zn(II) coordination polymer derived from multisite N,O donor Schiff base ligand (H2L1)

    Science.gov (United States)

    Majumdar, Dhrubajyoti; Surendra Babu, M. S.; Das, Sourav; Biswas, Jayanta Kumar; Mondal, Monojit; Hazra, Suman

    2017-06-01

    A unique thiocyanato linked 1D chain of Zn(II) coordination polymer [Zn2L1(μ1,3-SCN)(η1SCN)]n (1) has been synthesized using potential multisite compartmental N,O donor Schiff base blocker ligand (L1H2) in presence of Zn(OAc)2 and KSCN. The Schiff base ligand [N, N‧-bis(3-methoxysalicylidenimino)-1,3-daminopropane] (L1H2) is 2:1 M ratio condensation product of O-vaniline and 1,3-diaminopropane in methanol medium. The characterization of Complex 1 was accomplished by means of different micro analytical techniques like elemental analyses, IR, UV-Vis, 1H NMR, emission spectroscopy and Single X-ray crystallographic study. Complex 1 crystallizes in Orthorhombic system, space group Pbca, with values a = 11.579(2), b = 18.538(3), and c = 22.160(4) Å; α = β = γ = 90.00°; V = 4756.6(14) and Z = 8. The single crystal X-ray revealed that the one dimensional chain system with the repeating unit [Zn2(μ1,3-SCN)(η1SCN)(L1)]n bridge by an end to end μ1,3 thiocyanate anion. Within each repeating unit two different types of Zn(II) ions are present. One of these is five-coordinate in a square pyramidal geometry while the other is six-coordinate in an octahedral geometry. A brief but lucid comparative approach has been demonstrated in between Schiff base (L1H2) and complex 1 with respect to their photoluminescence activities. Active luminescence behavior of complex 1 in presence of ligand (L1H2) is due to quenching of PET process which is mediated by 'chelating effect'. Complex 1 exhibits strong antimicrobial efficacy against some important Gram + ve and Gram -ve bacteria. Apart from antimicrobial potential, a combined experimental and theoretical investigation has been performed via DFT on molecular structure of complex 1 with respect to Hirshfeld surface analysis.

  8. Neutral dioxovanadium(V) complexes of biomimetic hydrazones ONO donor ligands of bioinorganic and medicinal relevance: Synthesis via air oxidation of bis(acetylaceto-nato)oxovanadium(IV), characterization, biological activity and 3D molecular modeling

    Science.gov (United States)

    Maurya, R. C.; Rajput, S.

    2007-05-01

    The interaction of bis(acetylacetonato)oxovanadium(IV), [VO(acac) 2] with biomimetic hydrazone ONO donor ligands HL in 1:1 mole ratio [where, HL = N-(4'-benzoylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-isonicotinic acid hydrazide (bmphp-inH, I), N-(4'-butyrylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-isonicotinic acid hydrazide (bumphp-inH, II), N-(4'-acetylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-isonicotinic acid hydrazide (amphp-inH, III), N-(3'-methyl-1'-phenyl-4'-propionylidene-2'-pyrazolin-5'-one)-isonicotinic acid hydrazide (mphpp-inH, IV) and N-(4'- iso-butyrylidene-3'-methyl-1'-phenyl-2'-pyrazolin-5'-one)-isonicotinic acid hydrazide ( iso-bumphp-inH, V)] in a mixed solvent (ethanol-methanol, 1:10) via aerial oxidation for 2-3 days yield dioxovanadium(V) complexes of composition [VO 2(L)(H 2O)] · H 2O. The compounds so obtained were characterized on the basis of elemental analyses, thermogravimetry, vanadium determination, IR, Electronic, 51V NMR, 1H NMR and mass spectral studies. The 3D molecular modeling and analysis for bond lengths and bond angles have also been carried out for one of the representative compounds, [VO 2(ampph-in)(H 2O)] ( 3).

  9. Bipodal surface organometallic complexes with surface N-donor ligands and application to the catalytic cleavage of C-H and C-C bonds in n -Butane

    KAUST Repository

    Bendjeriou-Sedjerari, Anissa

    2013-11-27

    We present a new generation of "true vicinal" functions well-distributed on the inner surface of SBA15: [(Sî - Si-NH 2)(≡Si-OH)] (1) and [(≡Si-NH2)2] (2). From these amine-modified SBA15s, two new well-defined surface organometallic species [(≡Si-NH-)(≡Si-O-)]Zr(CH2tBu) 2 (3) and [(≡Si-NH-)2]Zr(CH2tBu) 2 (4) have been obtained by reaction with Zr(CH2tBu) 4. The surfaces were characterized with 2D multiple-quantum 1H-1H NMR and infrared spectroscopies. Energy-filtered transmission electron microscopy (EFTEM), mass balance, and elemental analysis unambiguously proved that Zr(CH2tBu)4 reacts with these vicinal amine-modified surfaces to give mainly bipodal bis(neopentyl)zirconium complexes (3) and (4), uniformly distributed in the channels of SBA15. (3) and (4) react with hydrogen to give the homologous hydrides (5) and (6). Hydrogenolysis of n-butane catalyzed by these hydrides was carried out at low temperature (100 C) and low pressure (1 atm). While (6) exhibits a bis(silylamido)zirconium bishydride, [(≡Si-NH-)2]Zr(H) 2 (6a) (60%), and a bis(silylamido)silyloxozirconium monohydride, [(≡Si-NH-)2(≡Si-O-)]ZrH (6b) (40%), (5) displays a new surface organometallic complex characterized by an 1H NMR signal at 14.46 ppm. The latter is assigned to a (silylimido)(silyloxo)zirconium monohydride, [(≡Si-Nî)(≡Si-O-)]ZrH (5b) (30%), coexistent with a (silylamido)(silyloxo)zirconium bishydride, [(≡Si-NH-)(≡Si-O-)] Zr(H)2 (5a) (45%), and a silylamidobis(silyloxo)zirconium monohydride, [(≡Si-NH-)(≡Si-O-)2]ZrH (5c) (25%). Surprisingly, nitrogen surface ligands possess catalytic properties already encountered with silicon oxide surfaces, but interestingly, catalyst (5) with chelating [N,O] shows better activity than (6) with chelating [N,N]. © 2013 American Chemical Society.

  10. Synthesis and antimicrobial activity of N1-(3-chloro-4-fluorophenyl-N4-substituted semicarbazone derivatives

    Directory of Open Access Journals (Sweden)

    Mohamed Jawed Ahsan

    2016-09-01

    Full Text Available A series of 16 N1-(3-chloro-4-fluorophenyl-N4-substituted semicarbazone derivatives were synthesized and subjected to computational pharmacokinetic studies to predict molecular properties. All the title compounds (4a–p followed the Lipinski “Rule of Five”. The synthesized compounds were characterized by elemental analyses and spectral data and the compounds (4a–p were evaluated for antimicrobial activities. Among them the compound 2-(4-hydroxybenzylidene-N-(3-chloro-4-fluorolphenylhydrazinecarboxamide (4f was found to be the most active compound that showed good antibacterial activity while the compound 2-(4-methoxybenzylidene-N-(3-chloro-4-fluorolphenylhydrazinecarboxamide (4g was moderately active against fungal strains. We have noticed that the compounds, (4f, 4k and 4d bearing OH and NO2 groups on the phenyl ring at position 4 exhibited good antibacterial activity while compound (4g bearing OCH3 on the phenyl ring at position 4 exhibited moderate antifungal activity.

  11. and Tetradentate N,O-donor Ligands

    African Journals Online (AJOL)

    NICO

    The reaction mixture was heated at reflux for 1 h, after which the dark green solution was cooled and filtered. The slow evaporation of this solution yielded green crystals that were suitable for X-ray crystallo-. RESEARCH ARTICLE. P. Mayer, N.C. Yumata, T.I.A. Gerber and A. Abrahams,. 40. S. Afr. J. Chem., 2010, 63, 40–44,.

  12. Donor Tag Game

    Science.gov (United States)

    ... Donor Community > Games > Donor Tag Game Donor Tag Game This feature requires version 6 or later of ... of Needles LGBTQ+ Donors Blood Donor Community SleevesUp Games Facebook Avatars and Badges Banners eCards Make a ...

  13. Spectral characterization of a newly synthesized fluorescent semicarbazone derivative and its usage as a selective fiber optic sensor for copper(II).

    Science.gov (United States)

    Oter, Ozlem; Ertekin, Kadriye; Kirilmis, Cumhur; Koca, Murat

    2007-02-19

    In this work photoluminescent properties of highly Cu(2+) selective organic fluoroionophore, semicarbazone derivative; bis(naphtho[2,1-b]furan-2-yl)methanone semicarbazone (BNF) was investigated in different solvents (dichloromethane, tetrahydrofuran, toluene and ethanol) and in polymer matrices of polyvinylchloride (PVC) and ethyl cellulose (EC) by absorption and emission spectrometry. The BNF derivative displayed enhanced fluorescence emission quantum yield, Q(f)=6.1 x 10(-2) and molar extinction coefficient, epsilon=29,000+/-65 cm(-1)M(-1) in immobilized PVC matrix, compared to 2.6 x 10(-3) and 24,573+/-115 in ethanol solution. The offered sensor exhibited remarkable fluorescence intensity quenching upon exposure to Cu(2+) ions at pH 4.0 in the concentration range of 1.0 x 10(-9) to 3.0 x 10(-4)M [Cu(2+)] while the effects of the responding ions (Ca(2+), Hg(+), Pb(2+), Al(3+), Cr(3+), Mn(2+), Mg(2+), Sn(2+), Cd(2+), Co(2+) and Ni(2+)) were less pronounced.

  14. Organometallic chemistry of chiral diphosphazane ligands ...

    Indian Academy of Sciences (India)

    Unknown

    1. Introduction. Diphosphazanes constitute a class of versatile short-bite bidentate P-donor ligands that have given rise to a varied and extensive transition metal organometallic chemistry. The organometallic chemistry of diphosphazane ligands with almost every transition metal in the periodic table is well documented1–3.

  15. Recruitment of feces donors among blood donors

    DEFF Research Database (Denmark)

    Dahl Jørgensen, Simon Mark; Erikstrup, Christian; Dinh, Khoa Manh

    2018-01-01

    As the use of fecal microbiota transplantation (FMT) has gained momentum, an increasing need for continuous access to healthy feces donors has developed. Blood donors constitute a healthy subset of the general population and may serve as an appropriate group for recruitment. In this study, we...... investigated the suitability of blood donors as feces donors. In a prospective cohort study, we recruited blood donors onsite at a public Danish blood bank. Following their consent, the blood donors underwent a stepwise screening process: First, blood donors completed an electronic pre-screening questionnaire...... to rule out predisposing risk factors. Second, eligible blood donors had blood and fecal samples examined. Of 155 blood donors asked to participate, 137 (88%) completed the electronic pre-screening questionnaire, 16 declined, and 2 were excluded. Of the 137 donors who completed the questionnaire, 79 (58...

  16. C-H and C-C activation of n -butane with zirconium hydrides supported on SBA15 containing N-donor ligands: [(≡SiNH-)(≡SiX-)ZrH2], [(≡SiNH-)(≡SiX-)2ZrH], and[(≡SiN=)(≡SiX-)ZrH] (X = -NH-, -O-). A DFT study

    KAUST Repository

    Pasha, Farhan Ahmad

    2014-07-01

    Density functional theory (DFT) was used to elucidate the mechanism of n-butane hydrogenolysis (into propane, ethane, and methane) on well-defined zirconium hydrides supported on SBA15 coordinated to the surface via N-donor surface pincer ligands: [(≡SiNH-)(≡SiO-)ZrH2] (A), [(≡SiNH-)2ZrH2] (B), [(≡SiNH-)(≡SiO-) 2ZrH] (C), [(≡SiNH-)2(≡SiO-)ZrH] (D), [(≡SiN=)(≡Si-O-)ZrH] (E), and [(≡SiN=)(≡SiNH-)ZrH] (F). The roles of these hydrides have been investigated in C-H/C-C bond activation and cleavage. The dihydride A linked via a chelating [N,O] surface ligand was found to be more active than B, linked to the chelating [N,N] surface ligand. Moreover, the dihydride zirconium complexes are also more active than their corresponding monohydrides C-F. The C-C cleavage step occurs preferentially via β-alkyl transfer, which is the rate-limiting step in the alkane hydrogenolysis. The energetics of the comparative pathways over the potential energy surface diagram (PES) reveals the hydrogenolysis of n-butane into propane and ethane. © 2014 American Chemical Society.

  17. Coordination of a Hemilabile N,N,S Donor Ligand in the Redox System [CuL2](+/2+), L=2-Pyridyl-N-(2 '-alkylthiophenyl)methyleneimine

    Czech Academy of Sciences Publication Activity Database

    Schnödt, J.; Manzur, J.; García, A.-M.; Hartenbach, I.; Su, Ch. Y.; Fiedler, Jan; Kaim, W.

    -, č. 9 (2011), s. 1436-1441 ISSN 1434-1948 R&D Projects: GA ČR GA203/09/0705; GA MŠk(CZ) LD11082 Institutional research plan: CEZ:AV0Z40400503 Keywords : copper * diimines * ligand effects Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.049, year: 2011

  18. Synthesis, characterization, DFT calculations and biological studies of Mn(II), Fe(II), Co(II) and Cd(II) complexes based on a tetradentate ONNO donor Schiff base ligand

    Science.gov (United States)

    Abdel-Rahman, Laila H.; Ismail, Nabawia M.; Ismael, Mohamed; Abu-Dief, Ahmed M.; Ahmed, Ebtehal Abdel-Hameed

    2017-04-01

    This study highlights synthesis and characterization of a tetradentate ONNO Schiff base ligand namely (1, 1‧- (pyridine-2, 3-dimethyliminomethyl) naphthalene-2, 2‧-diol) and hereafter denotes as "HNDAP″ and selected metal complexes including Mn(II), Fe(II), Co(II) and Cd(II) as a central metal. HNDAP was synthesized from 1:2 M ratio condensation of 2, 3-diaminopyridine and 2- hydroxy-1-naphthaldhyde, respectively. The stoichiometric ratios of the prepared complexes were estimated using complementary techniques such as; elemental analyses (-C, H, N), FT-IR, magnetic measurements and molar conductivity. Furthermore, their physicochemical studies were carried out using thermal TGA, DTA and kinetic-thermodynamic studies along with DFT calculations. The results of elemental analyses showed that these complexes are present in a 1:1 metal-to- ligand molar ratio. Moreover, the magnetic susceptibilities values at room temperature revealed that Mn(II), Fe(II) and Co(II) complexes are paramagnetic in nature and have an octahedral (Oh) geometry. In contrast, Cd(II) is diamagnetic and stabilizes in square planar sites. The molar conductivity measurements indicated that all complexes are nonelectrolytes in dimethyl formamide. Spectral data suggested that the ligand is as tetradentate and coordinated with Co(II) ion through two phenolic OH and two azomethine nitrogen. However, for Mn(II), Fe(II) and Cd(II) complexes, the coordination occurred through two phenolic oxygen and two azomethine nitrogen with deprotonation of OH groups. The proposed chemical structures have been validated by quantum mechanics calculations. Antimicrobial activities of both the HNDAP Schiff base ligand and its metal complexes were tested against strains of Gram (-ve) E. coli and Gram (+ve) B. subtilis and S. aureus bacteria and C. albicans, A. flavus and T. rubrum fungi. All the prepared compounds showed good results of inhibition against the selected pathogenic microorganisms. The investigated

  19. Coordination of N,O-donor appended Schiff base ligand (H2L1) towards Zinc(II) in presence of pseudohalides: Syntheses, crystal structures, photoluminescence, antimicrobial activities and Hirshfeld surfaces

    Science.gov (United States)

    Majumdar, Dhrubajyoti; Biswas, Jayanta Kumar; Mondal, Monojit; Surendra Babu, M. S.; Metre, Ramesh K.; Das, Sourav; Bankura, Kalipada; Mishra, Dipankar

    2018-03-01

    A series of dinuclear Zn(II) complexes [Zn2 (L1) (CH3OH)2(SCN) (OAc)](1), [Zn2 (L1) (CH3OH)2(N3)2](2) and [Zn2 (L1) (Cl)2(CH3OH)]·CH3OH (3) have been synthesized by the reaction of compartmental Schiff base ligand (H2L1) [N,N‧-Bis(3-ethoxysalicylidenimino)-1,3-diaminopropane] with Zn(OAc)2·2H2O in presence of coligand like KSCN, NaN3 and NaCl respectively. X-ray diffraction analysis revealed that all the complexes are neutral and possess a 4-membered Zn2 (μ2-O)2 ring fastened by the unified coordination action of a doubly deprotonated ligand. In addition, solid state structure of the complexes display extensive intermolecular interaction which has been supported theoretically by Hirshfeld surface analysis with 2D Fingerprint plots. The synthesized Zn(II) metal complexes observed enhancement of luminescence emission compared to the parent Schiff base due to emanating ligand based intraligand (π→π∗) fluorescence. Additionally, Zn(II) metal complexes exhibited considerable antimicrobial potency against some important Gram +ve and Gram -ve bacteria.

  20. Two New Three-Dimensional Pillared-Layer Co(II and Cu(II Frameworks Involving a [M2(EO-N32] Motif from a Semi-Flexible N-Donor Ligand, 5,5′-Bipyrimidin: Syntheses, Structures and Magnetic Properties

    Directory of Open Access Journals (Sweden)

    Zu-Zhen Zhang

    2018-02-01

    Full Text Available Two new three-dimensional (3D Co(II- and Cu(II-azido frameworks, [Co2(N34(bpym2]n (1 and [Cu2(N34(bpym]n (2, were successfully synthesized by introducing a semi-flexible N-donor ligand, 5,5′-bipyrimidin (bpym, with different bridging modes and orientations. Compounds 1 and 2 were structurally characterized by X-ray crystallography, IR spectroscopy, thermogravimetry and elemental analysis. Compounds 1 and 2 are 3D pillared-layer frameworks with double end-on (EO azido bridged dinuclear motifs, [M2(EO-N32]. In Compound 1, the bpym ligands show trans μ2-bridging mode and the role as pillars to connect the Co(II-azido layers, composed of [Co2(EO-N32] motifs and single end-to-end (EE azido bridges, to a 3D network with BN topology. In contrast, in 2, the bpym ligand adopts a twisted μ4-bridging mode, which not only connects the adjacent [Cu2(EO-N32] units to a layer, but also functions as a pillar for the layers of the 3D structure. The structural diversities between the two types of architectures can be attributed to the coordination geometry preference of the metal ions (octahedral for Co2+ and square pyramidal for Cu2+. Magnetic investigations revealed that Compound 1 exhibits ferromagnetic-like magnetic ordering due to spin canting with a critical temperature, TC = 33.0 K, and furthers the field-induced magnetic transitions of metamagnetism at temperatures below TC. Compound 2 shows an antiferromagnetic ordering with TN = 3.05 K and a field-induced magnetic transition of spin-flop at temperatures below the TN.

  1. Spectroscopic studies on chromium(III), manganese(II), cobalt(II), nickel(II) and copper(II) complexes with hexadentate nitrogen-sulfur donor [N(2)S(4)] macrocyclic ligand.

    Science.gov (United States)

    Shukla, Deepak; Gupta, Lokesh Kumar; Chandra, Sulekh

    2008-12-01

    Complexes of transition metals have been synthesized with hexadentate ligand (2,6-bis(((2-mercaptophenyl)thio)methyl)pyridinato)metal(II). These complexes have been synthesized via the two step template reaction by using the benzene dithiol, 2,6-bis(chloro)methyl pyridine and corresponding metal salt as key raw materials. The structures of the complexes have been elucidated on the basis of elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All of the complexes were found to possess six-coordinated geometry and are of high spin type.

  2. Spectroscopic studies on chromium(III), manganese(II), cobalt(II), nickel(II) and copper(II) complexes with hexadentate nitrogen-sulfur donor [N 2S 4] macrocyclic ligand

    Science.gov (United States)

    Shukla, Deepak; Gupta, Lokesh Kumar; Chandra, Sulekh

    2008-12-01

    Complexes of transition metals have been synthesized with hexadentate ligand (2,6-bis(((2-mercaptophenyl)thio)methyl)pyridinato)metal(II). These complexes have been synthesized via the two step template reaction by using the benzene dithiol, 2,6-bis(chloro)methyl pyridine and corresponding metal salt as key raw materials. The structures of the complexes have been elucidated on the basis of elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All of the complexes were found to possess six-coordinated geometry and are of high spin type.

  3. Nyretransplantation med levende donor

    DEFF Research Database (Denmark)

    Kamper, A L; Løkkegaard, H; Rasmussen, F

    2000-01-01

    In recent years transplantation from living donors has accounted for 25-30% of all kidney transplants in Denmark corresponding to 40-45 per year. Most of these living donors are parents or siblings, although internationally an increasing number are unrelated donors. Donor nephrectomy is associated...

  4. Bio-affinity of copper(II) complexes with nitrogen and oxygen donor ligands: Synthesis, structural studies and in vitro DNA and HSA interaction of copper(II) complexes.

    Science.gov (United States)

    Jain, Surbhi; Khan, Tanveer A; Patil, Yogesh P; Pagariya, Darshana; Kishore, Nand; Tapryal, Suman; Naik, Anil D; Naik, Sunil G

    2017-09-01

    Reported herein the binding affinity between Human Serum Albumin and the DNA binding and cleavage activity of three copper(II) complexes, [Cu(phen)(o-van)ClO 4 ] (1), [Cu(phen)(gly)]ClO 4 (2) and [Cu(L 1 ) 2 (H 2 O) 2 ] (3) wherein 1 and 2 are synthesized with 1,10-phenanthroline (phen) and co-ligands (o-van: o-vanillin; gly: glycine) and 3 with a ligand 2-hydroxy-3-methoxybenzylidene-4H-1,2,4-triazol-4-amine (H 1 L 1 ). Complex 2 crystallizes in monoclinic (P21/n) space group shows square pyramidal geometry. The complex 3 crystallizes in monoclinic (P21/a) space group. All the three complexes exhibit binding affinity towards the transport protein Human Serum albumin (HSA). Quantitative evaluation of the thermodynamics of interaction and the results obtained from fluorescence spectroscopy suggest that metal coordinated glycynate, o-vanillin and perchlorate groups have a major role to play in the binding process, the latter two being stronger in the binding of complex 1. The coordinated water in complex 3 also plays an important role in the binding, which makes binding of complex 3 with HSA stronger than that of complex 2. Experimental results indicate that the binding affinity of the complexes towards CT-DNA is in the order 1>3>2 implying that complex 1 binds stronger than complex 3 and 2.The DNA cleaving activity of all the three complexes was explored in the presence of reactive oxygen compound, H 2 O 2 . All the three complexes have primarily shown the DNA cleaving activity. Copyright © 2017. Published by Elsevier B.V.

  5. Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions.

    Science.gov (United States)

    Balof, Shawna L; Nix, K Owen; Olliff, Matthew S; Roessler, Sarah E; Saha, Arpita; Müller, Kevin B; Behrens, Ulrich; Valente, Edward J; Schanz, Hans-Jörg

    2015-01-01

    Three new ruthenium alkylidene complexes (PCy3)Cl2(H2ITap)Ru=CHSPh (9), (DMAP)2Cl2(H2ITap)Ru=CHPh (11) and (DMAP)2Cl2(H2ITap)Ru=CHSPh (12) have been synthesized bearing the pH-responsive H2ITap ligand (H2ITap = 1,3-bis(2',6'-dimethyl-4'-dimethylaminophenyl)-4,5-dihydroimidazol-2-ylidene). Catalysts 11 and 12 are additionally ligated by two pH-responsive DMAP ligands. The crystal structure was solved for complex 12 by X-ray diffraction. In organic, neutral solution, the catalysts are capable of performing standard ring-opening metathesis polymerization (ROMP) and ring closing metathesis (RCM) reactions with standard substrates. The ROMP with complex 11 is accelerated in the presence of two equiv of H3PO4, but is reduced as soon as the acid amount increased. The metathesis of phenylthiomethylidene catalysts 9 and 12 is sluggish at room temperature, but their ROMP can be dramatically accelerated at 60 °C. Complexes 11 and 12 are soluble in aqueous acid. They display the ability to perform RCM of diallylmalonic acid (DAMA), however, their conversions are very low amounting only to few turnovers before decomposition. However, both catalysts exhibit outstanding performance in the ROMP of dicyclopentadiene (DCPD) and mixtures of DCPD with cyclooctene (COE) in acidic aqueous microemulsion. With loadings as low as 180 ppm, the catalysts afforded mostly quantitative conversions of these monomers while maintaining the size and shape of the droplets throughout the polymerization process. Furthermore, the coagulate content for all experiments stayed <2%. This represents an unprecedented efficiency in emulsion ROMP based on hydrophilic ruthenium alkylidene complexes.

  6. Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

    Directory of Open Access Journals (Sweden)

    Shawna L. Balof

    2015-10-01

    Full Text Available Three new ruthenium alkylidene complexes (PCy3Cl2(H2ITapRu=CHSPh (9, (DMAP2Cl2(H2ITapRu=CHPh (11 and (DMAP2Cl2(H2ITapRu=CHSPh (12 have been synthesized bearing the pH-responsive H2ITap ligand (H2ITap = 1,3-bis(2’,6’-dimethyl-4’-dimethylaminophenyl-4,5-dihydroimidazol-2-ylidene. Catalysts 11 and 12 are additionally ligated by two pH-responsive DMAP ligands. The crystal structure was solved for complex 12 by X-ray diffraction. In organic, neutral solution, the catalysts are capable of performing standard ring-opening metathesis polymerization (ROMP and ring closing metathesis (RCM reactions with standard substrates. The ROMP with complex 11 is accelerated in the presence of two equiv of H3PO4, but is reduced as soon as the acid amount increased. The metathesis of phenylthiomethylidene catalysts 9 and 12 is sluggish at room temperature, but their ROMP can be dramatically accelerated at 60 °C. Complexes 11 and 12 are soluble in aqueous acid. They display the ability to perform RCM of diallylmalonic acid (DAMA, however, their conversions are very low amounting only to few turnovers before decomposition. However, both catalysts exhibit outstanding performance in the ROMP of dicyclopentadiene (DCPD and mixtures of DCPD with cyclooctene (COE in acidic aqueous microemulsion. With loadings as low as 180 ppm, the catalysts afforded mostly quantitative conversions of these monomers while maintaining the size and shape of the droplets throughout the polymerization process. Furthermore, the coagulate content for all experiments stayed <2%. This represents an unprecedented efficiency in emulsion ROMP based on hydrophilic ruthenium alkylidene complexes.

  7. Synthesis and structure of ruthenium(IV) complexes featuring N-heterocyclic ligands with an N-H group as the hydrogen-bond donor: hydrogen interactions in solution and in the solid state.

    Science.gov (United States)

    Díez, Josefina; Gimeno, José; Merino, Isabel; Rubio, Eduardo; Suárez, Francisco J

    2011-06-06

    The synthesis and characterization of novel ruthenium(IV) complexes [Ru(η(3):η(3)-C(10)H(16))Cl(2)L] [L = 3-methylpyrazole (2b), 3,5-dimethylpyrazole (2c), 3-methyl-5-phenylpyrazole (2d), 2-(1H-pyrazol-5-yl)phenol (2e), 6-azauracile (3), and 1H-indazol-3-ol (4)] are reported. Complex 2e is converted to the chelated complex [Ru(η(3):η(3)-C(10)H(16))Cl(κ(2)-N,O-2-(1H-pyrazol-3-yl)phenoxy)] (5) by treatment with an excess of NaOH. All of the ligands feature N-H, O-H, or C═O as the potential hydrogen-bonding group. The structures of complexes 2a-2c, 2e, 3, and 5 in the solid state have been determined by X-ray diffraction. Complexes 2a-2c and 3, which contain the pyrazole N-H group, exhibit intra- and intermolecular hydrogen bonds with chloride ligands [N-H···Cl distances (Å): intramolecular, 2.30-2.78; intermolecular, 2.59-2.77]. Complexes 2e and 3 bearing respectively O-H and C═O groups also feature N-H···O interactions [intramolecular (2e), 2.27 Å; intermolecular (3), 2.00 Å]. Chelated complex 5, lacking the O-H group, only shows an intramolecular N-H···Cl hydrogen bonding of 2.42 Å. The structure of complex 3, which turns out to be a dimer in the solid state through a double intermolecular N-H···O hydrogen bonding, has also been investigated in solution (CD(2)Cl(2)) by NMR diffusion studies. Diffusion-ordered spectroscopy experiments reveal an equilibrium between monomer and dimer species in solution whose extension depends on the temperature, concentration, and coordinating properties of the solvent. Preliminary catalytic studies show that complex 3 is highly active in the redox isomerization of the allylic alcohols in an aqueous medium under very mild reaction conditions (35 °C) and in the absence of a base. © 2011 American Chemical Society

  8. A series of Zn/Cd coordination polymers constructed from 1,4-naphthalenedicarboxylate and N-donor ligands: Syntheses, structures and luminescence sensing of Cr{sup 3+} in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Dong-Cheng [College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou 515063 (China); Fan, Yan; Si, Chang-Dai; Wu, Ya-Jun; Dong, Xiu-Yan; Yang, Yun-Xia; Yao, Xiao-Qiang [College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Liu, Jia-Cheng, E-mail: jcliu8@nwnu.edu.cn [College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

    2016-09-15

    A novel series of Zn/Cd coordination polymers based on H{sub 3}L, namely, [Zn{sub 2}(HL){sub 2}(bipy){sub 2}(H{sub 2}O){sub 6}]{sub n} (1), [Zn(HL)(phen)]{sub n} (2), [Cd{sub 3}L{sub 2}(bbi){sub 3}]{sub n} (3), [Zn{sub 3}L{sub 2}(bbi){sub 3}]{sub n} (4) [(H{sub 3}L =4-[(1-carboxynaphthalen-2-yl)oxy]phthalic acid, bipy =4,4′-bipyridine, phen =1,10-phenanthroline, bbi =1,1′-(1,4-butanediyl)bis(imidazole] have been successfully synthesized by solvothermal reaction. Compound 1 possesses two diverse 1D chains constructed by different bipy coligands, which were further connected to form a 3D supramolecular architecture by hydrogen bonding interactions. Compound 2 possesses a complicated 1D chain based on secondary building unit (SBU) with binuclear Zn cluster. Compounds 3 and 4 exhibit similar 2D→3D framework, which can be rationalized as (3,4,4)-connected 3D net with a Schläfli symbol of (6{sup 3}.8.10{sup 2}){sub 2}(6{sup 3}){sub 2}(6{sup 4}.8.10). In particular, compound 3 exhibited a high sensitivity for Cr{sup 3+} in aqueous solutions, which suggest that compound 3 is a promising luminescent probe for selectively sensing Cr{sup 3+}. - Graphical abstract: A series of novel Zn/Cd coordination polymers have been successfully synthesized by solvothermal reaction. The unique 3D Cd{sup 2+} polymer containing bbi as second ligand demonstrates high sensitivity for detection of toxic Cr{sup 3+} in aqueous solutions. Display Omitted - Highlights: • π-conjugated semirigid tricarboxylate ligands with naphthalene rings(H{sub 3}L) were rationally designed. • Four Zn/Cd coordination polymers based on H{sub 3}L have been successfully synthesized by solvothermal reaction. • Compound 3 is a promising luminescent probe for selectively sensing Cr{sup 3+} with high sensitivity in aqueous solutions.

  9. Several novel N-donor tridentate ligands formed in chemical studies of new fac-Re(CO)3 complexes relevant to fac-99mTc(CO)3 radiopharmaceuticals: attack of a terminal amine on coordinated acetonitrile.

    Science.gov (United States)

    Perera, Theshini; Marzilli, Patricia A; Fronczek, Frank R; Marzilli, Luigi G

    2010-03-01

    To evaluate syntheses of fac-[Re(CO)(3)L](+) complexes in organic solvents, we treated fac-[Re(CO)(3)(CH(3)CN)(3)]PF(6)/BF(4) in acetonitrile with triamine ligands (L). When L had two primary or two tertiary terminal amine groups, the expected fac-[Re(CO)(3)L](+) complexes formed. In contrast, N,N-dimethyldiethylenetriamine (N,N-Me(2)dien) formed an unusual compound, fac-[Re(CO)(3)(DAE)]BF(4) {DAE = (Z)-N'-(2-(2-(dimethylamino)ethylamino)ethyl)acetimidamide = (Me(2)NCH(2)CH(2))NH(CH(2)CH(2)N=C(NH(2))Me)}. DAE is formed by addition of acetonitrile to the N,N-Me(2)dien terminal primary amine, converting this sp(3) nitrogen to an sp(2) nitrogen with a double bond to the original acetonitrile sp carbon. The three Ns bound to Re derive from N,N-Me(2)dien. The pathway to fac-[Re(CO)(3)(DAE)]BF(4) is suggested by a second unusual compound, fac-[Re(CO)(3)(MAE)]PF(6) {MAE = N-methyl-N-(2-(methyl-(2-(methylamino)ethyl)amino)ethyl)acetimidamide = MeN(H)-CH(2)CH(2)-N(Me)-CH(2)CH(2)-N(Me)-C(Me)=NH}, isolated after treating fac-[Re(CO)(3)(CH(3)CN)(3)]PF(6) with N,N',N''-trimethyldiethylenetriamine (N,N',N''-Me(3)dien). MAE chelates via a terminal and a central sp(3) N from N,N',N''-Me(3)dien and via one sp(2) NH in a C(Me)=NH group. This group is derived from acetonitrile by addition of the other N,N',N''-Me(3)dien terminal amine to the nitrile carbon. This addition creates an endocyclic NMe group within a seven-membered chelate ring. The structure and other properties of fac-[Re(CO)(3)(MAE)]PF(6) allow us to propose a reaction scheme for the formation of the unprecedented DAE ligand. The new compounds advance our understanding of the spectral and structural properties of Re analogues of (99m)Tc radiopharmaceuticals.

  10. Synthesis and photocatalytic studies of ZnS nanoparticles from heteroleptic complex of Zn(II) 1-cyano-1-carboethoxy-2,-2-ethylenedithiolato diisopropylthiourea and its adducts with N-donor ligands

    Science.gov (United States)

    Osuntokun, Jejenija; Ajibade, Peter A.; Onwudiwe, Damian C.

    2016-12-01

    Zinc complexes of the type [Zn(diptu)2(ced)] (1), [Zn(diptu)2(ced)py] (2), [Zn(diptu)2(ced)bpy] (3), and [Zn(diptu)2(ced)phen] (4), (where (diptu)2(ced) = 1-cyano-1-carboethoxyethylene-2,2-dithiolato-κS,S‧-bis(N,N-diisopropyllthiourea), py = pyridine, bpy = 2, 2‧ bipyridine and phen = 1, 10 phenanthroline have been synthesized and characterized by elemental analyses, Fourier transform infra-red (FTIR) and Nuclear magnetic resonance (NMR) spectroscopies. The parent complex (1) was formulated as four coordinate species, which gave rise to 5 coordinate complex in (2) and six coordinate compounds in (3) and (4), with the dithiolate acting as bidentate chelating ligand. The complexes were used as single-source precursors for the synthesis of HDA-capped ZnS nanoparticles. The nanoparticles gave different morphologies with sizes in the range of 1.92-4.72 nm as observed from the TEM analysis and supported by XRD. The UV-vis spectroscopy showed that all the ZnS nanoparticles are blue shifted, with respect to the bulk, which confirmed quantum confinement. The photoluminescence spectra showed narrow and broad emission peaks around 290 and 360 nm which are ascribed to spontaneous emission peaks from band to band transition and surface states respectively. Photocatalytic activities of all the nanoparticles were investigated with methylene blue (MB) acting as the organic dye, and the UV-vis spectral revealed a gradual decrease in absorption peak that confirmed the degradation of the MB.

  11. Transition metal complexes with thiosemicarbazide-based ligands. Part46. Synthesis and physico-chemical characterization of mixed ligand cobalt(III-complexes with salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine

    Directory of Open Access Journals (Sweden)

    VUKADIN M. LEOVAC

    2003-12-01

    Full Text Available Mixed ligand octahedral cobalt(III complexes with the tridentate salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine of general formula [CoIII(L11-3(py3]X (H2L1 = salicylaldehyde semicarbazone, X = [CoIICl3(py]-, ClO4- . H2O, I- . 0.5 I2; H2L2 = salicylaldehyde thiosemicarbazone, X = [CoIICl3(py]-, [CoIIBr3(py]-, ClO4- . H2O, I3-; H2L3 = salicylaldehyde S-methylisothiosemicarbazone, X = [ CoIIBr3(py ]-, ClO4- . H2O, BF4- were synthesized. The tridentate coordination of all the three dianionic forms of the ligands involves the phenol oxygen, hydrazine nitrogen and the chalcogen (O or S in case of salicylaldehyde semi-, thiosemicarbazone and the terminal nitrogen atom in the case of isothiosemicarbazone. For all the complexes, a meridial octahedral arrangement is proposed, which is a consequence of the planarity of the chelate ligand. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility, IR and electronic absorption spectra. The thermal decomposition of the complexes was investigated by thermogravimetry, coupled TG-MS measurements and DSC.

  12. AutoSite: an automated approach for pseudo-ligands prediction—from ligand-binding sites identification to predicting key ligand atoms

    Science.gov (United States)

    Ravindranath, Pradeep Anand; Sanner, Michel F.

    2016-01-01

    Motivation: The identification of ligand-binding sites from a protein structure facilitates computational drug design and optimization, and protein function assignment. We introduce AutoSite: an efficient software tool for identifying ligand-binding sites and predicting pseudo ligand corresponding to each binding site identified. Binding sites are reported as clusters of 3D points called fills in which every point is labelled as hydrophobic or as hydrogen bond donor or acceptor. From these fills AutoSite derives feature points: a set of putative positions of hydrophobic-, and hydrogen-bond forming ligand atoms. Results: We show that AutoSite identifies ligand-binding sites with higher accuracy than other leading methods, and produces fills that better matches the ligand shape and properties, than the fills obtained with a software program with similar capabilities, AutoLigand. In addition, we demonstrate that for the Astex Diverse Set, the feature points identify 79% of hydrophobic ligand atoms, and 81% and 62% of the hydrogen acceptor and donor hydrogen ligand atoms interacting with the receptor, and predict 81.2% of water molecules mediating interactions between ligand and receptor. Finally, we illustrate potential uses of the predicted feature points in the context of lead optimization in drug discovery projects. Availability and Implementation: http://adfr.scripps.edu/AutoDockFR/autosite.html Contact: sanner@scripps.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27354702

  13. Nyretransplantation med levende donor

    DEFF Research Database (Denmark)

    Kamper, A L; Løkkegaard, H; Rasmussen, F

    2000-01-01

    In recent years transplantation from living donors has accounted for 25-30% of all kidney transplants in Denmark corresponding to 40-45 per year. Most of these living donors are parents or siblings, although internationally an increasing number are unrelated donors. Donor nephrectomy is associate...... in cadaver transplantation. The ethical and psychological aspects related to transplantation from a living donor are complex and need to be carefully evaluated when this treatment is offered to the patients.......In recent years transplantation from living donors has accounted for 25-30% of all kidney transplants in Denmark corresponding to 40-45 per year. Most of these living donors are parents or siblings, although internationally an increasing number are unrelated donors. Donor nephrectomy is associated...... with only few complications. The long-term outcome for kidney donors is good without increase in mortality or risk for development of hypertension and renal failure; proteinuria may be seen. Living kidney transplantation is the optimal treatment of end-stage renal disease with better graft survival than...

  14. Laparoscopic donor nephrectomy

    Directory of Open Access Journals (Sweden)

    Gupta Nitin

    2005-01-01

    Full Text Available Of the various options for patients with end stage renal disease, kidney transplantation is the treatment of choice for a suitable patient. The kidney for transplantation is retrieved from either a cadaver or a live donor. Living donor nephrectomy has been developed as a method to address the shortfall in cadaveric kidneys available for transplantation. Laparoscopic living donor nephrectomy (LLDN, by reducing postoperative pain, shortening convalescence, and improving the cosmetic outcome of the donor nephrectomy, has shown the potential to increase the number of living kidney donations further by removing some of the disincentives inherent to donation itself. The technique of LLDN has undergone evolution at different transplant centers and many modifications have been done to improve donor safety and recipient outcome. Virtually all donors eligible for an open surgical procedure may also undergo the laparoscopic operation. Various earlier contraindications to LDN, such as right donor kidney, multiple vessels, anomalous vasculature and obesity have been overcome with increasing experience. Laparoscopic live donor nephrectomy can be done transperitoneally or retroperitoneally on either side. The approach is most commonly transperitoneal, which allows adequate working space and easy dissection. A review of literature and our experience with regards to standard approach and the modifications is presented including a cost saving model for the developing countries. An assessment has been made, of the impact of LDN on the outcome of donor and the recipient.

  15. Systems of donor transfer

    NARCIS (Netherlands)

    F.T. de Charro (Frank); J.E.M. Akveld (Hans); E. Hessing (Ellen)

    1993-01-01

    textabstractThe development of medical knowledge has resulted in a demand in society for donor organs, but the recruitment of donor organs for transplantation is difficult. This paper aims to provide some general insights into the complex interaction processes involved. A laissez-faire policy, in

  16. Dealing with Donor Anger.

    Science.gov (United States)

    McNamee, Mike

    1995-01-01

    Techniques that reduce donors' resistance to college fund-raising requests, either direct mail or telephone solicitations, are offered. These include: respecting the prospects' concerns about privacy; offering nonintrusive giving options; honesty and clarity of communication; reinforcing donor sense of control; connecting with prospects'…

  17. Activation of the manganese(I) tricarbonyl core by selective variation of bidentate ligands (L,L'-Bid = N,N' and N,O donor atom sets) in fac-[Mn(CO)3(L,L'-Bid)(CH3OH)](n) complexes.

    Science.gov (United States)

    Twala, T N; Schutte-Smith, M; Roodt, A; Visser, H G

    2015-02-21

    A range of fac-[Mn(CO)3(L,L'-Bid)(H2O)](n) (L,L'-Bid = neutral or monoanionic bidentate ligands with varied L,L' donor atoms, N,N' and N,O, 1,10-phenanthroline, 2,2'-bipyridine, 2-picolinate, 2,4-quinolinate; n = 0, +1) has been synthesized and the methanol substitution has been investigated for the first time. The complexes were characterized by UV/vis, IR and NMR spectroscopy and X-ray crystallographic studies of the compounds fac-[Mn(CO)3(Bipy)(H2O)][CF3SO3] () and fac-[Mn(CO)3(Phen)(H2O)][CF3SO3] () are reported. A two order-of-magnitude of activation for the methanol substitution is induced as manifested by the second order rate constants with (N,N'-Bid) fac-[Mn(CO)3(Phen)(CH3OH)](+) (2.39 ± 5) × 10(-3), (1.5 ± 0.3) × 10(-5), 159 ± 32; fac-[Mn(CO)3(2,4-QuinH)(CH3OH)] (4.5 ± 0.2), (4 ± 1) × 10(-2), 113 ± 29. Activation parameters (ΔH, kJ mol(-1); ΔS, J K(-1) mol(-1)) from Eyring plots for entering nucleophiles as indicated are as follows: fac-[Mn(CO)3(Phen)(CH3OH)](+) (bromide ions) 66.7 ± 0.6, -27 ± 2; (pyridine) 80 ± 3, -25 ± 11; fac-[Mn(CO)3(Pico)(CH3OH)] (bromide ions) 68 ± 2, -24 ± 5. A dissociative interchange mechanism is proposed.

  18. Complexation of trivalent actinides and lanthanides with hydrophilic N-donor ligands for Am(III)/Cm(III) and An(III)/Ln(III) separation; Komplexierung von trivalenten Actiniden und Lanthaniden mit hydrophilen N-Donorliganden zur Am(III)/Cm(III)- bzw. An(III)/Ln(III)-Trennung

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Christoph

    2017-07-24

    The implementation of actinide recycling processes is considered in several countries, aiming at the reduction of long-term radiotoxicity and heat load of used nuclear fuel. This requires the separation of the actinides from the fission and corrosion products. The separation of the trivalent actinides (An(III)) Am(III) and Cm(III), however, is complicated by the presence of the chemically similar fission lanthanides (Ln(III)). Hydrophilic N-donor ligands are employed as An(III) or Am(III) selective complexing agents in solvent extraction to strip An(III) or Am(III) from an organic phase loaded with An(III) and Ln(III). Though they exhibit excellent selectivity, the complexation chemistry of these ligands and the complexes formed during solvent extraction are not sufficiently characterized. In the present thesis the complexation of An(III) and Ln(III) with hydrophilic N-donor ligands is studied by time resolved laser fluorescence spectroscopy (TRLFS), UV/Vis, vibronic sideband spectroscopy and solvent extraction. TRLFS studies on the complexation of Cm(III) and Eu(III) with the Am(III) selective complexing agent SO{sub 3}-Ph-BTBP (tetrasodium 3,3{sup '},3'',3{sup '''}-([2,2{sup '}-bipyridine]-6,6{sup '}-diylbis(1,2,4-triazine-3,5,6-triyl)) tetrabenzenesulfonate) revealed the formation of [M(SO{sub 3}-Ph-BTBP){sub n}]{sup (4n-3)-} complexes (M = Cm(III), Eu(III); n = 1, 2). The conditional stability constants were determined in different media yielding two orders of magnitude larger β{sub 2}-values for the Cm(III) complexes, independently from the applied medium. A strong impact of ionic strength on the stability and stoichiometry of the formed complexes was identified, resulting from the stabilization of the pentaanionic [M(SO{sub 3}-Ph-BTBP){sub 2}]{sup 5-} complex with increasing ionic strength. Thermodynamic studies of Cm(III)-SO{sub 3}-Ph-BTBP complexation showed that the proton concentration of the applied medium impacts

  19. Silyl phosphorus and nitrogen donor chelates for homogeneous ortho borylation catalysis.

    Science.gov (United States)

    Ghaffari, Behnaz; Preshlock, Sean M; Plattner, Donald L; Staples, Richard J; Maligres, Peter E; Krska, Shane W; Maleczka, Robert E; Smith, Milton R

    2014-10-15

    Ir catalysts supported by bidentate silyl ligands that contain P- or N-donors are shown to effect ortho borylations for a range of substituted aromatics. The substrate scope is broad, and the modular ligand synthesis allows for flexible catalyst design.

  20. Marginal kidney donor

    Directory of Open Access Journals (Sweden)

    Ganesh Gopalakrishnan

    2007-01-01

    Full Text Available Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.

  1. Nickel(II) complexes containing ONS donor ligands: Synthesis ...

    Indian Academy of Sciences (India)

    Blanchard-Desce M 2002 Org. Lett. 4 719; (b) Wegner. G and Mullen K 1998 In Electronic Materials: The. Oligomer Approach (Weinheim: Wiley- VCH). 26. Beletskaya I P, Latyshev G V, Tsvetkov A V and. Lukashev N V 2003 Tetrahedron Lett. 44 5011. 27. Muthu Tamizh M and Karvembu R 2012 Inorg Chem. Commun 25 30.

  2. Nickel(II) complexes containing ONS donor ligands: Synthesis ...

    Indian Academy of Sciences (India)

    Phenylmagnesium chloride (10 mmol) was then added dropwise and the reaction mixture was stirred for 4 h at room temperature. Then the reaction was ended by addition of water. The mixture was extracted with ethyl acetate and the obtained organic layer was dried over MgSO4. The crude mix- ture was analyzed by gas ...

  3. COMPLEXES WITH TRIDENTATE N2,O-DONOR LIGAND

    African Journals Online (AJOL)

    The molar conductance of 10-3 M solutions of the metal complexes ... conductivity cell. Room temperature magnetic susceptibilities of the powdered samples. {calibrant Hg[Co(SCN)4]} were measured using a Johnson Mattey scientific ..... 2 and 4) complexes and the dinuclear complex 3 are neutral and non-electrolyte [21].

  4. A new inorganic-organic nanohybrid based on a copper(II) semicarbazone complex and the PMo.sub.12./sub.O.sup.3-./sup..sub.40./sub. polyanion: synthesis, characterization, crystal structure and photocatalytic activity for degradation of cationic dyes

    Czech Academy of Sciences Publication Activity Database

    Farhadi, S.; Mahmoudi, F.; Dušek, Michal; Eigner, Václav; Kučeráková, Monika

    2017-01-01

    Roč. 122, Jan (2017), s. 247-256 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA14-03276S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : inorganic-organic hybrid * semicarbazone complex * nanohybrid * photodegradation * cationic dyes Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 1.926, year: 2016

  5. Tuning the reactivity in classic low-spin d6 rhenium(I) tricarbonyl radiopharmaceutical synthon by selective bidentate ligand variation (L,L'-Bid; L,L'= N,N', N,O, and O,O' donor atom sets) in fac-[Re(CO)3(L,L'-Bid)(MeOH)]n complexes.

    Science.gov (United States)

    Schutte, Marietjie; Kemp, Gerdus; Visser, Hendrik G; Roodt, Andreas

    2011-12-19

    A range of fac-[Re(CO)(3)(L,L'-Bid)(H(2)O)](n) (L,L'-Bid = neutral or monoanionic bidentate ligands with varied L,L' donor atoms, N,N', N,O, or O,O': 1,10-phenanthroline, 2,2'-bipydine, 2-picolinate, 2-quinolinate, 2,4-dipicolinate, 2,4-diquinolinate, tribromotropolonate, and hydroxyflavonate; n = 0, +1) has been synthesized and the aqua/methanol substitution has been investigated. The complexes were characterized by UV-vis, IR and NMR spectroscopy and X-ray crystallographic studies of the compounds fac-[Re(CO)(3)(Phen)(H(2)O)]NO(3)·0.5Phen, fac-[Re(CO)(3)(2,4-dQuinH)(H(2)O)]·H(2)O, fac-[Re(CO)(3)(2,4-dQuinH)Py]Py, and fac-[Re(CO)(3)(Flav)(CH(3)OH)]·CH(3)OH are reported. A four order-of-magnitude of activation for the methanol substitution is induced as manifested by the second order rate constants with (N,N'-Bid) fac-[Re(CO)(3)(Phen)(MeOH)](+) (50 ± 3) × 10(-3), (5.9 ± 0.3) × 10(-4), 84 ± 7; fac-[Re(CO)(3)(2,4-dPicoH)(MeOH)] (15.7 ± 0.2) × 10(-3), (6.3 ± 0.8) × 10(-4), 25 ± 3; fac-[Re(CO)(3)(TropBr(3))(MeOH)] (7.06 ± 0.04) × 10(-2), (4 ± 1) × 10(-3), 18 ± 4; fac-[Re(CO)(3)(Flav)(MeOH)] 7.2 ± 0.3, 3.17 ± 0.09, 2.5 ± 2. Activation parameters (ΔH(k1)(++), kJmol(-1); ΔS(k1)(), J K(-1) mol(-1)) from Eyring plots for entering nucleophiles as indicated are as follows: fac-[Re(CO)(3)(Phen)(MeOH)](+) iodide 70 ± 1, -35 ± 3; fac-[Re(CO)(3)(2,4-dPico)(MeOH)] bromide 80.8 ± 6, -8 ± 2; fac-[Re(CO)(3)(Flav)(MeOH)] bromide 52 ± 5, -52 ± 15. A dissociative interchange mechanism is proposed. © 2011 American Chemical Society

  6. Independent donor ethical assessment: aiming to standardize donor advocacy.

    Science.gov (United States)

    Choudhury, Devasmita; Jotterand, Fabrice; Casenave, Gerald; Smith-Morris, Carolyn

    2014-06-01

    Living organ donation has become more common across the world. To ensure an informed consent process, given the complex issues involved with organ donation, independent donor advocacy is required. The choice of how donor advocacy is administered is left up to each transplant center. This article presents the experience and process of donor advocacy at University of Texas Southwestern Medical Center administered by a multidisciplinary team consisting of physicians, surgeons, psychologists, medical ethicists and anthropologists, lawyers, a chaplain, a living kidney donor, and a kidney transplant recipient. To ensure that advocacy remains fair and consistent for all donors being considered, the donor advocacy team at University of Texas Southwestern Medical Center developed the Independent Donor Ethical Assessment, a tool that may be useful to others in rendering donor advocacy. In addition, the tool may be modified as circumstances arise to improve donor advocacy and maintain uniformity in decision making.

  7. Design and Application of Latent Olefin Metathesis Catalysts Featuring S-Chelating Alkylidene Ligands

    Science.gov (United States)

    Szadkowska, Anna; Grela, Karol

    This review article is devoted to recent advances in the design and application of so-called “dormant” or “latent” ruthenium olefin metathesis catalysts bearing S-chelating alkylidene ligands. Selected ruthenium complexes containing S-donor ligands, which possess controllable initiation behaviour are presented. Applications of these complexes in olefin metathesis are described.

  8. Reactivity descriptors and electron density analysis for ligand ...

    Indian Academy of Sciences (India)

    We discuss evaluation of local descriptors using relaxed as well as frozen approximation and characterize the / acceptance/donor characteristics of the above ligands. The intermolecular reactivity sequence for the same systems is examined by the global and local philicity index. In addition, electron density analysis has ...

  9. Electronic structure and properties of uranyl compounds. Problems of electron-donor conception

    International Nuclear Information System (INIS)

    Glebov, V.A.

    1982-01-01

    Comparison of the series of the ligand mutual substitution in the uranyl compounds with the ligand series of d-elements and with the uranyl ''covalent model'', is made. The data on ionization potentials of the ligand higher valent levels and on the structure of some uranyl nitrate compounds are considered. It is concluded that the mechanism of the ligand effect on the properties of uranyl grouping is more complex, than it is supposed in the traditional representations on the nature of electron-donor interactions in the uranyl compounds

  10. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2002-01-01

    Wednesday 13 November 2002 in restaurant nr 2, from 8.30 to 16.30 hrs will be held a blood donors campaign, organized by the Etablissement de Transfusion de Haute-Savoie If you already have a card giving your blood group, please bring this with you.

  11. BLOOD DONORS CAMPAIGN

    CERN Multimedia

    Medical Service

    2002-01-01

    Tuesday 19 March 2002 in restaurant nr 2, from 9.00 to 16.30 hrs A blood donors campaign, organized by the Centre de Transfusion sanguine of Geneva If you already have a card giving your blood group, please bring this with you.

  12. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2001-01-01

    A blood donors campaign, organized by the Centre de Transfusion Sanguine of Geneva will be held at CERN on Tuesday 13 March 2001 in restaurant nr 2, from 9.00 to 16.30 hrs If you already have a card giving your blood group, please bring this with you.

  13. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2001-01-01

    A blood donors campaign, organized by the Centre de Transfusion d'Annemasse will be held at CERN on Tuesday 14 November 2001 in restaurant nr 2, from 9.00 to 16.30 hrs If you already have a card giving your blood group, please bring this with you.

  14. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2000-01-01

    A blood donors campaign, organized by the Établissement de Transfusion de Rhône-Alpes will be held at CERN on Tuesday 14 November 2000 in restaurant nr 2, from 8.30 to 16.30 hrs If you already have a card giving your blood group, please bring this with you.

  15. A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

    Directory of Open Access Journals (Sweden)

    Vladislav Vasilenko

    2016-04-01

    Full Text Available We report the modular synthesis of three different types of neutral κ2-P,N-ligands comprising an imine and a phosphine binding site. These ligands were reacted with rhodium, iridium and palladium metal precursors and the structures of the resulting complexes were elucidated by means of X-ray crystallography. We observed that subtle changes of the ligand backbone have a significant influence on the binding geometry und coordination properties of these bidentate P,N-donors.

  16. Donor transplant programme

    International Nuclear Information System (INIS)

    Abu Bakar Sulaiman

    1999-01-01

    The transplantation of organs and tissues from one human to another human has become an essential and well established form of therapy for many types of organ and tissue failure. In Malaysia, kidney, cornea and bone marrow transplantation are well established. Recently, liver, bone and heart transplanation have been performed. Unfortunately, because of the lack of cadaveric organ donation, only a limited number of solid organ transplantation have been performed. The cadaveric organ donor rate in Malaysia is low at less than one per million population. The first tissue transplanted in Malaysia was the cornea which was performed in the early 1970s. At that time and even now the majority of corneas came from Sri Lanka. The first kidney transplant was performed in 1975 from a live related donor. The majority of the 629 kidney transplants done at Hospital Kuala Lumpur to date have been from live related donors. Only 35 were from cadaver donors. Similarly, the liver transplantation programme which started in 1995 are from live related donors. A more concerted effort has been made recently to increase the awareness of the public and the health professionals on organ and tissue donation. This national effort to promote organ and tissue donation seems to have gathered momentum in 1997 with the first heart transplant successfully performed at the National Heart Institute. The rate of cadaveric donors has also increased from a previous average of I to 2 per year to 6 per year in the last one year. These developments are most encouraging and may signal the coming of age of our transplantati on programme. The Ministry of Health in conjunction with various institutions, organizations and professional groups, have taken a number of proactive measures to facilitate the development of the cadaveric organ donation programme. Efforts to increase public awareness and to overcome the negative cultural attitude towards organ donation have been intensified. Equally important are efforts

  17. 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

  18. Donor attention to reading materials.

    Science.gov (United States)

    O'Brien, S F; Osmond, L; Choquet, K; Yi, Q-L; Goldman, M

    2015-11-01

    Mandatory predonation reading materials inform donors about risk factors for transmissible disease, possible complications of donation and changes to the donation process. We aimed to assess the attention to predonation reading materials and factors which may affect attention. A national survey in 2008 of 18,108 blood donors asked about self-assessed attention to reading the materials. In face-to-face interviews, 441 donors completed additional questions about reading the materials and a literacy test. Qualitative interviews of 27 donors assessed their approach to reading. In the national survey, most of the first-time donors said they read all or most of the materials (90.9% first-time vs. 57.6% repeat donors, P reading them carefully (P read materials carefully, skimmed or did not read, most knew that donors are informed of positive transmissible disease test results (97.1%, 95.5, 98.0 P > 0.05), but fewer recalled seeing the definition of sex (77.2%, 56.9, 24.2 P read materials carefully, skimmed or did not read were compared (P > 0.05). Qualitative interviews showed that donors are reluctant to read any more than necessary and decide based on perceived importance or relevance. Attention to predonation reading materials tends to be better among first-time donors. The effectiveness is limited by low motivation to read, especially for repeat donors, as well as poor literacy. © 2015 International Society of Blood Transfusion.

  19. Study of killer cell immunoglobulin-like receptor genes and HLA C ligands in hematopoietic stem cell transplantation pairs in Vojvodina

    Directory of Open Access Journals (Sweden)

    Ademović-Sazdanić Dušica S.

    2016-01-01

    Full Text Available Objective: The aim of the study was to analyse KIR/HLA profiles and to create the predictive probabilities for the selection of the most suitable Hematopoietic Stem Cell Transplantation (HSCT donor. Materials and Methods: The study was conducted on 92 patients with malignant hematological deseases and 181 their first degree relatives, from the region of Vojvodina. HLA and KIR genotyping was performed by polymerase chain reaction-sequence specific primers (PCR-SSP assay. The analysis included the degree of HLA matching between transplant pairs, number of missing ligands for inhibitory KIR genes, existence of GvH / HvG ligand-ligand mismatches (specific for C1, C2 or Bw4 ligands and distribution of C1/C1, C1/C2, C2/C2 HLA ligand groups in patients. Results: There was no significant differences in HLA frequencies between donors and recipients as analyzed by pairwise comparison, the probability of finding HLA identical donor is only 0.154, the probability of finding the donor with ≥ 1 KIR-ligand mismatch is 0.939, the probability of finding the donor with KIR-ligand mismatch for the KIR 2DL1 gene is 0.298, probability of having favorable C1/C1 and C2/C2 HLA ligand groups is 0.565. Conclusion: The results of our study could be used as a basis for the HSCT outcome prediction representing a powerful tool for choosing the most suitable donor.

  20. Synthesis, characterization, DNA interaction, antioxidant and anticancer activity of new ruthenium(II) complexes of thiosemicarbazone/semicarbazone bearing 9,10-phenanthrenequinone.

    Science.gov (United States)

    Anitha, Panneerselvam; Chitrapriya, Nataraj; Jang, Yoon Jung; Viswanathamurthi, Periasamy

    2013-12-05

    A new series of octahedral ruthenium(II) complexes supported by tridentate ligands derived from phenanthrenequinone and derivatives of thiosemicarbazide/semicarbazide and other co-ligands have been synthesized and characterized. DNA binding experiments indicated that ruthenium(II) complexes can interact with DNA through non-intercalation and the apparent binding constant value (Kb) of [RuCl(CO)(PPh₃)(L₃)] (3) at room temperature was calculated to be 2.27 × 10(3)M(-1). The DNA cleavage studies showed that the complexes have better cleavage of pBR 322 DNA. Antioxidative activity proved that the complexes have significant radical scavenging activity against free radicals. Cytotoxic activities showed that the ruthenium(II) complexes exhibited more effective cytotoxic activity against selected cancer cells. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Synthesis and Characterization of Divalent Manganese, Iron, and Cobalt Complexes in Tripodal Phenolate/N-Heterocyclic Carbene Ligand Environments

    DEFF Research Database (Denmark)

    Käß, Martina; Hohenberger, Johannes; Adelhardt, Mario

    2014-01-01

    of the ligands is evident. Particularly, the molecular structure of 1in which a pyridine molecule is situated next to the Mn–Cl bondand those of azide complexes 2, 4, and 6 demonstrate the flexibility of these mixed-ligand derivatives, which, in contrast to the corresponding symmetrical TIMENR ligands, allow......Two novel tripodal ligands, (BIMPNMes,Ad,Me)− and (MIMPNMes,Ad,Me)2–, combining two types of donor atoms, namely, NHC and phenolate donors, were synthesized to complete the series of N-anchored ligands, ranging from chelating species with tris(carbene) to tris(phenolate) chelating arms....... The complete ligand series offers a convenient way of tuning the electronic and steric environment around the metal center, thus, allowing for control of the complex’s reactivity. This series of divalent complexes of Mn, Fe, and Co was synthesized and characterized by 1H NMR, IR, and UV/vis spectroscopy...

  2. Coordination chemistry of poly(thioether)borate ligands

    Science.gov (United States)

    Riordan, Charles G.

    2010-01-01

    This review traces the development and application of the tris(thioether)borate ligands, tripodal ligands with highly polarizable thioether donors. Areas of emphasis include the basic coordination chemistry of the mid-to-late first row transition metals (Fe, Ni, Co, Cu), and the role of the thioether substituent in directing complex formation, the modeling of zinc thiolate protein active sites, high-spin organo-iron and organo-cobalt chemistry, the preparation of monovalent complexes of Fe, Co and Ni, and dioxygen and sulfur activation by monovalent nickel complexes. PMID:20607091

  3. International collaborative donor project.

    Science.gov (United States)

    Ríos Zambudio, Antonio

    2018-02-01

    The International Donor Collaborative Project (PCID) research group was created in 1996 in Spain with the aim of promoting research in the field of organ donation and transplantation, led by Spanish surgeons. During this period they have developed the questionnaires of the PCID, both the attitude towards cadaver and live donation, which are the most used questionnaires in publications in indexed journals. They have been the driving group of stratified studies representative of the populations under study, and of the performance of multivariate statistical analyzes in the field of psycho-social research in organ donation and transplantation. The main contributions of the group focus on the analysis of health center professionals and emerging migrant groups. In recent years, studies have been extended to the United States, Latin America (mainly Mexico) and Europe. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Donor selection criteria and procurement

    International Nuclear Information System (INIS)

    Agcaoili, N.R.

    1999-01-01

    Donor selection is one of the most important aspects of tissue banking practice. Without a good donor selection criteria, the results of any effort of trying to preserve tissues will have disastrous outcome for the recipient of these tissues. While with a very good and strict donor selection the Tissue Bank can guarantee safe and effective tissue allografts. There are significant aspects in the history and physical examination of the donor that must be emphasized. A donor exclusion criteria has also been formulated together with a list of all the needed laboratory examinations to eliminate possible diseases that may be transferred from the donor. The methods of procurement of tissue allografts from living and cadaver donors will be described. The limitations and advantages of each will be taken.There are also special restrictions that are important in the practice of removing the tissues from the donors. All the necessary equipment should be ready and the potential risk on the personnel should be known to all doing Tissue Banking

  5. Heart transplantation from older donors

    Directory of Open Access Journals (Sweden)

    V. N. Poptsov

    2017-01-01

    Full Text Available In the current situation of the shortage of suitable donor organs, heart transplantation from older donors is one of the ways to increase the performance of more heart transplants, particularly, in patients with urgent need of transplantation. While planning a heart transplantation from older donor one should consider increased risk of early cardiac allograft dysfunction, preexisting coronary artery disease, accelerated transplant vasculopathy which may adversely affect early and long-term survival of recipients. Subject to careful selection of donor–recipient pairs, effective prevention and treatment of early cardiac allograft dysfunction, pre-existing atherosclerosis and transplant vasculopathy the early and long-term survival of heart transplant recipients from older donors is comparable to heart transplantation from young donors.

  6. Synthesis and transition metal coordination chemistry of a novel hexadentate bispidine ligand.

    Science.gov (United States)

    Comba, Peter; Rudolf, Henning; Wadepohl, Hubert

    2015-02-14

    Reported is the new bispidine-derived hexadentate ligand (L = 3-(2-methylpyridyl)-7-(bis-2-methylpyridyl)-3,7-diazabicyclo[3.3.1]nonane) with two tertiary amine and four pyridine donor groups. This ligand can form heterodinuclear and mononuclear complexes and, in the mononuclear compounds discussed here, the ligand may coordinate as a pentadentate ligand, with one of the bispyridinemethane-based pyridine groups un- or semi-coordinated, or as a hexadentate ligand, leading to a pentagonal pyramidal coordination geometry or, with an additional monodentate ligand, to a heptacoordinate pentagonal bipyramidal structure. The solution and solid state data presented here indicate that, with the relatively small Cu(II) and high-spin Fe(II) ions the fourth pyridine group is only semi-coordinated for steric reasons and, with the larger high-spin Mn(II) ion genuine heptacoordination is observed but with a relatively large distortion in the pentagonal equatorial plane.

  7. Voluntary whole-blood donors, and compensated platelet donors and plasma donors: motivation to donate, altruism and aggression.

    Science.gov (United States)

    Trimmel, Michael; Lattacher, Helene; Janda, Monika

    2005-10-01

    To establish if voluntary whole-blood donors and compensated platelet donors and plasma donors may differ in their motivation to donate, altruism, aggression and autoaggression. Whole-blood (n=51), platelet (n=52) and plasma donors (n=48) completed a battery of validated questionnaires while waiting to donate. Bivariate and multivariate analyses of variance and t-tests were performed to detect differences between groups as noted. Altruism (mean=40.2) was slightly higher in whole-blood donors than in platelet (mean=38.3) and plasma donors (mean=39.1) (p=0.07). Blood donors (mean=2.8) scored lower in the spontaneous aggression measure than platelet (mean=4.1) and plasma donors (mean=4.4) (p=0.01). Plasma donors (mean=4.9) had higher auto-aggression than whole-blood donors and platelet donors (mean for both groups=3.4) (p=0.01). Differences between the three groups were mediated by sociodemographic variables (MANCOVA). Whole-blood donors donated to help others, platelet and plasma donors mostly to receive the compensation. However, those platelet and plasma donors, who would continue to donate without compensation were similar in altruism and aggression to whole-blood donors. While most platelet donors and plasma donors were motivated by the compensation, those who stated that they would continue to donate without compensation had altruism and aggression scores similar to voluntary whole-blood donors.

  8. Multidentate Fluorinated Alkoxide Ligand Platforms for Oxophilic Metal Centers: From MOCVD Source Reagents to Polymerization Catalysts

    OpenAIRE

    Carpentier, Jean-François

    2010-01-01

    International audience; In contrast to simple fluorinated alkoxides, the coordination chemistry of multidentate ligands that incorporate OC(CF3)2CR2-type moieties and additional donors (N, O, etc.) has been briefly investigated. In this Perspective, we review some well-defined, unambiguously authenticated main group and transition metal complexes supported by multidentate fluorinated alkoxide ligands and we present aspects of their syntheses, structures, and reactivities. The first part is de...

  9. Donor milk: current perspectives

    Directory of Open Access Journals (Sweden)

    Giuliani F

    2014-07-01

    Full Text Available Francesca Giuliani,1 Ilaria Rovelli,1 Chiara Peila,1 Stefania Alfonsina Liguori,2 Enrico Bertino,1 Alessandra Coscia1 1SCDU Neonatologia, Dipartimento di Scienze Pediatriche e dell'Adolescenza, Università degli Studi di Torino, Torino, Italy; 2SC Neonatologia, Ospedale Maria Vittoria, Torino, Italy Abstract: Mother's own milk is widely recognized as the optimal feeding for term infants, but increasing evidence exists of its benefits also for sick and preterm infants in neonatal intensive care units. However, the nutritional needs for appropriate growth and neurodevelopmental outcomes of such a particular population of infants should be attentively evaluated, considering also the indication to an appropriate fortification of human milk. The target is to achieve growth potential for preterm newborns while ensuring good metabolic outcomes and normal neurological development. When mother's milk is unavailable or in short supply, donor human milk (DHM represents the second best choice and, although somewhat modified by the Holder pasteurization process, it preserves many benefits when compared to formula, as documented by more and more reports, randomized controlled trials, and meta-analyses published in the past few years. Evidence exists of the protection exerted by DHM from necrotizing enterocolitis, while further studies are required to look at possible beneficial effects regarding infections, bronchopulmonary dysplasia, long-term cardiovascular risk factors, feeding tolerance, neurological outcome, and allergy. Finally, the concern that the use of DHM might decrease preterm infant breastfeeding is being raised. Conversely, publications exist showing that the use of DHM in the neonatal unit increases breastfeeding rates at discharge for infants of very low birth weight. Keywords: human milk, preterm infant feeding, milk bank, breast milk, mother's own milk, pasteurized human milk, fortification

  10. Iron deficiency among blood donors

    DEFF Research Database (Denmark)

    Rigas, A S; Pedersen, O B; Magnussen, K

    2017-01-01

    and menopausal status are the strongest predictors of iron deficiency. Only little information on the health effects of iron deficiency in blood donors exits. Possibly, after a standard full blood donation, a temporarily reduced physical performance for women is observed. However, iron deficiency among blood...... donors is not reflected in a reduced self-perceived mental and physical health. In general, the high proportion of iron-deficient donors can be alleviated either by extending the inter-donation intervals or by guided iron supplementation. The experience from Copenhagen, the Capital Region of Denmark......, is that routine ferritin measurements and iron supplementation are feasible and effective ways of reducing the proportion of donors with low haemoglobin levels....

  11. Research Award: Donor Partnerships Division

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    2013-08-07

    . The successful candidate must be willing to work as a member of the DPD team in its ongoing acvies, including providing research analysis and coordinang the producon and disseminaon of informaon related to donor.

  12. Synthesis, Crystal Structure and Luminescent Property of A Novel Cd(II) Coordination Polymer with Bis-imidazole Ligand

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yong Hong [Huaibei Normal Univ., Huaibei (China)

    2013-04-15

    The key to the successful design of metal-organic coordination polymers is the judicious selection of organic ligand. Recently, polydentate aromatic nitrogen heterocyclic ligands with five-membered rings have been well-studied in the construction of supramolecular structure for their N-coordinated sites apt to coordinating to transition metals. Similar to six-membered N-heterocyclic ligands, the azole-based five-membered N-heterocyclic ligands, such as imidazoles, triazoles and tetrazoles have been extensively employed in the construction of various coordination polymers with diverse topologies and interesting properties. The bis(azole) ligands in which N-donor azole rings (imidazole, triazole, or tetrazole) are separated by alkyl, (CH{sub 2}){sub n}, spacers are good choices for flexible bridging ligands. The conformational flexibility of the spacers makes the ligands adaptable to various coordination networks with one-, two-, and three dimensional structures.

  13. Sterically demanding iminopyridine ligands

    NARCIS (Netherlands)

    Irrgang, Torsten; Keller, Sandra; Maisel, Heidi; Kretschmer, Winfried; Kempe, Rhett

    Two sterically demanding iminopyridine ligands, (2,6-diisopropylphenyl)[6-(2,4,6-triisopropylphenyl)pyridin-2-ylmeth- ylene]amine and (2,6-diisopropylphenyl)]6-(2,6-dimethylphenyl)pyridin-2-ylmethylene]amine, were prepared by a two-step process: first, condensation of 6-bromopyridine-2-carbaldehyde

  14. Living related donor liver transplantation.

    Science.gov (United States)

    Chen, C L; Chen, Y S; Liu, P P; Chiang, Y C; Cheng, Y F; Huang, T L; Eng, H L

    1997-10-01

    Living related liver transplantation (LRLT) has been developed in response to the paediatric organ donor shortage. According to the International Living Donor Registry, 521 transplants had been performed in 515 patients between December 8 1988 and January 19 1996 in 30 centres worldwide. The overall actuarial patient and graft survival rates were 82.7 and 80%, respectively. Between June 17 1994 and November 30 1996, the authors performed 11 LRLT at the Chung Gung Memorial Hospital. The living donors consisted of 10 mothers and one father. The mean graft weight was 303 g and the mean graft recipient weight ratio was 2.2%. Donor hepatectomy was performed without vascular inflow occlusion. The intra-operative blood loss ranged from 30 mL to 120 mL with an average of 61 mL, and blood transfusion was not required in all donors both intra-operatively and during the postoperative period. Underlying diseases of the recipients were biliary atresia (n = 10) and glycogen storage disease (n = 1). The mean graft cold ischaemia time was 106 min, the mean second warm ischaemia time was 51 min and the mean interval between portal and arterial reperfusion was 81 min. The initial LRLT results were promising with all donors having been discharged without complication. The recipients experienced a few complications, all of which were manageable with early intervention. All 11 recipients are alive and well. These are encouraging results and the authors hope to expand the use of live donors for liver transplantation to cope with demand.

  15. Synthesis and characterization of novel M(II (M = Mn(II, Ni(II, Cu(II or Zn(II complexes with tridentate N2,O-donor ligand (E-2-amino-N’-[1-(pyridin-2-yl- ethylidene]benzohydrazide

    Directory of Open Access Journals (Sweden)

    C. H. Kane

    2016-02-01

    Full Text Available The coordination chemistry towards the M(II metal centre (M = Mn, Ni, Cu or Zn of the hydrazone ligand (E-2-amino-N’-[1-(pyridin-2-ylethylidene]benzohydrazide (H3L has been explored and complexes having formulae [Mn(H2L2] (1, {[Ni(H2L2].DMF.0.4H2O} (2, {[Cu2(H2L2(µ-Cl2].DMF} (3 and [Zn(H2L2] (4 have been isolated and characterized by IR, UV-Visible spectroscopy, elemental analysis and X-ray crystal diffraction. Structural studies reveal that the mononuclear complexes (1, (2 and (4 adopt highly distorted octahedral geometries while the dinuclear complex (3 adopts a square pyramidal geometry around each copper(II ion. DOI: http://dx.doi.org/10.4314/bcse.v30i1.9

  16. Why Should Donors Care about Corruption?

    OpenAIRE

    Kolstad, Ivar

    2008-01-01

    Corruption is bad for donor business. Corruption reduces popular support for aid in donor countries. However, aid agencies should pay attention to corruption because it is the right thing to do, rather than just the smart thing to do. Donor anti-corruption policies require a strong grounding in ethics. Corruption produces bad development outcomes. This is the reasoning largely underlying donor anti-corruption efforts. The focus on consequences of corruption makes donor anticorruptioneffo...

  17. Kidney transplant outcomes from older deceased donors

    DEFF Research Database (Denmark)

    Pippias, Maria; Jager, Kitty J; Caskey, Fergus

    2018-01-01

    As the median age of deceased kidney donors rises, updated knowledge of transplant outcomes from older deceased donors in differing donor-recipient age groups is required. Using ERA-EDTA Registry data we determined survival outcomes of kidney allografts donated from the same older deceased donor ...... transplanted into differing donor-recipient age groups are better than previously reported. These allografts remain a valuable transplant resource, particularly for similar-aged recipients....

  18. Donor Hemovigilance with Blood Donation

    Science.gov (United States)

    Diekamp, Ulrich; Gneißl, Johannes; Rabe, Angela; Kießig, Stephan T.

    2015-01-01

    Background Reports on unexpected events (UEs) during blood donation (BD) inadequately consider the role of technical UEs. Methods Defined local and systemic UEs were graded by severity; technical UEs were not graded. On January 1, 2008, E.B.P.S.-Logistics (EBPS) installed the UE module for plasma management software (PMS). Donor room physicians entered UEs daily into PMS. Medical directors reviewed entries quarterly. EBPS compiled data on donors, donations, and UEs from January 1, 2008 to June 30, 2011. Results 6,605 UEs were observed during 166,650 BDs from 57,622 donors for a corrected incidence of 4.30% (0.66% local, 1.59% systemic, 2.04% technical UEs). 2.96% of BDs were accompanied by one UE and 0.45% by >1 UE (2-4). 6.3% of donors donating blood for their first time, 3.5% of those giving blood for their second time, and 1.9% of donors giving their third or more BD experienced UEs. Most common UEs were: discontinued collections due to venous access problems, repeated venipuncture, and small hematomas. Severe circulatory UEs occurred at a rate of 16 per 100,000 BDs. Conclusions Technical UEs were common during BD. UEs accompanied first and second donations significantly more often than subsequent donations. PMID:26195932

  19. Analysis of macromolecules, ligands and macromolecule-ligand complexes

    Science.gov (United States)

    Von Dreele, Robert B [Los Alamos, NM

    2008-12-23

    A method for determining atomic level structures of macromolecule-ligand complexes through high-resolution powder diffraction analysis and a method for providing suitable microcrystalline powder for diffraction analysis are provided. In one embodiment, powder diffraction data is collected from samples of polycrystalline macromolecule and macromolecule-ligand complex and the refined structure of the macromolecule is used as an approximate model for a combined Rietveld and stereochemical restraint refinement of the macromolecule-ligand complex. A difference Fourier map is calculated and the ligand position and points of interaction between the atoms of the macromolecule and the atoms of the ligand can be deduced and visualized. A suitable polycrystalline sample of macromolecule-ligand complex can be produced by physically agitating a mixture of lyophilized macromolecule, ligand and a solvent.

  20. 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

  1. Therapeutic androgen receptor ligands

    Science.gov (United States)

    Allan, George F.; Sui, Zhihua

    2003-01-01

    In the past several years, the concept of tissue-selective nuclear receptor ligands has emerged. This concept has come to fruition with estrogens, with the successful marketing of drugs such as raloxifene. The discovery of raloxifene and other selective estrogen receptor modulators (SERMs) has raised the possibility of generating selective compounds for other pathways, including androgens (that is, selective androgen receptor modulators, or SARMs). PMID:16604181

  2. A Stable Coordination Complex of Rh(IV) in an N,O-Donor Environment

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Shashi B. [Department of Chemistry, Yale University, 225 Prospect; Shopov, Dimitar Y. [Department of Chemistry, Yale University, 225 Prospect; Sharninghausen, Liam S. [Department of Chemistry, Yale University, 225 Prospect; Vinyard, David J. [Department of Chemistry, Yale University, 225 Prospect; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225 Prospect; Brudvig, Gary W. [Department of Chemistry, Yale University, 225 Prospect; Crabtree, Robert H. [Department of Chemistry, Yale University, 225 Prospect

    2015-12-10

    We describe facial and meridional isomers of [RhIII(pyalk)3], as well as meridional [RhIV(pyalk)3]+ {pyalk =2-(2-pyridyl)-2-propanoate}, the first coordination complex in an N,O-donor environment to show a clean, reversible RhIII/IV redox couple and to have a stable Rh(IV) form, which we characterize by EPR and UV–visible spectroscopy as well as X-ray crystallography. The unprecedented stability of the Rh(IV) species is ascribed to the exceptional donor strength of the ligands, their oxidation resistance, and the meridional coordination geometry.

  3. Being a Living Donor: Risks

    Science.gov (United States)

    ... to know FAQ Living donation What is living donation? Organs Types Being a living donor First steps Being ... are considering one of these types of living donation, please talk to your transplant center about the organ-specific risks. Psychological concerns You may also have ...

  4. Factors Influencing Donor Partnership Effectiveness

    International Development Research Centre (IDRC) Digital Library (Canada)

    (UN Global Compact Office, 2007); and “an alliance between organizations from two or more ... programs related to the environment, global health, and ..... partnering process and the factors of influence, drawing on an example of a flagship initiative with a bilateral donor for an environment-focused program. As in most joint ...

  5. Physician migration: donor country impact.

    Science.gov (United States)

    Aluwihare, A P R

    2005-01-01

    Physician migration from the developing to developed region of a country or the world occurs for reasons of financial, social, and job satisfaction. It is an old phenomenon that produces many disadvantages for the donor region or nation. The difficulties include inequities with the provision of health services, financial loss, loss of educated families, potential employers, and role models and diminished resources with which to conduct medical education. Staff for undergraduate and postgraduate education is depleted. The critical mass for research and development becomes difficult to achieve or maintain, and these disadvantages are not compensated for adequately by increased contacts, the introduction of new ideas, or financial inflow to the donor region or country. The political will of governments and international organizations regarding treaties about the ethics of physician recruitment is called into question by discrepancies between the text of agreements and the ground realities. Amelioration of this situation requires economic development and imaginative schemes by the donors and, ideally, ethical considerations from recipient governments. At the very least, adequate compensation should be made to the donor country for the gain obtained by the host country.

  6. 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

  7. Psychosocial counselling of identifiable sperm donors.

    Science.gov (United States)

    Visser, M; Mochtar, M H; de Melker, A A; van der Veen, F; Repping, S; Gerrits, T

    2016-05-01

    What do identifiable sperm donors feel about psychosocial counselling? Identifiable sperm donors found it important that psychosocial counselling focused on emotional consequences and on rules and regulations and they expected to have access to psychosocial counselling at the time that donor-offspring actually sought contact. Most studies on sperm donors are on anonymous donors and focus on recruitment, financial compensation, anonymity and motivations. There is limited knowledge on the value that identifiable sperm donors place on psychosocial counselling and what their needs are in this respect. We performed a qualitative study from March until June 2014 with 25 identifiable sperm donors, who were or had been a donor at the Centre for Reproductive Medicine of the Academic Medical Centre in Amsterdam any time between 1989 and 2014. We held semi-structured in-depth interviews with identifiable sperm donors with an average age of 44 years. The interviews were fully transcribed and analysed using the constant comparative method of grounded theory. Twelve out of 15 donors (former donors ITALIC! n = 8, active donors ITALIC! n = 7) who had received a counselling session during their intake procedure found it important that they had been able to talk about issues such as the emotional consequences of donation, disclosure to their own children, family and friends, future contact with donor-offspring and rules and regulations. Of the 10 former donors who had received no counselling session, 8 had regretted the lack of intensive counselling. In the years following their donation, most donors simply wanted to know how many offspring had been born using their sperm and had no need for further counselling. Nevertheless, they frequently mentioned that they were concerned about the well-being of 'their' offspring. In addition, they would value the availability of psychosocial counselling in the event that donor-offspring actually sought contact. A limitation of our study is its

  8. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    International Nuclear Information System (INIS)

    Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang; Gao, Ziwei

    2015-01-01

    A successive anchoring of Ti(NMe 2 ) 4 , cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, 13 C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, 13 C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated

  9. Psychosocial counselling of identifiable sperm donors

    NARCIS (Netherlands)

    Visser, M.; Mochtar, M.H.; de Melker, A.A.; van der Veen, F.; Repping, S.; Gerrits, T.

    2016-01-01

    STUDY QUESTION: What do identifiable sperm donors feel about psychosocial counselling? SUMMARY ANSWER: Identifiable sperm donors found it important that psychosocial counselling focused on emotional consequences and on rules and regulations and they expected to have access to psychosocial

  10. Psychosocial counselling of identifiable sperm donors

    NARCIS (Netherlands)

    Visser, M. [=Marja; Mochtar, M. H.; de Melker, A. A.; van der Veen, F.; Repping, S.; Gerrits, T.

    2016-01-01

    What do identifiable sperm donors feel about psychosocial counselling? Identifiable sperm donors found it important that psychosocial counselling focused on emotional consequences and on rules and regulations and they expected to have access to psychosocial counselling at the time that

  11. Distribution patterns of small-molecule ligands in the protein universe and implications for origin of life and drug discovery.

    Science.gov (United States)

    Ji, Hong-Fang; Kong, De-Xin; Shen, Liang; Chen, Ling-Ling; Ma, Bin-Guang; Zhang, Hong-Yu

    2007-01-01

    Extant life depends greatly on the binding of small molecules (such as ligands) with macromolecules (such as proteins), and one ligand can bind multiple proteins. However, little is known about the global patterns of ligand-protein mapping. By examining 2,186 well-defined small-molecule ligands and thousands of protein domains derived from a database of druggable binding sites, we show that a few ligands bind tens of protein domains or folds, whereas most ligands bind only one, which indicates that ligand-protein mapping follows a power law. Through assigning the protein-binding orders (early or late) for bio-ligands, we demonstrate that the preferential attachment principle still holds for the power-law relation between ligands and proteins. We also found that polar molecular surface area, H-bond acceptor counts, H-bond donor counts and partition coefficient are potential factors to discriminate ligands from ordinary molecules and to differentiate super ligands (shared by three or more folds) from others. These findings have significant implications for evolution and drug discovery. First, the chronology of ligand-protein binding can be inferred by the power-law feature of ligand-protein mapping. Some nucleotide-containing ligands, such as ATP, ADP, GDP, NAD, FAD, dihydro-nicotinamide-adenine-dinucleotide phosphate (NDP), nicotinamide-adenine-dinucleotide phosphate (NAP), flavin mononucleotide (FMN) and AMP, are found to be the earliest cofactors bound to proteins, agreeing with the current understanding of evolutionary history. Second, the finding that about 30% of ligands are shared by two or more domains will help with drug discovery, such as in finding new functions from old drugs, developing promiscuous drugs and depending more on natural products.

  12. Screening Donors for Rare Antigen Constellations.

    Science.gov (United States)

    Wagner, Franz F

    2009-01-01

    SCREENING BLOOD DONORS FOR RARE ANTIGEN CONSTELLATIONS HAS BEEN IMPLEMENTED USING SIMPLE PCR METHODS: PCR with enzyme digestion has been used to type donor cohorts for Dombrock antigens, and PCR with sequence-specific priming to identify donors negative for antigens of high frequency. The advantages and disadvantages of the methods as well as their current state is discussed.

  13. Predictors of hemoglobin in Danish blood donors

    DEFF Research Database (Denmark)

    Kotze, Sebastian Ranzi; Pedersen, Ole B; Petersen, Mikkel S

    2015-01-01

    BACKGROUND: It is well known that blood donors are at increased risk of iron deficiency and subsequent development of iron deficiency anemia. We aimed to investigate the effect of factors influencing hemoglobin (Hb) levels. STUDY DESIGN AND METHODS: Initiated in 2010, the Danish Blood Donor Study...... measurement as a method of risk assessment among blood donors....

  14. How do we choose the best donor for T-cell-replete, HLA-haploidentical transplantation?

    Directory of Open Access Journals (Sweden)

    Ying-Jun Chang

    2016-04-01

    Full Text Available Abstract In haploidentical stem cell transplantations (haplo-SCT, nearly all patients have more than one donor. A key issue in the haplo-SCT setting is the search for the best donor, because donor selection can significantly impact the incidences of acute and chronic graft-versus-host disease, transplant-related mortality, and relapse, in addition to overall survival. In this review, we focused on factors associated with transplant outcomes following unmanipulated haplo-SCT with anti-thymocyte globulin (ATG or after T-cell-replete haplo-SCT with post-transplantation cyclophosphamide (PT/Cy. We summarized the effects of the primary factors, including donor-specific antibodies against human leukocyte antigens (HLA; donor age and gender; killer immunoglobulin-like receptor-ligand mismatches; and non-inherited maternal antigen mismatches. We also offered some expert recommendations and proposed an algorithm for selecting donors for unmanipulated haplo-SCT with ATG and for T-cell-replete haplo-SCT with PT/Cy.

  15. 75 FR 58400 - Donor Management Research: Improvements in Clinical Management of Deceased Organ Donors

    Science.gov (United States)

    2010-09-24

    ... generally focused on specific organ systems and not on donor management approaches with the goal of... donor management. A Donor Management Task Force was convened in August 2010 to address relevant issues... Management Research: Improvements in Clinical Management of Deceased Organ Donors AGENCY: Health Resources...

  16. Donor conversion rates depend on the assessment tools used in the evaluation of potential organ donors

    NARCIS (Netherlands)

    Y.J. de Groot (Yorick); E.F.M. Wijdicks (Eelco); M. van der Jagt (Mathieu); J. Bakker (Jan); B. Roozenbeek (Bob); J.N.M. IJzermans (Jan); E.J.O. Kompanje (Erwin)

    2011-01-01

    textabstractPurpose: It is desirable to identify a potential organ donor (POD) as early as possible to achieve a donor conversion rate (DCR) as high as possible which is defined as the actual number of organ donors divided by the number of patients who are regarded as a potential organ donor. The

  17. Hyperbilirubinemia in normal healthy donors

    Directory of Open Access Journals (Sweden)

    Arora Veena

    2009-01-01

    Full Text Available The present study was carried out in B.A.R.C. Hospital Blood Bank over a span of five years, and includes 2734 donors. All the bags were screened for HIV, HBsAg, HCV and VDRL and the plasma in the pilot tubes of the blood bags was observed to detect any abnormality in color. In 27 cases plasma was found to be icteric and liver function tests were carried out on these samples. Two donors showed higher SGPT level, and were excluded. No significant increases in liver enzymes were recorded in the others. Causes of icteric plasma in these apparently healthy donors are discussed. Differential diagnosis includes Gilbert′s disease, hemolytic anemia, drug-induced anemia and other hepatic causes of hyperbilirubinemia, of which Gilbert′s disease is most probable cause with a prevalence of 0.91% in our population. As there are no studies to document the safety of the recipients receiving such abnormal colored plasma as well as to document the hazards in its transfusion, the question arises whether to transfuse such units or not. This study highlights this dilemma. A reassessment of existing policies and regulations is merited.

  18. 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.

  19. Supramolecular coordination and antimicrobial activities of constructed mixed ligand complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Abou-Dobara, M. I.; Seyam, H. A.

    2013-03-01

    A novel series of copper(II) and palladium(II) with 4-derivatives benzaldehyde pyrazolone (Ln) were synthesized. The mixed ligand complexes were prepared by using 1,10-phenanthroline (Phen) as second ligand. The structure of these complexes was identified and confirm by elemental analysis, molar conductivity, UV-Vis, IR and 1H NMR spectroscopy and magnetic moment measurements as well as thermal analysis. The ligand behaves as a neutral bidentate ligand through ON donor sites. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(Ln)2]Cl2ṡ2H2O. Schiff bases (Ln) were tested against bacterial species; namely two Gram positive bacteria (Staphylococcus aureus and Bacillus cereus) and two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) and fungal species (Aspergillus niger, Fusarium oxysporium, Penicillium italicum and Alternaria alternata). The tested compounds have antibacterial activity against S. aureus, B. cereus and K. pneumoniae.

  20. Aluminum complexes of the redox-active [ONO] pincer ligand.

    Science.gov (United States)

    Szigethy, Géza; Heyduk, Alan F

    2012-07-14

    A series of aluminum complexes containing the tridentate, redox-active ligand bis(3,5-di-tert-butyl-2-phenol)amine ([ONO]H(3)) in three different oxidation states were synthesized. The aluminum halide salts AlCl(3) and AlBr(3) were reacted with the doubly deprotonated form of the ligand to afford five-coordinate [ONHO(cat)]AlX(solv) complexes (1a, X = Cl, solv = OEt(2); 1b, X = Br, solv = THF), each having a trigonal bipyramidal coordination geometry at the aluminum and containing the [ONHO(cat)](2-) ligand with a protonated, sp(3)-hybridized nitrogen donor. The [ONO] ligand platform may also be added to aluminum through the use of the oxidized ligand salt [ONO(q)]K, which was reacted with AlCl(3) in the presence of either diphenylacetylacetonate (acacPh(2)(-)) or 8-oxyquinoline (quinO(-)) to afford [ONO(q)]Al(acacPh(2))Cl (2) or [ONO(q)]Al(quinO)Cl (3), respectively, with well-defined [ONO(q)](-) ligands. Quinonate complexes 2 and 3 were reduced by one electron to afford the corresponding complexes K{[ONO(sq)]Al(acacPh(2))(py)} (4) and K{[ONO(sq)]Al(quinO)(py)} (5), respectively, containing well-defined [ONO(sq)](2-) ligands. The addition of tetrachloro-1,2-quinone to 1a in the presence of pyridine resulted in the expulsion of HCl and the formation of an aluminum complex with two different redox active ligands, [ONO]Al(o-O(2)C(6)Cl(4))(py) (6). Similar results were obtained when 1a was reacted with 9,10-phenanthrenequinone to afford [ONO]Al(o-O(2)C(14)H(8))(py) (7) or with pyrene-4,5-dione to afford [ONO]Al(o-O(2)C(16)H(8))(py) (8). Structural, spectroscopic and preliminary magnetic measurements on 6-8 suggest ligand non-innocent redox behavior in these complexes.

  1. 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.

  2. The impact of HLA and KIR ligand mismatching on unrelated allogeneic hematopoietic stem cell transplantation in Korean adult patients.

    Science.gov (United States)

    Park, Hyewon; Rho, Eun Youn; In, Ji Won; Kim, Inho; Yoon, Sung-Soo; Park, Seonyang; Shin, Sue; Park, Kyoung Un; Song, Eun Young

    2015-01-01

    The impact of HLA and KIR ligand mismatching on the outcome of hematopoietic stem cell transplantation (HSCT) remains unclear. Previous reports have identified considerable ethnic differences in the impact of HLA and KIR ligand mismatches, as well as KIR ligand status, on HSCT; however, to date, no data has been acquired in Korean adult patients. We investigated the association of high-resolution HLA matching on five loci (HLA-A, -B, -C, -DRB1, and -DQB1), KIR ligand mismatching, and KIR ligand status on the outcome of allogeneic HSCT from unrelated donors in 154 Korean adult patients treated at Seoul National University Hospital. In a multivariate analysis, less than 9/10 allelic matches in five HLA loci was an independent risk factor for acute graft-versus-host disease (GVHD) (grade II to IV) (P=0.019, odds ratio [OR]=2.7). In addition, HLA-A allele mismatching was increasingly prevalent in patients with acute GVHD compared to patients without (61.9% vs. 34.5%, P=0.06). For KIR ligand status, the patient and donor combination of both C1/C1 ligands showed better event-free and overall survival than combinations with C2 ligand patients or donors (P=0.048, P=0.034, respectively) by log-rank test. Korean adult transplant patients with less than 9 of 10 HLA allele matches in the HLA-A, -B, -C, -DRB1, and DQB1 loci have a higher likelihood of developing acute GVHD (grade II to IV). Impact of KIR ligand status on clinical outcome should be further studied in a larger patient population.

  3. 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

  4. Simulation shows that HLA-matched stem cell donors can remain unidentified in donor searches

    Science.gov (United States)

    Sauter, Jürgen; Solloch, Ute V.; Giani, Anette S.; Hofmann, Jan A.; Schmidt, Alexander H.

    2016-02-01

    The heterogeneous nature of HLA information in real-life stem cell donor registries may hamper unrelated donor searches. It is even possible that fully HLA-matched donors with incomplete HLA information are not identified. In our simulation study, we estimated the probability of these unnecessarily failed donor searches. For that purpose, we carried out donor searches in several virtual donor registries. The registries differed by size, composition with respect to HLA typing levels, and genetic diversity. When up to three virtual HLA typing requests were allowed within donor searches, the share of unnecessarily failed donor searches ranged from 1.19% to 4.13%, thus indicating that non-identification of completely HLA-matched stem cell donors is a problem of practical relevance. The following donor registry characteristics were positively correlated with the share of unnecessarily failed donor searches: large registry size, high genetic diversity, and, most strongly correlated, large fraction of registered donors with incomplete HLA typing. Increasing the number of virtual HLA typing requests within donor searches up to ten had a smaller effect. It follows that the problem of donor non-identification can be substantially reduced by complete high-resolution HLA typing of potential donors.

  5. Issues in potential organ donor management.

    Science.gov (United States)

    Razek, T; Olthoff, K; Reilly, P M

    2000-06-01

    The shortage of organ donors has become a serious problem in modern medicine. Room for improvement exists in our ability to convert potential donors to actual donors based on the available numbers and a significant amount of recent research. A significant percentage of the potential donors represent head-injured patients, so a significant amount of responsibility falls on surgeons to optimize the opportunity for donation. There are clear steps along the pathway from potential to actual donor where physicians can have a significant effect on the rate of successful donation: 1. Identify all potential donors and institute a review system to verify that all potential donors are being identified in your area. 2. Establish an acceptable method to rapidly and accurately determine brain death in potential donors using the local available services. 3. Approach all potential donor families for consent, decouple death notification and consent request, use a member of the hospital team and an OPO representative to approach the family, and make the request in a private setting. 4. Use an aggressive, proactive approach to the medical management of the potential donor using the techniques described to limit the number of medical failures and maximize the number of organs donated per donor. Institute a review process to evaluate any medical failures that occur. Given the difference between the numbers of potential versus actual donors, the authors' significant contact with potential donors, and the clear opportunities for improvement in their approach, the surgical community must address these issues surrounding the optimal management of potential donors and their families.

  6. Chemistry of stannylene-based Lewis pairs: dynamic tin coordination switching between donor and acceptor character.

    Science.gov (United States)

    Krebs, Kilian M; Freitag, Sarah; Schubert, Hartmut; Gerke, Birgit; Pöttgen, Rainer; Wesemann, Lars

    2015-03-16

    The coordination chemistry of cyclic stannylene-based intramolecular Lewis pairs is presented. The P→Sn adducts were treated with [Ni(COD)2] and [Pd(PCy3)2] (COD = 1,5-cyclooctadiene, PCy3 = tricyclohexylphosphine). In the isolated coordination compounds the stannylene moiety acts either as an acceptor or a donor ligand. Examples of a dynamic switch between these two coordination modes of the P-Sn ligand are illustrated and the structures in the solid state together with heteronuclear NMR spectroscopic findings are discussed. In the case of a Ni(0) complex, (119)Sn Mössbauer spectroscopy of the uncoordinated and coordinated phosphastannirane ligand is presented. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Non-imidazole histamine NO-donor H3-antagonists.

    Science.gov (United States)

    Tosco, Paolo; Bertinaria, Massimo; Di Stilo, Antonella; Cena, Clara; Fruttero, Roberta; Gasco, Alberto

    2005-01-01

    Recently a series of H3-antagonists related to Imoproxifan was realised (I); in these products the oxime substructure of the lead was constrained in NO-donor furoxan systems and in the corresponding furazan derivatives. In this paper, a new series of compounds derived from I by substituting the imidazole ring with the ethoxycarbonylpiperazino moiety present in the non-imidazole H3-ligand A-923 is described. For all the products synthesis and preliminary pharmacological characterisation, as well as their hydrophilic-lipophilic balance, are reported. The imidazole ring replacement generally results in a decreased H3-antagonist activity with respect to the analogues of series I and, in some cases, induces relaxing effects on the electrically contracted guinea-pig ileum, probably due to increased affinity for other receptor systems.

  8. Laparoscopic nephrectomy in live donor

    Directory of Open Access Journals (Sweden)

    Mitre Anuar I.

    2004-01-01

    Full Text Available OBJECTIVE: To present the initial experience of videolaparoscopic nephrectomy in live renal donor. MATERIALS AND METHODS: In the period from April 2000 to August 2003, 50 left nephrectomies in live donor were performed by videolaparoscopy for transplantation. Twenty-eight patients were male (56% and 22 female (44%. Mean age was 37.2 years, and the mean body mass index (BMI was 27.1 kg/m². RESULTS: Mean surgical time was 179.5 minutes, and warm ischemia time of the graft was 3.79 minutes. The mean estimated bleeding was 141 mL. There was no need of blood transfusion or conversion to open surgery. In 42 cases (84%, the vascular portion of the graft was considered good by the recipient's surgical team and in all cases, the ureter was considered of proper size, though in one of them (2% its vascularization was considered improper. The transplanted kidneys produced urine still in the surgical room in 46 of the 50 transplantations considered. In only 2 cases opioid was required for analgesia. In average, 3.1 doses of dipyrone were used for each patient during hospital stay, and hospital discharge occurred, in average, after 3.2 days post-operatively. Two patients required re-operations and one of them evolved to death. CONCLUSIONS: The laparoscopic nephrectomy in live donor for renal transplantation is an alternative to conventional open surgery. In relation to the graft, no alteration, either anatomic or functional, was detected. Though there is already a large documentation in the international literature regarding this procedure, in our setting a prospective randomized study with the usual surgical study is still necessary in order to prove the advantages and disadvantages of the method.

  9. Crystal structure of a mixed-ligand dinuclear Ba—Zn complex with 2-methoxyethanol having triphenylacetate and chloride bridges

    Directory of Open Access Journals (Sweden)

    Józef Utko

    2015-07-01

    Full Text Available The dinuclear barium–zinc complex, μ-chlorido-1:2κ2Cl:Cl-chlorido-2κCl-bis(2-methoxyethanol-1κObis(2-methoxyethanol-1κ2O,O′bis(μ-triphenylacetato-1:2κ2O:O′bariumzinc, [BaZn(C20H15O22Cl2(C3H8O24], has been synthesized by the reaction of barium triphenylacetate, anhydrous zinc chloride and 2-methoxyethanol in the presence of toluene. The barium and zinc metal cations in the dinuclear complex are linked via one chloride anion and carboxylate O atoms of the triphenylacetate ligands, giving a Ba...Zn separation of 3.9335 (11 Å. The irregular nine-coordinate BaO8Cl coordination centres comprise eight O-atom donors, six of them from 2-methoxyethanol ligands (four from two bidentate O,O′-chelate interactions and two from monodentate interactions, two from bridging triphenylacetate ligands and one from a bridging Cl donor. The distorted tetrahedral coordination sphere of zinc comprises two O-atom donors from the triphenylacetate ligands and two Cl donors (one bridging and one terminal. In the crystal, O—H...Cl, O—H...O and C—H...Cl intermolecular interactions form a layered structure, lying parallel to (001.

  10. 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...... or slightly lower potencies than (S)-AA [e.g., EC(50) = 76 microM for (2S,4S)-4-methyl-AA (5a) as compared to EC(50) = 35 microM for (S)-AA]. The position of the methyl substituent had a profound effect on the observed pharmacology, whereas the absolute stereochemistry at the methylated carbon atom had a very......) analogs, and the synthesis, stereochemistry, and enantiopharmacology of 3-methyl-AA (4a-d), 4-methyl-AA (5a-d), 5-methyl-AA (6a-d), and (E)-Delta(4)-5-methyl-AA (7a and 7b) are reported. The compounds were resolved using chiral HPLC and the configurational assignments of the enantiomers were based on X...

  11. Genetic study of KIR and HLA ligands in 235 individuals from Northeastern Thailand.

    Science.gov (United States)

    Chaisri, Suwit; Leelayuwat, Chanvit; Romphruk, Amornrat

    The diversity of 17 KIR and HLA ligands (HLA-C1, C2, Bw4, A11) were investigated in two hundred and thirty-five unrelated healthy donors in Northeastern Thais (NETs) by the polymerase chain reaction with sequence-specific primer (PCR-SSP) method. The Hardy-Weinberg Equilibrium (HWE) was used to verify genotyping method for dimorphic KIR and HLA. They were in HWE (p>0.05). KIR and HLA ligands frequencies, genotypes, haplotypes and linkage disequilibrium (LD) were presented. The genetic data are available in allele Frequencies Net Database. Copyright © 2017. Published by Elsevier Inc.

  12. Ligand substitution reactions of a phenolic quinolyl hydrazone; oxidovanadium (IV complexes

    Directory of Open Access Journals (Sweden)

    Seleem Hussein S

    2011-08-01

    Full Text Available Abstract Background Quinoline ring has therapeutic and biological activities. Quinolyl hydrazones constitute a class of excellent chelating agents. Recently, the physiological and biological activities of quinolyl hydrazones arise from their tendency to form metal chelates with transition metal ions. In this context, we have aimed to study the competency effect of a phenolic quinolyl hydrazone (H2L; primary ligand with some auxiliary ligands (Tmen, Phen or Oxine; secondary ligands towards oxidovanadium (IV ions. Results Mono- and binuclear oxidovanadium (IV - complexes were obtained from the reaction of a phenolic quinolyl hydrazone with oxidovanadium (IV- ion in absence and presence of N,N,N',N'- tetramethylethylenediamine (Tmen, 1,10-phenanthroline (Phen or 8-hydroxyquinoline (Oxine. The phenolic quinolyl hydrazone ligand behaves as monobasic bidentate (NO- donor with O- bridging. All the obtained complexes have the preferable octahedral geometry except the oxinato complex (2 which has a square pyramid geometry with no axial interaction; the only homoleptic complex in this study. Conclusion The ligand exchange (substitution/replacement reactions reflect the strong competency power of the auxiliary aromatic ligands (Phen/Oxine compared to the phenolic quinolyl hydrazone (H2L towards oxidovanadium (IV ion; (complexes 2 and 3. By contrast, in case of the more flexible aliphatic competitor (Tmen, an adduct was obtained (4. The obtained complexes reflect the strength of the ligand field towards the oxidovanadium (IV- ion; Oxine or Phen >> phenolic hydrazone (H2L > Tmen.

  13. 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.

  14. Molecular determinants of ligand binding modes in the histamine H(4) receptor: linking ligand-based three-dimensional quantitative structure-activity relationship (3D-QSAR) models to in silico guided receptor mutagenesis studies.

    Science.gov (United States)

    Istyastono, Enade P; Nijmeijer, Saskia; Lim, Herman D; van de Stolpe, Andrea; Roumen, Luc; Kooistra, Albert J; Vischer, Henry F; de Esch, Iwan J P; Leurs, Rob; de Graaf, Chris

    2011-12-08

    The histamine H(4) receptor (H(4)R) is a G protein-coupled receptor (GPCR) that plays an important role in inflammation. Similar to the homologous histamine H(3) receptor (H(3)R), two acidic residues in the H(4)R binding pocket, D(3.32) and E(5.46), act as essential hydrogen bond acceptors of positively ionizable hydrogen bond donors in H(4)R ligands. Given the symmetric distribution of these complementary pharmacophore features in H(4)R and its ligands, different alternative ligand binding mode hypotheses have been proposed. The current study focuses on the elucidation of the molecular determinants of H(4)R-ligand binding modes by combining (3D) quantitative structure-activity relationship (QSAR), protein homology modeling, molecular dynamics simulations, and site-directed mutagenesis studies. We have designed and synthesized a series of clobenpropit (N-(4-chlorobenzyl)-S-[3-(4(5)-imidazolyl)propyl]isothiourea) derivatives to investigate H(4)R-ligand interactions and ligand binding orientations. Interestingly, our studies indicate that clobenpropit (2) itself can bind to H(4)R in two distinct binding modes, while the addition of a cyclohexyl group to the clobenpropit isothiourea moiety allows VUF5228 (5) to adopt only one specific binding mode in the H(4)R binding pocket. Our ligand-steered, experimentally supported protein modeling method gives new insights into ligand recognition by H(4)R and can be used as a general approach to elucidate the structure of protein-ligand complexes.

  15. Synthesis, characterization and anti-proliferative activity of Cd(II) complexes with NNN type pyrazole-based ligand and pseudohalide ligands as coligand

    Science.gov (United States)

    Hopa, Cigdem; Yildirim, Hatice; Kara, Hulya; Kurtaran, Raif; Alkan, Mahir

    2014-03-01

    Cd(II) complexes of tridentate nitrogen donor ligand, 2,6-bis(3,4,5-trimethylpyrazolyl)pyridine (btmpp), Cd(btmpp)X2 (X:Cl, ONO or N(CN)2) have been synthesized and characterized by elemental and spectral (FT-IR, 1H NMR, 13C NMR, UV-Vis) analyses, differential thermal analysis and single crystal X-ray diffraction studies. The molecular structure of reported complex 1, revealed distorted square-pyramidal geometry around Cadmium. Complexes 1-3 and corresponding ligand were tested for cytotoxic activity against the human carcinoma cell lines HEP3B (hepatocellular carcinoma), PC3 (prostate adenocarcinoma), MCF7 (breast adenocarcinoma) and Saos2 (osteosarcoma). The results show that, complexes are more cytotoxic than the free ligand and complex 2 is the most cytotoxic complex for PC3.

  16. Attitudes of sperm, egg and embryo donors and recipients towards genetic information and screening of donors.

    Science.gov (United States)

    Amor, David J; Kerr, Annabelle; Somanathan, Nandini; McEwen, Alison; Tome, Marianne; Hodgson, Jan; Lewis, Sharon

    2018-02-09

    Gamete and embryo donors undergo genetic screening procedures in order to maximise the health of donor-conceived offspring. In the era of genomic medicine, expanded genetic screening may be offered to donors for the purpose of avoiding transmission of harmful genetic mutations. The objective of this study was to explore the attitudes of donors and recipients toward the expanded genetic screening of donors. Qualitative interview study with thematic analysis, undertaken in a tertiary fertility centre. Semi-structured in-depth qualitative interviews were conducted with eleven recipients and nine donors from three different cohorts (sperm, egg and embryo donors/recipients). Donors and recipients acknowledged the importance of genetic information and were comfortable with the existing level of genetic screening of donors. Recipients recognised some potential benefits of expanded genetic screening of donors; however both recipients and donors were apprehensive about extended genomic technologies, with concerns about how this information would be used and the ethics of genetic selectivity. Participants in donor programs support some level of genetic screening of donors, but are wary of expanding genetic screening beyond current levels.

  17. Donor risk factors for graft failure in the cornea donor study.

    Science.gov (United States)

    Sugar, Joel; Montoya, Monty; Dontchev, Mariya; Tanner, Jean Paul; Beck, Roy; Gal, Robin; Gallagher, Shawn; Gaster, Ronald; Heck, Ellen; Holland, Edward J; Kollman, Craig; Malling, Jackie; Mannis, Mark J; Woody, Jason

    2009-10-01

    The purpose of this study was to assess the relationship between donor factors and 5-year corneal graft survival in the Cornea Donor Study. Donor corneas met criteria established by the Eye Bank Association of America, had an endothelial cell density of 2300 to 3300/mm, and were determined to be of good to excellent quality by the eye banks. Donor corneas were assigned using a random approach and surgeons were masked to information about the donor cornea including donor age. Surgery and postoperative care were performed according to the surgeons' usual routines and subjects were followed for 5 years. Donor and donor cornea factors were evaluated for their association with graft failure, which was defined as a regraft or a cloudy cornea that was sufficiently opaque to compromise vision for a minimum of 3 consecutive months. Graft failure was not significantly associated with the type of tissue retrieval (enucleation versus in situ), processing factors, timing of use of the cornea, or characteristics of the donor or the donor cornea. Adjusting for donor age did not affect the results. Donor and donor cornea characteristics do not impact graft survival rates for corneas comparable in quality to those used in this study.

  18. Prisoners as Living Donors: A Vulnerabilities Analysis.

    Science.gov (United States)

    Ross, Lainie Friedman; Thistlethwaite, J Richard

    2018-01-01

    Although national guidelines exist for evaluating the eligibility of potential living donors and for procuring their informed consent, no special protections or considerations exist for potential living donors who are incarcerated. Human research subject protections in the United States are codified in the Federal Regulations, 45 CFR 46, and special protections are given to prisoners. Living donor transplantation has parallels with human subject research in that both activities are performed with the primary goal of benefiting third parties. In this article, we describe what special considerations should be provided to prisoners as potential living donors using a vulnerabilities approach adapted from the human research subject protection literature.

  19. Transperitoneal laparoscopic live donor nephrectomy: Current status

    Directory of Open Access Journals (Sweden)

    A Srivastava

    2007-01-01

    Full Text Available Renal transplantation is the treatment of choice for a suitable patient with end stage renal disease. Unfortunately, the supply of donor organs is greatly exceeded by demand. In many countries the use of kidneys from living donors has been widely adopted as a partial solution. Traditionally donor nephrectomy has been performed via a open flank incision however with some morbidity like pain and a loin scar. Currently, the donor nephrectomy is increasingly being performed laparoscopically with the objective of reducing the morbidity. It is also hoped that this will lead to increasing acceptance of living donation. The first minimally invasive living donor nephrectomy was carried out in 1995 at the Johns Hopkins Medical Center and since then many centers have undertaken laparoscopic living donor nephrectomy. The laparoscopic approach substantially reduces the donor morbidity and wound related problems associated with open nephrectomy. The laparoscopic techniques thus have the potential to increase the number of living kidney donors. The present article attempts to review the safety and efficacy of transperitoneal laparoscopic donor nephrectomy.

  20. Improving syphilis screening in deceased organ donors.

    Science.gov (United States)

    Theodoropoulos, Nicole; Jaramillo, Andrés; Penugonda, Sudhir; Wasik, Carol; Brooks, Katarzyna; Ladner, Daniela P; Jendrisak, Martin D; Ison, Michael G

    2015-02-01

    Current U.S. policy requires screening of all deceased organ donors for syphilis infection. To date, information on syphilis test performance in this population is limited. All donors with a positive rapid plasma reagin (RPR) and matched donors with negative RPR who were evaluated by one organ procurement organization from January 1, 2000, to September 30, 2012, were retrospectively tested, using retained, residual serum, with two alternate RPR tests and four treponemal-specific tests: A fluorescent treponemal antibody absorption test, a microhemagglutination test, a chemiluminescence immunoassay (CLIA), and a Treponema pallidum particle agglutination (TP-PA) test. Thirty-two of 3,555 (0.9%) potential deceased organ donors screened during the study period showed a positive RPR; 61 RPR-negative matched donor samples were studied as well. Thirteen (40.6%) of the RPR-positive donors were found to be false-positive based on confirmatory TP-PA. As compared to TP-PA, the sensitivity of the fluorescent treponemal antibody absorption, microhemagglutination, and CLIA was 87.5%, 91.7% and 100%, respectively. The CLIA and TP-PA results were 100% concordant. Only 17 (53.1%) of the RPR-positive donors had a total of 46 organs recovered for transplantation. Current screening of deceased organ donors by RPR yields a significant number of false-positive results. Use of alternative tests or the routine use of confirmatory tests may reduce the frequency of false-positive results in deceased organ donors.

  1. Alternative Donor Transplantation for Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Nelli Bejanyan

    2015-06-01

    Full Text Available Allogeneic hematopoietic cell transplantation (allo-HCT is a potentially curative therapy for adult patients with acute myeloid leukemia (AML, but its use for consolidation therapy after first remission with induction chemotherapy used to be limited to younger patients and those with suitable donors. The median age of AML diagnosis is in the late 60s. With the introduction of reduced-intensity conditioning (RIC, many older adults are now eligible to receive allo-HCT, including those who are medically less fit to receive myeloablative conditioning. Furthermore, AML patients commonly have no human leukocyte antigen (HLA-identical or medically suitable sibling donor available to proceed with allo-HCT. Technical advances in donor matching, suppression of alloreactivity, and supportive care have made it possible to use alternative donors, such as unrelated umbilical cord blood (UCB and partially HLA-matched related (haploidentical donors. Outcomes after alternative donor allo-HCT are now approaching the outcomes observed for conventional allo-HCT with matched related and unrelated donors. Thus, with both UCB and haploidentical donors available, lack of donor should rarely be a limiting factor in offering an allo-HCT to adults with AML.

  2. Binuclear complexes of technetium. Evidence for bis(terdentate)bidentate coordination by the bridging ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine to technetium(V)

    International Nuclear Information System (INIS)

    Du Preez, J.G.H.; Gerber, T.I.A.; Gibson, M.L.; Geyser, R.

    1990-01-01

    The authors have used the potentially bis(terdentate) nitrogen aromatic heterocyclic ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) to prepare mono- and bimetallic technetium(V) complexes bound to tppz. The stimulus for the development of the coordination chemistry of the man-made element technetium is provided by the use of complexes of this element as anatomical imaging agents in nuclear medicine. Although the chemistry of technetium(V) with nitrogen donor ligands is well understood, no complexes have been prepared using potentially terdentate neutral nitrogen donor ligands of this metal in the +5 oxidation state

  3. Exploring the Hydrolytic Behavior of the Platinum(IV) Complexes with Axial Acetato Ligands.

    Science.gov (United States)

    Zhao, Jian; Xu, Zichen; Lin, Jing; Gou, Shaohua

    2017-08-21

    Platinum(IV) complexes are generally thought to be kinetically inert, and are expected to be stable enough to resist premature aquation before entering the cancer cells. Nevertheless, in this work, complex 2 with axial acetato ligands can hydrolyze relatively quickly under biologically relevant conditions with a half-life of 91.7 min, resulting in the loss of the equatorial chlorido ligand. Further study indicated that the fast hydrolysis of complex 2 may be attributed to the strong σ-donor ability of N-isopropyl-1R,2R-diaminocyclohexane, and an increasing σ-donor ability of the amine group can promote the hydrolysis rate of the corresponding platinum(IV) complex. The experiment results were proven by the corresponding DFT calculation. Our study can help to re-evaluate the aqueous properties of the platinum(IV) complexes with axial acetate, which may be less inert to hydrolysis than expected under biologically relevant conditions.

  4. Ligand-guided receptor optimization.

    Science.gov (United States)

    Katritch, Vsevolod; Rueda, Manuel; Abagyan, Ruben

    2012-01-01

    Receptor models generated by homology or even obtained by crystallography often have their binding pockets suboptimal for ligand docking and virtual screening applications due to insufficient accuracy or induced fit bias. Knowledge of previously discovered receptor ligands provides key information that can be used for improving docking and screening performance of the receptor. Here, we present a comprehensive ligand-guided receptor optimization (LiBERO) algorithm that exploits ligand information for selecting the best performing protein models from an ensemble. The energetically feasible protein conformers are generated through normal mode analysis and Monte Carlo conformational sampling. The algorithm allows iteration of the conformer generation and selection steps until convergence of a specially developed fitness function which quantifies the conformer's ability to select known ligands from decoys in a small-scale virtual screening test. Because of the requirement for a large number of computationally intensive docking calculations, the automated algorithm has been implemented to use Linux clusters allowing easy parallel scaling. Here, we will discuss the setup of LiBERO calculations, selection of parameters, and a range of possible uses of the algorithm which has already proven itself in several practical applications to binding pocket optimization and prospective virtual ligand screening.

  5. Differences in social representation of blood donation between donors and non-donors: an empirical study.

    Science.gov (United States)

    Guarnaccia, Cinzia; Giannone, Francesca; Falgares, Giorgio; Caligaris, Aldo Ozino; Sales-Wuillemin, Edith

    2015-11-04

    Both donors and non-donors have a positive image of blood donation, so donors and non-donors do not differ regarding their views on donation but do differ in converting their opinion into an active deed of donation. Several studies have identified altruism and empathy as the main factors underlying blood donation. However, a mixture of various motivational factors mould the complex behaviour of donation. This paper presents an exploratory study on differences of social representations of blood donation between blood donors and non-donors, in order to understand the reasons that bring someone to take the decision to become a blood donor. Participants filled in the Adapted Self-Report Altruism Scale, Toronto Empathy Questionnaire and answered a test of verbal association. Descriptive and correlation analyses were carried out on quantitative data, while a prototypic analysis was used for qualitative data. The study was carried out on a convenience sample of 786 individuals, 583 donors (mean age: 35.40 years, SD: 13.01 years; 39.3% female) and 203 non-donors (mean age: 35.10 years, SD: 13.30 years; 67.5% female). Social representations of donors seem to be more complex and articulated than those of non-donors. The terms that appear to be central were more specific in donors (life, needle, blood, help, altruism were the words most associated by non-donors; life, aid, altruism, solidarity, health, love, gift, generosity, voluntary, control, needed, useful, needle were the words most associated by donors). Furthermore, non-donors associated a larger number of terms referring to negative aspects of blood donation. Aspects related to training and the accuracy of any information on blood donation seem to be important in the decision to become a donor and stabilise the behaviour of donation over time, thus ensuring the highest levels of quality and safety in blood establishments.

  6. BLOODR: blood donor and requester mobile application.

    Science.gov (United States)

    Tatikonda, Vamsi Krishna; El-Ocla, Hosam

    2017-01-01

    With rapid increase in the usage of social networks sites across the world, there is also a steady increase in blood donation requests as being noticed in the number of posts on these sites such as Facebook and twitter seeking blood donors. Finding blood donor is a challenging issue in almost every country. There are some blood donor finder applications in the market such as Blood app by Red Cross and Blood Donor Finder application by Neologix. However, more reliable applications that meet the needs of users are prompted. Several software technologies including languages and framework are used to develop our blood-donor web application known as BLOODR application. These technologies comprise Ruby programming language (simply known as Ruby) along with JavaScript and PostgreSQL for database are used. Ruby on Rails (simply known as Rails) is an open source Web framework that makes it possible to quickly and easily create data-based web applications. We show screenshots for the BLOODR application for different types of users including requester, donor, and administrator. Various features of the application are described and their needs of use are analyzed. If a patient needs a blood at a clinic, blood donors in vicinity can be contacted through using a clinic management service provided in this application. Registered donors will get notification for the blood requests only if their blood group is compatible with the requested blood type and in the same city/region. Then matching blood donors can go to the requesting clinic and donate. BLOODR application provides a reliable platform to connect local blood donors with patients. BLOODR creates a communication channel through authenticated clinics whenever a patient needs blood donation. It is a useful tool to find compatible blood donors who can receive blood request posts in their local area. Clinics can use this web application to maintain the blood donation activity. Future improvement of the BLOODR is explained.

  7. Novel olfactory ligands via terpene synthases.

    Science.gov (United States)

    Touchet, Sabrina; Chamberlain, Keith; Woodcock, Christine M; Miller, David J; Birkett, Michael A; Pickett, John A; Allemann, Rudolf K

    2015-05-01

    A synthetic biology approach to the rational design of analogues of olfactory ligands by providing unnatural substrates for the enzyme synthesising (S)-germacrene D, an olfactory ligand acting as a plant derived insect repellent, to produce novel ligands is described as a viable alternative to largely unsuccessful ligand docking studies. (S)-14,15-Dimethylgermacrene D shows an unexpected reversal in behavioural activity.

  8. Exchange living-donor kidney transplantation: diminution of donor organ shortage.

    Science.gov (United States)

    Park, K; Lee, J H; Huh, K H; Kim, S I; Kim, Y S

    2004-12-01

    To alleviate the organ shortage, the use of more living donors is strongly recommended world wide. A living donor exchange (swap) program was launched in Korea. After the success of a direct swap program between two families, we have developed the swap-around program to expand the donor pool by enrolling many kinds of unrelated donors. Herein, we report our results of a living donor exchange program. This retrospectively review of 978 recipients of kidney transplants from living donors, included analysis of donor-recipient relationships, mode of donor recruitment, episodes of acute rejection, and 5-year patient/graft survivals. Transplantation was performed in 101 patients (10.3%) by way of the swap program. The proportion of swap patients among the number of unrelated donor renal transplants has been increasing from 4.2% to 46.6%. The incidence of acute rejection and 5-year patient/graft survival rates were comparable between the groups. We have achieved some success in reducing the organ shortage with a swap program in addition to our current unrelated living donor programs without jeopardizing graft survival. Potentially exchangeable donors should undergo strict medical evaluation by physicians and social evaluation by social workers and coordinators as a pre-requisite for kidney transplantation. Expanding the swap around program to a regional or national pool could be an option to reduce the organ donor shortage in the future.

  9. Dedicated donor unit transfusions reduces donor exposure in pediatric surgery patients

    Directory of Open Access Journals (Sweden)

    Satyam Arora

    2017-01-01

    Full Text Available Background: Many strategies have been explored to reduce multiple donor exposures in neonates such as use of restrictive transfusion protocols, limiting iatrogenic blood loss, use of recombinant erythropoietin and single donor programs. Method: In our study we assessed the feasibility of dedicating single donor units with reserving all the components from the same donor for the specified neonates/ infants undergoing surgery and estimating reduction of donor exposure. Fifty neonates undergoing surgery were included in the prospective study group and the transfusion details were compared with 50 retrospective cases with same inclusion criteria. Results: An intra-operative blood loss of >13 ml/Kg was significantly associated with transfusion (P<0.05 which was most frequently administered in the intra-operative period. Donor exposure rate of overall transfusion was 1.15 in the study group as compared to 4.03 in the retrospective control group. In study group Donor Exposure Rate (DER: Transfusion Rate (TR ratio was 1:1.5 and Transfusion per Donor Unit (TPDU of 1.5, means that one donor unit contributed to 1.5 transfusions in each patient and contributed to 50% reduction in donor exposure in each patient as compared to retrospective control group. Conclusion: Our study showed that by practicing dedicated donor unit transfusion policy, for neonates undergoing surgery we could significantly reduce the donor exposure.

  10. Dedicated donor unit transfusions reduces donor exposure in pediatric surgery patients

    Science.gov (United States)

    Arora, Satyam; Marwaha, Neelam; Dhawan, Hari Krishan; Rao, K. L. N.

    2017-01-01

    BACKGROUND: Many strategies have been explored to reduce multiple donor exposures in neonates such as use of restrictive transfusion protocols, limiting iatrogenic blood loss, use of recombinant erythropoietin and single donor programs. METHOD: In our study we assessed the feasibility of dedicating single donor units with reserving all the components from the same donor for the specified neonates/infants undergoing surgery and estimating reduction of donor exposure. Fifty neonates undergoing surgery were included in the prospective study group and the transfusion details were compared with 50 retrospective cases with same inclusion criteria. RESULTS: An intra-operative blood loss of >13 ml/Kg was significantly associated with transfusion (P <0.05) which was most frequently administered in the intra-operative period. Donor exposure rate of overall transfusion was 1.15 in the study group as compared to 4.03 in the retrospective control group. In study group Donor Exposure Rate (DER): Transfusion Rate (TR) ratio was 1:1.5 and Transfusion per Donor Unit (TPDU) of 1.5, means that one donor unit contributed to 1.5 transfusions in each patient and contributed to 50% reduction in donor exposure in each patient as compared to retrospective control group. CONCLUSION: Our study showed that by practicing dedicated donor unit transfusion policy, for neonates undergoing surgery we could significantly reduce the donor exposure. PMID:28970679

  11. Negotiating boundaries: Accessing donor gametes in India.

    Science.gov (United States)

    Widge, A; Cleland, J

    2011-01-01

    This paper documents how couples and providers access donor materials for conception in the Indian context and perceptions about using them. The objective is to facilitate understanding of critical issues and relevant concerns. A postal survey was conducted with a sample of 6000 gynaecologists and in-depth interviews were -conducted with 39 gynaecologists in four cities. Donor gametes are relatively more acceptable than a few years ago, especially if confidentiality can be -maintained, though lack of availability of donor materials is sometimes an impediment to infertility treatment. Donor sperms are usually accessed from in-house or commercial sperm banks, pathology laboratories, IVF centres, -professional donors, relatives or friends. There is scepticism about screening procedures of sperm banks. Donor eggs are usually accessed from voluntary donors, friends, relatives, egg sharing programmes, donation from other patients, advertising and commercial donors. There are several concerns regarding informed consent for using donated gametes, using -relatives and friends gametes, the unregulated use of gametes and embryos, record keeping and documentation, -unethical and corrupt practices and commercialisation. These issues need to be addressed by patients, providers and regulatory authorities by providing -information, counselling, ensuring informed consent, addressing exploitation and commercialisation, ensuring -monitoring, proper documentation and transparency.

  12. Normothermic machine perfusion for donor liver preservation

    NARCIS (Netherlands)

    Tolboom, H.

    2012-01-01

    Currently, liver transplantation is the only treatment for end-stage liver failure. Unfortunately, a sever shortage of donor organs causes significant mortality amongst patients awaiting transplantation. The donor organ shortage could be alleviated by using organs that are normally not accepted for

  13. Posttransplantation Disseminated Coccidioidomycosis Acquired from Donor Lungs

    OpenAIRE

    Miller, Melissa B.; Hendren, Ryan; Gilligan, Peter H.

    2004-01-01

    A North Carolinian developed fatal coccidioidomycosis immediately after bilateral lung transplantation. The donor had previously traveled to Mexico, and the recipient had no travel history to an area where Coccidioides immitis is endemic. Immunosuppresive therapy of the transplant recipient likely reactivated latent Coccidioides infection in the donor lungs, leading to posttransplant coccidioidomycosis.

  14. Research Award: Donor Partnership Division | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-09-07

    Sep 7, 2016 ... IDRC's Donor Partnerships division (DPD) initiates, builds, and maintains relationships with donors, international organizations, and research funders ... We are particularly interested in research related to public-private partnerships for development, bilateral investments in research, trends in private ...

  15. Psychosocial counselling in donor sperm treatment

    NARCIS (Netherlands)

    Visser, M.

    2018-01-01

    For decades, donor sperm treatment is offered to men and women to build a family. In daily life, parents, children and donors have to deal with the consequences of this treatment. The studies of this thesis show that there are gaps in knowledge about specialist psychosocial counselling and guidance

  16. Organ donors: deceased or alive? Quo vadis?

    Science.gov (United States)

    Rozental, R

    2006-01-01

    Irrespectively of universal shortage of donor organs there is a tendency of increasing the number of transplantations from living and deceased donors. Each of these two methods has positive and negative features. The main obstacles using living donors are health hazard, necessity to solve certain donor's social and psychological problems, possibility of organ trade and moving. The main problems connected with organ retrieval from deceased donors are possible conflicts with public opinion: difficulties in interpretation of brain death, legislation, obtaining of informed consent from donor's relatives, etc. Future progress in organ transplantation may take place through activation of organ retrieval from deceased donors. The most perspective ways are change to presumed consent in all countries, establishing of centralized system of donor detection and registration, intensification of transplant coordination, active contacts with mass-media, etc. It is necessary to increase (enhance) participation of the members of the public in organ donation process, to develop solidarity among the public members and to involve public authorities to deal with this problem. Bioethical standards should be put in accordance with common progress and some ethical traditions should be changed.

  17. Spectroscopic studies of some lanthanide(III nitrate complexes synthesized from a new ligand 2,6-bis-(salicylaldehyde hydrazone-4-chlorophenol

    Directory of Open Access Journals (Sweden)

    A.S. Sall

    2003-06-01

    Full Text Available The ligand 2,6-bis-(salicylaldehydehydrazone-4-chlorophenol (H5L and its binuclear lanthanide(III nitrate complexes {[Ln2(H4L3(NO3](NO32.mH2O} where Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb and Y, have been synthesized. The complexes were characterized by chemical analysis, conductance, magnetic moment measurements and infrared spectra. Infrared study indicates that the ligand behaves both as neutral and ionic O donors and as neutral N donors.

  18. PATHOMORPHOLOGY OF ZERO BIOPSIES OF DONOR KIDNEYS

    Directory of Open Access Journals (Sweden)

    M. L. Arefjev

    2011-01-01

    Full Text Available There is well known fact that kidney transplants from Extended Criteria Donors may increase risk of De- layed Graft Function and Primary Non-Function of transplants. We have collected and tested 65 «zero» kidney biopsies from cadaver donors aged from 19 to 71 years old. In the pool of elderly donors who died from cerebrovascular accident the frequency of nephrosclerosis presentation was higher than in donors of yonger age who died from craniocephalic trauma. Nevertheless in the general donor pool the number of sclerosed glomeruli was no more than 12%. We did not meet at all in the whole volume of material any bi- opsy with the severe degree of arteriosclerosis. The «zero» biopsies of cadaver kidneys is quite usable and unexpensive tool to measure the degree of nephrosclerosis in order to exclude kidneys which are not fitable for transplantation. 

  19. Non heart-beating donors in England

    Directory of Open Access Journals (Sweden)

    Eleazar Chaib

    2008-01-01

    Full Text Available When transplantation started all organs were retrieved from patients immediately after cardio-respiratory arrest, i.e. from nonheart-beating donors. After the recognition that death resulted from irreversible damage to the brainstem, organ retrieval rapidly switched to patients certified dead after brainstem testing. These heart-beating-donors have become the principal source of organs for transplantation for the last 30 years. The number of heart-beating-donors are declining and this is likely to continue, therefore cadaveric organs from non-heart-beating donor offers a large potential of resources for organ transplantation. The aim of this study is to examine clinical outcomes of non-heart-beating donors in the past 10 years in the UK as an way of decreasing pressure in the huge waiting list for organs transplantation.

  20. Potential organ donor audit in Ireland.

    LENUS (Irish Health Repository)

    Hegarty, M

    2010-11-01

    As increasing demand for organs is a challenge for transplant services worldwide it is essential to audit the process of organ donation. To address this, a national audit of potential organ donors was undertaken across hospitals with Intensive Care Units (N = 36). Questionnaires were returned on all patients (n = 2073) who died in these units from 1\\/9\\/07-31\\/8\\/08; 200 (10%) of these patients were considered for Brain Stem Testing (BST), 158 patients (79%) were diagnosed Brain Stem Dead (BSD) and 138 patients (87%) became potential donors. Consent for donation was given by 92 (69%) next of kin and 90 potential donors (65%) became organ donors. There was no evidence of a large number of potential organ donors being missed. Recommendations included completion of BSTs on all appropriate patients, development of support on BST, referral of all BSD patients to the Organ Procurement Service; enhanced co-ordination within hospitals and sustained information\\/education campaigns.

  1. Donor Conception and "Passing," or; Why Australian Parents of Donor-Conceived Children Want Donors Who Look Like Them.

    Science.gov (United States)

    Wong, Karen-Anne

    2017-03-01

    This article explores the processes through which Australian recipients select unknown donors for use in assisted reproductive technologies and speculates on how those processes may affect the future life of the donor-conceived person. I will suggest that trust is an integral part of the exchange between donors, recipients, and gamete agencies in donor conception and heavily informs concepts of relatedness, race, ethnicity, kinship, class, and visibility. The decision to be transparent (or not) about a child's genetic parentage affects recipient parents' choices of donor, about who is allowed to "know" children's genetic backgrounds, and how important it is to be able to "pass" as an unassisted conception. In this way, recipients must trust the process, institutions, and individuals involved in their treatment, as well as place trust in the future they imagine for their child. The current market for donor gametes reproduces normative conceptions of the nuclear family, kinship, and relatedness by facilitating "matching" donors to recipients by phenotype and cultural affinities. Recipient parents who choose not to prioritize "matching," and actively disclose the process of children's conceptions, may embark on a project of queering heteronormative family structures and place great trust in both their own children and changing social attitudes to reduce stigma and generate acceptance for non-traditional families.

  2. Thorium(IV) and zirconium(IV) complexes of oxygen donor ligands. Pt. 12

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Jain, P.C.; Kapur, V.; Sharma, S.; Srivastava, A.K.

    1980-01-01

    Crystalline thorium (IV) chelates with mono N-oxides of 2,2'-bipyridine (bipyNO) and 1,10-phenanthroline (phenNO), ThX 4 x 2L(X = Cl,Br,NO 3 or NCS) and ThX 4 x 3L(X = I or ClO 4 and L = bipyNO or phenNO) have been synthesised and characterized on the basis of i.r. spectra, molar conductance, molecular weights, t.g.a. and d.t.a. data. All the complexes are weakly diamagnetic and contain bipyNO and phenNO bonded to thorium(IV) through nitrogen and oxygen. The coordination number of thorium(IV) varies from six to twelve depending on the nature of the anions. (orig.) [de

  3. Studies on Th(IV) and Zr(IV) complexes of oxygen donor ligands

    International Nuclear Information System (INIS)

    Agarwal, R.K.; Srivastava, M.; Srivastava, A.K.

    1981-01-01

    In recent years a large number of complexes of amine N-oxides with a wide variety of metal salts have been isolated and characterized. Less attention has been paid to the aromatic amine N-oxides complexes with Th(IV) thiocyanate. In the present communication studies are reported on Th(IV) thiocyanate complexes of pyridine N-oxide (PyO), quinoline N-oxide (QO), isoquinoline N-oxide (IsqO), 2-picoline N-oxide (2-picO), 3-picoline N-oxide (3-picO) and 4-picoline N-oxide (4-picO) and comparisons are made with the existing complexes of 2,6-lutidine N-oxide (LNO), 2, 2'bipyridine N-N'-dioxide (BipyO 2 ), mono N-oxides of 2,2'-bipyridine (BipyNO) and 1,10-phenanthroline (PhenNO) and 1, 10-phenanthroline N-N'-dioxide (PhenO 2 ). The analytical data correspond to the composition Th(NCS) 4 .4L. The molar conductance of all the complexes in nitrobenzene in the range 2.5 to 4.5 Ω -1 cm 2 mol -1 indicate them to be non-electrolytes. The results of IR spectroscopy and thermogravimetry are given and discussed. (author)

  4. Synthesis and structural evaluation of five coordination complexes of benzenepentacarboxylic acid with aza-donor ligands

    Science.gov (United States)

    Shimpi, Manishkumar R.; Biswas, Sharmita Nandy; Sarkar, Sohini; Pedireddi, V. R.

    2016-06-01

    Synthesis and structural features of five new coordination assemblies, [Co(bpyH)(H2O)5](BPCH)·(bpyH2)0.5·(H2O) (1a), [{Cu(H2O)3}·{Cu0.5(bpy)0.5(H2O)0.5}2(μ-BPCH)] (1b), [{Cd0.5(BPCH)}2·{Cd0.5(bpy)(H2O)2}2]·6(H2O) (1c), [Cu(BPCH2)(bpyeaH)]·2(H2O) (1d) and [Cd2 (bpyea)0.5(oxalate)0.5(μ-BPC) (H2O)]·(bpyeaH2)·2(H2O) (1e), have been reported. All the assemblies were prepared by co-crystallization of benzenepentacarboxylic acid (BPCH5) either with 4,4‧-bipyridine (bpy) or 1,2-bis(4-pyridyl)ethane (bpyea) in the presence of a transition metal ion (either Co(II), Cu(II) or Cd(II)) as the case may be. All the five compounds were synthesized by hydrothermal method and structures were determined by single crystal X-ray diffraction. All the obtained compounds, 1a-1e, exhibit distinct 3-D polymeric architectures either in the form of stacked layers or host-guest networks in which water molecules play a pivotal role providing additional stabilization by coordinate bonds as well as hydrogen bonds. Other non-covalent interactions such as C-H … π and π … π stacking also participate in the formation of exotic 3-D structures of these complexes.

  5. Fission product interactions with nitrogen donor ligands used for spent nuclear fuel treatment

    Czech Academy of Sciences Publication Activity Database

    Aneheim, E.; Grüner, Bohumír; Ekberg, C.; Foreman, M.R.S.J.; Hájková, Zuzana; Löfström-Engdahl, E.; Drew, M. G. B.; Hudson, M.J.

    2013-01-01

    Roč. 50, č. 1 (2013), s. 154-163 ISSN 0277-5387 R&D Projects: GA MŠk(CZ) 7G08073 Grant - others:ACSEPT(XE) FP7-CP-2007-211 267 Institutional support: RVO:61388980 Keywords : BTBP * palladium * complexation * water solubility Subject RIV: CA - Inorganic Chemistry Impact factor: 2.047, year: 2013

  6. Synthesis, structure and magnetism of manganese and iron dipicolinates with N,N '-donor ligands

    Czech Academy of Sciences Publication Activity Database

    Uhrecký, Róbert; Svoboda, I.; Růžičková, Z.; Koman, M.; Dlháň, L.; Pavlík, J.; Moncol, J.; Boca, R.

    2015-01-01

    Roč. 425, JAN (2015), s. 134-144 ISSN 0020-1693 Institutional support: RVO:61388980 Keywords : Manganese * Iron * Dipicolinate complexes * Crystal structure * Magnetism Subject RIV: CA - Inorganic Chemistry Impact factor: 1.918, year: 2015

  7. Palladium(II Complexes of NS Donor Ligands Derived from Steroidal Thiosemicarbazones as Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Abdullah M. Asiri

    2010-07-01

    Full Text Available We have investigated the antibacterial activity of some new steroidal thiosemicarbazones and their Pd(II metal complexes were prepared by the reaction of the thiosemicarbazones with [Pd(DMSO2Cl2]. The steroidal thiosemicarbazones were prepared by the reaction of thiosemicarbazides with a steroidal ketone. The structures of these compounds were elucidated by IR, 1H-NMR, 13C-NMR, FAB mass spectroscopic methods, elemental analyses and TGA analysis. The antibacterial activity of these compounds were tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria. The results showed that steroidal complexes are better inhibitors of both types of the bacteria (Gram-positive and Gram-negative as compared to steroidal thiosemicarbazones. Compound Ia displays remarkable antibacterial activity as compared to amoxicillin.

  8. Nickel(II) complexes of N2S2 donor set ligand and halide ...

    Indian Academy of Sciences (India)

    Synthesis, crystal structure, DNA and bovine/human serum albumin interaction. ANIMESH ... Burdwan 713 104, India. bDepartment of Chemical and Pharmaceutical Sciences, Via Licio Giorgieri 1, 34127 Trieste, Italy ... and isothiocyanate anion (4)) have been synthesized and isolated in pure form. The complexes were ...

  9. DONOR CRITERIA FOR LIVER-TRANSPLANTATION - A COMPARATIVE-STUDY OF THE EFFECTS OF DONOR LIVER SELECTION

    NARCIS (Netherlands)

    PRUIM, J; TENVERGERT, EM; DEKEMPENAER, MGV; BONSEL, GJ; SLOOFF, MJH

    1993-01-01

    In a case-control study, the relevance of donor parameters used for donor selection on final transplant outcome was studied. Two matched groups of 17 donors were created: one group of 'ideal' donors and a control group not meeting the criteria for 'ideal' donors. Recipients of livers from both

  10. Higher organ donation consent rates by relatives of potential uncontrolled donors versus potential controlled donors after death

    NARCIS (Netherlands)

    Wind, J.; Mook, W.N. van; Willems, M.E.; Heurn, L.W. van

    2012-01-01

    BACKGROUND: Refusal to consent to organ donation is an important cause of the persisting gap between the number of potential organ donors and effectuated donors. In the Netherlands, organ donors include both uncontrolled donors: donors who die unexpectedly after cardiac death (DCD), after failed

  11. Multifunctional Transmembrane Protein Ligands for Cell-Specific Targeting of Plasma Membrane-Derived Vesicles.

    Science.gov (United States)

    Zhao, Chi; Busch, David J; Vershel, Connor P; Stachowiak, Jeanne C

    2016-07-01

    Liposomes and nanoparticles that bind selectively to cell-surface receptors can target specific populations of cells. However, chemical conjugation of ligands to these particles is difficult to control, frequently limiting ligand uniformity and complexity. In contrast, the surfaces of living cells are decorated with highly uniform populations of sophisticated transmembrane proteins. Toward harnessing cellular capabilities, here it is demonstrated that plasma membrane vesicles (PMVs) derived from donor cells can display engineered transmembrane protein ligands that precisely target cells on the basis of receptor expression. These multifunctional targeting proteins incorporate (i) a protein ligand, (ii) an intrinsically disordered protein spacer to make the ligand sterically accessible, and (iii) a fluorescent protein domain that enables quantification of the ligand density on the PMV surface. PMVs that display targeting proteins with affinity for the epidermal growth factor receptor (EGFR) bind at increasing concentrations to breast cancer cells that express increasing levels of EGFR. Further, as an example of the generality of this approach, PMVs expressing a single-domain antibody against green fluorescence protein (eGFP) bind to cells expressing eGFP-tagged receptors with a selectivity of ≈50:1. The results demonstrate the versatility of PMVs as cell targeting systems, suggesting diverse applications from drug delivery to tissue engineering. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Swedish sperm donors are driven by altruism, but shortage of sperm donors leads to reproductive travelling.

    Science.gov (United States)

    Ekerhovd, Erling; Faurskov, Anders; Werner, Charlotte

    2008-01-01

    Swedish legislation requires that sperm donors are identifiable to offspring. In Denmark sperm donors remain anonymous. The aim of this study was to examine sperm donation in Sweden by identifying socio-demographic backgrounds, motivations and attitudes among donors and to describe options and plans of sperm recipients. Furthermore, the willingness of Swedish health care providers to assist in treatment abroad, where sperm from an anonymous donor were to be used, was assessed. The extent of travelling to Denmark for reproductive purposes was also examined. Thirty Swedish sperm donors completed a questionnaire and were interviewed about their backgrounds, motivations and attitudes. Thirty couples where the infertility workup had shown azoospermia were interviewed about their options for achieving parenthood. The willingness to assist in fertility treatment abroad and the extent of reproductive cross border travelling were assessed by interviewing health care providers and by contacting Danish clinics. Almost all donors were Caucasian. The main motivation for sperm donors was to help others. Owing to shortage of sperm donors many Caucasian recipients intended to have treatment abroad. For most non-Caucasian recipients sperm from a donor of appropriate ethnicity were not available in Sweden. Whether the sperm donor was anonymous or identifiable was not of major importance to most sperm recipients. Health care providers expressed unanimous willingness to assist in treatment with sperm from an anonymous donor. Our inquiry indicated that more than 250 Swedish sperm recipients travel to Denmark annually. Identifiable sperm donors are driven by altruistic motives, but shortage of sperm donors leads to reproductive travelling. Recruitment strategies to increase the number of sperm donors in Sweden are therefore warranted.

  13. Development of Organ-Specific Donor Risk Indices

    Science.gov (United States)

    Akkina, Sanjeev K.; Asrani, Sumeet K.; Peng, Yi; Stock, Peter; Kim, Ray; Israni, Ajay K.

    2012-01-01

    Due to the shortage of deceased donor organs, transplant centers accept organs from marginal deceased donors, including older donors. Organ-specific donor risk indices have been developed to predict graft survival using various combinations of donor and recipient characteristics. We will review the kidney donor risk index (KDRI) and liver donor risk index (LDRI) and compare and contrast their strengths, limitations, and potential uses. The Kidney Donor Risk Index has a potential role in developing new kidney allocation algorithms. The Liver Donor Risk Index allows for greater appreciation of the importance of donor factors, particularly for hepatitis C-positive recipients; as the donor risk index increases, rates of allograft and patient survival among these recipients decrease disproportionately. Use of livers with high donor risk index is associated with increased hospital costs independent of recipient risk factors, and transplanting livers with high donor risk index into patients with Model for End-Stage Liver Disease scores Significant regional variation in donor quality, as measured by the Liver Donor Risk Index, remains in the United States. We also review other potential indices for liver transplant, including donor-recipient matching and the retransplant donor risk index. While substantial progress has been made in developing donor risk indices to objectively assess donor variables that affect transplant outcomes, continued efforts are warranted to improve these indices to enhance organ allocation policies and optimize allograft survival. PMID:22287036

  14. Investigation of Synthesis and some Properties of the Copper Complexes Containing Imidazole Ligand

    Directory of Open Access Journals (Sweden)

    Emin Erdem

    2016-06-01

    Full Text Available The copper(II complexes bearing tetrasubstituted imidazole derivatives containing oxygen donor as ligands (L1-6 were synthesized and characterized by spectroscopic methods, magnetic measurements, elemental and thermogravimetric analyses. The fluorescence efficiency of the ligands (L1-6 and their copper(II complexes were investigated at r.t. in DMF solution. Theoretical calculations were performed for the copper(II complex of L4 ligand, in this study. The molecular geometry, bond lengths, bond angles and vibrational wave numbers were calculated by using ab initio calculations based on the Hartree-Fock{HF/6-31G(d} and the density functional theory {B3LYP/6-31G(d} in the ground state. This work is licensed under a Creative Commons Attribution 4.0 International License.

  15. Multidentate fluorinated alkoxide ligand platforms for oxophilic metal centers: from MOCVD source reagents to polymerization catalysts.

    Science.gov (United States)

    Carpentier, Jean-François

    2010-01-07

    In contrast to simple fluorinated alkoxides, the coordination chemistry of multidentate ligands that incorporate OC(CF(3))(2)CR(2)-type moieties and additional donors (N, O, etc.) has been briefly investigated. In this Perspective, we review some well-defined, unambiguously authenticated main group and transition metal complexes supported by multidentate fluorinated alkoxide ligands and we present aspects of their syntheses, structures, and reactivities. The first part is devoted to the first syntheses of fluorinated alkoxy-imino and fluorinated alkoxy-amino ligand platforms and their application in the preparation of late transition (Ru, Co, Ir, Ni, Pd, Cu) and main group (Sr, Ba, Ga) metal complexes, many of which have been used as chemical vapor deposition (CVD) source reagents. In the second part, heteroleptic complexes based on oxophilic metals (Y, La, Ti, Zr, Hf, Al) and the catalytic performance of these systems in olefin polymerization and ring-opening polymerization (ROP) of cyclic esters are highlighted.

  16. Binary and ternary copper(II) complexes of a tridentate ONS ligand derived from 2-aminochromone-3 carboxaldehyde and thiosemicarbazide: Synthesis, spectral studies and antimicrobial activity

    Science.gov (United States)

    Shebl, Magdy; Ibrahim, M. A.; Khalil, Saied M. E.; Stefan, S. L.; Habib, H.

    2013-11-01

    A tridentate ONS donor ligand, HL, was synthesized by the condensation of 2-aminochromone-3-carboxaldehyde with thiosemicarbazide. The structure of the ligand was elucidated by elemental analyses, IR, 1H and 13C NMR, electronic and mass spectra. Reaction of the ligand with several copper(II) salts, including AcO-, NO3-, SO42-, Cl-, Br- and ClO4- afforded different metal complexes that reflect the non-coordinating or weakly coordinating power of the ClO4- and Br- anions as compared to the strongly coordinating power of AcO-, SO42-, Cl- and NO3- anions. Also, the ligand was allowed to react with Cu(II) ion in the presence of a secondary ligand (L‧) [N,O-donor; 8-hydroxyquinoline or N,N-donor; 1,10-phenanthroline]. Characterization and structure elucidation of the prepared complexes were achieved by elemental and thermal analyses, IR, electronic, mass and EPR spectra as well as conductivity and magnetic susceptibility measurements. The EPR spin Hamiltonian parameters of some complexes were calculated. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. The ligand and most of its metal complexes showed antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus).

  17. [Rare blood donors with irregular antibodies].

    Science.gov (United States)

    Milanović, Mirjana Krga; Bujandrić, Nevenka; Knezević, Natasa Milosavljević

    2013-01-01

    Blood groups are inherited biological characteristics that do not change throughout life in healthy people. Blood groups represent antigens found on the surface of red blood cells. Kell blood group system consists of 31 antigens. Kell antigen (K) is present in 0.2% of the population (the rare blood group). Cellano antigen is present in more than 99% (the high-frequency antigen). These antigens have a distinct ability to cause an immune response in the people after blood transfusion or pregnancy who, otherwise, did not have them before. This paper presents a blood donor with a rare blood group, who was found to have an irregular antibody against red blood cells by indirect antiglobulin test. Further testing determined the specificity of antibody to be anti-Cellano. The detected antibody was found in high titers (1024) with erythrocyte phenotype Kell-Cellano+. The blood donor was found to have a rare blood group KellKell. This donor was excluded from further blood donation. It is difficult to find compatible blood for a person who has developed an antibody to the high-frequency antigen. The donor's family members were tested and Cellano antigen was detected in her husband and child. A potential blood donor was not found among the family members. There was only one blood donor in the Register of blood donors who was compatible in the ABO and Kell blood group system. For the successful management of blood transfusion it is necessary to establish a unified national register of donors of rare blood groups and cooperate with the International Blood Group Reference Laboratory in Bristol with the database that registers donors of rare blood groups from around the world.

  18. Adult-to-Adult Living Donor Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Shimul A Shah

    2006-01-01

    Full Text Available The present review outlines the principles of living donor liver transplantation, donor workup, procedure and outcomes. Living donation offers a solution to the growing gap between the need for liver transplants and the limited availability of deceased donor organs. With a multidisciplinary team focused on donor safety and experienced surgeons capable of performing complex resection/reconstruction procedures, donor morbidity is low and recipient outcomes are comparable with results of deceased donor transplantation.

  19. Basicity of coordinating ligands in trivalent uranium and cerium metallocene complexes

    Energy Technology Data Exchange (ETDEWEB)

    Fabiano, M.D.

    1988-09-01

    Although much is known about the affinity of various Lewis bases for transition metal centers, the chemical literature contains only scant information about the relative affinities of Lewis bases for lanthanide and actinide metal centers. In terms of ligand affinities for f-metal centers, traditional HSAB theory characterizes trivalent and tetravalent f-metal cations as ''hard'' acids, preferring to be coordinated to ''hard'' Lewis bases (e.g., nitrogen or oxygen donor ligands) rather than ''soft'' (e.g., phosphorous or sulfur donor ligands) Lewis bases. Recent work by Brennan and Stults, however, has shown that, trimethylphosphine has a much greater affinity than does pyridine for the metal center in (MeC/sub 5/H/sub 4/)/sub 3/U and in (MeC/sub 5/H/sub 4/)/sub 3/Ce. This work established the ligand displacement series PMe/sub 3/, is quantitatively displaced by trimethylphosphine oxide in both the uranium and cerium systems. In the cerium system, trimethylphosphine sulfide and dimethyl sulfoxide were also found to quantitatively displace PMe/sub 3/. Trimethylphosphine oxide was found to be by far the strongest ligand in both systems, quantitatively displacing all ligands studied in both systems, with one exception: in the (me/sub 3/SiC/sub 5/H/sub 4/)/sub 3/U system, t-butyl isocyanide is displaced, but not completely displaced, by OPME/sub 3/. 9 refs.

  20. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang, E-mail: gfzhang@snnu.edu.cn; Gao, Ziwei, E-mail: zwgao@snnu.edu.cn

    2015-01-15

    A successive anchoring of Ti(NMe{sub 2}){sub 4}, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1′-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, {sup 13}C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands. - Graphical abstract: The ligand-tailored silica supported “single site” titanium complexes were synthesized by SOMC strategy and fully characterized. Their catalytic activity were evaluated by benzaldehyde silylcyanation. - Highlights: • Single-site silica supported Ti active species was prepared by SOMC technique. • O-donor ligand tailored Ti surface species was synthesized. • The surface species was characterized by XPS, {sup 13}C CP-MAS NMR, XANES etc. • Catalytic activity of the Ti active species in silylcyanation reaction was evaluated.

  1. Donor policy rules and aid effectiveness

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars

    2008-01-01

    The present paper examines the macroeconomic impact of aid, by introducing endogenous aid allocations into a neoclassical growth framework. On this basis it is shown that donor policies can have important implications for the trajectory of recipients' GDP per capita. Depending on specific donor...... policy choices, aid disbursements may lead to faster transitional growth, stagnation or cyclical growth. Moreover, the analysis also suggests that donor policies may be part of the reason why foreign aid is not found to be uniformly effective in raising long-run productivity across recipients...

  2. Shallow hydrogen-related donors in silicon

    International Nuclear Information System (INIS)

    Hartung, J.; Weber, J.

    1993-01-01

    Photothermal ionization spectroscopy on neutron-irradiated and subsequently hydrogen-plasma-treated silicon reveals the existence of new shallow donors. The binding energies of the observed effective-mass-like donors are between 34 and 53 meV. The optical dipole transitions of the different donors are shifted towards higher energies by ΔE=0.1--0.2 cm -1 , when deuterium is used in the plasma instead of hydrogen. This isotope shift of the optical dipole transitions between the electronic levels of the defects is direct proof of the incorporation of hydrogen in these defects

  3. Simulation Model for DMEK Donor Preparation.

    Science.gov (United States)

    Mittal, Vikas; Mittal, Ruchi; Singh, Swati; Narang, Purvasha; Sridhar, Priti

    2018-04-09

    To demonstrate a simulation model for donor preparation in Descemet membrane endothelial keratoplasty (DMEK). The inner transparent membrane of the onion (Allium cepa) was used as a simulation model for human Descemet membrane (DM). Surgical video (see Video, Supplemental Digital Content 1, http://links.lww.com/ICO/A663) demonstrating all the steps was recorded. This model closely simulates human DM and helps DMEK surgeons learn the nuances of DM donor preparation steps with ease. The technique is repeatable, and the model is cost-effective. The described simulation model can assist surgeons and eye bank technicians to learn steps in donor preparation in DMEK.

  4. Kidney for sale by live donor.

    Science.gov (United States)

    Brahams, D

    1989-02-04

    The capacity to consent to bodily harm is explored in relation to the trade in kidneys obtained from impoverished healthy live donors for cash. The British medical profession has unambiguously condemned the practice, but the law in Britain allows a donor to consent to serious injury where the act had some social purpose, recognized by the law as valid. Allegations against the private Humana Hospital Wellington that indigent Turks were brought to Britain to be paid kidney donors, and similar practices elsewhere, are discussed. Questions are raised about the illegality of such contracts in Britain and the possibility of a Parliamentary Act making brokerage and involvement with such cash transactions a criminal offense.

  5. 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.

  6. Donor-derived HLA antibody production in patients undergoing SCT from HLA antibody-positive donors.

    Science.gov (United States)

    Taniguchi, K; Yoshihara, S; Maruya, E; Ikegame, K; Kaida, K; Hayashi, K; Kato, R; Inoue, T; Fujioka, T; Tamaki, H; Okada, M; Onuma, T; Fujii, N; Kusunoki, Y; Soma, T; Saji, H; Ogawa, H

    2012-10-01

    Pre-existing donor-specific HLA antibodies in patients undergoing HLA-mismatched SCT have increasingly been recognized as a risk factor for primary graft failure. However, the clinical implications of the presence of HLA antibodies in donors remain unknown. We prospectively examined 123 related donors for the presence of HLA antibodies by using a Luminex-based single antigen assay. Of these, 1/57 (1.8%) male, 6/27 (22%) parous female and 0/39 (0%) nonparous female donors were HLA antibody-positive. Then, we determined the presence of HLA antibodies in seven patients who received SCT from antibody-positive donors. Of these, four became HLA antibody-positive after SCT. The specificities of the antibodies that emerged in the patients closely resembled those of the antibodies found in the donors, indicating their production by donor-derived plasma cells. Moreover, the kinetics of the HLA antibody levels were similar in all four patients: levels started increasing within 1 week after SCT and peaked at days 10-21, followed by a gradual decrease. These results suggest that donor-derived HLA antibody production frequently occurs in patients undergoing SCT from antibody-positive donors. Further studies are warranted for clarifying the clinical significance of donor-derived HLA antibodies, including the role of these antibodies in post transplant platelet transfusion refractoriness.

  7. Responses to recipient and donor B cells by genetically donor T cells from human haploidentical chimeras

    International Nuclear Information System (INIS)

    Schiff, S.; Sampson, H.; Buckley, R.

    1986-01-01

    Following administration of haploidentical stem cells to infants with severe combined immunodeficiency (SCID), mature T cells of donor karyotype appear later in the recipient without causing graft-versus-host disease. To investigate the effect of the host environment on the responsiveness of these genetically donor T cells, blood B and T lymphocytes from 6 SCID recipients, their parental donors and unrelated controls were purified by double SRBC rosetting. T cells were stimulated by irradiated B cells at a 1:1 ratio in 6 day cultures. Engrafted T cells of donor karyotype gave much smaller responses to irradiated genetically recipient B cells than did fresh donor T cells. Moreover, engrafted T cells of donor karyotype from two of the three SCIDs who are longest post-transplantation responded more vigorously (14,685 and 31,623 cpm) than fresh donor T cells (5141 and 22,709 cpm) to donor B cells. These data indicate that T lymphocytes which have matured from donor stem cells in the recipient microenvironment behave differently from those that have matured in the donor

  8. Donor Retention in Online Crowdfunding Communities: A Case Study of DonorsChoose.org.

    Science.gov (United States)

    Althoff, Tim; Leskovec, Jure

    2015-05-01

    Online crowdfunding platforms like DonorsChoose.org and Kick-starter allow specific projects to get funded by targeted contributions from a large number of people. Critical for the success of crowdfunding communities is recruitment and continued engagement of donors. With donor attrition rates above 70%, a significant challenge for online crowdfunding platforms as well as traditional offline non-profit organizations is the problem of donor retention. We present a large-scale study of millions of donors and donations on DonorsChoose.org, a crowdfunding platform for education projects. Studying an online crowdfunding platform allows for an unprecedented detailed view of how people direct their donations. We explore various factors impacting donor retention which allows us to identify different groups of donors and quantify their propensity to return for subsequent donations. We find that donors are more likely to return if they had a positive interaction with the receiver of the donation. We also show that this includes appropriate and timely recognition of their support as well as detailed communication of their impact. Finally, we discuss how our findings could inform steps to improve donor retention in crowdfunding communities and non-profit organizations.

  9. Human decellularized bone scaffolds from aged donors show improved osteoinductive capacity compared to young donor bone.

    Directory of Open Access Journals (Sweden)

    Christopher A Smith

    Full Text Available To improve the safe use of allograft bone, decellularization techniques may be utilized to produce acellular scaffolds. Such scaffolds should retain their innate biological and biomechanical capacity and support mesenchymal stem cell (MSC osteogenic differentiation. However, as allograft bone is derived from a wide age-range, this study aimed to determine whether donor age impacts on the ability an osteoinductive, acellular scaffold produced from human bone to promote the osteogenic differentiation of bone marrow MSCs (BM-MSC. BM-MSCs from young and old donors were seeded on acellular bone cubes from young and old donors undergoing osteoarthritis related hip surgery. All combinations resulted in increased osteogenic gene expression, and alkaline phosphatase (ALP enzyme activity, however BM-MSCs cultured on old donor bone displayed the largest increases. BM-MSCs cultured in old donor bone conditioned media also displayed higher osteogenic gene expression and ALP activity than those exposed to young donor bone conditioned media. ELISA and Luminex analysis of conditioned media demonstrated similar levels of bioactive factors between age groups; however, IGF binding protein 1 (IGFBP1 concentration was significantly higher in young donor samples. Additionally, structural analysis of old donor bone indicated an increased porosity compared to young donor bone. These results demonstrate the ability of a decellularized scaffold produced from young and old donors to support osteogenic differentiation of cells from young and old donors. Significantly, the older donor bone produced greater osteogenic differentiation which may be related to reduced IGFBP1 bioavailability and increased porosity, potentially explaining the excellent clinical results seen with the use of allograft from aged donors.

  10. THERMODYNAMIC ASSESSMENT OF ANIONIC LIGANDS ...

    African Journals Online (AJOL)

    DJFLEX

    2010-06-30

    Jun 30, 2010 ... The presence of the ligands (ethylenediaminettraacetic acid, EDTA, enthylenediamine, en,and chloride ion, Cl-) generally improved the sorption capacity for the adsorbent, the best being. Cl- at optimum pH of 2.0 (for Co2+) and 5.0 (for Ni2+ and Cd2+). The thermodynamic studies reveal that the adsorption.

  11. RESULTS OF THE SPECIAL BLOOD DONOR DAY

    CERN Document Server

    SC Unit

    2008-01-01

    Responding to the HUG (Hôpitaux Universitaires de Genève) hospitals’ urgent appeal for blood donations during this summer season, the CERN medical staff organised a day of blood donations for the Swiss bloodbank CTS on 30 July. They were supported by NOVAE (Restaurant No. 1), who provided donors with a free snack. This specially arranged campaign was a success, as the 135 volunteers included 66 first-time donors, and a total of 99 standard bags of blood were collected. (Swiss hospitals need 1300 bags every day!) The CTS and CERN’s medical staff wish to thank the donors and all others who helped make the event a success. Upcoming blood donor days at CERN: 12 November 2008 and 10 March 2009.

  12. RESULTS OF THE SPECIAL BLOOD DONOR DAY

    CERN Multimedia

    SC Unit

    2008-01-01

    Responding to the HUG (Hôpitaux Universitaires de Genève) hospitals’ urgent appeal for blood donations during this summer season, the CERN medical staff organised a day of blood donations for the Swiss bloodbank CTS on 30 July. They were supported by NOVAE (Restaurant No. 1), who provided donors with a free snack. This specially arranged campaign was a success, as the 135 volunteers included 66 first-time donors, and a total of 99 standard bags of blood was collected. (Swiss hospitals need 1300 bags every day!) The CTS and CERN’s medical staff want to thank the donors and all others who helped make the event a success. Upcoming blood donor days at CERN: 12 November 2008 and 10 March 2009.

  13. Complexation behavior of trivalent actinides and lanthanides with 1,10-phenanthroline-2,9-dicarboxylic acid based ligands: insight from density functional theory.

    Science.gov (United States)

    Manna, Debashree; Ghanty, Tapan K

    2012-08-21

    We have investigated the complexation behavior of preorganized 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) based ligands with trivalent lanthanides and actinides using density functional theory with various GGA type exchange-correlation functionals and different basis sets. New ligands have been designed from PDA through functionalization with soft donor atoms such as sulfur, resulting in mono-thio-dicarboxylic acids (TCA/TCA1) and di-thio-dicarboxylic acid (THIO). It has been found that selectivity in terms of complexation energy of actinides over lanthanides is the maximum with TCA1 where the metal-ligand binding is through the O atoms. This unusual feature where a softer actinide metal ion is bonded strongly with hard donor oxygen atoms has been explained using the popular chemical concepts, viz., Pearson's Hard-Soft-Acid-Base (HSAB) principle and the frontier orbital theory of chemical reactivity as proposed by Fukui. Detailed analysis within the framework of the HSAB principle indicates that the presence of softer nitrogen atoms in the phenanthroline moiety (which also act as donors to the metal ion) has a profound influence in changing the soft nature of the actinide ion, which in turn binds with the hard oxygen atoms in a stronger way as compared to the valence isoelectronic lanthanide ion. Also, the trends in the variation of calculated values of the metal-ligand bond distances and the corresponding complex formation energies have been rationalized using the Fukui reactivity indices corresponding to the metal ions and the donor sites. All the calculations have also been done in the presence of solvent. The "intra-ligand synergistic effect" demonstrated here for PDA or TCA1 with soft and hard donor centers might be very important in designing new ligands for selective extraction of various metal ions in a competitive environment. However, for TCA and THIO ligands with only soft donor centers, "intra-ligand synergism" may not be very efficient although

  14. Laparoscopic donor nephrectomy increases the supply of living donor kidneys: a center-specific microeconomic analysis.

    Science.gov (United States)

    Kuo, P C; Johnson, L B

    2000-05-27

    A tenet of microeconomics is that new technology will shift the supply curve to the right. Laparoscopic donor nephrectomy (LDN) is a new technique for removal of living donor kidneys. Centers performing this procedure have noted an increased number of patients presenting for donor evaluation. This has not been previously studied. The records of all LDN performed from May 1998 to February 1999 were reviewed. The following variables were examined: sex, age, related vs. unrelated donation, estimated blood loss, i.v. analgesia, length of stay, and time out of work. Donors undergoing traditional open donor nephrectomy during January 1997 to May 1998 served as the control group. A composite cost index was constructed. LDN significantly decreased length of stay, pain, and time out of work; the supply function shifted to the right. Telephone interviews revealed that 47% donated solely because of the LDN procedure. LDN increases the supply of living donor kidneys.

  15. Donor-Derived Myeloid Sarcoma in Two Kidney Transplant Recipients from a Single Donor

    Directory of Open Access Journals (Sweden)

    Amudha Palanisamy

    2015-01-01

    Full Text Available We report the rare occurrence of donor-derived myeloid sarcoma in two kidney transplant patients who received organs from a single deceased donor. There was no evidence of preexisting hematologic malignancy in the donor at the time of organ recovery. Both recipients developed leukemic involvement that appeared to be limited to the transplanted organ. Fluorescence in situ hybridization (FISH and molecular genotyping analyses confirmed that the malignant cells were of donor origin in each patient. Allograft nephrectomy and immediate withdrawal of immunosuppression were performed in both cases; systemic chemotherapy was subsequently administered to one patient. Both recipients were in remission at least one year following the diagnosis of donor-derived myeloid sarcoma. These cases suggest that restoration of the immune system after withdrawal of immunosuppressive therapy and allograft nephrectomy may be sufficient to control HLA-mismatched donor-derived myeloid sarcoma without systemic involvement.

  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. Promoting Organ Donor Registries Through Public Education: What Is the Cost of Securing Organ Donors?

    Science.gov (United States)

    Razdan, Manik; Smith, Kenneth J; Bryce, Cindy L; Degenholtz, Howard B

    2016-06-01

    Transplant medicine's impact on America's public health is seriously limited by acute shortage of transplantable organs. Consequently, the United Sates has witnessed considerable investment in the promotion of organ donor registries. Although there is no evidence to support that donor registry promotion alleviates organ shortage, this belief continues to drive investments into registry promotion. In this study, return on investment in donor registry promotion was examined using cost-outcomes analysis. Cost of promoting the donor registry was estimated in US dollars whereas the outcome was measured as the number of individuals who join the registry (registrants) and their value in terms of organ donors. The study was conducted from the perspective of a regional Organ Procurement Organization (OPO). Costs were directly obtained from the OPO. The number of new registrants was obtained from the OPO and the departments of motor vehicles that maintain the donor registry. The value of registrants in terms of organ donors was computed based on a registrant's age-dependent risk of dying and age-dependent probability of becoming an organ donor. Six thousand seven hundred eight individuals joined the organ donor registry (95% confidence interval [95% CI], 5429-7956) at a cost of $455 per registrant (95% CI, US $383-US $562). These individuals result in 4.2 present-day donors (95% CI, 2.5-6.6) at a cost of US $726 000 (95% CI, US $462000-US $1.2 million). Because the cost per registrant and cost per donor is less than society's willingness to pay, donor registry promotion offers positive return on investment. Investment in registry promotion should at the minimum be maintained at current levels.

  18. SYNTHESIS, STEREOCHEMISTRY AND ANTIMICROBIAL ...

    African Journals Online (AJOL)

    Preferred Customer

    KEY WORDS: 4-Phenylsemicarbazone, Metal complexes, Stereochemistry, Antimicrobial activity. INTRODUCTION ... stereochemistry of semicarbazone metal complexes [8-13], this group of ligands deserve further investigations. ..... The cytotoxicity of tested compounds generally increased with increase concentration and ...

  19. A control on hydrophobic and hydrophilic interactions between HEWL and metal Schiff-base complexes comprising of different metal ions and ligands

    Energy Technology Data Exchange (ETDEWEB)

    Koley Seth, Banabithi; Ray, Aurkie; Basu, Samita, E-mail: samita.basu@saha.ac.in

    2015-05-15

    The structural effects of different copper(II) and nickel(II) Schiff base complexes on hen egg white lysozyme (HEWL) have been investigated through steady state and time resolved absorption and fluorescence, and circular dichroism spectroscopy. The Schiff base ligands with N{sub 4} donor atoms show both hydrophobic and hydrophilic interactions, however hydrophilic interaction prevails with ligands having N{sub 2}O{sub 2} donor atoms. Variation of metal ions from Cu{sup 2+} to Ni{sup 2+} with each type of Schiff base ligand increases the probability of hydrophilic over hydrophobic interactions, which supports their significance in regulating the binding affinity between HEWL and metal complexes. On photo-excitation the complexes comprising of Cu{sup 2+} ion instead of Ni{sup 2+} ion and ligands with N{sub 4} donor system rather than N{sub 2}O{sub 2} donor system, increases the probability of intersystem crossing to populate the corresponding triplet state as observed from laser flash photolysis study. The better binding affinity of nickel complexes with different selectivities compared to copper complexes towards HEWL emphasizes the potentiality of less explored nickel complexes in drug–protein interactions. - Highlights: • Ni{sup II} and Cu{sup II} -Schiff base complexes bind hen egg white lysozyme spontaneously. • Both hydrophobic and hydrophilic interactions are effective for N{sub 4} ligands. • For N{sub 2}O{sub 2} ligands the hydrophilic is predominant over hydrophobic interaction. • Binding affinity and selectivity of Ni{sup II}-complexes are better than Cu{sup II}-complexes. • Replacement of Cu{sup 2+} by Ni{sup 2+} in a ligand enhances chance of hydrophilic interaction.

  20. Improved survival of acute lymphoblastic leukemia patients of HLA-A3/11 absent for donor KIR3DL2 after non-T-cell depleted HLA-identical sibling hematopoietic stem cells transplantation

    Directory of Open Access Journals (Sweden)

    farhad shahsavar

    2011-08-01

    Conclusion: These data indicate that the absence of HLA class I ligand in the recipient for donor-inhibitory KIR can be a prognostic factor for transplantation outcomes in non-T-cell depleted HLA-identical sibling hematopoietic stem-cell transplantation and that the lack of HLA-A3/11 for donor KIR3DL2 can contribute to improved survival for patients with ALL.

  1. Photochemical generation of strong one-electron reductants via light-induced electron transfer with reversible donors followed by cross reaction with sacrificial donors.

    Science.gov (United States)

    Shan, Bing; Schmehl, Russell

    2014-11-13

    This work illustrates a modified approach for employing photoinduced electron transfer reactions coupled to secondary irreversible electron transfer processes for the generation of strongly reducing equivalents in solution. Through irradiation of [Ru(LL)3](2+) (LL= diimine ligands) with tritolylamine (TTA) as quencher and various alkyl amines as sacrificial electron donors, yields in excess of 50% can be achieved for generation of reductants with E(0)(2+/1+) values between -1.0 and -1.2 V vs NHE. The key to the system is the fact that the TTA cation radical, formed in high yield in reaction with the photoexcited [Ru(LL)3](2+) complex, reacts irreversibly with various sacrificial electron donating amines that are kinetically unable to directly react with the photoexcited complex. The electron transfer between the TTA(+) and the sacrificial amine is an energetically uphill process. Kinetic analysis of these parallel competing reactions, consisting of bimolecular and pseudo first-order reactions, allows determination of electron transfer rate constants for the cross electron transfer reaction between the sacrificial donor and the TTA(+). A variety of amines were examined as potential sacrificial electron donors, and it was found that tertiary 1,2-diamines are most efficient among these amines for trapping the intermediate TTA(+). This electron-donating combination is capable of supplying a persistent reducing flux of electrons to catalysts used for hydrogen production.

  2. Impact of the cornea donor study on acceptance of corneas from older donors.

    Science.gov (United States)

    Sugar, Alan; Montoya, Monty M; Beck, Roy; Cowden, John W; Dontchev, Mariya; Gal, Robin L; Kollman, Craig; Malling, Jackie; Mannis, Mark J; Tennant, Bradley

    2012-12-01

    To evaluate retrospectively whether the findings from the Cornea Donor Study (CDS) led to changes in the transplantation of corneas from older donors. Eye banks in United States provided complete data on donor age and placement (domestic or international) for 86,273 corneas from 1998 to 2009. The data were analyzed by 3 periods, preceding CDS (1998-1999), during CDS (2000-2007), and after publication of CDS 5-year results (2008-2009), and separately for corneas placed within versus outside the United States. For corneal tissues transplanted in the United States, the percentage of donors who were 66 years or older increased from 19% before CDS to 21% during CDS and 25% after CDS (Pcorneas distributed outside the United States, with the percentage of donors 66 years and older decreasing from 56% to 42% to 34%, respectively. Donor age trends over time varied by eye bank. There was a modest overall increase in the donor age of corneas transplanted in the United States from 1998 to 2009, but the retrospective nature of the study limits our ability to attribute this change to the CDS. The modest increases in the donor age of corneas transplanted is a positive finding, but wider acceptance of older corneal donor tissue should be encouraged based on the 5-year evidence generated by the CDS.

  3. Impact of the Cornea Donor Study (CDS) on Acceptance of Corneas from Older Donors

    Science.gov (United States)

    Sugar, Alan; Montoya, Monty M.; Beck, Roy; Cowden, John W.; Dontchev, Mariya; Gal, Robin L.; Kollman, Craig; Malling, Jackie; Mannis, Mark J.; Tennant, Bradley

    2014-01-01

    Purpose Evaluate retrospectively whether findings from the Cornea Donor Study (CDS) led to changes in the transplantation of corneas from older donors. Methods United States eye banks provided complete data on donor age and placement (domestic or international) for 86,273 corneas from 1998 to 2009. The data were analyzed by 3 time periods: preceding CDS (1998–1999), during CDS (2000–2007) and after publication of CDS 5 year results (2008–2009), and separately for corneas placed within vs. outside the United States. Results For corneal tissues transplanted in the United States, the percentage of donors ≥66 years old increased from 19% before CDS to 21% during CDS and 25% after CDS (pcorneas distributed outside the United States with the percentage of donors ≥66 years old decreasing from 56% to 42% to 34%, respectively. Donor age trends over time varied by eye bank. Conclusions There was a modest overall increase in the donor age of corneas transplanted in the United States from 1998 to 2009, but the retrospective nature of the study limits our ability to attribute this change to the CDS. The modest increases in the donor age of corneas transplanted is a positive finding, but wider acceptance of older corneal donor tissue should be encouraged based on the five-year evidence generated by the CDS. PMID:22262218

  4. Short Term Donor Outcomes After Hepatectomy in Living Donor Liver Transplantation

    International Nuclear Information System (INIS)

    Dar, F. S.; Zia, H.; Bhatti, A. B. H.; Kazmi, R.; Rana, A.; Nazer, R.; Khan, E. U. D.; Khan, N. A.; Salih, M.; Shah, N. H.

    2016-01-01

    Objective: To determine the outcome of living-donor liver transplant (LDLT) donors from the first liver transplant program in Pakistan. Study Design: Cohort study. Place and Duration of Study: Shifa International Hospital, Islamabad, from April 2012 to August 2014. Methodology: A total of 100 live donors who underwent hepatectomy were included. Demographics, etiologies, graft characteristics and operative variables were retrospectively assessed. Outcome was assessed based on morbidity and mortality. Results: Median donor age was 28 (17 - 45) years and median body mass index (BMI) was 24 kg/m2 (15 - 36). Male to female ratio was 1.5:1. Hepatitis B and C were the most common underlying etiologies and accounted for 79/100 (79%) of LDLT's. Overall, 93/100 (93%) donors donated a right lobe graft. Median estimated graft weight to recipient body weight (GW/BW) ratio was 1.03 (0.78 - 2). Standard arterial anatomy was present in 56% donors. The 90-day morbidity was 13/100 (13%) and overall morbidity was 17/100 (17%). Bile leak was encountered in 3 (3%) patients. There was no donor mortality. Conclusion: Acceptable short-term donor outcomes were achieved in an LDLT program in Pakistan with careful donor selection and planning. (author)

  5. Donor registries, first-person consent legislation, and the supply of deceased organ donors.

    Science.gov (United States)

    Callison, Kevin; Levin, Adelin

    2016-09-01

    In this paper, we exploit the varied timing in state adoption of organ donor registries and first-person consent (FPC) legislation to examine corresponding changes in the supply of deceased organ donors. Results indicate that the establishment of a state organ donor registry leads to an increase in donation rates of approximately 8%, while the adoption of FPC legislation has no effect on the supply of organ donors. These results reinforce the need to encourage individuals to communicate their donation preferences, either explicitly via a registry or by discussing them with family. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. -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.

  7. Chelating ligands for nanocrystals' surface functionalization

    NARCIS (Netherlands)

    Querner, Claudia; Reiss, Peter; Bleuse, Joël; Pron, Adam

    2004-01-01

    A new family of ligands for the surface functionalization of CdSe nanocrystals is proposed, namely alkyl or aryl derivatives of carbodithioic acids (R-C(S)SH). The main advantages of these new ligands are as follows: they nearly quantitatively exchange the initial surface ligands (TOPO) in very mild

  8. Complexation of f elements by tripodal ligands containing aromatic nitrogens. Application to the selective extraction of actinides(III)

    International Nuclear Information System (INIS)

    Wietzke, Raphael

    1999-01-01

    This work initiates a research project, whose aim is the actinides(lll)/lanthanides(III) separation by liquid-liquid extraction. We were interested in the study of the coordination chemistry of lanthanides(III) and uranium(III) (uranium(III) as model for the actinides(III)), with the aim to show differences between the two families and to better understand the coordination properties involved in the extraction process. We studied the lanthanide(III) and uranium(III) complexation with tripodal ligands containing aromatic nitrogens. Several tripodal ligands were synthesized varying the type and the number of the donor atoms. The lanthanide(III) complexes have been characterized in the solid state and in solution (by several techniques: 1 H NMR, ESMS, luminescence, UV spectrophotometry, conductometry). Differences in the coordination were found depending on the nature of the donor atoms. The new ligands, tris(2-pyrazinylmethyl)amine (tpza) et tris(N,N-diethyl-2-carbamoyl-6- pyridylmethyl)amine (tpaa), have shown a selectivity for the actinides(III) with promising results in liquid-liquid extraction. The comparison between the lanthanum(III) and uranium(III) complexes with the ligand tpza showed differences in the bonding nature, which could be attributed to a covalent contribution to the metal-ligand bond. (author) [fr

  9. Highly stable [mambf6-n(o/h2o)n(ligand)2(solvent)x]n metal organic frameworks

    KAUST Repository

    Eddaoudi, Mohamed

    2016-10-13

    Provided herein are metal organic frameworks having high selectivity and stability in the present of gases and vapors including H2S, H2O, and CO2. Metal organic frameworks can comprise metal nodes and N-donor organic ligands. Further provided are methods of making metal organic frameworks.

  10. Synthesis and structural studies of Cp{sup *} rhodium and Cp{sup *} iridium complexes of picolinic hydrazine ligand

    Energy Technology Data Exchange (ETDEWEB)

    Palepu, Narasinga Rao; Kollipara, Mohan Rao [Centre for Advanced Studies in Chemistry, North-Eastern Hill University, Shillong (India); Kaminsky Werner [Dept. of Chemistry, University of Washington, Seattle (United States)

    2017-01-15

    A series of Cp{sup *}Rh and Cp{sup *}Ir complexes of picolinic hydrazine ligand are synthesized and characterized. Picolinic hydrazine has yielded only dinuclear complexes in the case of rhodium metal whereas both mono and dinuclear complexes with iridium metal. Iridium complexes are formed as quaternary salts by the migration of the N–H proton onto the adjacent amine group of the hydrazine after binding to the metal. Picolinic hydrazine acts as nitrogen and oxygen donor ligand in the form of bi and tetradentate bonding modes.

  11. Parvovirus B19 viraemia in Dutch blood donors

    NARCIS (Netherlands)

    Zaaijer, H. L.; Koppelman, M. H. G. M.; Farrington, C. P.

    2004-01-01

    Blood, donated by asymptomatic donors, may contain and transmit parvovirus B19. To investigate the dynamics of parvovirus viraemia in asymptomatic blood donors, we studied the amounts of parvovirus DNA in pools of donor plasma, the prevalence of parvovirus antibodies among blood donors in relation

  12. Prevalence of malaria parasitaemia among blood donors in Owerri ...

    African Journals Online (AJOL)

    A study of the prevalence of malaria parasitaemia among blood donors in the Federal Medical Centre, Owerri, Imo State, was carried out between December, 2003 and April, 2004. A total of 500 blood samples were collected from blood donors consisting of 262 commercial donors and 238 relation-donors, using ...

  13. Feasibility of liver graft procurement with donor gallbladder preservation in living donor liver transplantation.

    Science.gov (United States)

    Dong, Jia-Hong; Ye, Sheng; Duan, Wei-Dong; Ji, Wen-Bing; Liang, Yu-Rong

    2015-10-01

    Cholecystectomy is routinely performed at most transplant centers during living donor liver transplantation (LDLT). This study was performed to evaluate the feasibility of liver graft procurement with donor gallbladder preservation in LDLT. Eighty-nine LDLTs (from June 2006 to Dec 2012) were retrospectively analyzed at our hospital. The surgical approach for liver graft procurement with donor gallbladder preservation was assessed, and the anatomy of the cystic artery, the morphology and contractibility of the preserved gallbladder, postoperative symptoms, and vascular and biliary complications were compared among donors with or without gallbladder preservation. Twenty-eight donors (15 right and 13 left-liver grafts) successfully underwent liver graft procurement with gallbladder preservation. Among the 15 right lobectomy donors, for 12 cases (80.0 %) the cystic artery originated from right hepatic artery. From the left hepatic artery and proper hepatic artery accounted for 6.7 % (1/15), respectively. Postoperative symptoms among these 28 donors were slight, although donors with cholecystectomy often complained of fatty food aversion, dyspepsia, and diarrhea during an average follow-up of 58.6 (44-78) months. The morphology and contractibility of the preserved gallbladders were comparable with normal status; the rate of contraction was 53.8 and 76.7 %, respectively, 30 and 60 min after ingestion of a fatty meal. Biliary and vascular complications among donors and recipients, irrespective of gallbladder preservation, were not significantly different. These data suggest that for donors compliant with anatomical requirements, liver graft procurement with gallbladder preservation for the donor is feasible and safe. The preserved gallbladder was assessed as functioning well and postoperative symptoms as a result of cholecystectomy were significantly reduced during long-term follow-up.

  14. Tetradentate Schiff base ligands and their complexes: Synthesis, structural characterization, thermal, electrochemical and alkane oxidation

    Science.gov (United States)

    Ceyhan, Gökhan; Köse, Muhammet; McKee, Vickie; Uruş, Serhan; Gölcü, Ayşegül; Tümer, Mehmet

    Three Schiff base ligands (H2L1-H2L3) with N2O2 donor sites were synthesized by condensation of 1,5-diaminonapthalene with benzaldehyde derivatives. A series of Cu(II), Co(II), Ni(II), Mn(II) and Cr(III) complexes were prepared and characterized by spectroscopic and analytical methods. Thermal, electrochemical and alkane oxidation reactions of the ligands and their metal complexes were investigated. Extensive application of 1D (1H, 13C NMR) and 2D (COSY, HETCOR, HMBC and TOSCY) NMR techniques were used to characterize the structures of the ligands and establish the 1H and 13C resonance assignments of the three ligands. Ligands H2L1 and H2L3 were obtained as single crystals from THF solution and characterized by X-ray diffraction. Both molecules are centrosymmetric and asymmetric unit contains one half of the molecule. Catalytic alkane oxidation reactions with the transition metal complexes investigated using cyclohexane and cyclooctane as substrates. The Cu(II) and Cr(III) complexes showed good catalytic activity in the oxidation of cyclohexane and cyclooctane to desired oxidized products. Electrochemical and thermal properties of the compounds were also investigated.

  15. Alternative Affinity Ligands for Immunoglobulins.

    Science.gov (United States)

    Kruljec, Nika; Bratkovič, Tomaž

    2017-08-16

    The demand for recombinant therapeutic antibodies and Fc-fusion proteins is expected to increase in the years to come. Hence, extensive efforts are concentrated on improving the downstream processing. In particular, the development of better-affinity chromatography matrices, supporting robust time- and cost-effective antibody purification, is warranted. With the advances in molecular design and high-throughput screening approaches from chemical and biological combinatorial libraries, novel affinity ligands representing alternatives to bacterial immunoglobulin (Ig)-binding proteins have entered the scene. Here, we review the design, development, and properties of diverse classes of alternative antibody-binding ligands, ranging from engineered versions of Ig-binding proteins, to artificial binding proteins, peptides, aptamers, and synthetic small-molecular-weight compounds. We also provide examples of applications for the novel affinity matrices in chromatography and beyond.

  16. High-risk HLA alleles for severe acute graft-versus-host disease and mortality in unrelated donor bone marrow transplantation

    Science.gov (United States)

    Morishima, Satoko; Kashiwase, Koichi; Matsuo, Keitaro; Azuma, Fumihiro; Yabe, Toshio; Sato-Otsubo, Aiko; Ogawa, Seishi; Shiina, Takashi; Satake, Masahiro; Saji, Hiroh; Kato, Shunichi; Kodera, Yoshihisa; Sasazuki, Takehiko; Morishima, Yasuo

    2016-01-01

    HLA molecules play an important role for immunoreactivity in allogeneic hematopoietic stem cell transplantation. To elucidate the effect of specific HLA alleles on acute graft-versus-host disease, we conducted a retrospective analysis using 6967 Japanese patients transplanted with T-cell-replete marrow from an unrelated donor. Using unbiased searches of patient and donor HLA alleles, patient and/or donor HLA-B*51:01 (patient: HR, 1.37, PHLA-C*14:02 (HR, 1.35, PHLA-C*14:02 was not associated with severe acute graft-versus-host disease prompted us to elucidate the relation of these high-risk HLA alleles with patient and donor HLA-C allele mismatches. In comparison to HLA-C allele match, patient mismatched HLA-C*14:02 showed the highest risk of severe acute graft-versus-host disease (HR, 3.61, PHLA-C alleles. Although patient HLA-C*14:02 and donor HLA-C*15:02 mismatch was usually KIR2DL-ligand mismatch in the graft-versus-host direction, the risk of patient mismatched HLA-C*14:02 for severe acute graft-versus-host disease was obvious regardless of KIR2DL-ligand matching. The effect of patient and/or donor HLA-B*51:01 on acute graft-versus-host disease was attributed not only to strong linkage disequilibrium of HLA-C*14:02 and -B*51:01, but also to the effect of HLA-B*51:01 itself. With regard to clinical implications, patient mismatched HLA-C*14:02 proved to be a potent risk factor for severe acute graft-versus-host disease and mortality, and should be considered a non-permissive HLA-C mismatch in donor selection for unrelated donor hematopoietic stem cell transplantation. PMID:26768690

  17. 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)

  18. Ligand binding by PDZ domains

    DEFF Research Database (Denmark)

    Chi, Celestine N.; Bach, Anders; Strømgaard, Kristian

    2012-01-01

    The postsynaptic density protein-95/disks large/zonula occludens-1 (PDZ) protein domain family is one of the most common protein-protein interaction modules in mammalian cells, with paralogs present in several hundred human proteins. PDZ domains are found in most cell types, but neuronal proteins...... 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....

  19. 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....

  20. Killer immunoglobulin-like receptor (KIR) and KIR-ligand genotype do not correlate with clinical outcome of renal cell carcinoma patients receiving high-dose IL2.

    Science.gov (United States)

    Wang, Wei; Erbe, Amy K; Gallenberger, Mikayla; Kim, KyungMann; Carmichael, Lakeesha; Hess, Dustin; Mendonca, Eneida A; Song, Yiqiang; Hank, Jacquelyn A; Cheng, Su-Chun; Signoretti, Sabina; Atkins, Michael; Carlson, Alexander; Weiss, Jonathan M; Mier, James; Panka, David; McDermott, David F; Sondel, Paul M

    2016-12-01

    NK cells play a role in many cancer immunotherapies. NK cell activity is tightly regulated by killer immunoglobulin-like receptor (KIR) and KIR-ligand interactions. Inhibitory KIR-ligands have been identified as HLA molecules, while activating KIR-ligands are largely unknown. Individuals that have not inherited the corresponding KIR-ligand for at least one inhibitory KIR gene are termed the "KIR-ligand missing" genotype, and they are thought to have a subset of NK cells that express inhibitory KIRs for which the corresponding KIR-ligand is missing on autologous tissue, and thus will not be inhibited through KIR-ligand recognition. In some settings where an anticancer immunotherapeutic effect is likely mediated by NK cells, individuals with a KIR-ligand missing genotype have shown improved clinical outcome compared to individuals with an "all KIR-ligands present" genotype. In addition, patients receiving hematopoietic stem cell transplants for leukemia may do better if their donor has more activating KIR genes (i.e., KIR haplotype-B). In a recent multi-institution clinical trial of patients with metastatic renal cell carcinoma receiving high-dose IL2 (HD-IL2), 25 % of patients showed a complete or partial tumor response to this therapy. We genotyped KIR and KIR-ligand genes for these patients (n = 107) and tested whether KIR/KIR-ligand genotypes correlated with patient clinical outcomes. In these analyses, we did not find any significant association of KIR/KIR-ligand genotype (either KIR-ligand missing or the presence of KIR haplotype-B) with patient outcome in response to the HD-IL2 therapy.

  1. 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

  2. Tumor targeting via integrin ligands

    Directory of Open Access Journals (Sweden)

    Udaya Kiran eMarelli

    2013-08-01

    Full Text Available Selective and targeted delivery of drugs to tumors is a major challenge for an effective cancer therapy and also to overcome the side effects associated with current treatments. Overexpression of various receptors on tumor cells is a characteristic structural and biochemical aspect of tumors and distinguishes them from physiologically normal cells. This abnormal feature is therefore suitable for selectively directing anticancer molecules to tumors by using ligands that can preferentially recognize such receptors. Several subtypes of integrin receptors that are crucial for cell adhesion, cell signaling, cell viability and motility have been shown to have an upregulated expression on cancer cells. Thus, ligands that recognize specific integrin subtypes represent excellent candidates to be conjugated to drugs or drug carrier systems and be targeted to tumors. In this regard, integrins recognizing the RGD cell adhesive sequence have been extensively targeted for tumor specific drug delivery. Here we review key recent examples on the presentation of RGD-based integrin ligands by means of distinct drug delivery systems, and discuss the prospects of such therapies to specifically target tumor cells.

  3. 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

  4. DETERMINATION OF A MAXIMUM NUMBER OF ARTIFICIAL INSEMINATIONS BY DONOR CHILDREN PER SPERM DONOR

    NARCIS (Netherlands)

    DEBOER, A; Oosterwijk, JC; RIGTERSARIS, CAE

    Objective: To determine a safe maximum number of artificial insemination (donor insemination [DI]) children per anonymous sperm donor. Design: Multiparameter calculation model of contribution of DI to inbreeding. Setting: Data of the collaborative DI centers and demographic population data of The

  5. The blood donor identity survey: a multidimensional measure of blood donor motivations.

    Science.gov (United States)

    France, Christopher R; Kowalsky, Jennifer M; France, Janis L; Himawan, Lina K; Kessler, Debra A; Shaz, Beth H

    2014-08-01

    Evidence indicates that donor identity is an important predictor of donation behavior; however, prior studies have relied on diverse, unidimensional measures with limited psychometric support. The goals of this study were to examine the application of self-determination theory to blood donor motivations and to develop and validate a related multidimensional measure of donor identity. Items were developed and administered electronically to a sample of New York Blood Center (NYBC) donors (n=582) and then to a sample of Ohio University students (n=1005). Following initial confirmatory factor analysis (CFA) on the NYBC sample to identify key items related to self-determination theory's six motivational factors, a revised survey was administered to the university sample to reexamine model fit and to assess survey reliability and validity. Consistent with self-determination theory, for both samples CFAs indicated that the best fit to the data was provided by a six-motivational-factor model, including amotivation, external regulation, introjected regulation, identified regulation, integrated regulation, and intrinsic regulation. The Blood Donor Identity Survey provides a psychometrically sound, multidimensional measure of donor motivations (ranging from unmotivated to donate to increasing levels of autonomous motivation to donate) that is suitable for nondonors as well as donors with varying levels of experience. Future research is needed to examine longitudinal changes in donor identity and its relationship to actual donation behavior. © 2014 AABB.

  6. Oocyte cryopreservation for donor egg banking.

    Science.gov (United States)

    Cobo, Ana; Remohí, José; Chang, Ching-Chien; Nagy, Zsolt Peter

    2011-09-01

    Oocyte donation is an efficient alternative to using own oocytes in IVF treatment for different indications. Unfortunately, 'traditional' (fresh) egg donations are challenged with inefficiency, difficulties of synchronization, very long waiting periods and lack of quarantine measures. Given the recent improvements in the efficiency of oocyte cryopreservation, it is reasonable to examine if egg donation through oocyte cryopreservation has merits. The objective of the current manuscript is to review existing literature on this topic and to report on the most recent outcomes from two established donor cryobank centres. Reports on egg donation using slow freezing are scarce and though results are encouraging, outcomes are not yet comparable to a fresh egg donation treatment. Vitrification on the other hand appears to provide high survival rates (90%) of donor oocytes and comparable fertilization, embryo development, implantation and pregnancy rates to traditional (fresh) egg donation. Besides the excellent outcomes, the ease of use for both donors and recipients, higher efficiency, lower cost and avoiding the problem of synchronization are all features associated with the benefit of a donor egg cryobank and makes it likely that this approach becomes the future standard of care. Oocyte donation is one of the last resorts in IVF treatment for couples challenged with infertility problems. However, traditional (fresh) egg donation, as it is performed today, is not very efficient, as typically all eggs from one donor are given to only one recipient, it is arduous as it requires an excellent synchronization between the donor and recipient and there are months or years of waiting time. Because of the development of an efficient oocyte cryopreservation technique, it is now possible to cryo-store donor (as well as non-donor) eggs, maintaining their viability and allowing their use whenever there is demand. Therefore, creating a donor oocyte cryobank would carry many advantages

  7. Donor type semiconductor at low temperature as maser active medium

    OpenAIRE

    Kornyushin, Yuri

    2007-01-01

    In some semiconductors donor impurity atoms can attract additional electrons, forming negative donor impurity ions. Thus we have 3 energy levels for electrons: zero energy levels at the bottom of the conductivity band, negative energy levels of the bounded electrons of the negative donor impurity ions, and deeper negative energy levels of the outer electrons of the neutral donor impurity atoms. So the donor impurity atoms could serve as active centres for a maser. The maximum achievable relat...

  8. Increasing the donor pool in Chile.

    Science.gov (United States)

    Palacios, J M

    1998-12-01

    The purpose of this study was to evaluate organ donation in Chile following the creation of the "Corporación Nacional de Fomento de Trasplantes." The corporation was created in 1991 as a private, nonprofit organization whose main purpose was to increase the number of actual donors and multiorgan procurement. The organization is independent of the national government and acts as a link between the needs of patients and society and those of the National Ministry of Health. Following the creation of the corporation, the number of actual donors increased from 32 to 98. The number of potential donors increased 3-fold. Family refusal for organ donation was between 28% and 53.4%. Pediatric and marginal donors increased from 2% to 15%. Ninety-five percent of the donors came from Santiago, where 33% of the population lives and most of the efforts were concentrated. The corporation is working to increase organ donation throughout the rest of the country by organizing public campaigns; promoting knowledge about transplantation among medical and nursing personnel at hospitals, schools, universities, and social gatherings; evaluating technical and financial results; and helping with the processes of organ procurement.

  9. [Is syphilis test necessary in blood donors?].

    Science.gov (United States)

    Rivera-López, María Rebeca F; Arenas-Esqueda, Alfonso; Ambriz-Fernández, Raúl

    2009-01-01

    A syphilis test is performed in blood donors because the national transfusion law makes it mandatory, nevertheless the blood has not been found as an important vehicle of transmission for Treponema pallidum infection. Our objective was to know the prevalence of syphilis in blood donors. we reviewed tests from blood donors of the "Banco Central de Sangre del Centro Médico Nacional Siglo XXI" in two periods, the first from July 2001 to April 2003, and the second from March 2005 to June 2006. Both groups went through screening tests, such as VDRL or USR. and a second test for confirmation, FTA-ABS for the first group and TPHA for the second group. in the first group 111 030 blood donors were included. In this group the positive results from VDRL or USR tests were 471 (0.42 %). One hundred and ninety six were confirmed (0.17 %) with FTA-ABS. In the second group results from 80 578 blood donors were included; the positive results from VDRL or USR tests were 279 (0.34 %). In this group, only 0.08 % were confirmed for a syphilis infection.

  10. Role of N-Donor Sterics on the Coordination Environment and Dimensionality of Uranyl Thiophenedicarboxylate Coordination Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Thangavelu, Sonia G. [Department; Butcher, Ray J. [Department; Cahill, Christopher L. [Department

    2015-06-09

    Thiophene 2,5-dicarboxylic acid (TDC) was reacted with uranyl acetate dihydrate and one (or none) of six N-donor chelating ligands (2,2'-bipyridine (BPY), 4,4'-dimethyl-2,2'-bipyridine (4-MeBPY), 5,5'-dimethyl-2,2'-bipyridine (5-MeBPY), 6,6'-dimethyl-2,2'-bipyridine (6-MeBPY), 4,4',6,6'-tetramethyl-2,2'-bipyridine (4,6-MeBPY), and tetrakis(2-pyridyl)pyrazine (TPPZ) to result in the crystallization of seven uranyl coordination polymers, which were characterized by their crystal structures and luminescence properties. The seven coordination polymers, Na2[(UO2)2(C6H2O4S)3]·4H2O (1), [(UO2)4(C6H2O4S)5(C10H8N2)2]·C10H10N2·3H2O (2), [(UO2)(C6H2O4S)(C12H12N3)] (3), [(UO2)(C6H2O4S)(C12H12N3)]·H2O (4), [(UO2)2(C6H2O4S)3]·(C12H14N2)·5H2O (5), [(UO2)3(CH3CO2)(C6H2O4S)4](C14H17N2)3·(C14H16N2)·H2O (6), and [(UO2)2(C6H2O4S)3](C24H18N6) (7), consist of either uranyl hexagonal bipyramidal or pentagonal bipyramidal coordination geometries. In all structures, structural variations in the local and global structures of 1–7 are influenced by the positions (or number) of methyl groups or pyridyl rings on the N-donor species, thus resulting in a wide diversity of structures ranging from single chains, double chains, or 2-D sheets. Direct coordination of N-donor ligands to uranyl centers is observed in the chain structures of 2–4 using BPY, 4-MeBPY, and 5-MeBPY, whereas the N-donor species participate as guests (as either neutral or charge balancing species) in the chain and sheet structures of 5–7 using 6-MeBPY, 4,6-MeBPY, and TPPZ, respectively. Compound 1 is the only structure that does not contain any N-donor ligands and thus crystallizes as a 2-D interpenetrating sheet. The luminescent properties of 1–7 are influenced by the direct coordination or noncoordination of N-donor species to uranyl centers. Compounds 2–4 exhibit typical UO22+ emission upon direct coordination of N-donors, but its absence is observed in 1

  11. Ex-vivo partial nephrectomy after living donor nephrectomy: Surgical technique for expanding kidney donor pool

    Directory of Open Access Journals (Sweden)

    Yaw A Nyame

    2017-01-01

    Full Text Available Renal transplantation has profound improvements in mortality, morbidity, and overall quality of life compared to renal replacement therapy. This report aims to illustrate the use of ex-vivo partial nephrectomy in a patient with a renal angiomyolipoma prior to living donor transplantation. The surgical outcomes of the donor nephrectomy and recipient transplantation are reported with 2 years of follow-up. Both the donor and recipient are healthy and without any significant comorbidities. In conclusion, urologic techniques such as partial nephrectomy can be used to expand the living donor pool in carefully selected and well informed transplant recipients. Our experience demonstrated a safe and positive outcome for both the recipient and donor, and is consistent with other reported outcomes in the literature.

  12. Blood donation and blood donor mortality after adjustment for a healthy donor effect

    DEFF Research Database (Denmark)

    Ullum, Henrik; Rostgaard, Klaus; Kamper-Jørgensen, Mads

    2015-01-01

    investigated the relation between blood donation frequency and mortality within a large cohort of blood donors. In addition, our analyses also took into consideration the effects of presumed health differences linked to donation behavior. STUDY DESIGN AND METHODS: Using the Scandinavian Donation......BACKGROUND: Studies have repeatedly demonstrated that blood donors experience lower mortality than the general population. While this may suggest a beneficial effect of blood donation, it may also reflect the selection of healthy persons into the donor population. To overcome this bias, we...... and Transfusion database (SCANDAT), we assessed the association between annual number of donations in 5-year windows and donor mortality by means of Poisson regression analysis. The analyses included adjustment for demographic characteristics and for an internal healthy donor effect, estimated among elderly...

  13. The Auckland experience with laparoscopic donor nephrectomy.

    Science.gov (United States)

    Muthu, Carl; McCall, John; Windsor, John; Harman, Richard; Dittmer, Ian; Smith, Pat; Munn, Stephen

    2003-07-25

    To examine the initial experience of laparoscopic donor nephrectomy (LDN) in New Zealand and compare it with open donor nephrectomy (ODN). All LDNs performed between June 2000 and June 2002 were reviewed. An equal number of ODNs were reviewed. Data were also collected on the recipients of the grafts. Key clinical data were prospectively collected; remaining data were collected by retrospectively reviewing patient charts. Auckland Hospital databases were accessed for costing analysis. Thirty five cases of each procedure had been performed. There has been 100% LDN graft survival. There was no significant difference in graft function (serum creatinine) at one and 12 months (p = 0.25 and 0.35) between the two groups. There was no significant difference in donor morbidity (26% vs 31%, p = 0.59). LDN resulted in a shorter hospital stay (3 vs 6.5 days, p disadvantage of LDN is its higher cost compared with ODN.

  14. Eye bank procedures: donor selection criteria.

    Science.gov (United States)

    Sousa, Sidney Júlio de Faria E; Sousa, Stella Barretto de Faria E

    2018-01-01

    Eye banks use sterile procedures to manipulate the eye, antiseptic measures for ocular surface decontamination, and rigorous criteria for donor selection to minimize the possibility of disease transmission due to corneal grafting. Donor selection focuses on analysis of medical records and specific post-mortem serological tests. To guide and standardize procedures, eye bank associations and government agencies provide lists of absolute and relative contraindications for use of the tissue based on donor health history. These lists are guardians of the Hippocratic principle "primum non nocere." However, each transplantation carries risk of transmission of potentially harmful agents to the recipient. The aim of the procedures is not to eliminate risk, but limit it to a reasonable level. The balance between safety and corneal availability needs to be maintained by exercising prudence without disproportionate rigor.

  15. Compensatory Hypertrophy After Living Donor Nephrectomy.

    Science.gov (United States)

    Chen, K W; Wu, M W F; Chen, Z; Tai, B C; Goh, Y S B; Lata, R; Vathsala, A; Tiong, H Y

    2016-04-01

    Previous studies have shown that kidney volume enhances the estimation of glomerular filtration rate (eGFR) in kidney donors. This study aimed to describe the phenomenon of compensatory hypertrophy after donor nephrectomy as measured on computerized tomographic (CT) scans. An institutional Domain Specific Review Board (DSRB)-approved study involved approaching kidney donors to have a follow up CT scan from 6 months to 1 year after surgery; 29 patients participated; 55% were female. Clinical chart review was performed, and the patient's remaining kidney volume was measured before and after surgery based on CT scans. eGFR was determined with the use of the Modification of Diet in Renal Disease equation. Mean parenchymal volume of the remaining kidney for this population (mean age, 44.3 ± 8.5 y) was 204.7 ± 82.5 cc before surgery and 250.5 ± 113.3 cc after donor nephrectomy. Compensatory hypertrophy occurred in 79.3% of patients (n = 23). Mean increase in remaining kidney volume was 22.4 ± 23.2% after donor nephrectomy in healthy individuals. Over a median follow-up of 52.9 ± 19.8 months, mean eGFR was 68.9 ± 12.4 mL/min/1.73 m(2), with 24.1% of patients (n = 7) in chronic kidney disease grade 3. Absolute and relative change in kidney volume was not associated with sex, race, surgical approach, or background of hypertension (P = NS). There was a trend of decreased hypertrophy with increasing age (P = .5; Spearman correlation, -0.12). In healthy kidney donors, compensatory hypertrophy of the remaining kidney occurs in 79.3% of the patients, with an average increment of about 22.4%. Older patients may have a blunted compensatory hypertrophy response after surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Initial experience with purely laparoscopic living-donor right hepatectomy.

    Science.gov (United States)

    Hong, S K; Lee, K W; Choi, Y; Kim, H S; Ahn, S W; Yoon, K C; Kim, H; Yi, N J; Suh, K S

    2018-03-26

    There may be concerns about purely laparoscopic donor right hepatectomy (PLDRH) compared with open donor right hepatectomy, especially when performed by surgeons accustomed to open surgery. This study aimed to describe technical tips and pitfalls in PLDRH. Data from donors who underwent PLDRH at Seoul National University Hospital between December 2015 and July 2017 were analysed retrospectively. Endpoints analysed included intraoperative events and postoperative complications. All operations were performed by a single surgeon with considerable experience in open living donor hepatectomy. A total of 26 donors underwent purely laparoscopic right hepatectomy in the study interval. No donor required transfusion during surgery, whereas two underwent reoperation. In two donors, the dissection plane at the right upper deep portion of the midplane was not correct. One donor experienced portal vein injury during caudate lobe transection, and one developed remnant left hepatic duct stenosis. One donor experienced remnant portal vein angulation owing to a different approach angle, and one experienced arterial damage associated with the use of a laparoscopic energy device. One donor had postoperative bleeding due to masking of potential bleeding foci owing to intra-abdominal pressure during laparoscopy. Two donors experienced right liver surface damage caused by a xiphoid trocar. Purely laparoscopic donor hepatectomy differs from open donor hepatectomy in terms of angle and caudal view. Therefore, surgeons experienced in open donor hepatectomy must gain adequate experience in laparoscopic liver surgery and make adjustments when performing PLDRH. © 2018 BJS Society Ltd Published by John Wiley & Sons Ltd.

  17. The effect of a protocol of aggressive donor management: Implications for the national organ donor shortage.

    Science.gov (United States)

    Salim, Ali; Martin, Matthew; Brown, Carlos; Rhee, Peter; Demetriades, Demetrios; Belzberg, Howard

    2006-08-01

    The disparity between the number of people awaiting organ transplantation and the number of organs available has become a public health crisis. As many as 25% of potential donors are lost as a result of cardiovascular collapse (CVC) before organ harvest. A policy of aggressive donor management (ADM) may decrease the number of cadaveric donors lost as a result of CVC. Retrospective analysis of potential brain-dead donors evaluated from January 1995 to December 2003 at nine American College of Surgeons-verified Level I trauma centers covered by a regional organ procurement agency. One center (Los Angeles County + University of Southern California Medical Center [LAC]) had an ADM protocol in place instituted January 1999; the remaining eight centers with no ADM protocol were grouped as Center A. The incidence of CVC and organ donation demographics were compared between centers and within LAC before (LAC-Pre) and after (LAC-Post) adoption of ADM. ADM consists of early identification of potential organ donors, a dedicated team that provides medical management, and aggressive fluid resuscitation as well as hormone replacement therapy with solumedrol and thyroxin. The incidence of CVC was significantly higher in LAC-Pre (odds ratio [OR] 15.0, p organs harvested per potential donor for LAC-Post (2.4) was significantly higher than LAC-Pre (2.0, p = 0.02) and Center A (2.1, p organs per potential donor.

  18. Peer-to-peer milk donors' and recipients' experiences and perceptions of donor milk banks.

    Science.gov (United States)

    Gribble, Karleen D

    2013-07-01

    To explore the intersection of peer-to-peer milk sharing and donor milk banks. A descriptive survey design containing closed and open-ended questions was used to examine women's perceptions of peer-to-peer milk sharing and milk banking. Closed-ended questions were analyzed using descriptive statistics and conventional qualitative content analysis was used to analyze open-ended responses. Participants were recruited via the Facebook sites of two online milk-sharing networks (Human Milk 4 Human Babies and Eats on Feet). Ninety-eight milk donors and 41 milk recipients who had donated or received breast milk in an arrangement that was facilitated via the Internet. One half of donor recipients could not donate to a milk bank because there were no banks local to them or they did not qualify as donors. Other respondents did not donate to a milk bank because they viewed the process as difficult, had philosophical objections to milk banking, or had a philosophical attraction to peer sharing. Most donor respondents felt it was important to know the circumstances of their milk recipients. No recipient respondents had obtained milk from a milk bank; it was recognized that they would not qualify for banked milk or that banked milk was cost prohibitive. Peer-to-peer milk donors and recipients may differ from milk bank donors and recipients in significant ways. Cooperation between milk banks and peer sharing networks could benefit both groups. © 2013 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  19. Comparison of donor, and early and late recipient outcomes following hand assisted and laparoscopic donor nephrectomy.

    Science.gov (United States)

    Lucas, Steven M; Liaw, Aron; Mhapsekar, Rishi; Yelfimov, Daniel; Goggins, William C; Powelson, John A; Png, Keng Siang; Sundaram, Chandru P

    2013-02-01

    While laparoscopic donor nephrectomy has encouraged living kidney donation, debate exists about the safest laparoscopic technique. We compared purely laparoscopic and hand assisted laparoscopic donor nephrectomies in terms of donor outcome, early graft function and long-term graft outcome. We reviewed the records of consecutive laparoscopic and hand assisted laparoscopic donor nephrectomies performed by a single surgeon from 2002 to 2011. Donor operative time and perioperative morbidity were compared. Early graft function for kidneys procured by each technique was evaluated by rates of delayed graft function, need for dialysis and recipient discharge creatinine. Long-term outcomes were evaluated by graft function. A total of 152 laparoscopic donor nephrectomies were compared with 116 hand assisted laparoscopic donor nephrectomies. Hand assisted procedures were more often done for the right kidney (41.1% vs 17.1%, p recipient outcomes were also similar. Delayed function occurred after 0% hand assisted vs 0.9% purely laparoscopic nephrectomies, dialysis was required in 0.9% vs 1.7% and rejection episodes developed in 9.7% vs 18.4% (p >0.05). At last followup the organ was nonfunctioning in 6.1% of hand assisted and 7.7% of purely laparoscopic cases (p >0.05). The recipient glomerular filtration rate at discharge home was similar in the 2 groups. Hand assisted laparoscopic donor nephrectomy had shorter warm ischemia time but perioperative donor morbidity and graft outcome were comparable. The choice of technique should be based on patient and surgeon preference. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. [Survey of blood donors on the topic of "reimbursement for blood donors"].

    Science.gov (United States)

    Zeiler, T; Kretschmer, V

    1995-02-01

    Remuneration for blood donors, in the way as presently handled by governmental and communal blood transfusion services in Germany, is not generally accepted. It is feared that donors are recruited with increased risk to transmit infectious diseases, especially AIDS. Alternative incentives are discussed. After the so-called AIDS scandal in Germany, a change in the donor motivation was to be expected, associated with an increased willingness to renounce remuneration. Therefore, we performed the present survey, in which we evaluated the donor's willingness to renounce remuneration, possibilities of cashless remuneration and other alternative incentives. During March and April 1994, a total of 1,157 blood donors of the University Blood Bank Marburg were questioned anonymously by a questionnaire in the framework of whole-blood donations. Beside the above-mentioned aspects demoscopic data were included (age, sex, profession, journey). Cutting of remuneration without any other compensation was refused by 86.1% of the donors, 77% would not want to further donate blood in this case. Transfer of money to a bank account instead of cash payment was accepted by 78.6%, the use of non-negotiable cheques by 68.7%. Alternative compensation by tickets for theater, concert, cinema or coupons for restaurants met with the approval of only 27.3%; under these circumstances, 36.9% would be willing to continue blood donation. With increasing age and number of donations, but largely independent of social status, donors attached greater importance to retention of remuneration. Cutting of remuneration would result in a considerable reduction of the willingness to donate blood within the population of donors of the governmental and communal blood transfusion services. However, an increase of virus safety of the blood products would not be reached in this way, since especially the long-term donors would be driven away. Considerable bottlenecks, particularly in the specific blood supply of

  1. Isolation of Uranyl Dicyanamide Complexes from N-Donor Ionic Liquids.

    Science.gov (United States)

    Kelley, Steven P; Rogers, Robin D

    2015-11-02

    An ionic liquid (IL) approach for soft-donor f-element chemistry has been demonstrated by the isolation of several new uranyl dicyanamide complexes through reactions of UO2(NO3)2·6H2O with dicyanamide ([N(CN)2](-))-containing ILs. The [N(CN)2](-) ions are able to rapidly substitute uranium's O-donor ligands, as evidenced by single-crystal X-ray diffraction studies on two anhydrous adducts of UO2(NO3)2 with [N(CN)2](-) ILs as well as by IR and NMR spectroscopic studies on solutions of UO2(NO3)2 in these ILs. By contrast, the slow reaction of UO2(OAc)2·2H2O with a nitrile-functionalized imidazolium dicyanamide IL in solvent and the reaction of UO2(NO3)2·6H2O with NaN(CN)2 at elevated temperature resulted in irreversible hydrolysis. The reaction of UO2SO4 with [N(CN)2](-) ions in an acidified aqueous solution resulted in the crystallization of a [UO2](2+) complex with biuret, a N(CN)2](-) hydrolysis product. [N(CN)2](-) ions in the form of ILs react rapidly with [UO2](2+) at room temperature, allowing ligand substitution with [N(CN)2](-) to out-compete the slower hydrolysis reaction, enabling the isolation of uranyl dicyanamide complexes and challenging assumptions regarding the affinity of uranium for O-donors.

  2. Reduction of Relapse after Unrelated Donor Stem Cell Transplantation by KIR-Based Graft Selection

    Science.gov (United States)

    Heidenreich, Silke; Kröger, Nicolaus

    2017-01-01

    Besides donor T cells, natural killer (NK) cells are considered to have a major role in preventing relapse after allogeneic hematopoietic stem cell transplantation (HSCT). After T-cell-depleted haploidentical HSCT, a strong NK alloreactivity has been described. These effects have been attributed to killer-cell immunoglobulin-like receptors (KIR). Abundant reports suggest a major role of KIR not only on outcome after haploidentical HSCT but also in the unrelated donor setting. In this review, we give a brief overview of the mechanism of NK cell activation, nomenclature of KIR haplotypes, human leukocyte antigen (HLA) groups, and distinct models for prediction of NK cell alloreactivity. It can be concluded that KIR-ligand mismatch seems to provoke adverse effects in unrelated donor HSCT with reduced overall survival and increased risk for high-grade acute graft-versus-host disease. The presence of activating KIR, as seen in KIR haplotype B, as well as the patient’s HLA C1/x haplotype might reduce relapse in myeloid malignancies. PMID:28228753

  3. Compliance with donor age recommendations in oocyte donor recruitment advertisements in the USA.

    Science.gov (United States)

    Alberta, Hillary B; Berry, Roberta M; Levine, Aaron D

    2013-04-01

    IVF using donated oocytes offers benefits to many infertile patients, yet the technique also raises a number of ethical concerns, including worries about potential physical and psychological risks to oocyte donors. In the USA, oversight of oocyte donation consists of a combination of federal and state regulations and self-regulatory guidelines promulgated by the American Society for Reproductive Medicine. This study assesses compliance with one of these self-regulatory guidelines - specifically, ASRM's preferred minimum age for donors of 21. To assess compliance, 539 oocyte donor recruitment advertisements from two recruitment channels (Craigslist and college newspapers) were collected and evaluated. Of these, 61% in the Craigslist dataset and 43% in the college newspaper dataset listed minimum ages between 18 and 20, which is inconsistent with ASRM's preferred minimum age recommendation of 21. Advertisements placed by oocyte donor recruitment agencies were more likely than advertisements placed by clinics to specify minimum ages between 18 and 20. These results indicate that ASRM should evaluate and consider revising its donor age guidelines. IVF using donated human eggs can help many patients who have difficulty having children. However, the technique also raises ethical concerns, including concerns about potential physical and psychological harms to egg donors. In the USA, oversight of egg donation relies on a combination of federal and state regulation and professional self-regulation. Governmental regulations address only limited aspects of egg donation, such as the potential spread of infectious diseases and the reporting of success rates, leaving voluntary guidelines developed by an association of medical professionals to address most issues, including ethical concerns raised by the practice. One of these voluntary guidelines recommends that egg donors should be at least 21 years of age. In this article, we analysed 539 egg donor recruitment advertisements

  4. Electrostatically defined silicon quantum dots with counted antimony donor implants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M., E-mail: msingh@sandia.gov; Luhman, D. R.; Lilly, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87175 (United States); Pacheco, J. L.; Perry, D.; Garratt, E.; Ten Eyck, G.; Bishop, N. C.; Wendt, J. R.; Manginell, R. P.; Dominguez, J.; Pluym, T.; Bielejec, E.; Carroll, M. S. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2016-02-08

    Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors in 100 nm × 150 nm windows straddling quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular Coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants.

  5. 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.

  6. Syntheses of donor-acceptor-functionalized dihydroazulenes

    DEFF Research Database (Denmark)

    Broman, Søren Lindbæk; Jevric, Martyn; Bond, Andrew

    2014-01-01

    The dihydroazulene (DHA)/vinylheptafulvene (VHF) photo/thermoswitch has been of interest for use in molecular electronics and advanced materials. The switching between the two isomers has previously been found to depend strongly on the presence of donor and acceptor groups. The fine-tuning of opt...

  7. Hyperpolarizability studies of some nonconjugated twin donor ...

    Indian Academy of Sciences (India)

    Administrator

    Nonlinear optics; oscillator strength; optical gap; polarizability. 1. Introduction. The design of materials with large ... strength and optical gaps of the twin donor acceptor sys- tems by varying the number of alkyl groups .... The microscopic first hyperpolarizability, β is a 3rd rank tensor, which has 27 tensor components.

  8. BLOOD DONOR HAEMATOLOGY PARAMETERS IN TWO ...

    African Journals Online (AJOL)

    hi-tech

    2005-03-03

    Mar 3, 2005 ... Objectives: To determine the status of blood donor haematology in two regional sites in Kenya and to assess the potential role of automated haematology in National blood bank process control. Design: A cross sectional descriptive study. Setting: Two regional blood banks - Nairobi and its environs (Blood ...

  9. Organ Donor Recognition: Practical and Ethical Considerations

    NARCIS (Netherlands)

    Y.J. de Groot (Yorick)

    2012-01-01

    textabstractThe brain dead patient is the ideal multiorgan donor. Conditions that can lead to the state of brain death are limited. A subarachnoid haemorrhage, intracerebral haemorrhage or traumatic brain injury precede in 83% of the cases the state of brain death. Because of better prevention and

  10. The Dutch Living Donor Kidney Exchange Program

    NARCIS (Netherlands)

    M. de Klerk (Marry)

    2010-01-01

    textabstractKidney transplantation is the optimal option for patients with an end-stage renal disease. The first successful transplantation with a living genetically related donor has been performed since 26 October 1954, when an identical twin transplant was performed in Boston. In the years that

  11. FORUM Paediatric living donor liver transplantation

    African Journals Online (AJOL)

    biliary anatomy. In general, children are well served by receiving a left lateral segment graft. Donor safety is the over-riding concern and has been excellent after left lateral segmentectomy, with a usually quoted .... Langnas AN, Marujo WC, Inagaki M, Stratta RJ, Wood RP, Shaw BW Jr. The results of reduced-size.

  12. Cancellous bone autografts: Donor sites, indications, techniques ...

    African Journals Online (AJOL)

    A prospective study of patients who had cancellous bone-graft was conducted to identify the indications and complications related to the techniques used in harvesting such grafts from the ilium, distal femur and proximal tibia. The commonest indication for cancellous bone graft was non-union. Donor site pain was the most ...

  13. Potential Pediatric Organ Donors After Cardiac Death.

    Science.gov (United States)

    Pregernig, A; Karam, O

    2016-10-01

    More than 50 people die each year on the Swiss transplant waiting list. To increase their organ donors pool, some centers have developed a post-cardiac death organ donation program. Information about its impact in the pediatric population is still scarce. The aim of this work was to determine the potential impact of a program of organ donation after cardiac in a pediatric population. This was a retrospective study of all children deceased from 2005 to 2014 in a tertiary pediatric and neonatal intensive care unit. The deceased were categorized as brain dead, deceased despite maximal resuscitation, deceased after withholding of care, and deceased after withdrawal of care. Potential organ donors were identified by the absence of medical contraindication and agonal time organ donors. A further 67 (35%) died despite maximal resuscitation, 31 (16%) after withholding of care, and 55 (29%) after withdrawal of care. Regarding the latter category, median agonal time was 16 minutes. Eighteen children could potentially have given ≥1 organ each. Development of organ donation after cardiac death in children could generate a 4-fold increase of the donor population. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Electron Donor Acceptor Interactions. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Ana L. [Arizona State Univ., Tempe, AZ (United States)

    2002-08-16

    The Gordon Research Conference (GRC) on Electron Donor Acceptor Interactions was held at Salve Regina University, Newport, Rhode Island, 8/11-16/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  15. Choosing the order of deceased donor and living donor kidney transplantation in pediatric recipients: a Markov decision process model.

    Science.gov (United States)

    Van Arendonk, Kyle J; Chow, Eric K H; James, Nathan T; Orandi, Babak J; Ellison, Trevor A; Smith, Jodi M; Colombani, Paul M; Segev, And Dorry L

    2015-02-01

    Most pediatric kidney transplant recipients eventually require retransplantation, and the most advantageous timing strategy regarding deceased and living donor transplantation in candidates with only 1 living donor remains unclear. A patient-oriented Markov decision process model was designed to compare, for a given patient with 1 living donor, living-donor-first followed if necessary by deceased donor retransplantation versus deceased-donor-first followed if necessary by living donor (if still able to donate) or deceased donor (if not) retransplantation. Based on Scientific Registry of Transplant Recipients data, the model was designed to account for waitlist, graft, and patient survival, sensitization, increased risk of graft failure seen during late adolescence, and differential deceased donor waiting times based on pediatric priority allocation policies. Based on national cohort data, the model was also designed to account for aging or disease development, leading to ineligibility of the living donor over time. Given a set of candidate and living donor characteristics, the Markov model provides the expected patient survival over a time horizon of 20 years. For the most highly sensitized patients (panel reactive antibody > 80%), a deceased-donor-first strategy was advantageous, but for all other patients (panel reactive antibody Markov model illustrates how patients, families, and providers can be provided information and predictions regarding the most advantageous use of deceased donor versus living donor transplantation for pediatric recipients.

  16. Ruthenium Cumulenylidene Complexes Bearing Heteroscorpionate Ligands

    OpenAIRE

    Strinitz, Frank

    2014-01-01

    In previous work of the BURZLAFF group, the design of suitable N,N,O ligands for a wide variety of applications ranging from catalysis to bioinorganic model compounds has been extensively investigated. Especially the methyl substituted bis(3,5-dimethylpyrazol-1-yl) acetate (bdmpza) ligand has shown manifold chemistry, comparable to the anionic cyclopentadienyl (Cp) and hydridotris(pyrazol-1-yl)borato (Tp) ligand. In the first part of this thesis the new tricarbonylmanganese(I) complexes be...

  17. 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

  18. Donor-derived aspergillosis from use of a solid organ recipient as a multiorgan donor.

    Science.gov (United States)

    Mueller, N J; Weisser, M; Fehr, T; Wüthrich, R P; Müllhaupt, B; Lehmann, R; Imhof, A; Aubert, J-D; Genoni, M; Kunz, R; Weber, M; Steiger, J

    2010-02-01

    The growing need for organs and the scarcity of donors has resulted in an increased use of extended criteria donors. We report a case where a recipient of a cardiac graft was used as an organ donor. Death of the recipient occurred 9 days after transplantation and was attributed to presumed cerebral hemorrhage, which post mortem was diagnosed as invasive aspergillosis of the brain. One recipient of a kidney transplant lost the graft due to infection with Aspergillus fumigatus, whereas prompt initiation of therapy successfully prevented disseminated aspergillosis in the other recipients. Despite the pressure to extend the use of organs by lowering the acceptance criteria, organs should only be accepted if the cause of death of the donors is unequivocally explained.

  19. Living donor hepatectomy in female donors with ongoing menstruation: Safety and ethical issues

    Directory of Open Access Journals (Sweden)

    Horng-Ren Yang

    2017-01-01

    Conclusions: Our study shows safety of right lobe living donation in female donors with ongoing menstruation with no increased risk of intraoperative excessive bleeding and postoperative physiological impact on their general health.

  20. Unusual coordination of the. cap alpha. -dioxime ligand in bis(camphorquinone dioximato)nickel(II)

    Energy Technology Data Exchange (ETDEWEB)

    Ma, M.S. (Iowa State Univ. Ames); Angelici, R.J.; Powell, D.; Jacobson, R.A.

    1978-10-25

    The complex was prepared by refluxing a methanol solution of Ni(NO/sub 3/)/sub 3/ . 6H/sub 2/O and dimethyl glyoximatic acid for 10m; refluxing for an additional 2h after the addition of sodium methoxide in methanol, filtering while warm, followed by evaporation of the solution under vacuum. X-ray diffraction study of a single crystal placed it in the orthorhombic space group P2,2,2, with a = 13.175(1), b = 13,652(2), c = 12.031(3)A; z = 4, and P/sub calcd./ = 1.378 g/cc. The nickel atom was found to be in an almost square-planar configuration. The HCQD/sup -/ ligand coordinates to the N via N and O donor atoms rather than the common N-N coordination characteristic of other ..cap alpha..-dioxime ligands. Bond lengths and bond angles are also included.

  1. Synthesis, physicochemical studies and biological evaluation of unimetallic and heterobimetallic complexes of hexadentate dihydrazone ligands

    Directory of Open Access Journals (Sweden)

    Fathy A. El Saied

    2017-03-01

    Full Text Available A new coordination unimetallic and heterobimetallic complexes of hexadentate N2O4 donor dihydrazone ligands were prepared by the condensation of 4-formyl antipyrine with adipic dihydrazide and succinic dihydrazide. The ligands (1 and (11 and their complexes thoroughly characterized using various analytical, physical and spectroscopic techniques, which indicate a distorted octahedral geometry around the metal ions. The ESR spectra of solid copper(II complexes (2–4 and (12–14 showed axial symmetry with g||>g⊥ > ge, indicating distorted octahedral structure and the presence of the unpaired electron in a d(x2−y2 orbital with significant covalent bond character. The antimicrobial activity results of the metal compounds (2–5, (7, (10, (12–15 and (17 show that, all these complexes exhibit inhibitory moderate to mild effects towards Bacillus subtilis, Escherichia coli and Aspergillus niger.

  2. Ligand additivity in the valence photoelectron spectroscopy of phosphine-substituted molybdenum carbonyls

    International Nuclear Information System (INIS)

    Bursten, B.E.; Darensbourg, D.J.; Kellogg, G.E.; Lichtenberger, D.L.

    1984-01-01

    The He I valence photoelectron spectra in the 6-9-eV ionization region are reported for seven phosphine-substituted molybdenum carbonyls. The observation of vibrational structure due to excitation of a CO stretching mode in several of the spectra aids band assignment. These data are used to test the validity of the model of ligand additivity for determining the energetics of the dπ electrons in octahedral d 6 complexes. It is shown that the model successfully correlates the positions, intensities, and number of the ionization bands for the molybdenum compounds. A comparison of the results for the complexes of different phosphine ligands indicates that the trimethyl (PMe 3 ), triethyl (PEt 3 ), and tri-n-butyl (P-n-Bu 3 ) phosphines are comparable π-acceptors, but that the sigma-donor strength increases as PMe 3 3 3

  3. Synthesis and characterization of 6,6'-bis(2-hydroxyphenyl)-2,2'-bipyridine ligand and its interaction with ct-DNA

    Science.gov (United States)

    Selamat, Norhidayah; Heng, Lee Yook; Hassan, Nurul Izzaty; Karim, Nurul Huda Abd

    2015-09-01

    The tetradentate ligand with four donor atoms OONN was synthesized. Bis(phenoxy)bipyridine ligand was prepared by Suzuki coupling reaction between 6,6'-dibromo-2,2'-bipyridyl and 2-hydroxyphenylboronic acid with presence of palladium (II) acetate. Bis(phenoxy)bipyridine ligand was also synthesized by demethylating of 6,6'-bis(2-methoxyphenyl)-2,2'-bipyridyl ligand through solvent free reaction using pyridine hydrocloride. The formation of both phenoxy and methoxy ligands was confirmed by 1H, 2D cosy and 13C NMR spectroscopy, ESI-MS spectrometry, FTIR spectroscopy. The purity of the ligand was confirmed by melting point. Binding studies of small molecules with DNA are useful to understand the reaction mechanism and to provide guidance for the application and design of new and more efficient drugs targeted to DNA. In this study, the binding interaction between the synthesized ligand with calf thymus-DNA (ct-DNA) has been investigated by UV/Vis DNA titration study. From the UV/Vis DNA study, it shows that bis(phenoxy)bipyridine ligand bind with ct-DNA via outside binding with binding contant Kb = 1.19 × 103 ± 0.08 M-1.

  4. Synthesis and characterization of 6,6’-bis(2-hydroxyphenyl)-2,2’-bipyridine ligand and its interaction with ct-DNA

    International Nuclear Information System (INIS)

    Selamat, Norhidayah; Heng, Lee Yook; Hassan, Nurul Izzaty; Karim, Nurul Huda Abd

    2015-01-01

    The tetradentate ligand with four donor atoms OONN was synthesized. Bis(phenoxy)bipyridine ligand was prepared by Suzuki coupling reaction between 6,6’-dibromo-2,2’-bipyridyl and 2-hydroxyphenylboronic acid with presence of palladium (II) acetate. Bis(phenoxy)bipyridine ligand was also synthesized by demethylating of 6,6’-bis(2-methoxyphenyl)-2,2’-bipyridyl ligand through solvent free reaction using pyridine hydrocloride. The formation of both phenoxy and methoxy ligands was confirmed by 1 H, 2D cosy and 13 C NMR spectroscopy, ESI-MS spectrometry, FTIR spectroscopy. The purity of the ligand was confirmed by melting point. Binding studies of small molecules with DNA are useful to understand the reaction mechanism and to provide guidance for the application and design of new and more efficient drugs targeted to DNA. In this study, the binding interaction between the synthesized ligand with calf thymus-DNA (ct-DNA) has been investigated by UV/Vis DNA titration study. From the UV/Vis DNA study, it shows that bis(phenoxy)bipyridine ligand bind with ct-DNA via outside binding with binding contant K b = 1.19 × 10 3 ± 0.08 M −1

  5. Synthesis and characterization of 6,6’-bis(2-hydroxyphenyl)-2,2’-bipyridine ligand and its interaction with ct-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Selamat, Norhidayah; Heng, Lee Yook; Hassan, Nurul Izzaty; Karim, Nurul Huda Abd [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43650 Bangi, Selangor (Malaysia)

    2015-09-25

    The tetradentate ligand with four donor atoms OONN was synthesized. Bis(phenoxy)bipyridine ligand was prepared by Suzuki coupling reaction between 6,6’-dibromo-2,2’-bipyridyl and 2-hydroxyphenylboronic acid with presence of palladium (II) acetate. Bis(phenoxy)bipyridine ligand was also synthesized by demethylating of 6,6’-bis(2-methoxyphenyl)-2,2’-bipyridyl ligand through solvent free reaction using pyridine hydrocloride. The formation of both phenoxy and methoxy ligands was confirmed by {sup 1}H, 2D cosy and {sup 13}C NMR spectroscopy, ESI-MS spectrometry, FTIR spectroscopy. The purity of the ligand was confirmed by melting point. Binding studies of small molecules with DNA are useful to understand the reaction mechanism and to provide guidance for the application and design of new and more efficient drugs targeted to DNA. In this study, the binding interaction between the synthesized ligand with calf thymus-DNA (ct-DNA) has been investigated by UV/Vis DNA titration study. From the UV/Vis DNA study, it shows that bis(phenoxy)bipyridine ligand bind with ct-DNA via outside binding with binding contant K{sub b} = 1.19 × 10{sup 3} ± 0.08 M{sup −1}.

  6. ِAnalysis of donor motivations in living donor liver transplantation

    Directory of Open Access Journals (Sweden)

    Hesham eAbdeldayem

    2014-07-01

    Full Text Available Objectives: The introduction of the living donor liver transplantation (LDLT in Egypt as in elsewhere, has raised important psychological conflicts and ethical questions. The objective of this study was to get better understanding of the potential donors’ motives towards LDLT.Methods:This study was conducted on consecutive 193 living –liver donors who underwent partial hepatectomy as donors for LDLT during the period between April 2003 and January 2013, at the National Liver Institute Menoufeyia University, Egypt. Potential donors were thoroughly evaluated preoperatively through a screening questionnaire and interviews as regard their demographic data, relationship to the potential recipient and motives towards proceeding to surgery. They were assured that the information shared between them and the transplant centre is confidential. Results.The donors’ mean age was 25.53± 6.39 years with a range of 18-45 years. Males represented 64.7 % and females were 35.3%. The most common donors (32.1%, n_62, were sons and daughters to their parents (sons: n_43, daughters: n_19 while parents to their offsprings represent 15% (mothers: n_21, fathers: n_8. Brothers and sisters represent 16.5 % (brothers: n_22, sisters: n_10. Nephews & nieces giving their uncles or aunts were 14%. The number of wives donating to their husbands was 11 (5.7%. Interestingly, there was no single husband who donated his wife. Among the remaining donors, there were 11 cousins & one uncle. Unrelated donors were 20 (10.4%. Several factors seemed to contribute to motivation for donation: the seriousness of the potential recipient condition, the relationship and personal history of the donor to the potential recipient, the religious beliefs, the trust in the health care system, and family dynamics and obligations.Conclusions. Absolute absence of coercion on the living-liver donor’s motives may not be realistic because of the serious condition of the potential recipient. It is

  7. Lung Transplantation From Donors After Previous Cardiac Surgery: Ideal Graft in Marginal Donor?

    Science.gov (United States)

    Palleschi, A; Mendogni, P; Tosi, D; Montoli, M; Carrinola, R; Mariolo, A V; Briganti, F; Nosotti, M

    2017-05-01

    Lung transplantation is a limited by donor pool shortage. Despite the efforts to extend the graft acceptability with recurrent donor criteria reformulations, previous cardiothoracic surgery is still considered a contraindication. A donor who underwent cardiac surgery could potentially provide an ideal lung but high intraoperative risks and intrinsic technical challenges are expected during the graft harvesting. The purpose of this study is to present our dedicated protocol and four clinical cases of successful lung procurements from donors who had a previous major cardiac surgery. One donor had ascending aortic root (AAR) substitution, another had mitral valve substitution, and two had coronary artery bypass surgery. The others' eligibility criteria for organ allocation, such as ABO compatibility, PaO 2 /FiO 2 ratio, absence of aspiration, or sepsis were respected. In one of the cases with previous coronary bypass grafting, the donor had a veno-arterial extracorporeal membrane oxygenation support. Consequently, the grafts required an ex vivo lung perfusion evaluation. We report the technical details of procurement and postoperative courses of recipients. All procurements were uneventful, without lung damage or waste of abdominal organs related to catastrophic intraoperative events. All recipients had a successful clinical outcome. We believe that successful transplantation is achievable even in a complicated setting, such as cases involving donors with previous cardiac surgery frequently are. Facing lung donor shortage, we strongly support any effort to avoid the loss of possible acceptable lungs. In particular, previous major cardiac surgery does not strictly imply a poor quality of lungs as well as unsustainable graft procurement. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Liver Transplantation With Older Donors: A Comparison With Younger Donors in a Context of Organ Shortage.

    Science.gov (United States)

    Barbier, Louise; Cesaretti, Manuela; Dondero, Federica; Cauchy, François; Khoy-Ear, Linda; Aoyagi, Takeshi; Weiss, Emmanuel; Roux, Olivier; Dokmak, Safi; Francoz, Claire; Paugam-Burtz, Catherine; Sepulveda, Ailton; Belghiti, Jacques; Durand, François; Soubrane, Olivier

    2016-11-01

    Older liver grafts have been considered in the past decade due to organ shortage. The aim was to compare outcomes after liver transplantation with either younger or older donors. Patients transplanted in our center between 2004 and 2014 with younger donors (younger than 60 years; n = 253) were compared with older donors (older than 75 years; n = 157). Multiorgan transplantations, split grafts, or non-heart-beating donors were not included. Donors in the older group were mostly women deceased from stroke, and only 3 patients had experienced cardiac arrest. Liver tests were significantly better in the older group than in the younger group. There was no difference regarding cold ischemia time, model for end-stage liver disease score, and steatosis. There was no significant difference regarding primary nonfunction and dysfunction, hepatic artery and biliary complications, and retransplantation rates. Graft survival was not different (65% and 64% in the older and younger groups, P = 0.692). Within the older group, hepatitis C infection, retransplantation, and emergency transplantation were associated with poor graft survival. Provided normal liver tests and the absence of cardiac arrest in donors, older liver grafts (>75 years) may be safely attributed to non-hepatitis C-infected recipients in the setting of a first and nonurgent transplantation.

  9. Computer Algorithms in the Search for Unrelated Stem Cell Donors

    Directory of Open Access Journals (Sweden)

    David Steiner

    2012-01-01

    Full Text Available Hematopoietic stem cell transplantation (HSCT is a medical procedure in the field of hematology and oncology, most often performed for patients with certain cancers of the blood or bone marrow. A lot of patients have no suitable HLA-matched donor within their family, so physicians must activate a “donor search process” by interacting with national and international donor registries who will search their databases for adult unrelated donors or cord blood units (CBU. Information and communication technologies play a key role in the donor search process in donor registries both nationally and internationaly. One of the major challenges for donor registry computer systems is the development of a reliable search algorithm. This work discusses the top-down design of such algorithms and current practice. Based on our experience with systems used by several stem cell donor registries, we highlight typical pitfalls in the implementation of an algorithm and underlying data structure.

  10. Insulin mimetic peroxo complexes of vanadium containing uracil or Cytosine as ligand.

    Science.gov (United States)

    Sarkar, A R; Mandal, S

    2000-01-01

    Mixed ligand oxo peroxo complexes of vanadium (V), M[VO(O(2))L(2)].nH(2)O where M = K or NH(4), HL = uracil or cytosine and n = 1 or 2, have been isolated from aqueous methanolic medium. The complexes were characterised by elemental analysis, conductance, TGA, UV-Visible, IR and NMR spectral studies. Both the peroxide and the other ligands acts as chelates coordinating through their oxygen at C (2) and nitrogen at N (3) and the presence of monomeric oxoperoxovanadium (V) species, have been established by IR, (1)H and (51)V NMR studies. The complexes appeared to possess pentagonal bipyramidal geometry. The terminal oxo ligand and the oxygen of the uracil or cytosine at C (2) occupy the axial position while the peroxide and the other donor ligands are in the equatorial position. The UV spectral studies confirm the presence of Vanadium in its +5 oxidation state. The administration of the potassium salts of the complexes reduces the blood glucose level in Swiss Albino mice compared to that of KVO(3). The complexes also readily oxidise cysteine to Cystine in aqueous solution. The possible mechanism for the insulin-mimic activity of the complexes is discussed.

  11. Thermodynamics of the complex formation between thorium(IV) and some polydentate ligands in aqueous solution

    International Nuclear Information System (INIS)

    Di Bernado, P.; Cassol, A.; Tomat, G.; Bismondo, A.; Magon, L.

    1983-01-01

    The changes in free energy, enthalpy, and entropy for the formation of thorium(IV)-oxydiacetate, -iminodiacetate, -thiodiacetate, and -succinate complexes have been determined by potentiometric and calorimetric titrations at 25 deg C in aqueous 1 mol dm - 3 sodium perchlorate. All the ligands form 1:1 chelate complexes with the thorium(IV) ion the stability of which is dependent on both the chelate ring dimensions and the nature of the donor group in the chain. The order of the relative stabilities (iminodiacetate > oxydiacetate > thiodiacetate > succinate) is mainly dependent on the reaction enthalpies, since the δS values are close to each other. In the thorium(IV)-oxydiacetate system the maximum number of three ligands for every metal ion was reached. Because of precipitation of solid compounds in the other systems, it was only possible to define complexes with a lower number of co-ordinated ligands: two for succinate and thiodiacetate, and one for iminodiacetate. Owing to the lower stability of the chelate ring of thiodiacetate and succinate complexes and the high basicity of the amino-group of iminodiacetate, these ligands form also unchelated protonated complexes. (author)

  12. Ligand-tailored single-site silica supported titanium catalysts: Synthesis, characterization and towards cyanosilylation reaction

    Science.gov (United States)

    Xu, Wei; Li, Yani; Yu, Bo; Yang, Jindou; Zhang, Ying; Chen, Xi; Zhang, Guofang; Gao, Ziwei

    2015-01-01

    A successive anchoring of Ti(NMe2)4, cyclopentadiene and a O-donor ligand, 1-hydroxyethylbenzene (PEA), 1,1‧-bi-2-naphthol (Binol) or 2,3-dihydroxybutanedioic acid diethyl ester (Tartrate), on silica was conducted by SOMC strategy in moderate conditions. The silica, monitored by in-situ Fourier transform infrared spectroscopy (in-situ FT-IR), was pretreated at different temperatures (200, 500 and 800 °C). The ligand tailored silica-supported titanium complexes were characterized by in-situ FT-IR, 13C CP MAS-NMR, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) and elemental analysis in detail, verifying that the surface titanium species are single sited. The catalytic activity of the ligand tailored single-site silica supported titanium complexes was evaluated by a cyanosilylation of benzaldehyde. The results showed that the catalytic activity is dependent strongly on the dehydroxylation temperatures of silica and the configuration of the ligands.

  13. Synthesis, Characterization and Biological Evaluation of Transition Metal Complexes Derived from N, S Bidentate Ligands

    Directory of Open Access Journals (Sweden)

    Enis Nadia Md Yusof

    2015-05-01

    Full Text Available Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC with 2-methoxybenzaldehyde (2MB and 3-methoxybenzaldehyde (3MB. The ligands were reacted separately with acetates of Cu(II, Ni(II and Zn(II yielding 1:2 (metal:ligand complexes. The metal complexes formed were expected to have a general formula of [M(NS2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1 and S2M3MBH (2 were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7 and estrogen receptor-negative (MDA-MB-231 breast cancer cell lines. Only the Cu(II complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II complexes have a strong DNA binding affinity.

  14. Trends in organ donor management: 2002 to 2012.

    Science.gov (United States)

    Callahan, Devon S; Kim, Dennis; Bricker, Scott; Neville, Angela; Putnam, Brant; Smith, Jennifer; Bongard, Frederic; Plurad, David

    2014-10-01

    Refinements in donor management have resulted in increased numbers and quality of grafts after neurologic death. We hypothesize that the increased use of hormone replacement therapy (HRT) has been accompanied by improved outcomes over time. Using the Organ Procurement and Transplant Network donor database, all brain-dead donors procured from July 1, 2001 to June 30, 2012 were studied. Hormone replacement therapy was identified by an infusion of thyroid hormone. An expanded criteria donor was defined as age 60 years or older. Incidence of HRT administration and number of donors and organs recovered were calculated. Using the Organ Procurement and Transplant Network thoracic recipient database transplant list, wait times were examined. There were 74,180 brain-dead donors studied. Hormone replacement therapy use increased substantially from 25.6% to 72.3% of donors. However, mean number of organs procured per donor remained static (3.51 to 3.50; p = 0.083), and the rate of high-yield donors decreased (46.4% to 43.1%; p donors decreased (42.1% to 33.9%; p donors (22.1% to 26%). Despite this, there has been an increase in the raw number of donors (20,558 to 24,308; p organs (5,857 to 6,945; p organs per traumatic brain injury donor (4.02 to 4.12; p = 0.002) and a decrease in days on the waiting list (462.2 to 170.4 days; p donors has been accompanied by increased organ availability overall. Potential mechanisms might include successful conversion of previously unacceptable donors and improved recovery in certain subsets of donors. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Macrocyclic ligands for uranium complexation

    Energy Technology Data Exchange (ETDEWEB)

    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{sup 0} chemistry, this procedure should make a variety of substituted 4-vinylpyridines available for the first time. 3 refs.

  16. 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

  17. Donors and archives a guidebook for successful programs

    CERN Document Server

    Purcell, Aaron D

    2015-01-01

    Donors and Archives: A Guidebook for Successful Programs highlights the importance of development and fundraising for archives, while focusing on the donor and potential donor. Their interest, their support, their enthusiasm, and their stuff are vital to the success of archival programs.

  18. Explaining differences between hospitals in number of organ donors

    NARCIS (Netherlands)

    Friele, R. D.; Coppen, R.; Marquet, R. L.; Gevers, J. K. M.

    2006-01-01

    The shortage of donor organs calls for a careful examination of all improvement options. In this study, 80 Dutch hospitals were compared. They provided 868 donors in a 5-year period, constituting 91% of all donors in that period in The Netherlands. Multilevel regression analysis was used to explain

  19. When disaster strikes: death of a living organ donor.

    Science.gov (United States)

    Ratner, L E; Sandoval, P R

    2010-12-01

    Donor safety is of paramount importance in living donor transplantation. Yet, living donor deaths occur. We believe that problems exist in our system of live donor transplantation that can be summarized in a series of simple statements: (1) Donor mortality can never be completely eliminated; (2) Live donor risk has not been mitigated so that it is as low as possible; (3) After a donor death, systematic reviews are not routinely performed to identify correctable causes; (4) The lessons learned from any donor death are not adequately communicated to other programs and (5) The administrative mechanisms and resources are not universally available at all transplant centers to implement lessons learned. To rectify these problems, we propose the following: (1) A national living donor death task force be established with the purpose of performing systematic reviews of any donor death. (2) Findings of these reviews be disseminated to all institutions performing live donor transplants on a secure, password-protected website. (3) A no-fault donor death indemnity fund be established to provide a financial imperative for institutions to cooperate with this external peer-review. These measures will serve the best interests of the involved institutions, the transplant community, and most importantly, the patients and their families.

  20. Viral Infectivity Markers in Donor Blood: A Retrospective Study of ...

    African Journals Online (AJOL)

    A total of 12,540 homologous donors seen between 1993 and 1999 at the University of Maiduguri Teaching Hospital (U.M.T.H) blood bank were analysed with respect to the frequency of viral infectivity markers (HBsAg and HIV antibodies) as it relates to donor categories. Fifteen percent and 4.07% of voluntary donors were ...

  1. 21 CFR 640.66 - Immunization of donors.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Immunization of donors. 640.66 Section 640.66 Food... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.66 Immunization of donors. If specific immunization of a donor is to be performed, the selection and scheduling of the injection of the...

  2. Noneligible Donors as a Strategy to Decrease the Organ Shortage.

    Science.gov (United States)

    Croome, K P; Lee, D D; Keaveny, A P; Taner, C B

    2017-06-01

    Organ procurement organization (OPO) performance is generally evaluated by the number of organ procurement procedures divided by the number of eligible deaths (donation after brain death [DBD] donors aged donation after cardiac death donors and DBD donors aged >70 years) is not tracked. The present study aimed to investigate the variability in the proportion of noneligible liver donors by the 58 donor service areas (DSAs). Patients undergoing liver transplant (LT) between 2011 and 2015 were obtained from the United Network for Organ Sharing Standard Transplant Analysis and Research file. LTs from noneligible and eligible donors were compared. The proportion of noneligible liver donors by DSA varied significantly, ranging from 0% to 19.6% of total liver grafts used. In transplant programs, the proportion of noneligible liver donors used ranged from 0% to 35.3%. On linear regression there was no correlation between match Model for End-Stage Liver Disease score for programs in a given DSA and proportion of noneligible donors used from the corresponding DSA (p = 0.14). Noneligible donors remain an underutilized resource in many OPOs. Policy changes to begin tracking noneligible donors and learning from OPOs that have high noneligible donor usage are potential strategies to increase awareness and pursuit of these organs. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

  3. Exploring the Mental Health of Living Kidney Donors

    NARCIS (Netherlands)

    L. Timmerman (Lotte)

    2015-01-01

    markdownabstractAbstract Living donor kidney transplantation is the best option for extending and improving the lives of patients with end-stage renal disease. The benefits for the donor are less straightforward: a donor is a healthy person who undergoes a surgery in the first place for the

  4. [Towards the development of living donor kidney transplantation].

    Science.gov (United States)

    Macher, Marie-Alice

    2016-12-01

    Living donor kidney transplantation has been increasing since 2008. Living donors represent a significant potential for organ transplants, in a context where the needs outstrip the availability of organs from deceased donors. However, patients are still poorly informed regarding the conditions in which these transplants are possible. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Prediction models for hemoglobin deferral in whole blood donors

    NARCIS (Netherlands)

    Baart, A.M.

    2013-01-01

    Each year, a relevant proportion of the invited blood donors is eventually deferred from donation because of low hemoglobin (Hb) levels. Deferrals are meant to protect donors from developing iron deficiency anemia after a blood donation, however, they may increase the risk of donor lapse, even

  6. Crosstalk between complement and Toll-like receptor activation in relation to donor brain death and renal ischemia-reperfusion injury.

    Science.gov (United States)

    Damman, Jeffrey; Daha, Mohamed R; van Son, Willem J; Leuvenink, Henri G; Ploeg, Rutger J; Seelen, Marc A

    2011-04-01

    Two central pathways of innate immunity, complement and Toll-like receptors (TLRs), play an important role in the pathogenesis of renal injury inherent to kidney transplantation. Recent findings indicate close crosstalk between complement and TLR signaling pathways. It is suggested that mitogen activated protein kinases (MAPKs) might be the key molecules linking both the complement and TLR pathways together. Complement and TLRs are important mediators of renal ischemia-reperfusion injury (IRI). Besides IRI, complement C3 can also be upregulated and activated in the kidney before transplantation as a direct result of brain death (BD) in the donor. This local upregulation and activation of complement in the donor kidney has been proven to be detrimental for renal allograft outcome. Also TLR4 and several of its major ligands are upregulated by donor BD compared to living donors. Important and in line with the observations above, kidney transplant recipients have a benefit when receiving a kidney from a TLR4 Asp299Gly/Thr399Ile genotypic donor. The role of complement and TLRs and crosstalk between these two innate immune systems in relation to renal injury during donor BD and ischemia-reperfusion are focus of this review. Future strategies to target complement and TLR activation in kidney transplantation are considered. ©2011 The Authors Journal compilation©2011 The American Society of Transplantation and the American Society of Transplant Surgeons.

  7. The next chapter in MOF pillaring strategies: Trigonal heterofunctional ligands to access targeted high-connected three dimensional nets, isoreticular platforms

    KAUST Repository

    Eubank, Jarrod F.

    2011-11-09

    A new pillaring strategy, based on a ligand-to-axial approach that combines the two previous common techniques, axial-to-axial and ligand-to-ligand, and permits design, access, and construction of higher dimensional MOFs, is introduced and validated. Trigonal heterofunctional ligands, in this case isophthalic acid cores functionalized at the 5-position with N-donor (e.g., pyridyl- or triazolyl-type) moieties, are designed and utilized to pillar pretargeted two-dimensional layers (supermolecular building layers, SBLs). These SBLs, based on edge transitive Kagomé and square lattices, are cross-linked into predicted three-dimensional MOFs with tunable large cavities, resulting in isoreticular platforms. © 2011 American Chemical Society.

  8. Ligand based pharmacophore modelling of anticancer histone ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... HDAC ligands (Chen et al., 2008b). The knowledge of common properties of the binding group is essential for the determination of the type of inhibitor binding the target. Major goal of modern drug design is identification and development of new ligands with high affinity of binding toward a given protein.

  9. Cofactor-Controlled Chirality of Tropoisomeric Ligand

    NARCIS (Netherlands)

    Théveau, L.; Bellini, R.; Dydio, P.; Szabo, Z.; van der Werf, A.; Sander, R.A.; Reek, J.N.H.; Moberg, C.

    2016-01-01

    A new tropos ligand with an integrated anion receptor receptor site has been prepared. Chiral carboxylate and phosphate anions that bind in the anion receptor unit proved capable of stabilizing chiral conformations of the achiral flexible bidentate biaryl phosphite ligand, as shown by variable

  10. Ligand modification for mono- and biphasic oxosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Haerter, P.; Herrmann, W.A.; Baskakov, D. [Technische Univ. Muenchen (Germany). Dept. Chemie

    2006-07-01

    The use of aqueous/organic biphasic systems has attracted huge interest in catalytic reactions by transition metal complexes. [1,2,3] The biphasic systems have benefits in catalyst separation and recycling, and the reduction or elimination of organic solvents is also advantageous for the development of economical and environmentally friendly processes. The key for such biphasic catalysis is the use of water soluble phosphines as ligands. Since the launch of the commercial propylene hydroformylation process by Ruhrchemie/Rhone-Poulenc, sulfonated ligands such as TPPTS (1), and BINAS (2) have been widely used as ligands in hydroformylation, hydrogenation and related reactions catalyzed by transition metals. One of the draw backs of ligands 1 and 2 are corrosive production conditions and therefore unfavorable costs. With the synthesis of aminoacid based trishydroxymethylphosphine derivatives (THMP-aminoacid) we introduce to our knowledge a new group of water soluble and cheap to produce ligands [8]. The properties of catalysts based on these compounds in the hydroformylation reaction of propene are discussed in comparison to normally used catalyst systems. In a second part the performance of catalysts containing NHC-ligands in the hydroformylation of 1-octene is discussed [9]. These investigations show, that the activity can be influenced by the electron donating ability of the NHC ligand. Sterical variations on the NHC ligands have no effect on the selectivity performance of the the catalysts. (orig.)

  11. Organometallic chemistry of chiral diphosphazane ligands ...

    Indian Academy of Sciences (India)

    Unknown

    organometallic chemistry of diphosphazane ligands with almost every transition metal in the periodic table is well documented1–3. A very attractive feature of diphosphazane ligands is that 'chirality' can be incorporated at the phosphorus centres as well as at the substituents attached to the nitrogen and the two phosphorus ...

  12. 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 exam...

  13. Diet and Asthma: Vitamins and Methyl Donors

    Science.gov (United States)

    Han, Yueh-Ying; Blatter, Josh; Brehm, John M.; Forno, Erick; Litonjua, Augusto A; Celedón, Juan C.

    2014-01-01

    SUMMARY Dietary changes may partly explain the high burden of asthma in industrialized nations. Experimental studies have motivated a significant number of observational studies of the relation between vitamins (A, C, D, and E) or nutrients acting as methyl donors (folate, vitamin B12, and choline) and asthma. Because observational studies are susceptible to several sources of bias, well-conducted randomized controlled trials (RCTs) remain the “gold standard” to determine whether a vitamin or nutrient has an effect on asthma. Evidence from observational studies and/or relatively few RCTs most strongly justify ongoing and future RCTs of: 1) vitamin D to prevent or treat asthma, 2) choline supplementation as adjuvant treatment for asthma, and 3) vitamin E to prevent the detrimental effects of air pollution in subjects with asthma. At this time, there is insufficient evidence to recommend supplementation with any vitamin or nutrient acting as a methyl donor to prevent or treat asthma. PMID:24461761

  14. South Korea as an emerging donor

    DEFF Research Database (Denmark)

    Chun, Hong-Min; Munyi, Elijah Nyaga; Lee, Heejin

    2010-01-01

    South Korea's official development assistance (ODA) has been increasing rapidly and will continue to do so. Korea is one of the few countries which have successfully transitioned from a recipient to a donor. It became a member of DAC (development assistance committee), OECD in November 2009. Korea......'s ODA policy, along with its growth in quantity, is at a crossroads for the enhancement of its quality. Discussions and debates are going on regarding the reforms in Korea's ODA activities, and this paper examines key issues raised. It first reviews the past and present of Korea's ODA, and identifies...... like the objective of ODA, positioning of Korea's ODA as an emerging donor and the nature of aid to North Korea. We also argue that a shift of ODA policy is required to promote reform, based on a thorough reflection on the role of ODA in the alleviation of poverty and promoting sustainable development...

  15. Biomimetic affinity ligands for protein purification.

    Science.gov (United States)

    Sousa, Isabel T; Taipa, M Angela

    2014-01-01

    The development of sophisticated molecular modeling software and new bioinformatic tools, as well as the emergence of data banks containing detailed information about a huge number of proteins, enabled the de novo intelligent design of synthetic affinity ligands. Such synthetic compounds can be tailored to mimic natural biological recognition motifs or to interact with key surface-exposed residues on target proteins and are designated as "biomimetic ligands." A well-established methodology for generating biomimetic or synthetic affinity ligands integrates rational design with combinatorial solid-phase synthesis and screening, using the triazine scaffold and analogues of amino acids side chains to create molecular diversity.Triazine-based synthetic ligands are nontoxic, low-cost, highly stable compounds that can replace advantageously natural biological ligands in the purification of proteins by affinity-based methodologies.

  16. External validation of the Donor Risk Index and the Eurotransplant Donor Risk Index on the French liver transplantation registry.

    Science.gov (United States)

    Winter, Audrey; Féray, Cyrille; Audureau, Etienne; Écochard, René; Jacquelinet, Christian; Roudot-Thoraval, Françoise; Duvoux, Christophe; Daurès, Jean-Pierre; Landais, Paul

    2017-08-01

    A major limitation to liver transplantation is organ shortage leading to the use of non-optimal liver grafts. The Donor Risk Index has been validated and recommended to select donors/organs. The Eurotransplant Donor Risk Index was derived from the Donor Risk Index. The objective of our study was to perform an external validation of both Donor Risk Index and Eurotransplant-Donor Risk Index against the French liver transplantation Cristal registry according to recommendations of the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis. Liver transplantations performed in France between 2009 and 2013 were used to perform the validation study for the Donor Risk Index and the Eurotransplant-Donor Risk Index respectively. We applied on the French data the models used to construct the Donor Risk Index and the Eurotransplant-Donor Risk Index respectively. Neither the Donor Risk Index nor the Eurotransplant-Donor Risk Index were validated against this dataset. Discrimination and calibration of these scores were not preserved according to our data. Important donor and candidates differences between our dataset and the Organ Procurement and Transplantation Network or the Eurotransplant datasets may explain why the Donor Risk Index and the Eurotransplant-Donor Risk Index appeared unadapted to the French transplant registry. Neither of these risk indexes were suitable to optimize the French liver allocation system. Thus, our next step will be to propose a general adaptive model for a Donor Risk Index. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Increasing the Supply of Kidneys for Transplantation by Making Living Donors the Preferred Source of Donor Kidneys

    OpenAIRE

    Testa, Giuliano; Siegler, Mark

    2014-01-01

    Abstract At the present time, increasing the use of living donors offers the best solution to the organ shortage problem. The clinical questions raised when the first living donor kidney transplant was performed, involving donor risk, informed consent, donor protection, and organ quality, have been largely answered. We strongly encourage a wider utilization of living donation and recommend that living donation, rather than deceased donation, become the first choice for kidney transplantation....

  18. Higher organ donation consent rates by relatives of potential uncontrolled donors versus potential controlled donors after death.

    Science.gov (United States)

    Wind, Jentina; van Mook, Walther N K A; Willems, Monique E C; van Heurn, L W Ernest

    2012-11-01

    Refusal to consent to organ donation is an important cause of the persisting gap between the number of potential organ donors and effectuated donors. In the Netherlands, organ donors include both uncontrolled donors: donors who die unexpectedly after cardiac death (DCD), after failed resuscitation and donors in whom death can be expected and donors after brain death, and controlled DCD donors: those who die after the withdrawal of treatment. Different donor type implies a different setting in which relatives are requested to consent to organ donation. It is unknown whether the setting influences the eventual decision for donation or not. Therefore, we compared the consent rate in potential donors who died unexpectedly (UD group) and in whom death was expected. A total of 523 potential organ donors between 2003 and 2011 in the 715-bed Maastricht University Medical Centre, the Netherlands were included. Both the patients' registration in the national donor register (DR) and the relatives' refusal rate in the two groups were retrospectively assessed using data from the donation application database. There were 109 unexpected and 414 expected potential donors The potential donors in the UD group were younger (mean age 52 versus 55 years, P = 0.032) and more often male (68 versus 52%, P = 0.003). There were no significant differences in registration in the DR between the groups. The relatives' consent rate in non-registered potential donors, or those who mandated the relatives for that decision, was higher in the UD group (53 versus 29%, P organ donation. The relatives of potential donors who died unexpectedly consented more often to donation than those in whom death was expected.

  19. Cardiovascular and demographic characteristics in whole blood and plasma donors: results from the Donor InSight study.

    Science.gov (United States)

    Atsma, Femke; Veldhuizen, Ingrid; de Vegt, Femmie; Doggen, Carine; de Kort, Wim

    2011-02-01

    Within blood establishments little comparative information is available about donors versus the general population. In this study, a description of the donor pool was made in terms of demographic factors and cardiovascular risk factors. The general Dutch population was used as a reference group. The Donor InSight study provided information on donors. Extensive information has been gathered by a self-administered questionnaire addressing various topics, like demographics, lifestyle, and health. Aggregated donor responses were compared with general population summary data. The study population consisted of 15,076 donors. The median age was 46.3 years and 47.3% were men. Donors were more likely to be highly educated (34.6%), married (71.7%), and of Dutch origin (97.4%), when compared to the general population. Donors were less often smokers (donors, 17.1%; general population, 31.8%), more often moderate drinkers (donors, 82.8%; general population, 74.7%), and physically more active (donors, 2.0 hr/week; general population, 1.0 hr/week). Male donors were more often moderately overweight (47.7%) than men from the general population (39.9%). In donors, 0.9% reported to have Type 2 diabetes versus 1.9% in the general population. In donors, 3.4% reported high cholesterol versus 4.6% in the general population. The study provided important knowledge about demographic distributions and cardiovascular risk factors within donors. A proper understanding of demographic characteristics of donors will help us to focus recruitment and retention strategies. The reported beneficial cardiovascular profile suggests a need for further research on the role of blood donation in cardiovascular risk reduction. © 2010 American Association of Blood Banks.

  20. Hemochromatosis Patients as Voluntary Blood Donors

    Directory of Open Access Journals (Sweden)

    Tara E Power

    2004-01-01

    Full Text Available The present study was designed to investigate hemochromatosis patients' suitability as blood donors as well as their perceptions and experience with the current public donation system. Participants were gathered from a list of current hemochromatosis patients (n=120 and members of the Canadian Hemochromatosis Society (n=1000. Of the 1120 surveys mailed out to these groups, 801 surveys were returned completed. The sample respondents had a mean age of 57.44 years (SD=12.73; range 19 to 87 years, and 57% were men. It was found that 20% (160 of the respondents have donated blood since their diagnosis; however, only 12% of the respondents indicated that they use voluntary blood donation as a means of maintaining their iron levels. Forty per cent of the respondents indicated that they had been refused from voluntary donation. Despite the fact that in May 2001 the Canadian Blood Services, in collaboration with the Canadian Hemochromatosis Society, began a promotion campaign to encourage hemochromatosis patients to become voluntary blood donors, the present study found that 15% of the respondents reported having been refused from the voluntary blood donation service due to the diagnosis of hemochromatosis. With respect to quality of life, it was found that individuals who donate blood were generally healthier with respect to physical functioning and bodily pain, however, these findings may indicate that hemochromatosis patients who are healthier are better able to donate at public blood banks, rather than that voluntary blood donation has an effect on the donors' physical functioning over phlebotomy clinic users. These study findings suggest that although there may be other medical factors limiting individuals from donating, hemochromatosis patients are interested in being voluntary blood donors and this potential resource is currently under-used.

  1. The effect of World Blood Donor Day on digital information seeking and donor recruitment.

    Science.gov (United States)

    Kranenburg, Floris J; Kreuger, Aukje L; Arbous, M Sesmu; Laeijendecker, Daphne; van Kraaij, Marian G J

    2017-10-01

    The purpose of World Blood Donor Day (WBDD) is to raise awareness for the importance of blood donation. The aim of this study was to quantify the impact of WBDD on digital information seeking and donor recruitment. Google Trends data were used to quantify seeking behavior on "blood donation" and "blood donor." Differences in relative search volume (RSV) between the 3 weeks surrounding WBDD and the rest of the year were calculated. Second, mean differences in RSV were compared to assess the additional effect of hosting using translated search terms. Third, we compared the period around WBDD with the control period regarding page views of the Sanquin website and Facebook likes and number of newly registered donors in 2016. The mean RSV for "blood donation" in the period of interest was 78.6, compared to 72.1 in the control period (difference, 6.5; 95% confidence interval [95% CI], 1.2-11.8). For "blood donor" this was 78.9 compared to 65.9 (difference, 12.9; 95% CI, 8.1-17.8). We found no additional effect of hosting. In the period of interest, the website of Sanquin was visited 6862 times a day and 4293 times in the control period (difference, 2569; 95% CI, 1687-3451). In June 2016, 54.6% (95% CI, 53.0-56.2) more new donors were registered compared to the control period. An international campaign like WBDD raises the awareness of blood donation and is effective in convincing people to register as blood donors. © 2017 AABB.

  2. Donor conversion and procurement failure: the fate of our potential organ donors.

    Science.gov (United States)

    Branco, Bernardino C; Inaba, Kenji; Lam, Lydia; Salim, Ali; Barmparas, Galinos; Teixeira, Pedro G R; Talving, Peep; Demetriades, Demetrios

    2011-02-01

    Donor availability remains the primary limiting factor for organ transplantation today. The purpose of this study was to examine the causes of procurement failure amongst potential organ donors. After Institutional Review Board approval, all surgical intensive care unit (SICU) patients admitted to the LAC+USC Medical Center from 01/2006 to 12/2008 who became potential organ donors were identified. Demographics, clinical data, and procurement data were abstracted. In non-donors, the causes of procurement failure were documented. During the 3-year study period, a total of 254 patients were evaluated for organ donation. Mean age was 44.8±18.7 years; 191 (75.2%) were male, 136 (53.5%) were Hispanic, and 148 (58.3%) were trauma patients. Of the 254 patients, 116 (45.7%) were not eligible for donation: 34 had multi-system organ failure, 24 did not progress to brain death and had support withdrawn, 18 had uncontrolled sepsis, 15 had malignancy, 6 had human immunodeficiency virus or hepatitis B or C, and 19 patients had other contraindications to organ donation. Of the remaining 138 eligible patients, 83 (60.2%) did not donate: 56 because the family denied consent, 9 by their own choice. In six, next of kin could not be located, five died because of hemodynamic instability before organ procurement was possible, four had organs that could not be placed, and three had their organs declined by the organ procurement organization. The overall consent rate was 57.5% (n=67). From the 55 donors, 255 organs were procured (yield 4.6 organs/donor). Of all patients screened for organ donation, only a fifth actually donated. Denial of consent was the major potentially preventable cause of procurement failure, whereas hemodynamic instability accounted for only a small percentage of donor losses. With such low conversion rates, the preventable causes of procurement failure warrant further study.

  3. Uterus retrieval process from brain dead donors.

    Science.gov (United States)

    Gauthier, Tristan; Piver, Pascal; Pichon, Nicolas; Bibes, Romain; Guillaudeau, Angelique; Piccardo, Alessandro; Pesteil, Francis; Tricard, Jeremy; Gardet, Emmanuel; Laskar, Marc; Lalloué, Fabrice; Marquet, Pierre; Aubard, Yves

    2014-08-01

    To describe the feasibility of human uterus retrieval after donation after brain death. Single-center, prospective study. University hospital. Female brain dead donors. The families of female brain dead donors were informed about consent to uterus donation. A specific organ retrieval procedure was performed. At the end of the procedure the uterus was removed together with the hypogastric vessels, parametria, and vaginal fornix. The tolerance of the uterus to cold ischemia was evaluated with histology and TUNEL reaction up to 24 hours. Rate of uterus donation refusal. Between August 1, 2012 and July 31, 2013, seven uteri were retrieved from 14 female multiorgan donors. No refusal to uterus donation occurred. Our surgical protocol did not interfere with vital organ retrieval and was readily accepted by the other transplantation teams. The hypogastric vessels could be preserved in all cases but for one vein loss in the first retrieval. Histology studies did not find major morphologic changes after 24 hours of cold ischemia. Apoptosis was rare. Uterus retrieval could be part of a reproducible multiorgan procurement procedure. Uterus donation seems readily accepted. This preliminary study is a necessary step before any transplantation project. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Donor Tissue Preparation for Bowman Layer Transplantation.

    Science.gov (United States)

    Groeneveld-van Beek, Esther A; Parker, Jack; Lie, Jessica T; Bourgonje, Vincent; Ham, Lisanne; van Dijk, Korine; van der Wees, Jacqueline; Melles, Gerrit R J

    2016-12-01

    To describe and compare 2 preparation techniques for Bowman layer (BL) grafts for use in BL transplantation. A retrospective evaluation of the 2 methods for preparing BL grafts was performed, that is, BL graft preparation from donor globes not eligible for penetrating keratoplasty or endothelial keratoplasty (technique I, n = 36) and BL graft preparation from previously excised corneoscleral buttons (technique II, n = 36) that could not be used for PK or had been denuded of Descemet membrane and endothelium for Descemet membrane endothelial keratoplasty graft preparation. BL graft preparation difficulties were recorded, and the preparation failure rate was examined and compared between the techniques. Overall, BL graft preparation was successful in 51 cases (51/72; 70.8%), of which 25 preparations were successful using technique I, and 26 using technique II, representing a success rate of 69.4% (25/36) and 72.2% (26/36) for techniques I and II, respectively. Reasons for discarding a BL graft were tearing of the BL tissue during the preparation (n = 19) and stroma attached to the graft (n = 2). Isolated BL grafts can be prepared from both whole donor globes and corneoscleral rims with equivalent success. Preparation from corneoscleral rims may offer the advantage that, from one donor cornea, the posterior layers can be used for Descemet membrane endothelial keratoplasty graft preparation and the anterior part for BL graft preparation.

  5. Donor human milk for preterm infants.

    Science.gov (United States)

    Wight, N E

    2001-06-01

    As survival rates for preterm infants improve, more attention is being focused on improving the quality of survival through optimal nutritional management. The benefits of human milk for term infants are well recognized, with current research suggesting that human milk may especially benefit the preterm infant. Some mothers are unable or unwilling to provide breastmilk for their infants. Although not as well studied as mother's own milk, pasteurized donor human milk can provide many of the components and benefits of human milk while eliminating the risk of transmission of infectious agents. Pasteurization does affect some of the nutritional and immunologic components of human milk, but many immunoglobulins, enzymes, hormones, and growth factors are unchanged or minimally decreased. In California donor human milk costs approximately $3.00 per ounce to purchase. A reduction in length of stay, necrotizing enterocolitis and sepsis may result in a relative saving of approximately $11 to the NICU or healthcare plan for each $1 spent for pasteurized donor milk.

  6. Higher refusal rates for organ donation among older potential donors in the Netherlands: impact of the donor register and relatives.

    NARCIS (Netherlands)

    Leiden, H.A. van; Jansen, N.E.; Haase-Kromwijk, B.J.; Hoitsma, A.J.

    2010-01-01

    BACKGROUND: The availability of donor organs is considerably reduced by relatives refusing donation after death. There is no previous large-scale evaluation of the influence of the Donor Register (DR) consultation and the potential donor's age on this refusal in The Netherlands. METHODS: This study

  7. The effect of the central donor in bis(benzimidazole)-based cobalt catalysts for the selective cis-1,4-polymerisation of butadiene.

    Science.gov (United States)

    Cariou, Renan; Chirinos, Juan J; Gibson, Vernon C; Jacobsen, Grant; Tomov, Atanas K; Britovsek, George J P; White, Andrew J P

    2010-10-14

    A series of bis(benzimidazole)-based cobalt(II) dichloride complexes containing a range of different central donors has been synthesized and characterized. The nature of the central donor affects the binding of the ligand to the cobalt centre and determines the coordination geometry of the metal complexes. All complexes have been shown to catalyse the polymerization of butadiene, in combination with MAO as the co-catalyst, to give cis-1,4-polybutadiene with high selectivity. The nature of the central donor has a marked influence on the polymerization activity of the catalysts, but does not affect the polymer microstructure. The addition of PPh(3) generally increases the polymerization activity of these cobalt catalysts and results in predominantly (60-70%) 1,2-vinyl-polybutadiene.

  8. Ruthenium-based olefin metathesis catalysts bearing pH-responsive ligands: External control of catalyst solubility and activity

    Science.gov (United States)

    Balof, Shawna Lynn

    2011-12-01

    Sixteen novel, Ru-based olefin metathesis catalysts bearing pH responsive ligands were synthesized. The pH-responsive groups employed with these catalysts included dimethylamino (NMe2) modified NHC ligands as well as N-donor dimethylaminopyridine (DMAP) and 3-(o-pyridyl)propylidene ligands. These pH-responsive ligands provided the means by which the solubility and/or activity profiles of the catalysts produced could be controlled via acid addition. The main goal of this dissertation was to design catalyst systems capable of performing ring opening metathesis (ROMP) and ring closing metathesis (RCM) reactions in both organic and aqueous media. In an effort to quickly gain access to new catalyst structures, a template synthesis for functionalized NHC ligand precursors was designed, in addition to other strategies, to obtain ligand precursors with ancillary NMe2 groups. Kinetic studies for the catalysts produced from these precursors showed external control of catalyst solubility was afforded via protonation of the NMe2 groups of their NHC ligands. Additionally, this protonation afforded external control of catalyst propagation rates for several catalysts. This is the first known independent external control for the propagation rates of ROMP catalysts. The incorporation of pH-responsive N-donor ligands into catalyst structures also provided the means for the external control of metathesis activity, as the protonation of these ligands resulted in an increased initiation rate based on their fast and irreversible dissociation from the metal center. The enhanced external control makes these catalysts applicable to a wide range of applications, some of which have been explored by us and/or through collaboration. Three of the catalysts designed showed remarkable metathesis activity in aqueous media. These catalysts displayed comparable RCM activity in aqueous media to a class of water-soluble catalysts reported by Grubbs et al., considered to be the most active catalyst for

  9. Spin noise spectroscopy on donors in GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Bernien, Hannes; Mueller, Georg; Roemer, Michael; Huebner, Jens; Oestreich, Michael [Institute for Solid State Physics, Gottfried Wilhelm Leibniz University Hannover (Germany)

    2009-07-01

    In recent experiments spin noise spectroscopy (SNS) has proven to be a very sensitive technique to study electron spin dynamics in semiconductors at thermal equilibrium. Here we present SNS-measurements on donor bound electrons in very low doped bulk GaAs. In this environment the donors do not interact with each other and form artificial atoms. We discuss the detection of single donor bound electron spins, which should have extremely long spin relaxation times compared to ensemble spin relaxation times. In further experiments the electron bound to the donor will be used to probe and study the local nuclear magnetic field at the donor site.

  10. Decay time shortening of fluorescence from donor-acceptor pair proteins using ultrafast time-resolved fluorescence resonance energy transfer spectroscopy

    International Nuclear Information System (INIS)

    Baba, Motoyoshi; Suzuki, Masayuki; Ganeev, Rashid A.; Kuroda, Hiroto; Ozaki, Tsuneyuki; Hamakubo, Takao; Masuda, Kazuyuki; Hayashi, Masahiro; Sakihama, Toshiko; Kodama, Tatsuhiko; Kozasa, Tohru

    2007-01-01

    We improved an ultrafast time-resolved fluorescence resonance energy transfer (FRET) spectroscopy system and measured directly the decrease in the fluorescence decay time of the FRET signal, without any entanglement of components in the picosecond time scale from the donor-acceptor protein pairs (such as cameleon protein for calcium ion indicator, and ligand-activated GRIN-Go proteins pair). The drastic decrease in lifetime of the donor protein fluorescence under the FRET condition (e.g. a 47.8% decrease for a GRIN-Go protein pair) proves the deformation dynamics between donor and acceptor fluorescent proteins in an activated state of a mixed donor-acceptor protein pair. This study is the first clear evidence of physical contact of the GRIN-Go proteins pair using time-resolved FRET system. G protein-coupled receptors (GPCRs) are the most important protein family for the recognition of many chemical substances at the cell surface. They are the targets of many drugs. Simultaneously, we were able to observe the time-resolved spectra of luminous proteins at the initial stage under the FRET condition, within 10 ns from excitation. This new FRET system allows us to trace the dynamics of the interaction between proteins at the ligand-induced activated state, molecular structure change and combination or dissociation. It will be a key technology for the development of protein chip technology

  11. The donor advocacy team: a risk management program for living organ, tissue, and cell transplant donors.

    Science.gov (United States)

    Eguchi, Susumu; Soyama, Akihiko; Nagai, Kazuhiro; Miyazaki, Yasushi; Kurihara, Shintaro; Hidaka, Masaaki; Ono, Shinichiro; Adachi, Tomohiko; Natsuda, Koji; Hara, Takanobu; Fujita, Fumihiko; Kanetaka, Kengo; Takatsuki, Mistuhisa

    2017-08-01

    Although the incidence of living donor death is low in Japan, statistics show one living liver donor death in more than 7000 living liver transplants. Thus, medical transplant personnel must recognize that the death of a living organ or tissue transplant donor can occur and develop an appropriate risk management program. We describe how Nagasaki University Hospital established and implemented a Donor Advocacy Team (DAT) program: a risk management program for initiation in the event of serious, persistent, or fatal impairment of an organ, tissue, or cell transplantation from a living donor. The purposes of the DAT program are as follows: 1. To disclose official information without delay. 2. To provide physical and psychological care to the patient experiencing impairment and their family. 3. To provide psychological care to the medical staff in charge of the transplant. 4. To standardize the responses of the diagnosis and treatment department staff and other hospital staff. 5. To minimize the damage that the whole medical transplantation system may suffer and leverage the occurrence for improvement. To address (1) and (5), actions, such as reporting and responses to the government, mass media, transplant-related societies, and organ transplant networks, have been established to ensure implementation.

  12. Substantial increase in cadaveric organ donors in hospitals implementing the donor action program in Finland.

    Science.gov (United States)

    Höckerstedt, K; Heikkiläl, M-L; Holmberg, C

    2005-10-01

    The results of solid organ transplantation have improved during the last decade. Five-year patient survivals over 80% and graft survivals over 70% are common in many transplant centers. Also, quality-of-life assessments show that not only adults but even small children have a good quality of life after successful organ transplantation. Furthermore, transplantation programs have proved to be cost-effective. However, the organ shortage is a worldwide problem, which has in many countries led to prolonged waiting times, deaths on the waiting list, increased living related donations, acceptance of lower-quality organs, and in some instances even commercialization of the organ supply. Thus, it is extremely important to find strategies that increase the number of cadaveric organs for donation. In Finland organ transplantation is concentrated in one center with about 250 transplantations of different organs performed annually. The number of patients needing a new cadaveric organ is steadily increasing, but the number of donors has remained the same during the last decade. To improve cadaveric organ procurement the Donor Action (DA) program, which consists of a Hospital Attitude Survey and a medical records review performed by the donor hospital, has proved to increase the number of cadaveric donors. We introduced the DA program in Finland in 2000. Here in we report the results of this program in terms of its impact on the availability of cadaveric donors.

  13. Laparoscopic donor nephrectomy: effect of perirenal fat upon donor operative time.

    Science.gov (United States)

    Anderson, Kirk M; Lindler, Tekisha U; Lamberton, Gregory R; Baron, Pedro W; Ojogho, Okechukwu K; Baldwin, D Duane

    2008-10-01

    Previous attempts to correlate preoperative patient characteristics with operative complexity and operative time prior to laparoscopic donor nephrectomy have found few consistent relationships. The purpose of this study is to determine the effect of abdominal and perirenal fat measured with preoperative computerized tomography (CT) upon subsequent operative time and complexity during hand-assisted laparoscopic donor nephrectomy. A retrospective chart, database, and CT angiogram review was conducted on 103 consecutive patients who underwent a hand-assisted laparoscopic donor nephrectomy. Perirenal fat and abdominal wall fat were correlated with a variety of parameters including operative time. Univariate and multivariate regression analysis was performed and p valuesfat measurements, or spleno-renal distance. There was a significant positive correlation between operative time and anterior perirenal fat (r=0.28, p=0.005), posterior perirenal fat (r=0.20, p=0.05), and donor CPK levels (r=0.53, pperirenal fat, while women had greater abdominal fat. A multivariate model including anterior perirenal fat measurement accounted for 20% of the variance in operative time. This is the first study to demonstrate that increased perirenal fat increases operative complexity as measured by operative time. This information may potentially be used to help predict operative complexity based upon measurable preoperative variables and help improve operating room efficiency and donor and recipient outcomes.

  14. Anonymous living liver donation: donor profiles and outcomes.

    Science.gov (United States)

    Reichman, T W; Fox, A; Adcock, L; Wright, L; Abbey, S E; Levy, G; Grant, D R

    2010-09-01

    There are no published series of the assessment process, profiles and outcomes of anonymous, directed or nondirected live liver donation. The outcomes of 29 consecutive potential anonymous liver donors at our center were assessed. We used our standard live liver assessment process, augmented with the following additional acceptance criteria: a logical rationale for donation, a history of social altruism, strong social supports and a willingness to maintain confidentiality of patient information. Seventeen potential donors were rejected and 12 donors were ultimately accepted (six male, six female). All donors were strongly motivated by a desire and sense of responsibility to help others. Four donations were directed toward recipients who undertook media appeals. The donor operations included five left lateral segmentectomies and seven right hepatectomies. The overall donor morbidity was 40% with one patient having a transient Clavien level 3 complication (a pneumothorax). All donors are currently well. None expressed regret about their decision to donate, and all volunteered the opinion that donation had improved their lives. The standard live liver donor assessment process plus our additional requirements appears to provide a robust assessment process for the selection of anonymous live liver donors. Acceptance of anonymous donors enlarges the donor liver pool. © 2010 The Authors Journal compilation © 2010 The American Society of Transplantation and the American Society of Transplant Surgeons.

  15. Transplantation and differentiation of donor cells in the cloned pigs

    International Nuclear Information System (INIS)

    Shimada, Arata; Tomii, Ryo; Kano, Koichiro; Nagashima, Hiroshi

    2006-01-01

    The application of nuclear transfer technology is an interesting approach to investigate stem and progenitor cell transplantation therapy. If stem cells are used as a nuclear donor, donor cells can engraft into cloned animals without histocompatible problems. However, it is still uncertain whether donor cells can engraft to cloned animal and differentiate in vivo. To address this problem, we transplanted donor cells to dermal tissues of cloned pigs developed by using preadipocytes as donor cells. Preadipocytes are adipocytic progenitor which can differentiate to mature adipocytes in vitro. We showed that the donor preadipocytes were successfully transplanted into the cloned pigs without immune rejection and they differentiated into mature adipocytes in vivo 3 weeks after transplantation. In contrast, allogenic control preadipocytes, which can differentiate in vitro, did not differentiate in vivo. These results indicate that donor progenitor cells can differentiate in cloned animal

  16. 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

  17. 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

  18. Chemistry of marine ligands and siderophores.

    Science.gov (United States)

    Vraspir, Julia M; Butler, Alison

    2009-01-01

    Marine microorganisms are presented with unique challenges to obtain essential metal ions required to survive and thrive in the ocean. The production of organic ligands to complex transition metal ions is one strategy to both facilitate uptake of specific metals, such as iron, and to mitigate the potential toxic effects of other metal ions, such as copper. A number of important trace metal ions are complexed by organic ligands in seawater, including iron, cobalt, nickel, copper, zinc, and cadmium, thus defining the speciation of these metal ions in the ocean. In the case of iron, siderophores have been identified and structurally characterized. Siderophores are low molecular weight iron-binding ligands produced by marine bacteria. Although progress has been made toward the identity of in situ iron-binding ligands, few compounds have been identified that coordinate the other trace metals. Deciphering the chemical structures and production stimuli of naturally produced organic ligands and the organisms they come from is fundamental to understanding metal speciation and bioavailability. The current evidence for marine ligands, with an emphasis on siderophores, and discussion of the importance and implications of metal-binding ligands in controlling metal speciation and cycling within the world's oceans are presented.

  19. 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

  20. Emergency department referral for organ donation: more organ donors and more organs per donor.

    Science.gov (United States)

    Miller, Lisabeth D; Gardiner, Stuart K; Gubler, K Dean

    2014-05-01

    This study sought to determine whether early referral from the emergency department (ED) would increase the number of organ donors and the number of organs transplanted per donor (OTPD). This is a retrospective cohort analysis of all patients referred to a single organ procurement organization for a period of 60 months. Patients referred for organ donation evaluation from the ED were more likely to become organ donors than patients referred from the intensive care unit (19.3% vs 5.2%, P organ donation from the ED is associated with an increased likelihood of organ recovery and with an increased number of OTPD. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Studium využití některých N-donorových ligandů a jejich komplexů s ionty přechodných kovů

    Czech Academy of Sciences Publication Activity Database

    Cibulka, R.; Svobodová, E.; König, B.; Ludvík, Jiří; Hampl, F.; Liška, F.

    2007-01-01

    Roč. 101, č. 11 (2007), s. 886-894 ISSN 0009-2770 Institutional research plan: CEZ:AV0Z40400503 Keywords : N-donor ligands * oximes * cyclen Subject RIV: CG - Electrochemistry Impact factor: 0.683, year: 2007

  2. Monitoring ligand-dependent assembly of receptor ternary complexes in live cells by BRETFect.

    Science.gov (United States)

    Cotnoir-White, David; El Ezzy, Mohamed; Boulay, Pierre-Luc; Rozendaal, Marieke; Bouvier, Michel; Gagnon, Etienne; Mader, Sylvie

    2018-03-13

    There is currently an unmet need for versatile techniques to monitor the assembly and dynamics of ternary complexes in live cells. Here we describe bioluminescence resonance energy transfer with fluorescence enhancement by combined transfer (BRETFect), a high-throughput technique that enables robust spectrometric detection of ternary protein complexes based on increased energy transfer from a luciferase to a fluorescent acceptor in the presence of a fluorescent intermediate. Its unique donor-intermediate-acceptor relay system is designed so that the acceptor can receive energy either directly from the donor or indirectly via the intermediate in a combined transfer, taking advantage of the entire luciferase emission spectrum. BRETFect was used to study the ligand-dependent cofactor interaction properties of the estrogen receptors ERα and ERβ, which form homo- or heterodimers whose distinctive regulatory properties are difficult to dissect using traditional methods. BRETFect uncovered the relative capacities of hetero- vs. homodimers to recruit receptor-specific cofactors and regulatory proteins, and to interact with common cofactors in the presence of receptor-specific ligands. BRETFect was also used to follow the assembly of ternary complexes between the V2R vasopressin receptor and two different intracellular effectors, illustrating its use for dissection of ternary protein-protein interactions engaged by G protein-coupled receptors. Our results indicate that BRETFect represents a powerful and versatile technique to monitor the dynamics of ternary interactions within multimeric complexes in live cells.

  3. Stabilization of enzyme by using hydrophobic ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ota, H.; Yamahara, K.; Kuboi, R. [Osaka University, Osaka (Japan)

    1998-02-01

    The protection (stabilization) effect of various hydrophobic ligands on the denaturation and aggregation of carbonic anhydrase from bovine (CAB) has been quantitatively investigated under various heat stress conditions. In a limited temperature range (40-60degC), where the protein was only partially denatured and the local hydrophobicities (LH) of CAB were positive effective stabilization of the protein is achieved by the addition of various ligands. The importance of balance between hydrophobic head and hydrophilic tail of the ligands is hypothesized. 18 refs., 5 figs.

  4. 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....

  5. Synthesis, spectroscopic studies and inhibitory activity against bactria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand

    Science.gov (United States)

    Abou-Hussein, A. A.; Linert, Wolfgang

    2015-04-01

    Two series of new mono and binuclear complexes with a Schiff base ligand derived from the condensation of 3-acetylcoumarine and diethylenetriamine, in the molar ratio 2:1 have been prepared. The ligand was characterized by elemental analysis, IR, UV-visible, 1H-NMR and mass spectra. The reaction of the Schiff base ligand with cobalt(II), nickel(II), copper(II), zinc(II) and oxovanadium(IV) lead to mono or binuclear species of cyclic or macrocyclic complexes, depending on the mole ratio of metal to ligand and as well as on the method of preparation. The Schiff base ligand behaves as a cyclic bidentate, tetradendate or pentaentadentae ligand. The formation of macrocyclic complexes depends significantly on the dimension of the internal cavity, the rigidity of the macrocycles, the nature of its donor atoms and on the complexing properties of the anion involved in the coordination. Electronic spectra and magnetic moments of the complexes indicate that the geometries of the metal centers are either square pyramidal or octahedral for acyclic or macro-cyclic complexes. The structures are consistent with the IR, UV-visible, ESR, 1H-NMR, mass spectra as well as conductivity and magnetic moment measurements. The Schiff base ligand and its metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

  6. Why search for a sperm donor online? The experiences of women searching for and contacting sperm donors on the internet.

    Science.gov (United States)

    Jadva, Vasanti; Freeman, Tabitha; Tranfield, Erika; Golombok, Susan

    2017-04-28

    Whilst studies have examined the experiences of women who use clinic donors, to date there has been limited research investigating women's motivations and experiences of searching for a sperm donor online. A total of 429 women looking for a sperm donor on Pride Angel (a website that facilitates contact between donors and recipients) completed an online survey. Fifty-eight percent (249) saw advantages of obtaining donated sperm online with the most common advantage reported as being able to connect with and meet the donor (n = 50 (24%)). A third (n = 157 (37%)) of the participants gave disadvantages, the most common reported was encountering 'dishonest donors' (n = 63 (40%)). Most recipients (n = 181 (61%)) wanted the donor to be 'just a donor' (i.e. to provide sperm and have no further contact). Whilst it was important for recipients to know the identity of the donor, some did not see this as important for the child and thus the level of information that parents have about the donor, and that which the child has, can differ. Finding a donor online blurs the distinction between categories of 'anonymous', 'known' and 'identity release' donations. Whilst the survey had a large sample size, the representativeness of the sample is not known.

  7. Synthesis, spectral, thermal, potentiometric and antimicrobial studies of transition metal complexes of tridentate ligand

    Directory of Open Access Journals (Sweden)

    Sarika M. Jadhav

    2014-01-01

    Full Text Available A series of metal complexes of Cu(II, Ni(II, Co(II, Fe(III and Mn(II have been synthesized with newly synthesized biologically active tridentate ligand. The ligand was synthesized by condensation of dehydroacetic acid (3-acetyl-6-methyl-(2H pyran-2,4(3H-dione or DHA, o-phenylene diamine and fluoro benzaldehyde and characterized by elemental analysis, molar conductivity, magnetic susceptibility, thermal analysis, X-ray diffraction, IR, 1H-NMR, UV–Vis spectroscopy and mass spectra. From the analytical data, the stoichiometry of the complexes was found to be 1:2 (metal:ligand with octahedral geometry. The molar conductance values suggest the non-electrolyte nature of metal complexes. The IR spectral data suggest that the ligand behaves as a dibasic tridentate ligand with ONN donor atoms sequence towards central metal ion. Thermal behaviour (TG/DTA and kinetic parameters calculated by the Coats–Redfern and Horowitz–Metzger method suggest more ordered activated state in complex formation. To investigate the relationship between stability constants of metal complexes and antimicrobial activity, the dissociation constants of Schiff bases and stability constants of their binary metal complexes have been determined potentiometrically in THF–water (60:40% solution at 25 ± 1 °C and at 0.1 M NaClO4 ionic strength. The potentiometric study suggests 1:1 and 1:2 complexation. Antibacterial and antifungal activities in vitro were performed against Staphylococcus aureus, Escherichia coli and Aspergillus niger, Trichoderma, respectively. The stability constants of the metal complexes were calculated by the Irving–Rosotti method. A relation between the stability constant and antimicrobial activity of complexes has been discussed. It is observed that the activity enhances upon complexation and the order of antifungal activity is in accordance with stability order of metal ions.

  8. High-risk HLA alleles for severe acute graft-versus-host disease and mortality in unrelated donor bone marrow transplantation.

    Science.gov (United States)

    Morishima, Satoko; Kashiwase, Koichi; Matsuo, Keitaro; Azuma, Fumihiro; Yabe, Toshio; Sato-Otsubo, Aiko; Ogawa, Seishi; Shiina, Takashi; Satake, Masahiro; Saji, Hiroh; Kato, Shunichi; Kodera, Yoshihisa; Sasazuki, Takehiko; Morishima, Yasuo

    2016-04-01

    HLA molecules play an important role for immunoreactivity in allogeneic hematopoietic stem cell transplantation. To elucidate the effect of specific HLA alleles on acute graft-versus-host disease, we conducted a retrospective analysis using 6967 Japanese patients transplanted with T-cell-replete marrow from an unrelated donor. Using unbiased searches of patient and donor HLA alleles, patient and/or donor HLA-B*51:01 (patient: HR, 1.37,PHLA-C*14:02 (HR, 1.35,Pdisease. The finding that donor HLA-C*14:02 was not associated with severe acute graft-versus-host disease prompted us to elucidate the relation of these high-risk HLA alleles with patient and donor HLA-C allele mismatches. In comparison to HLA-C allele match, patient mismatched HLA-C*14:02 showed the highest risk of severe acute graft-versus-host disease (HR, 3.61,PHLA-C alleles. Although patient HLA-C*14:02 and donor HLA-C*15:02 mismatch was usually KIR2DL-ligand mismatch in the graft-versus-host direction, the risk of patient mismatched HLA-C*14:02 for severe acute graft-versus-host disease was obvious regardless of KIR2DL-ligand matching. The effect of patient and/or donor HLA-B*51:01 on acute graft-versus-host disease was attributed not only to strong linkage disequilibrium of HLA-C*14:02 and -B*51:01, but also to the effect of HLA-B*51:01 itself. With regard to clinical implications, patient mismatched HLA-C*14:02 proved to be a potent risk factor for severe acute graft-versus-host disease and mortality, and should be considered a non-permissive HLA-C mismatch in donor selection for unrelated donor hematopoietic stem cell transplantation. Copyright© Ferrata Storti Foundation.

  9. Communicating identifiability risks to biobank donors

    DEFF Research Database (Denmark)

    Kasperbauer, T. J.; Gjerris, Mickey; Waldemar, Gunhild

    2018-01-01

    can track individuals across multiple databases. This article focuses on the communication of identifiability risks in the process of obtaining consent for donation and research. Most ethical discussions of identifiability risks have focused on the severity of the risk and how it might be mitigated......, and what precisely is at stake in pervasive data sharing. However, there has been little discussion of whether and how to communicate the risk to potential donors. We review the ethical arguments behind favoring different types of risk communication in the consent process, and outline how identifiability...... concerns can be incorporated into either a detailed or a simplified method of communicating risks during the consent process....

  10. Brain-Dead Donors on Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Bronchard, Régis; Durand, Louise; Legeai, Camille; Cohen, Johana; Guerrini, Patrice; Bastien, Olivier

    2017-10-01

    To describe donors after brain death with ongoing extracorporeal membrane oxygenation and to analyze the outcome of organs transplanted from these donors. Retrospective analysis of the national information system run by the French Biomedicine Agency (CRISTAL database). National registry data of all donors after brain death in France and their organ recipients between 2007 and 2013. Donors after brain death and their organ recipients. None. During the study period, there were 22,270 brain-dead patients diagnosed in France, of whom 161 with extracorporeal membrane oxygenation. Among these patients, 64 donors on extracorporeal membrane oxygenation and 10,805 donors without extracorporeal membrane oxygenation had at least one organ retrieved. Donors on extracorporeal membrane oxygenation were significantly younger and had more severe intensive care medical conditions (hemodynamic, biological, renal, and liver insults) than donors without extracorporeal membrane oxygenation. One hundred nine kidneys, 37 livers, seven hearts, and one lung were successfully transplanted from donors on extracorporeal membrane oxygenation. We found no significant difference in 1-year kidney graft survival (p = 0.24) and function between recipients from donors on extracorporeal membrane oxygenation (92.7% [85.9-96.3%]) and matching recipients from donors without extracorporeal membrane oxygenation (95.4% [93.0-97.0%]). We also found no significant difference in 1-year liver recipient survival (p = 0.91): 86.5% (70.5-94.1) from donors on extracorporeal membrane oxygenation versus 80.7% (79.8-81.6) from donors without extracorporeal membrane oxygenation. Brain-dead patients with ongoing extracorporeal membrane oxygenation have more severe medical conditions than those without extracorporeal membrane oxygenation. However, kidney graft survival and function were no different than usual. Brain-dead patients with ongoing extracorporeal membrane oxygenation are suitable for organ procurement.

  11. Controlling Signal Transduction with Synthetic Ligands

    Science.gov (United States)

    Spencer, David M.; Wandless, Thomas J.; Schreiber, Stuart L.; Crabtree, Gerald R.

    1993-11-01

    Dimerization and oligomerization are general biological control mechanisms contributing to the activation of cell membrane receptors, transcription factors, vesicle fusion proteins, and other classes of intra- and extracellular proteins. Cell permeable, synthetic ligands were devised that can be used to control the intracellular oligomerization of specific proteins. To demonstrate their utility, these ligands were used to reduce intracellular oligomerization of cell surface receptors that lacked their transmembrane and extracellular regions but contained intracellular signaling domains. Addition of these ligands to cells in culture resulted in signal transmission and specific target gene activation. Monomeric forms of the ligands blocked the pathway. This method of ligandregulated activation and termination of signaling pathways has the potential to be applied wherever precise control of a signal transduction pathway is desired.

  12. Allyl functionalized phosphinite and phosphonite ligands: Synthesis ...

    Indian Academy of Sciences (India)

    Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions. SINGAPPAGUDEM GOVINDARAJUa, GUDDEKOPPA S ANANTHNAGa, SUSMITA NAIKa,. SHAIKH M MOBINb and MARAVANJI S BALAKRISHNAa,∗. aPhosphorus Laboratory, Department of ...

  13. Organometallic chemistry of chiral diphosphazane ligands ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 114; Issue 4. Organometallic chemistry of chiral diphosphazane ligands: Synthesis and structural characterisation. Kannan Raghuraman Swadhin K Mandal T S Venkatakrishnan Setharampattu S Krishnamurthy Munirathinam Nethaji. Volume 114 Issue 4 August 2002 ...

  14. 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...

  15. 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...

  16. Chemistry of Marine Ligands and Siderophores

    OpenAIRE

    Vraspir, Julia M.; Butler, Alison

    2009-01-01

    Marine microorganisms are presented with unique challenges to obtain essential metal ions required to survive and thrive in the ocean. The production of organic ligands to complex transition metal ions is one strategy to both facilitate uptake of specific metals, such as iron, and to mitigate the potential toxic effects of other metal ions, such as copper. A number of important trace metal ions are complexed by organic ligands in seawater, including iron, cobalt, nickel, copper, zinc, and cad...

  17. Synthesis and Characterization of 1,2-bis(4-(pent- 3-en-4yl-2-one)ethane), a novel quardidentate ligand and its transition meta complexes

    International Nuclear Information System (INIS)

    Shabbir, M.; Akhter, Z.; Gul, A.

    2014-01-01

    A novel crystalline enaminoketone ligand was synthesized by reacting 1, 2-di (4-aminophenyloxy) ethylene with acetyl acetone. After that it was complexed with different metal acetates to prepare chromium Cr (II), cobalt Co (II), copper Cu (II) and zinc Zn (II) complexes. Elemental analysis, magnetic susceptibility measurements, thermogravimetric analysis, x-rays crystallographic studies, UV-visible spectroscopy were carried out for structural elucidation and property exploration. The ligand exhibited quardidentate structure with two N-donor and two O-donor atoms with central methylene bridge in the gauche conformation which was stabilized by two intramolecular N-H--O hydrogen bonds The dihedral angle between the two aromatic rings was 45.1 degree. All complexes were thermally stable and exhibit square planar or tetrahedral geometries. (author)

  18. Evaluation of DNA/Protein interactions and cytotoxic studies of copper(II) complexes incorporated with N, N donor ligands and terpyridine ligand.

    Science.gov (United States)

    Tummalapalli, Kiran; C S, Vasavi; Munusami, Punnagai; Pathak, Madhvesh; M M, Balamurali

    2017-02-01

    A series of four new copper(II) heteroleptic complexes, [Cu(2‴-pytpy) (L)] (NO 3 ) 2 ·2H 2 O (1-4), where 2‴-pytpy=4'-(2'''-Pyridyl)-2, 2':6', 2''-terpyridine, L=bipyridyl (bpy), 1, 10 phenanthroline(phen), dipyridoquinoxaline(dpq) and dipyridophenazine (dppz) were synthesized and characterized by spectroscopic techniques. Further, the molecular structure of the complex (2) was confirmed by single crystal X-ray diffraction technique and the data revealed a penta coordinated, distorted square-pyramidal geometry with triclinic system. The interactions of four complexes with calf thymus DNA and bovine serum albumin (BSA) were investigated by electronic absorption, fluorescence and circular dichroism spectroscopy techniques. Spectral studies substantiated an intercalative binding mode of metal complexes with ct-DNA. Significant binding interactions of the complexes with protein have been further revealed from fluorescence studies. Furthermore, all the four complexes show potential cytotoxicity towards the human liver carcinoma cell line (HepG-2). Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 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.

  20. Exploiting ligand-protein conjugates to monitor ligand-receptor interactions.

    Directory of Open Access Journals (Sweden)

    Hirohito Haruki

    Full Text Available We introduce three assays for analyzing ligand-receptor interactions based on the specific conjugation of ligands to SNAP-tag fusion proteins. Conjugation of ligands to different SNAP-tag fusions permits the validation of suspected interactions in cell extracts and fixed cells as well as the establishment of high-throughput assays. The different assays allow the analysis of strong and weak interactions. Conversion of ligands into SNAP-tag substrates thus provides access to a powerful toolbox for the analysis of their interactions with proteins.

  1. Li+-ligand binding energies and the effect of ligand fluorination on the binding energies

    Science.gov (United States)

    Bauschlicher, Charles W.

    2018-02-01

    The Li+-ligand binding energies are computed for seven ligands and their perfluoro analogs using Density Functional Theory. The bonding is mostly electrostatic in origin. Thus the size of the binding energy tends to correlate with the ligand dipole moment, however, the charge-induced dipole contribution can be sufficiently large to affect the dipole-binding energy correlation. The perfluoro species are significantly less strongly bound than their parents, because the electron withdrawing power of the fluorine reduces the ligand dipole moment.

  2. 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.

  3. Q-FISH measurement of hepatocyte telomere lengths in donor liver and graft after pediatric living-donor liver transplantation: donor age affects telomere length sustainability.

    Directory of Open Access Journals (Sweden)

    Youichi Kawano

    Full Text Available Along with the increasing need for living-donor liver transplantation (LDLT, the issue of organ shortage has become a serious problem. Therefore, the use of organs from elderly donors has been increasing. While the short-term results of LDLT have greatly improved, problems affecting the long-term outcome of transplant patients remain unsolved. Furthermore, since contradictory data have been reported with regard to the relationship between donor age and LT/LDLT outcome, the question of whether the use of elderly donors influences the long-term outcome of a graft after LT/LDLT remains unsettled. To address whether hepatocyte telomere length reflects the outcome of LDLT, we analyzed the telomere lengths of hepatocytes in informative biopsy samples from 12 paired donors and recipients (grafts of pediatric LDLT more than 5 years after adult-to-child LDLT because of primary biliary atresia, using quantitative fluorescence in situ hybridization (Q-FISH. The telomere lengths in the paired samples showed a robust relationship between the donor and grafted hepatocytes (r = 0.765, p = 0.0038, demonstrating the feasibility of our Q-FISH method for cell-specific evaluation. While 8 pairs showed no significant difference between the telomere lengths for the donor and the recipient, the other 4 pairs showed significantly shorter telomeres in the recipient than in the donor. Multiple regression analysis revealed that the donors in the latter group were older than those in the former (p = 0.001. Despite the small number of subjects, this pilot study indicates that donor age is a crucial factor affecting telomere length sustainability in hepatocytes after pediatric LDLT, and that the telomeres in grafted livers may be elongated somewhat longer when the grafts are immunologically well controlled.

  4. Counted Sb donors in Si quantum dots

    Science.gov (United States)

    Singh, Meenakshi; Pacheco, Jose; Bielejec, Edward; Perry, Daniel; Ten Eyck, Gregory; Bishop, Nathaniel; Wendt, Joel; Luhman, Dwight; Carroll, Malcolm; Lilly, Michael

    2015-03-01

    Deterministic control over the location and number of donors is critical for donor spin qubits in semiconductor based quantum computing. We have developed techniques using a focused ion beam and a diode detector integrated next to a silicon MOS single electron transistor to gain such control. With the diode detector operating in linear mode, the numbers of ions implanted have been counted and single ion implants have been detected. Poisson statistics in the number of ions implanted have been observed. Transport measurements performed on samples with counted number of implants have been performed and regular coulomb blockade and charge offsets observed. The capacitances to various gates are found to be in agreement with QCAD simulations for an electrostatically defined dot. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  5. Bone Marrow Donors Worldwide: a successful exercise in international cooperation.

    Science.gov (United States)

    Oudshoorn, M; van Leeuwen, A; vd Zanden, H G; van Rood, J J

    1994-07-01

    Bone marrow transplantation using unrelated donors has become a clinical reality but a large number of challenges remain. One of the most important and a crucial one is locating a suitable donor. To cope with this very large registries have been formed but each of these lacks donors with phenotypes which occur in other registries. To facilitate the search process a collation system designated Bone Marrow Donors Worldwide (BMDW) was started. Several times a year it collects the phenotypes of all donors from all participating registries on a worldwide basis. The data are sorted by phenotype number of the broad antigens; the splits are specified immediately after the broad phenotypes. Here the experience with the first 11 editions is summarized. Although there is a steady increase in the numbers of donors and phenotypes included in BMDW, origin.

  6. Addressing the Donor Liver Shortage with EX VIVO Machine Perfusion

    Directory of Open Access Journals (Sweden)

    Maria-Louisa Izamis

    2012-01-01

    Full Text Available Despite a critical shortage of viable donor livers for transplantation, only a fraction of the available organs are used. Donor organ defects, which in the majority of cases are caused by extensive exposure to ischemia, cannot be reversed by static cold storage, the current gold standard of organ preservation. In this review, the role of machine perfusion (MP in the recovery of non-transplantable ischemic donor organs is discussed. Though still in the experimental phase, various models of MP have consistently demonstrated that ischemic donor organs can be recovered to a transplantable state through continuous perfusion. MP can also provide dynamic quantitative assessments of the extent of ischemia, in addition to predicting the likelihood of organ recovery. Continued endeavors to translate MP into clinical use and eventually incorporate it into routine donor organ care will have a significant impact on the quality and availability of transplantable donor organs.

  7. How to kill gamete donation: retrospective legislation and donor anonymity.

    Science.gov (United States)

    Pennings, Guido

    2012-10-01

    Victoria (Australia) is considering retrospective legislation on the abolition of gamete donor anonymity. Retrospective legislation evokes many negative emotions mainly because it is considered unfair. It also makes it impossible for citizens to organize their life with reasonable certainty of the consequences. Introduction of this law for donor anonymity is defended by the right of the child to know its genetic origins. Against this law, people appeal to the right to privacy and confidentiality of the donor. This paper analyses the arguments for and against a retrospective law on donor anonymity by looking at the conditions that should be respected when two principles (the donor's right to privacy and the child's right to genetic information) have to be balanced. It is concluded that the justification for introducing retrospective law is lacking: the conditions are not fulfilled. Moreover, retroactive laws in the context of gamete donation may jeopardize the whole practice by destroying the trust of candidate donors and recipients in the government.

  8. Deceased donor uterus retrieval: A novel technique and workflow.

    Science.gov (United States)

    Testa, G; Anthony, T; McKenna, G J; Koon, E C; Wallis, K; Klintmalm, G B; Reese, J C; Johannesson, L

    2018-03-01

    Uterus transplantation has proven successful when performed with a living donor. Subsequently, interest in the novel field of reproductive transplantation is growing. The procedure is still considered experimental, with fewer than 25 cases performed worldwide, and the techniques of both uterus procurement and transplantation are still developing. We detail a new approach to deceased donor uterus procurement. In contrast to reported techniques and our own initial experience, in which the deceased donor uterus was procured post cross-clamp and after other organs were procured, our approach now is to perform the uterus procurement prior to the procurement of other organs in a multiorgan donor and hence prior to cross-clamp. We describe our practical experience in developing and implementing the logistical workflow for deceased donor uterus procurement in a deceased multiorgan donor setting. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  9. Approach to the Pretransplant Evaluation of the Living Kidney Donor

    Directory of Open Access Journals (Sweden)

    Mala Sachdeva

    2011-01-01

    Full Text Available Evaluation of the potential kidney donor is a complex activity that differs substantially from other types of preoperative assessments. The well being of the donor, who derives no medical benefit from this surgery, must be assured in both the short term and long term, and the potential adverse consequences to the recipient must be determined as well. The criteria that must be met for a person to donate a kidney are rigorous and include medical, social, psychosocial, ethical, and legal issues. Donor evaluation can be divided into assessments to protect the health and safety of the donor and assessments to protect the health and safety of the recipient. This article provides an approach to evaluating a donor, focusing on the complex issues that an evaluator is faced with. A careful assessment of risks and benefits to both the donor and recipient can lead to favorable outcomes.

  10. Mini-donor nephrectomy: A viable and effective alternative

    Directory of Open Access Journals (Sweden)

    Sandeep Guleria

    2010-01-01

    Full Text Available Live kidney donation is an excellent way of increasing the donor pool. The introduction of the laparoscopic donor nephrectomy has resulted in an increase in live organ donation in the western hemisphere. There is no data on its impact on organ donation in India. However attractive as it may seem, the procedure is associated with a definite learning curve and does compromise donor safety. The procedure is also expensive in terms of the equipment required. The mini-donor nephrectomy is an excellent alternative, has no learning curve and is ideally suited for donors in India who have a low BMI. The procedure is also relatively inexpensive. We are in need of a donor registry rather than reports from single institutions to fully evaluate the risks and benefits of both procedures.

  11. 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.

  12. Nuclease Activity via Self-Activation and Anticancer Activity of Mononuclear Copper(II) Complex: Novel Role of Tertiary Butyl Group in the Ligand Frame

    OpenAIRE

    Ghosh, Kaushik; Kumar, Pramod; Mohan, Varun; Singh, Udai P.; Kasiri, Sahba; Mandal, Subhrangsu S.

    2012-01-01

    Copper complex [Cu(tBuPhimp)(Cl)] (1) derived from tridentate ligand tBuPhimpH having N2O donors was synthesized and molecular structure was determined. Phenoxyl radical complex was generated in solution at room temperature using Ce(IV) salt. Nuclease activity and anticancer activity of 1 was investigated. Roles of tert-butyl group and singlet oxygen in DNA cleavage activity were also discussed.

  13. Interaction of cobalt(II) and nickel(II) with a gamma-linked, bis-beta-diketone ligand to yield an unusual coordination motif.

    Science.gov (United States)

    Zheng, Bai-Shu; Zhang, Xiao-Yi; Zhu, Huai-Wu; Luo, Shi-Xia; Lindoy, Leonard F; McMurtrie, John C; Turner, Peter; Wei, Gang

    2005-04-21

    Discrete cobalt(II) and nickel(II) complexes of type ML (where L is a bis(2,4-pentanedionate) derivative incorporating a -SCH2CH2S- bridge between the gamma-carbons of respective beta-diketone units) have been synthesised and represent the first examples in which a gamma-substituted, thioether-containing beta-diketone ligand coordinates via a sulfur and oxygen donor in preference to the classical coordination mode involving both beta-diketonate oxygens.

  14. Effects of Ligands on a Ternary Hydroxo Complex Formation with Eu(III) in a Aqueous Solution: Comparison of a Pyridine-2,6-dicarboxylate with a Phthalate

    International Nuclear Information System (INIS)

    Park, K. K.; Cho, H. R.; Kim, W. H.; Jung, E. C.

    2008-01-01

    The interaction of a radionuclide with ligands in a groundwater influences its migration through a hydrogeological system due to a change in the characteristics of a dissolution and a sorption. Actinide ions are classified as a hard acid and strongly interact with ligands having an oxygen donor atom of a hard base such as a hydroxide, carbonate and carboxylate. These ligands reveal a large ionic bonding character. A number of experimental results on a binary complex formation of actinides have been reported. However, actinides may easily form a ternary complex by interacting simultaneously with two different ligands, since an ionic bonding does not restrict the spatial orientation of a ligand. In previous studies, a ternary hydroxo complex formation was investigated by using pyridine-2,6-dicarboxylate (PDA) or phthalate as an organic ligand and Eu(III) as an analogue of an actinide(III) ion. Although these organic ligands equally contain two carboxylate groups that interact with an Eu(III) ion, their stabilities reveal big differences. PDA is a tridentate ligand forming two 5-membered chelates, while phthalate is a bidentate ligand forming a 7-membered chelate. The latter reveals a lower stability than the former due to an angle strain. This is one of the reasons for the lower stability of the Eu(III)-phthalate than that of the Eu(III)- PDA. The difference in the stabilities of binary complexes, EuL + (L=organic ligand), influences the stabilities of the ternary hydroxo complexes, Eu(OH)L. The coordination of a phenylic or pyridine ligand can greatly enhance the fluorescence of an Eu(III) ion due to the high absorbance of a ligand by a π → π * transition and the transfer of this energy to an Eu(III) ion. These fluorescence characteristics in a binary complex system could be changed in a ternary complex. In this study, the effect of a ligand on the stability of a ternary hydroxo complex is reported by comparing the stabilities of Eu-PDA with Eu-phthalate systems

  15. Thalassemia and Hemoglobin E in Southern Thai Blood Donors

    OpenAIRE

    Nuinoon, Manit; Kruachan, Kwanta; Sengking, Warachaya; Horpet, Dararat; Sungyuan, Ubol

    2014-01-01

    Thalassemia and hemoglobin E (Hb E) are common in Thailand. Individuals with thalassemia trait usually have a normal hemoglobin concentration or mild anemia. Therefore, thalassemic individuals who have minimum acceptable Hb level may be accepted as blood donors. This study was aimed at determining the frequency of α-thalassemia 1 trait, β-thalassemia trait, and Hb E-related syndromes in Southern Thai blood donors. One hundred and sixteen voluntary blood donors, Southern Thailand origin, were ...

  16. Xenotransplantation: A Potential Solution to the Critical Organ Donor Shortage

    OpenAIRE

    K Howe Sim; Anton Marinov; Gary A Levy

    1999-01-01

    The success of allotransplantation as a treatment for end-stage organ failure has resulted in the need for an increasing number of organ donors. Attempts to meet this need include the use of organs from living related and unrelated donors, financial or other incentives for the donor family, and even the reuse of transplanted organs. Despite these initiatives, the supply of organs for transplantation still falls far short of the demand, as evidenced by longer waiting times for transplantation ...

  17. Human body donation in Thailand: Donors at Khon Kaen University.

    Science.gov (United States)

    Techataweewan, N; Panthongviriyakul, C; Toomsan, Y; Mothong, W; Kanla, P; Chaichun, A; Amarttayakong, P; Tayles, N

    2018-03-01

    Culture, society and spirituality contribute to variability in the characteristics of human body donors and donation programmes worldwide. The donors and the body donation programme at Khon Kaen University, northeast Thailand, reflect all these aspects of Thailand, including the status accorded to the donors and the ceremonial acknowledgement of the donors and their families. Data from the programme records and from surveys of samples of currently registering donors and recently received donor bodies are analysed to define the characteristics of both registering and received donors, including motivation, demography, socio-economic status, health, and use of the bodies. The body donation programme at Khon Kaen University currently has a very high rate of registration of body donors, with gender and age differences in the patterns of donation. Registrants include more females than males, a long-standing pattern, and are an average age of 50 years. The bodies of 12% of registrants are received after death and include more males than females. Both sexes are of an average age of 69 years. Males had registered their donation eight years prior to death and females ten years prior. Current registrants identified altruistic motives for their decision to donate, although the coincidence of body donation by a highly revered monk with a surge in donations in 2015 suggests that Buddhism plays a primary role in motivation. The opportunity to make merit for donors and their families, and respect shown to donors and the nature of the ceremonies acknowledging the donors and their families, including the use of the Royal Flame at the cremation ceremony, all contribute to decisions to donate. The characteristics of body donors and the body donation programme at Khon Kaen University are reflective of Thai society and the centrality of Buddhism to Thai culture. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. Crystal structure and ligand binding properties of the truncated hemoglobin from Geobacillus stearothermophilus.

    Science.gov (United States)

    Ilari, Andrea; Kjelgaard, Peter; von Wachenfeldt, Claes; Catacchio, Bruno; Chiancone, Emilia; Boffi, Alberto

    2007-01-01

    A novel truncated hemoglobin has been identified in the thermophilic bacterium Geobacillus stearothermophilus (Gs-trHb). The protein has been expressed in Escherichia coli, the 3D crystal structure (at 1.5 Angstroms resolution) and the ligand binding properties have been determined. The distal heme pocket displays an array of hydrogen bonding donors to the iron-bound ligands, including Tyr-B10 on one side of the heme pocket and Trp-G8 indole nitrogen on the opposite side. At variance with the highly similar Bacillus subtilis hemoglobin, Gs-trHb is dimeric both in the crystal and in solution and displays several unique structural properties. In the crystal cell, the iron-bound ligand is not homogeneously distributed within each distal site such that oxygen and an acetate anion can be resolved with relative occupancies of 50% each. Accordingly, equilibrium titrations of the oxygenated derivative in solution with acetate anion yield a partially saturated ferric acetate adduct. Moreover, the asymmetric unit contains two subunits and sedimentation velocity ultracentrifugation data confirm that the protein is dimeric.

  19. Impact of protein and ligand impurities on ITC-derived protein-ligand thermodynamics.

    Science.gov (United States)

    Grüner, Stefan; Neeb, Manuel; Barandun, Luzi Jakob; Sielaff, Frank; Hohn, Christoph; Kojima, Shun; Steinmetzer, Torsten; Diederich, François; Klebe, Gerhard

    2014-09-01

    The thermodynamic characterization of protein-ligand interactions by isothermal titration calorimetry (ITC) is a powerful tool in drug design, giving valuable insight into the interaction driving forces. ITC is thought to require protein and ligand solutions of high quality, meaning both the absence of contaminants as well as accurately determined concentrations. Ligands synthesized to deviating purity and protein of different pureness were titrated by ITC. Data curation was attempted also considering information from analytical techniques to correct stoichiometry. We used trypsin and tRNA-guanine transglycosylase (TGT), together with high affinity ligands to investigate the effect of errors in protein concentration as well as the impact of ligand impurities on the apparent thermodynamics. We found that errors in protein concentration did not change the thermodynamic properties obtained significantly. However, most ligand impurities led to pronounced changes in binding enthalpy. If protein binding of the respective impurity is not expected, the actual ligand concentration was corrected for and the thus revised data compared to thermodynamic properties obtained with the respective pure ligand. Even in these cases, we observed differences in binding enthalpy of about 4kJ⋅mol(-1), which is considered significant. Our results indicate that ligand purity is the critical parameter to monitor if accurate thermodynamic data of a protein-ligand complex are to be recorded. Furthermore, artificially changing fitting parameters to obtain a sound interaction stoichiometry in the presence of uncharacterized ligand impurities may lead to thermodynamic parameters significantly deviating from the accurate thermodynamic signature. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Quality of life of elderly live kidney donors.

    Science.gov (United States)

    Klop, Karel W J; Dols, Leonienke F C; Weimar, Willem; Dooper, Ine M; IJzermans, Jan N M; Kok, Niels F M

    2013-10-15

    Expanding the use of elderly live donors may help meet the demand for kidney transplants. The aim of this study was to quantify the effect of the surgical procedure on the quality of life (QOL) of elderly donors compared with younger donors. Alongside three prospective studies (two randomized) running between May 2001 and October 2010, we asked 501 live donors to fill out the Short Form-36 questionnaire preoperatively and at 1, 3, 6, and 12 months postoperatively. We defined live donors 60 years or older as elderly. Between-group analyses regarding QOL were adjusted for baseline values and gender. One hundred thirty-five donors were older and 366 donors were younger than 60 years. The response rate was high, with 87% at 12 months postoperatively. Elderly donors less often scored as American Society of Anaesthesiology classification 1 (60% vs. 81%; Pvitality" (5 points; P=0.008). At 3 months, "bodily pain" (3 points, P=0.04) and "role physical" (8 points, P=0.02) were still in favor of the older group. At 6 and 12 months, "physical function" was in favor of the younger group (3 and 5 points, respectively; P=0.04 and P<0.001). This study demonstrates that elderly donors recover relatively fast. The perspective of excellent postoperative QOL may help convince elderly individuals to donate.

  1. Characterization of blood donors with high haemoglobin concentration

    DEFF Research Database (Denmark)

    Magnussen, K; Hasselbalch, H C; Ullum, H

    2013-01-01

    Background and Objectives  The literature contains little on the prevalence and causes of high predonation haemoglobin levels among blood donors. This study aimed to characterize and develop an algorithm to manage would-be donors with polycythaemia. Materials and Methods  Between November 2009...... and November 2011, we offered haematology consultations to blood donors with repeated haemoglobin concentration (Hb) above the WHO limit for polycythaemia vera (PV) (10·2 and 11·5 mm/16·5 and 18·5 g/dl for women and men, respectively). Investigation of such donors included Hb, haematocrit, mean cell volume...

  2. Improving the organ donor card system in Switzerland.

    Science.gov (United States)

    Shaw, David

    2013-08-22

    This paper analyses the current organ donor card system in Switzerland and identifies five problems that may be partially responsible for the country's low deceased organ donation rates. There are two minor issues concerning the process of obtaining a donor card: the Swisstransplant website understates the prospective benefits of donation, and the ease with which donor cards can be obtained raises questions regarding whether any consent to donation provided is truly informed. Furthermore, there are two major practical problems that might affect those who carry an organ donor card: the lack of a central donor registry increases the likelihood that donors' wishes will be "lost", and there is a high probability that family members will veto organ donation. The fact that these two practical problems are not mentioned to potential donors by Swisstransplant constitutes the fifth problem. Donation rates would probably improve if more accurate information about the benefits of donation were provided to potential donors, a central donor registry were created, and families were not permitted to veto donation from those on the registry.

  3. Epigenetic Modification of the Repair Donor Regulates Targeted Gene Correction

    Directory of Open Access Journals (Sweden)

    Olivier Humbert

    2012-01-01

    Full Text Available Optimizing design of vectors is critical to effective gene therapy. In targeted gene correction (TGC, cleavage of chromosomal DNA near a mutation stimulates homology-directed repair of a target gene using a donor provided in trans. We have systematically addressed epigenetic parameters of donor design, using a flow-based assay to quantify correction frequencies and expression levels of a green fluorescent protein (GFP reporter gene in a human cell line. We show that active transcription of the donor increased correction frequency by threefold, establishing that a proximal promoter enhances donor use. Conversely, CpG methylation of the donor diminished correction frequency and reduced expression of the repaired gene. However, bisulfite sequencing of the target revealed no transfer of methylation marks during repair with a methylated donor. Treatment with histone deacetylase (HDAC inhibitors can partially compensate for epigenetic inactivation, suggesting a role for class I and II HDACs in regulation of donor use. These results establish that epigenetic status of a trans-donor determines both the efficiency and outcome of gene correction, and identify and clarify parameters that should guide donor design for targeted gene therapy.

  4. The influence of donor factors on corneal organ culture contamination.

    Science.gov (United States)

    Gruenert, Anja K; Rosenbaum, Katja; Geerling, Gerd; Fuchsluger, Thomas A

    2017-11-01

    To evaluate the contamination rate and the corresponding spectrum of microbes and to identify donor risk factors for corneal organ culture contaminations. A total of 3306 organ-cultured donor corneas were included in the study. We performed a retrospective database analysis to evaluate donor factors such as gender, age, death-to-explantation interval (DEI), procurement site and cause of death and to determine their influence on donor cornea contaminations. Odds ratios (ORs) were calculated for each factor. The overall contamination rate was 7.8% (n = 259). Younger donor age (OR: 2.2, p = 0.003, chi-squared test), a DEI of more than 24 hr (OR: 1.6, p donor gender did not have an effect on donor cornea contaminations. The most frequently isolated microbes were Enterococci (19%), Staphylococci (10.8%) and Candida (37.4%). This study helps to estimate the contamination risk of a cultured cornea based on specific donor factors. However, donors with risk factors should not be generally excluded from cornea donation. Further studies including antibiograms might clarify whether a change in the antibiotic composition of the culture medium would be useful to deal with the increasing number of multi-resistant microbes. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  5. Donor management parameters and organ yield: single center results.

    Science.gov (United States)

    Marshall, George Ryne; Mangus, Richard S; Powelson, John A; Fridell, Jonathan A; Kubal, Chandrashekhar A; Tector, A Joseph

    2014-09-01

    Management of organ donors in the intensive care unit is an emerging subject in critical care and transplantation. This study evaluates organ yield outcomes for a large number of patients managed by the Indiana Organ Procurement Organization. This is a retrospective review of intensive care unit records from 2008-2012. Donor demographic information and seven donor management parameters (DMP) were recorded at admission, consent, 12 h after consent, and before procurement. Three study groups were created: donors meeting 0-3, 4, or 5-7 DMP. Active donor Organ Procurement Organization management began at consent; so, data analysis focuses on the 12-h postconsent time point. Outcomes included organs transplanted per donor (OTPD) and transplantation of individual solid organs. Complete records for 499 patients were reviewed. Organ yield was 1415 organs of 3992 possible (35%). At 12 h, donors meeting more DMP had more OTPD: 2.2 (0-3) versus 3.0 (4) versus 3.5 (5-7) (P organ except intestine. Oxygen tension, vasopressor use, and central venous pressure were the most frequent independent predictors of organ usage. There were significantly more organs transplanted for donors meeting all three of these parameters (4.5 versus 2.7, P organs, with analysis of individual parameters suggesting that appropriate management of oxygenation, volume status, and vasopressor use could lead to more organs procured per donor. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Increasing the supply of kidneys for transplantation by making living donors the preferred source of donor kidneys.

    Science.gov (United States)

    Testa, Giuliano; Siegler, Mark

    2014-12-01

    At the present time, increasing the use of living donors offers the best solution to the organ shortage problem. The clinical questions raised when the first living donor kidney transplant was performed, involving donor risk, informed consent, donor protection, and organ quality, have been largely answered. We strongly encourage a wider utilization of living donation and recommend that living donation, rather than deceased donation, become the first choice for kidney transplantation. We believe that it is ethically sound to have living kidney donation as the primary source for organs when the mortality and morbidity risks to the donor are known and kept extremely low, when the donor is properly informed and protected from coercion, and when accepted national and local guidelines for living donation are followed.

  7. Liver transplantation from maastricht category 2 non-heart-beating donors: a source to increase the donor pool?

    Science.gov (United States)

    Otero, A; Gómez-Gutiérrez, M; Suárez, F; Arnal, F; Fernández-García, A; Aguirrezabalaga, J; García-Buitrón, J; Alvarez, J; Máñez, R

    2004-04-01

    The demand for liver transplantation has increasingly exceeded the supply of cadaver donor organs. Non-heart-beating donors (NHBDs) may be an alternative to increase the cadaver donor pool. The outcome of 20 liver transplants from Maastricht category 2 NHBD was compared with that of 40 liver transplants from heart-beating donors (HBDs). After unsuccessful cardiopulmonary resuscitation (CPR), cardiopulmonary support with simultaneous application of chest and abdominal compression (CPS; n = 6) or cardiopulmonary bypass (CPB; n = 14) was used to maintain the donors. At a minimum follow-up of 2 years, actuarial patient and graft survival rates with livers from Maastricht category 2 NHBD were 80% and 55%, respectively. Transplantation of organs from these donors was associated with a significantly higher incidence of primary nonfunction, biliary complications, and more severe initial liver dysfunction compared with organs from HBDs. The graft survival rates was 83% for livers from NHBDs preserved with CPS and 42% in those maintained with CPB.

  8. Living-Donor Liver Transplant: An Analysis of Postoperative Outcome and Health-Related Quality of Life in Liver Donors.

    Science.gov (United States)

    Benzing, Christian; Schmelzle, Moritz; Oellinger, Robert; Gruettner, Katharina; Muehlisch, Anja-Kathrin; Raschzok, Nathanael; Sauer, Igor; Bahra, Marcus; Pratschke, Johann; Guel-Klein, Safak

    2018-01-02

    Living-donor liver transplant represents an established alternative to deceased-donor liver transplant. The procedure is considered safe for donors; however, concerns about the donors' health-related quality of life and health status have not been fully addressed. Here, we aimed to assess the health-related quality of life and postoperative and 1-year clinical outcomes in living liver transplant donors. All patients undergoing liver resection for adult-to-adult living-donor liver transplant at our center between December 1999 and March 2013 were evaluated retrospectively. Health-related quality of life was evaluated in a second assessment through written health-related quality of life questionnaires (the Short Form 36 assessment tool) sent to all patients who underwent liver resection for living-donor liver transplant between 1989 and 2012. We identified 104 patients who underwent liver resection for living-donor liver donation between December 1999 and March 2013. Postoperative morbidity was 35.9%, with 56.8% of patients having minor complications. No postoperative, 30-day, or 90-day mortality was evident. At year 1 after transplant, 30 patients (28.8%) had (ongoing) complications, of which 80% were considered minor according to Clavien-Dindo classification. Regarding health-related quality of life, liver donors were characterized as having significantly higher scores in the general health perception component in the Short Form 36 assessment tool (P .05). Liver donors are characterized by an excellent health-related quality of life that is comparable to the general population. Because some donors tend to have concerns regarding their employment status after the procedure, a comprehensive and critical evaluation of potential donors is needed.

  9. Immobilisation of ligands by radio-derivatized polymers; Immobilisering av ligander med radioderiverte polymerer

    Energy Technology Data Exchange (ETDEWEB)

    Varga, J.M.; Fritsch, P.

    1995-01-30

    The invention relates to radio-derivatized polymers and a method of producing them by contacting non-polymerizable conjugands with radiolysable polymers in the presence of irradiation. The resulting radio-derivatized polymers can be further linked with ligand of organic or inorganic nature to immobilize such ligands. 2 figs., 5 tabs.

  10. Dual kidney transplants from adult marginal donors successfully expand the limited deceased donor organ pool.

    Science.gov (United States)

    Stratta, Robert J; Farney, Alan C; Orlando, Giuseppe; Farooq, Umar; Al-Shraideh, Yousef; Palanisamy, Amudha; Reeves-Daniel, Amber; Doares, William; Kaczmorski, Scott; Gautreaux, Michael D; Iskandar, Samy S; Hairston, Gloria; Brim, Elizabeth; Mangus, Margaret; El-Hennawy, Hany; Khan, Muhammad; Rogers, Jeffrey

    2016-04-01

    The need to expand the organ donor pool remains a formidable challenge in kidney transplantation (KT). The use of expanded criteria donors (ECDs) represents one approach, but kidney discard rates are high because of concerns regarding overall quality. Dual KT (DKT) may reduce organ discard and optimize the use of kidneys from marginal donors. We conducted a single-center retrospective review of outcomes in adult recipients of DKTs from adult marginal deceased donors (DD) defined by limited renal functional capacity. If the calculated creatinine clearance in an adult DD was donors, and 10 from standard criteria donors (SCD). Mean adult DD and recipient ages were both 60 yr, including 29 DDs and 26 recipients ≥65 yr of age. Mean pre-DKT waiting and dialysis vintage times were 12 months and 25 months, respectively. Actual patient and graft survival rates were 84.7% and 70.8%, respectively, with a mean follow-up of 58 months. One yr and death-censored graft survival rates were 90% and 80%, respectively. Outcomes did not differ by DD category, recipient age, or presence of delayed graft function (DGF). Eleven patients died at a mean of 32 months post-DKT (eight with functioning grafts) and 13 other patients experienced graft losses at a mean of 33 months. The incidence of DGF was 25%; there were two cases (2.8%) of primary non-function. Mean length of initial hospital stay was 7.2 d. Mean serum creatinine and glomerular filtration rate levels at 12 and 24 months were 1.5 and 53 and 1.5 mg/dL and 51 mL/min/1.73 m(2) , respectively. DKT graft survival and function were superior to concurrent single ECD and similar to concurrent SCD KTs. Two patients underwent successful kidney retransplantation, so the dialysis-free rate in surviving patients was 87%. The proportion of total renal function transplanted from adult DD to DKT recipients was 77% compared to 56% for patients receiving single KTs. Dual kidney transplantation using kidneys from adult marginal DDs that

  11. Higher refusal rates for organ donation among older potential donors in the Netherlands: impact of the donor register and relatives.

    Science.gov (United States)

    van Leiden, Hendrik A; Jansen, Nichon E; Haase-Kromwijk, Bernadette J J M; Hoitsma, Andries J

    2010-09-27

    The availability of donor organs is considerably reduced by relatives refusing donation after death. There is no previous large-scale evaluation of the influence of the Donor Register (DR) consultation and the potential donor's age on this refusal in The Netherlands. This study examines 2101 potential organ donors identified in intensive care units between 2005 and 2008 and analyzes the association of DR consultation and subsequent refusal by relatives and the relationship with the potential donor's age. Of the 1864 potential donor cases where the DR was consulted, the DR revealed no registration in 56%, 20% registration of consent, and 18% objection. In the other 6.5% of cases, where the DR indicated that relatives had to decide, the relatives' refusal rate was significantly lower than in the absence of a DR registration (46% vs. 63%). In 6% of the cases where the DR recorded donation consent, relatives still refused donation. DR registration, objection in the DR, and the relatives' refusal rate if the DR was not decisive increased with donor age. Despite the introduction of a DR, relatives still play an equally important role in the final decision for organ donation. The general public should be encouraged to register their donation preferences in the DR and also to discuss their preferences with their families. The higher refusal rate of older potential donors means that this group should receive more information about organ donation, especially because the cohort of available donors is ageing.

  12. Multiple organ procurement from one donor.

    Science.gov (United States)

    Brodman, R F; Veith, F J; Goldsmith, J; Sisto, D A; Montefusco, C M

    1985-02-01

    To maximize organ utilization, we assessed the feasibility of retrieving the heart and two single lungs or the heart and a separate bilateral lung block for transplantation into multiple recipients. In eight dogs the excision of the heart-lung block or of the left lung was followed by six hours of lung preservation. Four of these lungs and all eight hearts were transplanted successfully. In addition, satisfactory retrieval of the three separate organs or of the heart and a separate bilateral lung block was done in six human cadavers. An appropriate division of the left atrial wall provided suitable cuffs for individual transplantation of the three organs or for the heart and bilateral lung block. This study demonstrates the feasibility of multiple organ donation from a single donor followed by separate organ transplantation.

  13. A General Ligand Design for Gold Catalysis allowing Ligand-Directed Anti Nucleophilic Attack of Alkynes

    Science.gov (United States)

    Wang, Yanzhao; Wang, Zhixun; Li, Yuxue; Wu, Gongde; Cao, Zheng; Zhang, Liming

    2014-01-01

    Most homogenous gold catalyses demand ≥0.5 mol % catalyst loading. Due to the high cost of gold, these reactions are unlikely to be applicable in medium or large scale applications. Here we disclose a novel ligand design based on the privileged biphenyl-2-phosphine framework that offers a potentially general approach to dramatically lowering catalyst loading. In this design, an amide group at the 3’ position of the ligand framework directs and promotes nucleophilic attack at the ligand gold complex-activated alkyne, which is unprecedented in homogeneous gold catalysis considering the spatial challenge of using ligand to reach antiapproaching nucleophile in a linear P-Au-alkyne centroid structure. With such a ligand, the gold(I) complex becomes highly efficient in catalyzing acid addition to alkynes, with a turnover number up to 99,000. Density functional theory calculations support the role of the amide moiety in directing the attack of carboxylic acid via hydrogen bonding. PMID:24704803

  14. A new class of PN3-pincer ligands for metal–ligand cooperative catalysis

    KAUST Repository

    Li, Huaifeng

    2014-12-01

    Work on a new class of PN3-pincer ligands for metal-ligand cooperative catalysis is reviewed. While the field of the pyridine-based PN3-transition metal pincer complexes is still relatively young, many important applications of these complexes have already emerged. In several cases, the PN3-pincer complexes for metal-ligand cooperative catalysis result in significantly improved or unprecedented activities. The synthesis and coordination chemistry of PN3-pincer ligands are briefly summarized first to cover the synthetic routes for their preparation, followed by a focus review on their applications in catalysis. A specific emphasis is placed on the later section about the role of PN3-pincer ligands\\' dearomatization-rearomatization steps during the catalytic cycles. The mechanistic insights from density functional theory (DFT) calculations are also discussed.

  15. Estimated organ donor potential in German maximum care hospitals.

    Science.gov (United States)

    Kirchner, C; Raduenz, S; Fruehauf, N R; Heuer, M; Juntermanns, B; Paul, A; Kaiser, G M

    2013-05-01

    The decreasing number of organ donors in Germany remains a major issue in transplantation medicine. The aim of this study was to estimate the organ donor potential at German maximum care hospitals. To critically review potential in comparison with organ donation rates in 2010. We separated Maximum care hospitals into university institutions (A-level) and centers with a neurosurgical unit (B-level) based upon the size of hospital as indicated by the total number of beds. To estimate the number of possible organ donors, we adopted the American model previously published by Sheehy et al: the potential was 0.015 organ donors/bed/year for hospitals with more than 350 beds. In 2010 overall in Germany there were 1296 organ donations resulting in 4205 transplanted organs. University hospitals realized 397 organ donations namely 0.008 organ donors/bed/year (57% of calculated organ donor potential), whereas B-level hospitals accounted for 555 of organ donors with a rate of 0.007 organ donors/bed/year (48% of calculated organ donor potential). Large variations in realizing organ donations occurred among single hospitals. Our results indicated a substantial potential to increase organ donation rates in German maximum care hospitals. These hospitals (n = 145) are responsible for 73% (non-maximum care hospital n = 1195) of the absolute organ donor pool. Further studies are needed to evaluate possibilities to address the organ shortage particularly with regard to donor detection in intensive care units and also the refusal rate by families. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Stability of Organ Donor Designations on Driver's Licenses.

    Science.gov (United States)

    Sehgal, N K R; Sullivan, C; Figueroa, M; Pencak, J A; Thornton, J D

    2016-01-01

    Little is known about the stability of decisions that people make to be organ donors. We sought to determine the rate of stability of organ donor designations on driver's licenses. With the use of a cross-sectional study design, we reviewed the health records of 2500 randomly selected primary-care patients at a large urban safety-net medical system to obtain their demographic and medical characteristics. We also examined the two most recent unique driver's licenses, state identification cards, or learner's permits that were scanned into electronic health records as part of the patient registration process. We obtained organ donor designations from these documents for each patient. Of all patients, 1174 (47%) had two driver's licenses, identification cards, or permits in their electronic medical records. The two documents were issued an average of 3.5 years apart. Overall, 114 (10%) patients had differing organ donor designations on their two documents. Among the 502 patients who were designated as organ donors on the first document, 32 (6%) were not designated as organ donors on the second document. Among the 672 patients who were not designated as organ donors on the first document, 82 (12%) were designated as organ donors on the second document. There was little relationship between stability of organ donor designations and patient demographic and medical characteristics. About 1 of every 10 patients changed their organ donor designation, but stability was not associated with any demographic or medical factors. Further work is needed to understand why individuals change their organ donor designation. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Effects of PPARγ ligands on vascular tone.

    Science.gov (United States)

    Salomone, Salvatore; Drago, Filippo

    2012-06-01

    Peroxisome Proliferator-Activated Receptor γ (PPARγ), originally described as a transcription factor for genes of carbohydrate and lipid metabolism, has been more recently studied in the context of cardiovascular pathophysiology. Here, we review the available data on PPARγ ligands as modulator of vascular tone. PPARγ ligands include: thiazolidinediones (used in the treatment of type 2 diabetes mellitus), glitazars (bind and activate both PPARγ and PPARα), and other experimental drugs (still in development) that exploit the chemistry of thiazolidinediones as a scaffold for PPARγ-independent pharmacological properties. In this review, we examine both short (mostly from in vitro data)- and long (mostly from in vivo data)-term effects of PPARγ ligands that extend from PPARγ-independent vascular effects to PPARγ-dependent gene expression. Because endothelium is a master regulator of vascular tone, we have attempted to differentiate between endothelium-dependent and endothelium-independent effects of PPARγ ligands. Based on available data, we conclude that PPARγ ligands appear to influence vascular tone in different experimental paradigms, most often in terms of vasodilatation (potentially increasing blood flow to some tissues). These effects on vascular tone, although potentially beneficial, must be weighed against specific cardiovascular warnings that may apply to some drugs, such as rosiglitazone.

  18. LIBRA: LIgand Binding site Recognition Application.

    Science.gov (United States)

    Hung, Le Viet; Caprari, Silvia; Bizai, Massimiliano; Toti, Daniele; Polticelli, Fabio

    2015-12-15

    In recent years, structural genomics and ab initio molecular modeling activities are leading to the availability of a large number of structural models of proteins whose biochemical function is not known. The aim of this study was the development of a novel software tool that, given a protein's structural model, predicts the presence and identity of active sites and/or ligand binding sites. The algorithm implemented by ligand binding site recognition application (LIBRA) is based on a graph theory approach to find the largest subset of similar residues between an input protein and a collection of known functional sites. The algorithm makes use of two predefined databases for active sites and ligand binding sites, respectively, derived from the Catalytic Site Atlas and the Protein Data Bank. Tests indicate that LIBRA is able to identify the correct binding/active site in 90% of the cases analyzed, 90% of which feature the identified site as ranking first. As far as ligand binding site recognition is concerned, LIBRA outperforms other structure-based ligand binding sites detection tools with which it has been compared. The application, developed in Java SE 7 with a Swing GUI embedding a JMol applet, can be run on any OS equipped with a suitable Java Virtual Machine (JVM), and is available at the following URL: http://www.computationalbiology.it/software/LIBRAv1.zip. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Dockomatic - automated ligand creation and docking.

    Science.gov (United States)

    Bullock, Casey W; Jacob, Reed B; McDougal, Owen M; Hampikian, Greg; Andersen, Tim

    2010-11-08

    The application of computational modeling to rationally design drugs and characterize macro biomolecular receptors has proven increasingly useful due to the accessibility of computing clusters and clouds. AutoDock is a well-known and powerful software program used to model ligand to receptor binding interactions. In its current version, AutoDock requires significant amounts of user time to setup and run jobs, and collect results. This paper presents DockoMatic, a user friendly Graphical User Interface (GUI) application that eases and automates the creation and management of AutoDock jobs for high throughput screening of ligand to receptor interactions. DockoMatic allows the user to invoke and manage AutoDock jobs on a single computer or cluster, including jobs for evaluating secondary ligand interactions. It also automates the process of collecting, summarizing, and viewing results. In addition, DockoMatic automates creation of peptide ligand .pdb files from strings of single-letter amino acid abbreviations. DockoMatic significantly reduces the complexity of managing multiple AutoDock jobs by facilitating ligand and AutoDock job creation and management.

  20. Dockomatic - automated ligand creation and docking

    Directory of Open Access Journals (Sweden)

    Hampikian Greg

    2010-11-01

    Full Text Available Abstract Background The application of computational modeling to rationally design drugs and characterize macro biomolecular receptors has proven increasingly useful due to the accessibility of computing clusters and clouds. AutoDock is a well-known and powerful software program used to model ligand to receptor binding interactions. In its current version, AutoDock requires significant amounts of user time to setup and run jobs, and collect results. This paper presents DockoMatic, a user friendly Graphical User Interface (GUI application that eases and automates the creation and management of AutoDock jobs for high throughput screening of ligand to receptor interactions. Results DockoMatic allows the user to invoke and manage AutoDock jobs on a single computer or cluster, including jobs for evaluating secondary ligand interactions. It also automates the process of collecting, summarizing, and viewing results. In addition, DockoMatic automates creation of peptide ligand .pdb files from strings of single-letter amino acid abbreviations. Conclusions DockoMatic significantly reduces the complexity of managing multiple AutoDock jobs by facilitating ligand and AutoDock job creation and management.

  1. Chelating ligands for nanocrystals' surface functionalization.

    Science.gov (United States)

    Querner, Claudia; Reiss, Peter; Bleuse, Joël; Pron, Adam

    2004-09-22

    A new family of ligands for the surface functionalization of CdSe nanocrystals is proposed, namely alkyl or aryl derivatives of carbodithioic acids (R-C(S)SH). The main advantages of these new ligands are as follows: they nearly quantitatively exchange the initial surface ligands (TOPO) in very mild conditions; they significantly improve the resistance of nanocrystals against photooxidation because of their ability of strong chelate-type binding to metal atoms; their relatively simple preparation via Grignard intermediates facilitates the development of new bifunctional ligands containing, in addition to the anchoring carbodithioate group, a second function, which enables the grafting of molecules or macromolecules of interest on the nanocrystal surface. To give an example of this approach, we report, for the first time, the grafting of an electroactive oligomer from the polyaniline family-aniline tetramer-on CdSe nanocrystals after their functionalization with 4-formyldithiobenzoic acid. The grafting proceeds via a condensation reaction between the aldehyde group of the ligand and the terminal primary amine group of the tetramer. The resulting organic/inorganic hybrid exhibits complete extinction of the fluorescence of its constituents, indicating efficient charge or energy transfer between the organic and the inorganic semiconductors.

  2. Ligand identification using electron-density map correlations

    International Nuclear Information System (INIS)

    Terwilliger, Thomas C.; Adams, Paul D.; Moriarty, Nigel W.; Cohn, Judith D.

    2007-01-01

    An automated ligand-fitting procedure is applied to (F o − F c )exp(iϕ c ) difference density for 200 commonly found ligands from macromolecular structures in the Protein Data Bank to identify ligands from density maps. A procedure for the identification of ligands bound in crystal structures of macromolecules is described. Two characteristics of the density corresponding to a ligand are used in the identification procedure. One is the correlation of the ligand density with each of a set of test ligands after optimization of the fit of that ligand to the density. The other is the correlation of a fingerprint of the density with the fingerprint of model density for each possible ligand. The fingerprints consist of an ordered list of correlations of each the test ligands with the density. The two characteristics are scored using a Z-score approach in which the correlations are normalized to the mean and standard deviation of correlations found for a variety of mismatched ligand-density pairs, so that the Z scores are related to the probability of observing a particular value of the correlation by chance. The procedure was tested with a set of 200 of the most commonly found ligands in the Protein Data Bank, collectively representing 57% of all ligands in the Protein Data Bank. Using a combination of these two characteristics of ligand density, ranked lists of ligand identifications were made for representative (F o − F c )exp(iϕ c ) difference density from entries in the Protein Data Bank. In 48% of the 200 cases, the correct ligand was at the top of the ranked list of ligands. This approach may be useful in identification of unknown ligands in new macromolecular structures as well as in the identification of which ligands in a mixture have bound to a macromolecule

  3. The impact of meeting donor management goals on the number of organs transplanted per donor: results from the United Network for Organ Sharing Region 5 prospective donor management goals study.

    Science.gov (United States)

    Malinoski, Darren J; Patel, Madhukar S; Daly, Michael C; Oley-Graybill, Chrystal; Salim, Ali

    2012-10-01

    Many organ procurement organizations have implemented critical care end points as donor management goals in efforts to increase organs transplanted per donor after neurologic determination of death. Although retrospective studies have demonstrated an association between meeting donor management goals and organ yield, prospective studies are lacking. In June 2008, nine donor management goals were prospectively implemented as a checklist and every donor after neurologic determination of death was managed to meet them. The donor management goals represented normal cardiovascular, pulmonary, renal, and endocrine end points. Data were collected for 7 months. Donor management goals "met" was defined a priori as achieving any seven of the nine donor management goals, and this was recorded at the time of consent, 12-18 hrs later, and prior to organ recovery. The primary outcome measure was ≥4 organs transplanted per donor, and binary logistic regression was used to identify independent predictors of this outcome with a porgan procurement organizations in the five Southwestern United States (United Network for Organ Sharing Region 5). All standard criteria donors after neurologic determination of deaths. Prospective implementation of a donor management goal checklist. There were 380 standard criteria donors with 3.6±1.7 organs transplanted per donor. Fifteen percent had donor management goals met at the time of consent, 33% at 12-18 hrs, and 38% prior to organ recovery. Forty-eight percent had ≥4 organs transplanted per donor. Donors with ≥4 organs transplanted per donor had significantly more individual donor management goals met at all three time points. Independent predictors of ≥4 organs transplanted per donor were age (odds ratio=0.95 per year), final creatinine (odds ratio=0.75 per 1-unit increase), donor management goals "met" at consent (odds ratio=2.03), donor management goals "met" prior to organ recovery (odds ratio=2.34), and a change in the number of

  4. Improving first-time donor attendance rates through the use of enhanced donor preparation materials.

    Science.gov (United States)

    Masser, Barbara; France, Christopher R; Foot, Jayne; Rozsa, Amy; Hayman, Jane; Waller, Daniel; Hunder, Everard

    2016-06-01

    Many nondonors are positive about blood donation and this motivates booking an appointment to donate. However, as their appointment approaches barriers to donating-such as anxiety-may become salient and deter attendance. Building on research of France and colleagues demonstrating the positive effect of enhanced preparation materials on donor recruitment, this study sought to determine whether these materials could effectively boost first donation appointment attendance. A field study comprising a 3 (brochure: none, e-mail, hard copy) × 2 (national call center [NCC] contact: none, call) between-subjects design was conducted with 3646 nondonors who had scheduled their first appointment. Participants in the brochure conditions received either a hard copy or an e-mailed link to electronic materials modeled on the donor preparation research of France and colleagues. Participants in the NCC call condition also received a call scripted in line with these preparation materials. The key outcome was new donor attendance rate. Although first-appointment attendance rates were high in the control (no additional contact) condition at 85.07% of those not canceling in advance, dual exposure to the preparation materials through a NCC call and an electronic brochure boosted attendance. The relative risk of attending in the NCC call and electronic brochure condition was 1.0836 (95% confidence interval, 1.0352-1.1343; p = 0.0006), with attendance 8.36% higher than in the control. This gain in attendance came at a relative increase in recruitment costs of 2%. The use of tailored communication to address new donors' concerns and prepare them for donating bolsters attendance rates. © 2016 AABB.

  5. Quantity ratio stability of complexes of lanthanide ions with aminopolycarboxylic acids when adding the second molecule of ligand

    International Nuclear Information System (INIS)

    Meshkova, S.B.; Poluehktov, N.S.; Danilkovich, M.M.

    1985-01-01

    Changes in stability of lanthanide (Ln) complexes when the second molecule of ligand (Lig) is added, are considered, using the ratios, which have been previously derived, that correlate properties of Ln trivalent ions or their compounds with the number of f-electrons (Nsub(F)), and with spin S and orbital L quantum numbers of their ground states: lgKsub(Ln)=lgKsub(La)+αNsub(F)+βxS+γ'xLsub(1-6) (γ''Lsub(8-13)) On the basis of calculated values of correlation coefficients α, β, γ' and γ'' the change in the complex stability from LnLig to LnLig 2 , in which interaction of spin and orbital angular momenta of Ln 3+ and ligand donor atom can produce both stabilizing and destabilizing effect on the complex stability, has been explained. The interaction is different for aminopolycarbonic acid of different dentate nature

  6. Supramolecular Isomers of Metal-Organic Frameworks Derived from a Partially Flexible Ligand with Distinct Binding Motifs

    KAUST Repository

    Abdul Halim, Racha Ghassan

    2016-01-04

    Three novel metal-organic frameworks (MOFs) were isolated upon reacting a heterofunctional ligand 4 (pyrimidin-5 yl)benzoic acid (4,5-pmbc) with mixed valence Cu(I,II) under solvothermal conditions. X-ray crystal structural analysis reveals that the first compound is a layered structure composed of one type of inorganic building block, dinuclear paddlewheel [Cu2(O2C–)4], which are linked through 4,5-pmbc ligands. The two other supramolecular isomers are composed of the same Cu(II) dinuclear paddlewheel and a dinuclear Cu2I2 cluster, which are linked via the 4,5-pmbc linkers to yield two different 3-periodic frameworks with underlying topologies related to lvt and nbo. The observed structural diversity in these structures is due to the distinct coordination modes of the two coordinating moieties (the carboxylate group on the phenyl ring and the N-donor atoms from the pyrimidine moiety).

  7. Characteristic molecular vibrations of adenosine receptor ligands.

    Science.gov (United States)

    Chee, Hyun Keun; Yang, Jin-San; Joung, Je-Gun; Zhang, Byoung-Tak; Oh, S June

    2015-02-13

    Although the regulation of membrane receptor activation is known to be crucial for molecular signal transduction, the molecular mechanism underlying receptor activation is not fully elucidated. Here we study the physicochemical nature of membrane receptor behavior by investigating the characteristic molecular vibrations of receptor ligands using computational chemistry and informatics methods. By using information gain, t-tests, and support vector machines, we have identified highly informative features of adenosine receptor (AdoR) ligand and corresponding functional amino acid residues such as Asn (6.55) of AdoR that has informative significance and is indispensable for ligand recognition of AdoRs. These findings may provide new perspectives and insights into the fundamental mechanism of class A G protein-coupled receptor activation. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  8. Effects of PPARγ Ligands on Leukemia

    Directory of Open Access Journals (Sweden)

    Yoko Tabe

    2012-01-01

    Full Text Available Peroxisome proliferator-activated receptors (PPARs and retinoic acid receptors (RARs, members of the nuclear receptor superfamily, are transcription factors that regulate a variety of important cellular functions. PPARs form heterodimers retinoid X receptor (RXR, an obligate heterodimeric partner for other nuclear receptors. Several novel links between retinoid metabolism and PPAR responses have been identified, and activation of PPAR/RXR expression has been shown to increase response to retinoids. PPARγ has emerged as a key regulator of cell growth and survival, whose activity is modulated by a number of synthetic and natural ligands. While clinical trials in cancer patients with thiazolidinediones (TZD have been disappointing, novel structurally different PPARγ ligands, including triterpenoids, have entered clinical arena as therapeutic agents for epithelial and hematopoietic malignancies. Here we shall review the antitumor advances of PPARγ, alone and in combination with RARα ligands in control of cell proliferation, differentiation, and apoptosis and their potential therapeutic applications in hematological malignancies.

  9. Current status of malaria parasite among blood donors in Port ...

    African Journals Online (AJOL)

    Donors having the blood group O were more infected (60.70%) than the other blood groups and the lowest was blood group AB (5.40%). This result shows that there is a relatively high prevalence of malaria parasite among the blood donors in Port Harcourt, Nigeria. It is, therefore, recommended that malaria parasite ...

  10. Prevalence of HIV positive blood donors among screened ...

    African Journals Online (AJOL)

    Two thousand five hundred and thirty two (2,532) males, aged 25 – 50 years potential blood donors were randomly selected from the total number of volunteer blood donors who satisfied the initial screening criteria for donating blood, and were screened for HIV using Immunocomb II (HIV 1 and 2 Bispot) and Recombigen ...

  11. Unconfirmed reactive screening tests and their impact on donor management

    International Nuclear Information System (INIS)

    Rahman, M.; Khan, S.A.

    2008-01-01

    To determine the percentage of false positive testing for transfusion transmitted infections (TTIs) using immunochromatographic test (ICT) as first line of screening tests and its effect on loss of volunteer blood donors. Over a period of three months, samples from blood bags of donors undergoing phlebotomy at teaching hospital blood banks in Lahore were screened for human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV) by immunochromatographic tests. Those found positive on initial screening were re-tested by ELISA method at the screening laboratory of the Institute of Haematology and Blood Transfusion Service, Punjab. Lahore. Out of a total of 62090 voluntary blood donors, 469 donors were found to be initially reactive for either HIV, HBV or HCV. Amongst these 96 (0.15%) blood donors were found to have tested falsely positive for HIV, HBV or HCV as compared to testing by ELISA. False positive testing rate of 0.15% or 96 out of a total of 62090 donors is rather small in terms of loss of voluntary donors and appropriate utilization of available resources. Although immunochromatographic testing is not the gold standard, however it serves an important purpose of initial donor screening. (author)

  12. The Prevalence of Syphilis Among Blood Donors in a Centralized ...

    African Journals Online (AJOL)

    BACKGROUND: Syphilis is one of the mandatory transfusion transmissible infections to be tested for in any unit of blood for homologous transfusion. The paucity of voluntary blood donors in Nigeria has compelled health care providers to rely on paid and family replacement donors for blood. AIMS: This study was carried ...

  13. Transfusion of the dangerous universal donor blood leading to ...

    African Journals Online (AJOL)

    Background: In a health-care setting in which group-identical donor blood is not always available for transfusion, group O whole blood, in the obsolete concept of its being a universal donor, is sometimes given to group A and B recipients without necessary precautions. Objectives: The objective is to draw attention to the ...

  14. Live nondirected uterus donors: Psychological characteristics and motivation for donation.

    Science.gov (United States)

    Warren, A M; Testa, G; Anthony, T; McKenna, G J; Klintmalm, G B; Wallis, K; Koon, E C; Gunby, R T; Johannesson, L

    2018-01-24

    Emerging research suggests that uterus transplantation is a viable option for women without a uterus who want to become pregnant and carry a child to term. Currently, no knowledge exists regarding nondirected uterus donors. This study (NCT 02656550) explored the baseline psychological characteristics of nondirected uterus donors at a single study site. Of the 62 potential donors who underwent initial screening, 6 nondirected donors were chosen and participated in uterus donation. Participants received a comprehensive evaluation, which included clinical history and psychological assessments. The mean age of the donors was 42 years; most (83%) were white/not Hispanic, and all had a college degree. Current depression was reported by 2 participants, past depression was reported in 2 participants, and past anxiety was reported in 3 participants. Based on several different psychological measures, donors had a higher general well-being than the normative sample, and none of the participants' scores indicated psychological distress. All 6 women indicated that giving another woman an opportunity to carry her own child was a motivation for pursuing uterus donation. Further research on potential psychological motives and gains for the donor as well as long-term effects on donors is crucial for ethical practice. © 2018 The American Society of Transplantation and the American Society of Transplant Surgeons.

  15. Seroprevalence of hiv and hepatitis viruses in directed blood donors ...

    African Journals Online (AJOL)

    Aims: To determine the seroprevalence of HIV and Hepatitis B viruses in directed blood donors in Nguru and also to see if there is co-infection of these viruses in this category of donor population. Method: This is a prospective study carried out at the blood bank of the Federal Medical Centre Nguru, Yobe State between ...

  16. Seroprevalence of Treponema Pallidum in Donor Blood at the ...

    African Journals Online (AJOL)

    Objectives: To determine the Seroprevalence of Treponema pallidum in Donor blood at University of Benin Teaching Hospital Benin City. Materials and Method: This is a descriptive hospital based study. Donor blood supplied to the hospital blood bank was screened for syphilis. The study was conducted between February ...

  17. Adverse reactions in voluntary whole blood donors: Experience at ...

    African Journals Online (AJOL)

    Materials and methods: A prospective study was conducted and data collected from January 2006 to December 2012 at the National Blood Transfusion Centre in Kinshasa, Democratic Republic of Congo. In this centre, all blood donors are voluntary and blood donation is only of whole blood. All donor events and ...

  18. Haemoglobin variants among voluntary blood donors in Jos, Nigeria ...

    African Journals Online (AJOL)

    This study aimed to determine the haemoglobin variants among voluntary blood donors in Jos. METHOD: Records of the age, sex, Haemoglobin level, and the haemoglobin genotype of all voluntary blood donors who donated blood at the National Blood Transfusion Service Centre, Jos, Nigeria between January 2011 and ...

  19. 21 CFR 640.63 - Suitability of donor.

    Science.gov (United States)

    2010-04-01

    ... the plasma; (9) Freedom from any disease, other than malaria, transmissible by blood transfusion... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified...

  20. 21 CFR 640.3 - Suitability of donor.

    Science.gov (United States)

    2010-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Whole Blood § 640.3 Suitability of donor. (a) Method of determining. The suitability of a donor as a source of Whole Blood shall be determined by a... transmissible by blood transfusion, insofar as can be determined by history and examinations indicated above...