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Mononuclear
Terms modified by Mononuclear Selected AbstractsThe Role of Functionalisation, Asymmetry and Shape of a New Macrocyclic Compartmental Ligand in the Formation of Mononuclear, Homo- and Heterodinuclear Lanthanide(III) ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2009Sergio Tamburini Abstract The compartmental [1+1] macrocycle H3L, obtained by self-condensation of the formyl precursor 3,3,-(3,6-dioxaoctane-1,8-diyldioxy)bis(2-hydroxybenzaldehyde) with the amine precursor N,N -bis(2-aminoethyl)-2-hydroxybenzylamine, contains one inner ON3O2 Schiff base and one outer O2O4 crown-like chamber. According to the experimental conditions it forms, by a template process, the stable mononuclear complexes Ln(H3L)(Cl)2(CH3COO)·nS·mHCl or [Ln(L)]·nS (Ln = La, Lu, Y, Yb, Er, Dy, Tb, Gd, Eu, Ce) with the lanthanide(III) ion encapsulated in the crown-ether-like and in the Schiff base site. The mononuclear complexes Ln(H3L)(Cl)2(CH3COO)·nS·mHCl, by further complexation with a different lanthanide(III) ion, give rise to the related heterodinuclear complexes [LnLn,(L)(Cl)2(CH3COO)]·nS while the homodinuclear and the heterodinuclear complexes [Ln2(L)](Cl)3·nH2O and [LnLn,(L)](Cl)3·nS could be prepared by a template reaction using the appropriate molar ratio of reactants. Their properties have been studied by using SEM-EDS microscopy, IR and NMR spectroscopy and their compositions confirmed by thermal and ESI-Mass spectrometric analyses. In the heterodinuclear complexes, the site occupancy of the different lanthanide(III) ions was determined by 1H and 13C NMR spectroscopy in CD3OD or (CD3)2SO , it was found that heterodinuclear complexation occurs in methanol with the smaller lanthanide(III) ion mainly coordinating to the Schiff base site and the larger lanthanide(III) ion to the crown site whereas, in dimethyl sulfoxide, demetalation of the weaker coordinated lanthanide(III) ion into the crown ether chamber occurs with the subsequent formation of mononuclear species in solution. The thermal decomposition of the heterodinuclear complexes forms the related mixed oxides, the stoichiometries and properties of which were determined by SEM-EDS microscopy and X-ray powder diffraction studies (XRD). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Zidovudine-loaded PLA and PLA,PEG blend nanoparticles: Influence of polymer type on phagocytic uptake by polymorphonuclear cellsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 1 2009Rubiana Mara Mainardes Abstract Mononuclear (macrophages) and polymorphonuclear leucocytes cells play an important role in the immunopathogenesis of acquired immunodeficiency syndrome. Zidovudine is a broad-spectrum drug used in current antiretroviral therapy. The development of controlled drug delivery systems for the treatment of chronic diseases is of great interest since these systems can act as vectors, carrying the drug only to the target, and the adverse effects can be reduced. In this study, PLA and PLA/PEG blend nanoparticles containing zidovudine were developed and their uptake by polymorphonuclear leucocytes were studied in vitro. The influence of polymer type on particle size, Zeta potential and particle uptake by polymorphonuclear leucocytes was investigated. The cells were isolated from rat peritoneal exudate and their activation by nanoparticles was measured by luminol-dependent chemiluminescence and microscopical analysis. The PEG in the blend modified the Zeta potential suggested the formation of a PEG coat on the particle surface. The phagocytosis depended on the PEG and its ratio in the blend, the results showed that the PLA nanoparticles were more efficiently phagocytosed than PLA/PEG blends. The blend with the highest PEG proportion did not prevent phagocytosis, indicating that the steric effect of PEG was concentration dependent. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:257,267, 2009 [source] The histopathology of alopecia areata in vertical and horizontal sectionsDERMATOLOGIC THERAPY, Issue 4 2001David A. Whiting Alopecia areata (AA) is a relatively common disease affecting 1.7% of Americans by the age of 50 years. The diagnosis is usually made on clinical grounds. In some cases the diagnosis is elusive and biopsies are necessary. In other cases biopsies are useful from a prognostic point of view to determine whether there are enough follicles left for possible future regrowth. In view of the active research being conducted into AA, biopsies provide valuable material for further investigation. The diagnosis of AA is improved by the use of horizontal sections in addition to or instead of vertical sections of scalp biopsies. The histopathologic features favoring the diagnosis of AA include peribulbar and intrabulbar mononuclear infiltrates, degenerative changes in the hair matrix, decreased numbers of terminal anagen follicles, increased numbers of terminal catagen and telogen follicles, an increased number of follicular stelae, an increased number of miniaturized vellus hair follicles, and pigment incontinence of hair bulbs and follicular stelae. Follicular counts with horizontal sections are particularly helpful in making the diagnosis of AA when the biopsy has been taken between acute episodes and the characteristic peribulbar inflammatory infiltrate is absent. [source] Fine-needle aspiration of brown tumor of bone: Cytologic features with radiologic and histologic correlationDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2009Ph.D., Sasha Pavlovic M.D. Abstract We report the case of a 40-year-old man with tertiary hyperparathyroidism due to end stage renal disease who initially presented with acute-onset paraplegia, elevated serum parathyroid hormone, and multiple bone abnormalities, including a large extradural intraspinal mass seen by magnetic resonance imaging. In contrast with imaging features, fine-needle aspiration cytology showed numerous benign-appearing multinucleated osteoclast-type giant cells that are the characteristics of either brown tumor or benign giant cell tumor of bone. Sheets of mononuclear spindled stromal cells were also noted. A core-needle biopsy confirmed the diagnostic features of brown tumor of hyperparathyroidism. Diagn. Cytopathol. 2009. © 2008 Wiley-Liss, Inc. [source] Ion-Selective Electrodes for Thiocyanate Based on the Dinuclear Zinc(II) Complex of a Bis- N,O -bidentate Schiff BaseELECTROANALYSIS, Issue 12 2004Philippe Bühlmann Abstract An ion selective electrode based on the dinuclear complex formed by two zinc(II) ions and two molecules of the bis- N,O -bidentate Schiff base 2,2,-[methylenebis(4,1-phenylenenitrilomethylidyne)]bisphenol exhibits thiocyanate selectivity with a good discrimination of nitrite, nitrate, and azide. The selectivities of electrode membranes with various compositions indicate that this potentiometric selectivity is based on the formation of a 1,:,1 complex between the thiocyanate anion and the dinuclear ionophore. The 2,:,1 ratio of thiocyanate ions and the dinuclear ionophore that results from higher ratios of cationic sites and ionophore worsens the selectivity, suggesting that binding of a thiocyanate to both zinc(II) centers of the dinuclear ionophore is not favorable. Interestingly, the selectivity patterns of these electrodes differ radically from that of a highly sulfate selective electrode based on a compound reported previously to be the analogous mononuclear 1,:,1 complex of zinc(II) and the same Schiff base. It is suggested that the previously reported 1,:,1 complex with zinc(II) may indeed have been a polymer of the same elemental composition. [source] A ,3 -Alkoxo-Bridged Tetranuclear [Cu4L2] Copper(II) Complex of a Hexadentate N2O4 Donor Ligand with a [6 + 0] Cu4O4 Cubane Core: Synthesis, Crystal Structure, and Magnetic PropertiesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2010Dipankar Maity Abstract A novel hexacoordinating non-Schiff base ligand (H4L) with N2O4 donor atoms has been synthesized by simple Mannich reactions. The use of this ligand with Cu(ClO4)2·6H2O in different molar ratios as well as pH leads to the formation of a mononuclear species and a tetranuclear CuII complex possessing a cubane [Cu4L2] core with almost equal Cu···Cu separation. In the presence of an excess amount of copper(II) ions and triethylamine at reflux, the mononuclear [CuH2L] species can be converted into the tetranuclear one, whereas the reverse process was not observed even after prolonged reaction time. Both the complexes have been characterized by single-crystal X-ray diffraction and magnetic measurements. Magnetic studies reveal that complex 1 displays a paramagnetic Curie-type behavior whereas 2 displays a singlet-spin ground state induced by strong intramolecular antiferromagnetic interactions. [source] Syntheses, Structures and Magnetic Properties of Trinuclear CuIIMIICuII (M = Cu, Ni, Co and Fe) and Tetranuclear [2×1+1×2] CuIIMnII,2CuII Complexes Derived from a Compartmental Ligand: The Schiff Base 3-Methoxysalicylaldehyde Diamine Can also Stabilize a CocrystalEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 20 2010Arpita Biswas Abstract The present investigation describes syntheses, characterization and studies of the mononuclear compound [CuIIL,(H2O)] (1), the triangular, trinuclear monophenoxido-bridged compounds [{CuIIL}2MII(H2O)2](ClO4)2·nH2O [2 (M = Cu, n = 0), 3 (M = Ni, n = 3), 4 (M = Co, n = 0), 5 (M = Fe, n = 0)] and the tetrametallic self-assembled complex [{CuIILMnII(H2O)3}{CuIIL}2](ClO4)2·H2O (6) derived from compartmental Schiff base ligand, H2L, which is the [2+1] condensation product of 3-methoxysalicylaldehyde and trans -1,2-diaminocyclohexane. Single-crystal X-ray structures of 2, 5 and 6 were determined. Two pairs of terminal···central metal ions in the trinuclear cores in 2 and 5 are monophenoxido-bridged. Interestingly, the CuO6 and FeO6 environments have tetragonally compressed octahedral geometries. On the other hand, the structure of 6 reveals that it is a [2×1+1×2] cocrystal of one diphenoxido-bridged dinuclear [CuIILMnII(H2O)3]2+ dication and two mononuclear [CuIIL] moieties. Cocrystallization in 6 takes place as a result of water encapsulation. The variable-temperature (2,300 K) magnetic susceptibilities of compounds 2,6 have been measured. The exchange integrals obtained are: the CuII3 compound 2, J = ,78.9 cm,1; the CuIINiIICuII compound 3, J = ,22.8 cm,1; the CuIICoIICuII compound 4, J = ,7.8 cm,1; the CuIIFeIICuII compound 5, J = ,3.0 cm,1; the CuII3MnII compound 6, J = ,15.1 cm,1. The monophenoxido-bridging core in 3 and 4 has been proposed after comparison of the structures and magnetic properties of these two compounds with those of 2, 5 and related other compounds. This paper presents rare examples of monophenoxido-bridged CuIIMIICuII (M = Cu, Ni, Co and Fe) compounds, provides an understanding of the structures from magnetic exchange integrals, and, most importantly, reports on the first example of a cocrystal derived from a 3-methoxysalicylaldehyde diamine compartmental ligand. [source] Studies on the Formation of CdS Nanoparticles from Solutions of (NMe4)4[Cd10S4(SPh)16]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2010Maria Bendova Abstract The stepwise cluster growth, and formation of CdS nanoparticles from solutions of (NMe4)4[Cd10S4(SPh)16] in dimethyl sulfoxide (DMSO), dimethylformamide (DMF) and acetonitrile was investigated. Cluster growth is fast in DMSO and DMF at room temperature, and slow in acetonitrile at elevated temperatures. Larger sulfide clusters (initially Cd32, then Cd54) are initially formed, which upon further growth eventually give rise to CdS nanoparticles. Strong evidence was found that the byproduct formed during the reaction in DMSO is mononuclear [Cd(SPh)x(DMSO)y](2,x) (x , 3). [source] Nucleophilic Addition of Water and Alcohols to Dicyanonitrosomethanide: Ligands with Diverse Bonding Modes in Magnetically Coupled d-Block ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2010Anthony S. R. Chesman Abstract Ligands resulting from the transition-metal-promoted nucleophilic addition of water or an alcohol to dicyanonitrosomethanide ions (dcnm) have been utilised in the formation of a large series of polynuclear complexes. Addition of water to dcnm results in formation of carbamoylcyanonitrosomethanide (ccnm); deprotonation of this ligand gives amidocarbonyl(cyano)nitrosomethanide (acnm), which has been incorporated into the trinuclear complex [Cu3(acnm)2(dmae)2(H2O)2] [dmae = 2-(dimethylamino)ethoxide] (1) which shows strong antiferromagnetic coupling with an exchange coupling constant, J = ,500 cm,1. [Cu(acnm)(NH3)2], (2) marks the first instance of acnm facilitating the formation of a coordination polymer, namely a 1D chain with intramolecular hydrogen bonding. Attempts to synthesise 2 through different reaction conditions instead resulted in the mononuclear [Cu(acnm)(NH3)2(py)] (py = pyridine) (3). The addition of ethanol to dcnm results in cyano[imino(ethoxy)methyl]nitrosomethanide (cenm) which features in the mononuclear [Cu(cenm)2(H2O)2] (4) and polymeric {[Cu(cenm)2]2·H2O}, (5). The latter is the first example of the cenm ligand in a coordination polymer and has a highly unusual coordination mode through the nitrile groups and extremely weak antiferromagnetic coupling. {[Mn3(ccnm)2(EtOH)2(OAc)4]·2EtOH}, (6) and (Et4N)2[Cu(ccnm)4] (7) contain previously unobserved coordination modes of the ccnm ligand while the complex [Mn(cmnm)3Mn(bipy)(MeOH)](ClO4) (8) {cmnm = cyano[imino(methoxy)methyl]nitrosomethanide, bipy = 2,2,-bipyridine} displays weak antiferromagnetic coupling between manganese atoms with J = ,1.44 cm,1. A change in the solvent systems used in the synthesis of 7 results in the formation of the mononuclear complexes [Mn(bipy)2(dcnm)2] (9) or [Mn(bipy)2(H2O)(dcnm)](dcnm)·H2O (10) and [Mn(bipy)2(dcnm)(H2O)](dcnm) (11). The addition of ethlyene glycol monomethyl ether to dcnm gives cyano[imino(2-methoxyethoxy)methyl]nitrosomethanide (cgnm) and the formation of [Cu(cgnm)2(H2O)2] (12). [source] Unconventional Spin Crossover in Dinuclear and Trinuclear Iron(III) Complexes with Cyanido and Metallacyanido BridgesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2009alitro Abstract A nonsymmetrical triamine, 1,6-diamino-4-azahexane, was Schiff-condensed with (X-substituted) o -salicylaldehyde to yield pentadentate ligands X-L5: salpet and MeBu-salpet. These ligands form mononuclear, dinuclear, and trinuclear FeIII complexes, whose structures were determined by single-crystal X-ray analysis. Of the mononuclear complexes, [FeIII(salpet)Cl] and [FeIII(MeBu-salpet)Cl] are high spin (S = 5/2), whereas [FeIII(salpet)CN]·MeOH is low spin (S = 1/2). The dinuclear and trinuclear complexes show a kind ofthermally induced spin crossover. The dinuclear complex [L5FeIII(CN)FeIIIL5](ClO4)·2H2O (L5 = salpet) is a mixed-spin assembly: the C -coordinated FeIII center is low spin (L) and the N -coordinated FeIII center is high spin (H) at low temperature; an antiferromagnetic interaction occurs between them. This LH reference state is mixed with the LL one. Upon heating, the system shows an increasing content of the HH state. Also, the dinuclear complex [L5FeIII(CN)FeIIIL5](BPh4)·2MeCN (L5 = MeBu-salpet) exhibits a spin transition between LH and HH spin pairs. The mixed-valence trinuclear complex [L5FeIII{FeII(CN)5(NO)}FeIIIL5]·0.5MeOH·3.75H2O (L5 = salpet) shows spin crossover with a residual high-spin fraction at liquid He temperature owing to the LL + LH ground state. The metallacyanido-bridged complex [L5FeIII{Ni(CN)4}FeIIIL5]·2MeOH (L5 = MeBu-salpet) contains a high-spin pair, HH, over the whole temperature interval with a ferromagnetic exchange interaction. A theoretical model was outlined that allows simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, high-spin mole fraction obtained from the Mössbauer spectra) on a common set of parameters. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis, Structure, Conductivity, and Calculated Nonlinear Optical Properties of Two Novel Bis(triphenylphosphane)copper(I) Dithiocarbamates,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2009Abhinav Kumar Abstract A centrosymmetric binuclear [{Cu(PPh3)2}2(piperzdtc)] (1) [piperzdtc2, = piperazinebis(dithiocarbamate)] and another mononuclear [{Cu(PPh3)2}(BzMedtc)] (2) (BzMedtc, = N -benzyl- N -methyldithiocarbamate) complex have been synthesized and characterized by elemental analyses, IR, 1H, 13C, and 31P NMR spectroscopy and by X-ray crystallography. The nonlinear optical properties of 2 have been investigated by density functional theory and its electronic absorption bands have been assigned by time-dependent density functional theory (TD-DFT). Both complexes are weakly conducting (,rt , 10,8 S,cm,1) because of the absence of M···S/S···S intermolecular stacking and exhibit semiconductivity with band gaps of 0.94 and 1.24 eV, respectively.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis, Protonation and CuII Complexes of Two Novel Isomeric Pentaazacyclophane Ligands: Potentiometric, DFT, Kinetic and AMP Recognition StudiesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2009Andrés G. Algarra Abstract The synthesis and coordination chemistry of two novel ligands, 2,6,9,12,16-pentaaza[17]metacyclophane (L1) and 2,6,9,12,16-pentaaza[17]paracyclophane (L2), is described. Potentiometric studies indicate that L1 and L2 form a variety of mononuclear complexes the stability constants of which reveal a change in the denticity of the ligand when moving from L1 to L2, a behaviour that can be qualitatively explained by the inability of the paracyclophanes to simultaneously use both benzylic nitrogen atoms for coordination to a single metal centre. In contrast, the formation of dinuclear hydroxylated complexes is more favoured for the paraL2 ligand. DFT calculations have been carried out to compare the geometries and relative energies of isomeric forms of the [CuL]2+ complexes of L1 and L2 in which the cyclophane acts either as tri- or tetradentate. The results indicate that the energy cost associated with a change in the coordination mode of the cyclophane from tri- to tetradentate is moderate for both ligands so that the actual coordination mode can be determined not only by the characteristics of the first coordination sphere but also by the specific interactions with additional nearby water molecules. The kinetics of the acid promoted decomposition of the mono- and dinuclear CuII complexes of both cyclophanes have also been studied. For both ligands, dinuclear complexes convert rapidly to mononuclear species upon addition of excess acid, the release of the first metal ion occurring within the mixing time of the stopped-flow instrument. Decomposition of the mononuclear [CuL2]2+ and [CuHL2]3+ species occurs with the same kinetics, thus showing that protonation of [CuL2]2+ occurs at an uncoordinated amine group. In contrast, the [CuL1]2+ and [CuHL1]3+ species show different decomposition kinetics indicating the existence of significant structural reorganisation upon protonation of the [CuL1]2+ species. The interaction of AMP with the protonated forms of the cyclophanes and the formation of mixed complexes in the systems Cu,L1 -AMP, Cu,L2 -AMP, and Cu,L3 -AMP, where L3 is the related pyridinophane containing the same polyamine chain and 2,6-dimethylpyridine as a spacer, is also reported. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis, Crystal Structure, and Magnetic Properties of Two Manganese(II) Polymers Bearing Ferrocenecarboxylato LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2007Zilu Chen Abstract Reactions of Mn(ClO4)2·6H2O with FcCO2Na [Fc = (,5 -C5H4)Fe(,5 -C5H5)] in methanol solution gave [Mn3(FcCO2)6(CH3OH)4]n (1), and, in the presence of 4,4,-bipyridine (4,4,-bpy), [Mn3(FcCO2)6(H2O)2(4,4,-bpy)]n (2). Both complexes have the similar chains with a sequence of ,Mn,(,2 -COO)n,Mn,(,2 -COO),Mn,(,2 -COO),Mn,(,2 -COO)n,Mn, (n = 4 and 2 for complex 1 and 2, respectively), which are constructed alternatively from mononuclear [MnII] units and dinuclear [Mn2(FcCO2)4] units by ,2 -ferrocenecarboxylato- O,O, bridging. The two MnII ions in the dinuclear [Mn2(FcCO2)4] units of complex 1 are connected by four ferrocenecarboxylato ligands to form a swastika-like shaped skeleton, which is rare in metallocenecarboxylato complexes. However, the two MnII ions in the dinuclear [Mn2(FcCO2)4] units of complex 2 are bridged only by two carboxylato ligands, and the other two ferrocenecarboxylato ligands in this unit bind in a chelating mode. The chains in complex 2 are further interconnected by the coordinated 4,4,-bipyridine molecules to form two-dimensional coordination sheets. Magnetic susceptibility measurements revealed a weak antiferromagnetic coupling for both complexes. A model Heisenberg chain comprising classical spins coupled through alternating exchange interactions J1,J1,J2 (AF1,AF1,AF2) is proposed to describe the magnetic behavior. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Hexaazamacrocycle Containing Pyridine and Its Dicopper Complex as Receptors for Dicarboxylate AnionsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2005Feng Li Abstract The host,guest binding interactions of the hexaazamacrocycle [26]py2N4, in its tetraprotonated form H4[26]py2N44+ as well as in its dicopper(II) complex [Cu2([26]py2N4)(H2O)4]4+, with dicarboxylate anions of different stereoelectronicrequirements, such as oxalate (ox2,), malonate (mal2,), succinate (suc2,), fumarate (fu2,) and maleate (ma2,), were evaluated. The association constants were determined using potentiometric methods in aqueous solution, at 298.0 K and 0.10 mol·dm,3 KCl. These values for the tetraprotonated ditopic receptor with the dicarboxylate anions revealed that the main species in solution corresponds to the formation of {H4[26]py2N4(A)}2+ (pH , 4,9), A being the substrate anion. The values determined are not especially high, but the receptor exhibits selectivity for the malonate anion. The study of the cascade complexes revealed several species in solution, involving mononuclear and dinuclear complexes, mainly protonated and hydrolysed species, as well as the expected complexes [Cu2([26]py2N4)(A)(H2O)x]2+ or [Cu2([26]py2N4)(A)2(H2O)y]. Ox2, and mal2, form cascade complexes with only one anion, which will necessarily bridge the two copper atoms because of the symmetrical arrangement of the dinuclear complex. The two other studied anions, suc2, and ma2,, form species involving two substrate anions, although species with only one suc2, anion were also found. UV/Vis and EPR spectroscopy have shown that the dicopper complex can operate as a sensor to detect and quantitatively determine oxalate spectrophotometrically because of the red shift of the maximum of the visible band observed by addition of ox2, to an aqueous solution of the dinuclear copper complex. However the selectivity of [Cu2([26]py2N4)(H2O)4]4+ as a receptor for ox2, in the studied series is not sufficiently high to detect ox2, spectrophotometrically in the presence of the other anions. Molecular dynamics simulations indicated that the H4[26]py2N44+ receptor provides a large and flexible cavity to accommodate the studied anions. Molecular recognition is based in electrostatic interactions rather than in multiple hydrogen-bonding interactions acting cooperatively. By contrast, the [Cu2([26]py2N4)]4+ receptor has a well-shaped cavity with adequate size to uptake these anions as bridging ligands with formation of four Cu,O bonds. The ox2, anion is encapsulated within the cascade complex while the remaining anions are located above the N6 macrocyclic plane, suggesting a selective coordination behaviour of this receptor. In spite of our molecular simulation being carried out in gas phase, the modelling results are consistent with the solution studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Mössbauer Investigation of Peroxo Species in the Iron(III),EDTA,H2O2 SystemEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2005Virender K. Sharma Abstract The reaction of a diiron(III),EDTA complex with H2O2 in alkaline medium is studied by Mössbauer spectroscopy in conjunction with the rapid-freeze/quench technique in order to identify possible intermediate species during the formation and decomposition of the purple (EDTA)FeIII(,2 -O2)3, complex ion. Starting from the six-coordinate [FeIIIEDTA], species at acidic pH, it is demonstrated that mononuclear complexes formed at a pH of about 1 are convert into the diiron(III),EDTA complex [(EDTA)FeIII -O-FeIII(EDTA)]4, upon raising the pH to around 10.4. H2O2 reacts with the diiron(III) complex to give peroxide/hydroperoxide related adducts. Initially, the reaction tears apart the dimers to form a peroxo adduct, namely the seven-coordinate mononuclear [(EDTA)FeIII(,2 -O2)]3,, which is stable only at very high pH. The decomposition of this peroxo adduct gives two new species, which are reported for the first time. The Mössbauer parameters of these species suggest a six-coordinate ,-peroxodiiron(III) complex [(EDTA)FeIII -(OO)-FeIII(EDTA)]4, and a seven-coordinate ,-hydroxo-,-peroxodiiron(III) complex [(EDTA)FeIII -(OO)(OH)-FeIII(EDTA)]5,. A badly resolved, extremely broad component is observed in the Mössbauer spectra during the conversion of the monomer to dimeric peroxo species, which may be attributed to the short-lived [(EDTA)FeIII -OO]3, or [(EDTA)FeIII -OOH]2, intermediate species. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Metal-Controlled Stereoselectivity in Complex Formation: Assembly of Tetranuclear Copper(I) Complexes with Four Stereogenic Nitrogen Donor Functions in all-(R) and all-(S) ConfigurationsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2003Jörg Schneider Abstract The reaction of N,N, -dialkyl-3,7-diazanonane-1,9-dithiolate (NR2S2) ligands (R = Me, Et) with monovalent copper resulted in the formation of the chiral complexes [Cu4(NMe2S2)2] (1) and [Cu4(NEt2S2)2] (2) which were characterised by means of X-ray diffraction and spectroscopic techniques. They contain copper atoms in both linear {S,Cu,S} fragments, which act as linkers between mononuclear [Cu(NR2S2)], subsites, and in {CuS2N2} units within these building blocks, which can be described as incomplete coordination octahedra of unusual design. Due to favourable interplay between the spatial demands of the ligand system and the electronic requirements of the copper atom, the nitrogen donor atoms within the [Cu(NR2S2)], metallo ligands are restricted to identical absolute configurations. The combination of two [Cu(NR2S2)], metallo ligands with two further CuI ions to give the tetranuclear complexes 1 or 2 via S,Cu,S bridges underlies stereochemical control, resulting in optically active systems with (R,R,R,R) and (S,S,S,S) configurations. Consequently, metallo ligands in their enantiomeric forms cannot combine via S,Cu,S bridges to form optically inactive meso complexes with the (R,R,S,S) configuration. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] New Insights on Near-Infrared Emitters Based on Er-quinolinolate Complexes: Synthesis, Characterization, Structural, and Photophysical Properties,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2007F. Artizzu Abstract Erbium quinolinolates, commonly assumed to be mononuclear species with octahedral co-ordination geometry, have been proposed as promising materials for photonic devices but difficulties in obtaining well defined products have so far limited their use. We report here the conditions to obtain in high yields three different kinds of pure neutral erbium quinolinolates by mixing an erbium salt with 8-quinolinol (HQ) and 5,7-dihalo-8-quinolinol (H5,7XQ: X,=,Cl and Br): i),the trinuclear complex Er3Q9 (1) which is obtained with HQ deprotonated by NH3 in water or ethanol/water mixtures; ii),the already known dimeric complexes based on the unit [Er(5,7XQ)3(H2O)2] [X,=,Cl (2) and Br (3)]; iii) the mononuclear [Er(5,7XQ)2(H5,7XQ)2Cl] [X,=,Cl (4) and Br (5)] complexes, obtained in organic solvents without base addition, where the ion results coordinated to four ligands, two deprotonated chelating, and two as zwitterionic monodentate oxygen donors. These results represent a further progress with respect to a recent reinvestigation on this reaction, which has shown that obtaining pure and anhydrous octahedral ErQ3, the expected reaction product, is virtually impossible, but failed in the isolation of 1 and of the neutral tetrakis species based on H5,7XQ ligands. Structural data provide a detailed description of the molecules and of their packing which involves short contacts between quinoxaline ligands, due to ,,, interactions. Electronic and vibrational studies allow to select the fingerprints to distinguish the different products and to identify the presence of water. The structure/property relationship furnishes a satisfactory interpretation of the photo-physical properties. Experimental evidence confirms that the most important quenchers for the erbium emission are the coordinated water molecules and shows that the ligand emission is significantly affected by the ,,, interactions. [source] Synthesis and Characterization of Copper Complexes Containing the Tripodal N7 Ligand Tris{2-[(pyridin-2-ylmethyl)amino]ethyl}amine (=N,-(Pyridin-2-ylmethyl)- N,N -bis{2-[(pyridin-2-ylmethyl)amino]ethyl}ethane-1,2-diamine): Equilibrium, Spectroscopic Data, and Crystal Structures of Mono- and Trinuclear Copper(II) ComplexesHELVETICA CHIMICA ACTA, Issue 9 2005Christian Gérard The stability constants of the CuII chelates with the tripodal heptadentate ligand tris{2-[(2-pyridylmethyl)amino]ethyl}amine (=N,-(pyridin-2-ylmethyl)- N,N -bis{2-[(pyridin-2-ylmethyl)amino]ethyl}ethane-1,2-diamine; tpaa), determined by potentiometry and UV spectrometry, show the formation of [Cu(tpaaH)]3+ and [Cu(tpaa)]2+ species. In the solid state, two mononuclear CuII compounds, [Cu(tpaa)](PF6)2 (1) and [Cu(tpaaH)](ClO4)3,H2O (2), and one trinuclear [Cu3(tpaa)2(ClO4)2](ClO4)4,2,H2O (3) complex were isolated and characterized by IR, UV/VIS, and EPR spectroscopy. An X-ray structure of the mononuclear protonated complex 2 shows that the Cu2+ ion has a distorted square-pyramidal geometry (,=0.21). and the proton is bound to the secondary-amine function of one uncoordinated arm of the tripod ligand (Fig.,4). The crystal lattice for 2 is stabilized by the H-bonds between the N-atom of the free pyridinyl group with the proton of the free secondary-amine function of the neighboring molecule. The linear trinuclear complex 3 consists of two entities of the pyramidal mononuclear complex 1 bound to the third central Cu2+ ion by the free unprotonated arms of the ligands in equatorial position (Fig.,5). The octahedral geometry of the third CuII atom is achieved by two perchlorate anions in the axial positions. The redox properties of 1,3 compounds was examined by cyclic voltammetry. [source] CCR5 deficiency exacerbates T-cell,mediated hepatitis in mice,HEPATOLOGY, Issue 4 2005Christophe Moreno Experimental T-cell,mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A,induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5,/,) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5,/, mice also exhibited increased production of interleukin 4, tumor necrosis factor ,, CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1+. In vivo neutralization of CCR5 ligands in CCR5,/, mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell,mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immunomediated liver injury. (HEPATOLOGY 2005;42:854,862.) [source] Antimicrobial activity studies of the metal complexes derived from cyclobutane-substituted thiazole carbamate ligandsHETEROATOM CHEMISTRY, Issue 7 2001Alaaddin Çukuroval Two novel monodentate carbamate ligands derived mainly from 4-(1-methyl-1-phenylcyclobutyl-3-yl)-2-aminothiazole and 4-(1-phenyl-1-methylcyclobutane-3-yl)-2-(N -methyl)aminothiazole, have been prepared. The ligands and their metal complexes have been characterized by elemental analyses, IR, 13C, and 1H NMR spectra, as well as UV,Vis, and magnetic susceptibility measurements. Both ligands contain 1 mole of water of crystallization and all complexes are mononuclear. Antimicrobial activities of the ligands and their complexes have been screened against the Bacillus subtitis IMG 22 (bacteria), Micrococcus luteus LA 2971 (bacteria), Escherichia coli DM (bacteria), Staphylococcus aureus COWAN I (bacteria), Saccharamyces cerevisiae UGA 102 (yeast), and Candida albicans CCM 314 (yeast). Thermal properties of the ligands and their complexes have been studied by thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC). © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:665,670, 2001 [source] Detection of bone marrow-disseminated breast cancer cells using an RT-PCR assay of MUC5B mRNAINTERNATIONAL JOURNAL OF CANCER, Issue 4 2003Nora Berois Abstract The evaluation of disseminated epithelial tumor cells in breast cancer patients has generated considerable interest due to its potential association with disease recurrence. Our work was performed to analyze the usefulness of 5 mucin genes expression (MUC2, MUC3, MUC5B, MUC6 and MUC7), using RT-PCR assays, to detect disseminated cancer cells in patients with operable breast cancer. The highest frequencies of positive RT-PCR tests in breast tumor extracts were observed for MUC5B (7/15) and MUC7 (5/12). The best specificity, negative results on all peripheral blood mononuclear (PBMN) cell samples from healthy donors, were shown for MUC2, MUC5B and MUC6 RT-PCR assays. Thus, we selected MUC5B as a target gene for further evaluation. Using a nested RT-PCR, MUC5B mRNA transcripts were detected in 16/31 primary breast tumors (but not in 36 samples of normal PBMN cells) and in the human MCF-7 breast cancer cell line but not in BT20, MDA, T47D and ZR-75 breast cancer cell lines, indicating that MUC5B mRNA is expressed in a population of breast cancer cells. Using this method, 9/46 patients (19.5%) who underwent curative surgery showed positive MUC5B mRNA in bone marrow aspirates obtained prior to surgery, including 5/24 patients (20.8%) with stage I or II breast cancer, without histopathologic lymph node involvement. These results indicate that MUC5B mRNA could be a specific marker applicable to the molecular diagnosis of breast cancer cell dissemination. A comparative evaluation between MUC5B mRNA, cytokeratin 19 (CK19) mRNA and carcinoembryonic antigen (CEA) mRNA in all bone marrow aspirates suggests a putative complementation for molecular detection of disseminated carcinoma cells. Considering that breast cancer is characterized by a great phenotypic heterogeneity, the use of multimarker approach could contribute to tumor cell detection in bone marrow and blood. © 2002 Wiley-Liss, Inc. [source] Eccrine squamous syringometaplasia mimicking a herpetic infectionINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2006Vicent Alonso MD A 69-year-old woman with a history of hypertension and essential tremor was diagnosed with a Burkitt-like diffuse large-cell lymphoma. She received chemotherapy with cyclophosphamide, vincristine and adriamycin (HyperCVAD). Ten days after starting the second cycle of chemotherapy (HyperCVAD), she presented with well-defined, intense, erythematous macules which coalesced to form a symmetric diffuse erythema located on the upper back. Later, the lesions progressed and affected the lower back and perineal areas, extending to the groin. In a few days, a gradual diminution of the erythema was seen, with subsequent development of postinflammatory gray-brownish hyperpigmentation. On the lower back, there were also superficial erosions. Some asymptomatic, closely grouped, gray papules, vesicles, and blisters were found in the groin, resembling the typical lesions of herpetic infection (Fig. 1). Two biopsies of the groin and one of the upper back were performed, and were processed for histopathologic and microbiologic study. Figure 1. Closely grouped gray papules, vesicles, and blisters on the groin mimicking a herpetic infection The histopathologic study showed epidermal hyperplasia with acanthosis and papillomatosis. In both biopsies, eccrine ducts covered by mature squamous epithelium were found in the reticular dermis (Fig. 2a,c). In the sample from the groin, an intracorneal bulla was found. Numerous normal isolated cornified cells were seen within the lumen of the bulla (Fig. 2d). An inflammatory mononuclear infiltrate was also present in a periductal and perivascular distribution. No multinucleation, ground-glass nuclei, or peripheral margination of chromatin were found. Therefore, no morphologic evidence of herpes virus infection was present. Figure 2. Low (a), medium (b), and high (c) magnification showing epidermal hyperplasia and squamous syringometaplasia involving dermal eccrine ducts. (d) Medium power magnification of the intracorneal bulla (hematoxylin and eosin staining; a, ×40; b, ×100; c, ×400; d, ×100) Cultures and serologic analyses for herpes simplex virus (HSV) 1 and 2, varicella zoster virus (VZV), and cytomegalovirus (CMV) were negative. The lesions were treated with topical corticosteroids, with a good response in a few days. [source] Large B-cell lymphoma of the legINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2001Elsa Vasquez-del-Mercado MD A 74-year-old Mexican man presented with an 18-month history of multiple, violaceous, coalescing, firm, tender nodules with an ulcer in the anterior aspect of the right leg (Fig. 1) and slightly infiltrated, ill-defined erythematous plaques affecting the left leg and both forearms. He had not received any treatment for his condition. Past medical history was relevant for noninsulin-dependent diabetes mellitus and hypertension without formal treatment and a history of heavy alcohol intake in his youth. A biopsy specimen of both plaque-type lesions of the forearm and tumorous lesions of the leg showed a diffuse, nonepidermotropic mononuclear infiltrate throughout the dermis and extending to the subcutis. The infiltrate was composed of pleomorphic, atypical, large mononuclear cells (Fig. 2). Immunostaining with CD20 was positive for the atypical cells while CD3 was positive for normal appearing lymphocytes, characterized as reactive T cells. Additional laboratory and image studies ruled out extracutaneous involvement. The diagnosis of primary cutaneous large B cell lymphoma of the leg (LBCLL) was made. The patient was initiated on radiotherapy localized to the right leg with a very good initial response, nevertheless resolution was not achieved and the plaques in the rest of the limbs remained unchanged. Thus, the patient started chemotherapy with CHOP (Cyclophosphamide, Vincristine, Doxorubicin, Prednisone). He has currently finished his fourth cycle with this chemotherapy regimen. The tumorous lesions involuted leaving only residual hyperpigmentation (Fig. 3) and the plaques in the rest of the limbs disappeared, the area of the ulcer diminished considerably. There is still no evidence of extracutaneous involvement. Figure 1. Nodules and ulcer in the anterior aspect of the right leg Figure 2. Atypical lymphocytes, with large, pleomorphic nuclei and multiple nucleoles. Positivity for CD20 antigen was demonstrated by immunohistochemical analysis (hematoxylin and eosin; X 600) Figure 3. Residual hyperpigmentation and granulation tissue after chemotherapy [source] Acute generalized exanthematous pustulosis mimicking toxic epidermal necrolysisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 7 2001Arnon D. Cohen MD A 91-year-old patient presented with a nonfebrile, pruritic, widespread eruption that appeared 10 days after starting therapy with cefuroxime tablets, 1000 mg/day, due to stasis dermatitis with secondary infection. The patient was also treated with paracetamol tablets, 500,1000 mg/day, 10 days before the onset of the eruption. Previous diseases included congestive heart disease, hyperglycemia, and ectropion. There was no personal or family history of psoriasis. Additional medications, taken for more than 2 years at the time of the eruption, included indomethacin, captopril, hydrochlorothiazide, isosorbide-5-mononitrate tablets, and a combination drug Laxative®. Examination revealed widespread erythema involving 95% of the total body surface area, with numerous 1,2 mm nonfollicular pustules (Fig. 1). There was no predilection to the body folds. Within 24 h of hospitalization, during intravenous therapy with cefuroxime, the patient's condition worsened and bullae containing clear fluid appeared. Nikolsky's sign was positive on erythematous skin, and eventually skin detachment involved 41% of the total body surface area (Fig. 2). There were no target or target-like lesions and there was no involvement of the mucous membranes. Figure 1. Numerous, 1,2 mm, nonfollicular pustules, with confluence (viewed in the lower left part of the photograph), on erythematous skin Figure 2. Widespread skin detachment An early biopsy from a pustule revealed subcorneal and intraepidermal spongiform pustules, papillary edema, perivascular mononuclear infiltrate with a few eosinophils in the dermis, and leukocytoclastic vasculitis. A later biopsy showed similar findings with no evidence of full-thickness epidermal necrosis or necrotic keratinocytes. Direct immune fluorescence (DIF) taken from erythematous skin was negative. Laboratory studies showed the following results: sedimentation rate, 80 mm/h; white blood cell count, 26,200/mm3 with 87% polymorphonuclears and 1.8% eosinophils; hemoglobin, 13.0 g/dL; albumin, 2.8 g/dL (normal, 3.5,5.5 g/dL); other blood chemistry tests were normal. Immunologic studies for rheumatoid factor, antinuclear antibodies, antismooth muscle antibodies, antiparietal cell antibodies, antimitochondrial antibodies, C3, and C4 were normal or negative. Serology for venereal disease research laboratory (VDRL) test, Epstein,Barr virus, cytomegalovirus, hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and antistreptolysin titer was negative. Chest X-ray was normal. Blood cultures were negative. Swab cultures taken from the pustules revealed Staphylococcus aureus as well as coagulase-negative Staphylococcus. All systemic drugs, including intravenous cefuroxime, were withdrawn with close monitoring for signs of heart failure or infection. Topical therapy consisted of application of wet dressings. Within 10 days, the eruption resolved with re-epithelialization of the erosions and the appearance of widespread post-pustular desquamation (Fig. 3) Figure 3. Post-pustular desquamation on the trunk [source] Hereditary palmoplantar keratoderma (four cases in three generations)INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 2 2001Virendra N. Sehgal MD A 39-year-old man reported with progressive thickening of the skin of the hands and feet and an inability to flex his hand. It was largely asymptomatic; however, brisk walking caused excessive sweating, pain, and widening of the fissures on the soles of the feet. He was unable to walk barefooted. According to his mother, the first episode presented with blistering at 7 days of age. Ever since, the condition has steadily worsened to acquire the current status. He was married at the age of 18 years, and had a stillborn child 18 months afterwards. Presently, he has three children, two girls aged 14 and 12 years and a son aged 10 years. Both the daughters are similarly affected. While cataloguing the details of the pattern of inheritance, the mother of the index case was also found to be affected (Fig. 1). The natural history of the disease was identical. Figure 1. Palmoplantar keratoderma: pattern of inheritance; black indicates affected individuals Examination of the palms was marked by pronounced thickening of the skin resulting in the masking of palmar creases. The thickening was well demarcated and its margins were prominent and surrounded by an erythematous halo. The color of the skin was yellow and waxy (Fig. 2a). Contractures were present on all the fingers; nevertheless, the deformity of the middle and distal interphalangeal joints of the little finger was prominent. The soles of the feet had a similar morphology. In addition, marked fissuring was obvious (Fig. 2b). His daughters had an identical affliction of the palms and soles. The texture and morphology of the nails were normal. Light microscopy performed on scrapings from the fissures, mounted on 10% potassium hydroxide, revealed mycelia (hyphae) and spores. Figure 2. Well-demarcated hyperkeratosis depicting the yellow, waxy color of the palms, with masking of creases (a). Marked fissuring on the soles was prominent (b) Hematoxylin and eosin-stained microsections from the palms and soles showed exquisite changes in the epidermis characterized by considerable uniform orthohyperkeratosis. Hypergranulosis and acanthosis were other associated changes. In addition, perinuclear vacuolization and keratohyalin granules of varying sizes and shapes were located at the periphery of the cells. A sparse mononuclear infiltrate was located at the dermo-epidermal junction. Hyphae and spores of fungi were also identified in the stratum corneum (Fig. 3). Figure 3. Orthohyperkeratosis, hypergranulosis, and acanthosis. Perinuclear vacuolization and keratohyalin granules at the periphery of the cells; a sparse mononuclear infiltrate was also present (hematoxylin and eosin, ×,40 (a), ×,400 (b)) Itraconazole, 400 mg/day in two equally divided doses, was administered with major meals for 7 days. In addition, high doses of vitamin A (100,000 IU) were given daily for 2 weeks, supplemented by 12% salicylic acid (Salicylix SF12) ointment for daytime application and an ointment containing 6% coal tar and 3% salicylic acid (Salytar) for night-time application. This treatment is useful in recalcitrant cases. [source] Automated counting of white and red blood cells in the cerebrospinal fluidINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2000M.W. Aune Summary The objective of this study was to examine to what extent the automated method of the Bayer H*2 instrument could replace the visual counting of white and red blood cells in cerebrospinal fluid. The number of white blood cells as well as the percentage of mononuclear and polymorphonuclear cells were counted in the ,Baso channel' (Research screen 3) whereas the number of red cells were registered as the ,R-count' (Research screen 1). All automated cell counts were compared to visual estimates. The automated count yielded reliable results down to 5 × 106 white blood cells/l and 5 × 108 red blood cells/l. In some samples ,noise' was present in the Baso channel. A correct white blood cell count could then be obtained by counting the cells directly as dots on the screen. It was possible to differentiate between polymorphnuclear cells and mononuclear cells at all WBC concentrations. The automated counting of cerebrospinal fluid can be performed without changing thresholds or sample volumes of the instrument. Thus, in the routine practice it will be possible to alternate between automated counting of whole blood samples and cerebrospinal fluid samples. [source] Synthesis of Schiff Base-Ruthenium Complexes and Their Applications in Catalytic ProcessesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14 2005Renata Drozdzak Abstract The synthesis of various Schiff base mononuclear and binuclear ruthenium complexes, whose additional ligands around the metal core have been selected from an array of motifs, is described. These types of ruthenium complexes, conveniently prepared from commonly available ruthenium sources, are rather stable, display good tolerance towards diverse organic functionalities and also to air and moisture. Remarkably, they exhibit a high activity and chemoselectivity in a variety of catalytic processes such as ring-closing metathesis (RCM), Kharasch addition, alkyne dimerization, enol ester synthesis, ring-opening metathesis polymerization (ROMP) and atom-transfer radical polymerization (ATRP). This review covers both homogeneous and heterogeneous hybrid Schiff base-ruthenium complexes. [source] Theoretical study of the microhydration of mononuclear and dinuclear uranium(VI) species derived from solvolysis of uranyl nitrate in waterJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 12 2010Milan On Abstract The structures and energetics of mononuclear and dinuclear uranium species formed upon speciation of uranyl(VI) nitrate, UO2(NO3)2, in water are investigated by quantum chemistry using density functional theory and the wavefunction-based methods (MP2, CCSD, CCSD(T)). We provide a discussion of the basic coordination patterns of the various mono- and dinuclear uranyl compounds [(UO2)m(X,Y)2m,1(H2O)n]+ (m = 1, 2; n = 0,4) found in a recent mass spectrometric study (Tsierkezos et al., Inorg Chem 2009, 48, 6287). The energetics of the complexation of the uranyl dication to the counterions OH, and NO3, as well as the degradation of the dinuclear species were studied by reference to a test set of 16 representative molecules with the MP2 method and the B3LYP, M06, M06-HF, and M06-2X DFT functionals. All DFT functionals provide structures and energetics close to MP2 results, with M06 family being slightly superior to the standard B3LYP functional. © 2010 Wiley Periodicals, Inc. J Comput Chem 2010 [source] Computational analyses of singlet,singlet and singlet,triplet transitions in mononuclear gold-capped carbon-rich conjugated complexesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 12 2005Zexing Cao Abstract Density functional theory and CASSCF calculations have been used to determine equilibrium geometries and vibrational frequencies of metal-capped one-dimensional ,-conjugated complexes (H3P)Au(CC)n(Ph) (n = 1,6), (H3P)Au(CCC6H4)(CCPh), and H3PAu(CCC6H4)CCAuPH3 in their ground states and selected low-lying ,,* excited states. Vertical excitation energies for spin-allowed singlet,singlet and spin-forbidden singlet,triplet transitions determined by the time-dependent density functional theory show good agreement with available experimental observations. Calculations indicate that the lowest energy 3(,,*) excited state is unlikely populated by the direct electronic excitation, while the low-lying singlet and triplet states, slightly higher in energy than the lowest triplet state, are easily accessible by the excitation light used in experiments. A series of radiationless transitions among related excited states yield the lowest 3(,,*) state, which has enough long lifetimes to exhibit its photochemical reactivities. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1214,1221, 2005 [source] Oral mucosa alterations induced by cyclosporin in mice: morphological featuresJOURNAL OF PERIODONTAL RESEARCH, Issue 6 2002A. T. Meller Background and objective:, The mechanisms involved in the pathogenesis of cyclosporin A-induced gingival hyperplasia are not well understood. The present work aimed at developing a mouse model with the characteristics of the human process, i.e. time of appearance, dose dependency and the capacity of developing in a variety of genetic backgrounds. This model would present the advantages of using a very well known animal species, small and easy to handle, with a number of experimental reagents (antibodies, etc.) already available against its products. Methods:, Three different strains of mice were used: CBA, F1(C57Bl × DBA), Balb/c. Groups of mice received different concentrations of cyclosporin A (CSA) (10 mg/kg, 25 mg/kg and 40 mg/kg body weight) intraperitoneally five times a week. Anatomical and histological alterations were recorded at various time intervals. Results:, All strains of mice presented gingival hyperplasia after 8 weeks of CSA treatment. A dose-dependency was observed with regard to the time of first appearance of alterations. Increased redness was seen in all animals at the sixth week, independent of the dosage used. Histologic examination exhibited increased vascularization, epithelial and connective tissue thickening, edema and a mononuclear infiltrate. Conclusions:, It was possible to develop CSA-induced gingival hyperplasia in mice with the characteristics described in humans and other species. The use of this animal model may help in the elucidation of the process involved in CSA-induced gingival overgrowth. [source] | ||||||||||||||||||||||||||||||||||