lanthan

The organic-inorganic complex salt, (C8 H10 N3 )3 [La(NO3 )6 ], comprises a network of N-protonated 2-amino-1-methyl-benzimidazolium cations and hexa-kis-(nitrato)lanthanate(III) anions. The LaIII atom is twelve-coordinate within a distorted icosa-hedral environment. In the unit cell, each pair of the LaIII atoms lie nearly on one of the crystallographic glide planes. In the crystal structure, there are several N-H⋯O hydrogen-bonding inter-actions between the cations and terminal oxygen atoms from the nitrate moieties of the [La(NO3 )6 ]3- anion...

We report a new high-yield synthesis of so far not accessible tetraphenylphosphonium methylcarbonate Ph4 P[OCO2 Me] via solvothermal fluoride-induced demethylation and MeF elimination at Me2 CO3 (DMC) by Ph4 P-F, structurally characterized as λ5 -fluorophosphoran by XRD. The synthetic value of Ph4 P[OCO2 Me] key compound for preparing nearly all kinds of other Ph4 P[anion] salts with perfectly crystallizing (not symmetry frustrated) cation is demonstrated by examples beyond ionic liquid research: a complete set of silylchalcogenide salts Ph4 P[ESiMe3 ] (E = S, Se, and Te) including the first example of a structurally characterized non-coordinating, naked [Te-SiMe3 ]- anion is presented...

The molecular structures of potassium tetrakis(hexafluoro-acetylacetonato)lanthanate(III) complexes [KLn(hfa) 4 ] (Ln = La, Gd, Lu; hfa = C 5 HF 6 O 2 ,) were studied by synchronous gas-phase elec-tron diffraction / mass spectrometry (GED/MS) supported by quan-tum-che-mical (DFT/PBE0) calculations. The compounds subli-mate con-gru-ently and the vapors contain single molecular species - the hete-ro--binuclear complex [KLn(hfa) 4 ]. All molecules are of C 1 sym-me-try with the lanthanide atom in the center of a coordination poly-hedron LnO 8 , while the potassium atom is coordinated by three ligands under formation of three K-O and three K-F bonds...

BACKGROUND/AIMS: Studies of pathways to care in first-episode psychosis have documented a substantial treatment delay occurring after patients enter mental health services. An initial presentation with neurotic rather than psychotic symptoms is common in first-episode psychosis. The term "lanthanic patient" has been used to refer to patients presenting with a reason for help-seeking that is unrelated to the underlying pathology. The aim of this study is to explore whether a lanthanic presentation is related to prolonged service delay...

Immunoglobulin A (IgA) nephropathy is one of the most common glomerulonephritis and its frequency is probably underestimated because in most patients the disease has an indolent course and the kidney biopsy is essential for the diagnosis. In the last years its pathogenesis has been better identified even if still now several questions remain to be answered. The genetic wide association studies have allowed to identifying the relevance of genetics and several putative genes have been identified. The genetics has also allowed explaining why some ancestral groups are affected with higher frequency...

The principal building units in the crystal structure of ammonium aqua-bis(sulfato)-lanthanate(III) are slightly distorted SO4 tetra-hedra, LaO9 polyhedra in the form of distorted tricapped trigonal prisms, and NH4 (+) ions. The La(3+) cation is coordinated by eight O atoms from six different sulfate tetra-hedra, two of which are bidentate coordinating and four monodentate, as well as one O atom from a water mol-ecule; each sulfate anion bridges three La(3+) cations. These bridging modes result in the formation of a three-dimensional anionic [La(SO4)2(H2O)](-) framework that is stabilized by O-H⋯O hydrogen-bonding inter-actions...

During meiosis resumption, oocytes undergo a series of nuclear and cytosolic changes that prepare them for fertilization and that are referred to as oocyte maturation. These events are characterized by germinal vesicle breakdown (GVBD), chromatin condensation and spindle formation and, among cytosolic changes, organelle redistribution and maturation of Ca2+-release mechanisms. The progression of the meiotic cell cycle is regulated by M phase/maturation-promoting factor (MPF) and mitogen-activated protein kinase (MAPK)...

The title compound, (C(8)H(15)N(2))[LaCl(4)(CH(3)OH)(C(3)H(7)OH)], consists of one 1-butyl-3-methyl-imidazolium (BMI(+)) cation and one hexa-hedral tetra-chlorido(methanol)(propan-2-ol)lanthanate anion. The La(III) ion is eight-coordinate, with the La(III) ion bridged by a pair of Cl atoms, so forming chains propagating along the a-axis direction. Each La(III) ion is further coordinated by two isolated Cl atoms, one methanol and one propan-2-ol mol-ecule. The coordinated methanol and propan-2-ol mol-ecules of the anion form O-H⋯Cl hydrogen bonds with the Cl atoms of inversion-related anions...

The title mixed aqua-fluoride complex, [CrF(C(10)H(8)N(2))(2)(H(2)O)](ClO(4))(2)·2H(2)O, has been synthesized by aqua-tion of the corresponding difluoride complex using lanthan-ide(III) ions as F(-) acceptors. The complex crystallizes with a Cr(III) ion at the center of a distorted octa-hedral coordination polyhedron with a cis arrangement of ligands. The crystal packing shows a hydrogen-bonding pattern involving water mol-ecules, the coordinated F atom and the perchlorate anions.

Connection between the level of NO generation and its cytotoxic influence was investigated on two models of tumor cells (breast adenocarcinoma MCF-7) culture: monolayer and spheroids. Conditions of microenvironment were modified by Ca2+ channels blockers: EGTA, nitrendipine and Cl-lanthan. It was discovered in the work that deviation in concentration of extracellular Ca2+ under the influence of EGTA leads to reducing of the level of extracellular NO to 50% (P < or = 0.05) of control and increasing of the number of live cells by 10-40% (P < or = 0...

Under static ultrahigh vacuum (10(-9) torr), we have studied the optical properties of lanthanum and praseodymium thin films. It is shown that these films behave similarly in the 2000-8000 A spectral range. Results are identical for other light rare-earth thin films. We suggest that indirect transitions are responsible for the presence of a maximum in the optical absorption near 5,8 eV.

INTRODUCTION: Because of the high associated morbi-mortality, phosphate and calcium disorders remain a major therapeutic challenge for nephrologists. Previous studies showed that only few patients had serum calcium, phosphate and parathyroid hormone within Kidney-Disease Outcomes Quality Initiative (K/DOQI) targets. PATIENTS AND METHODS: The French calcium and phosphate observatory monitors mineral metabolism at local, regional and national level and its follow-up every six months since 2005...

Tetrakis(naphthoyltrifluoroacetonato)lanthanate(III) complexes (Ln = Eu, Gd) containing the cations tetrabutylammonium, [NBu(4)](+); 1-butyl-3-methylimidazolium, [C(4)mim](+); and 1-butyl-3-methylpyridinium, [C(4)mpyr](+), have been prepared and structurally characterized by single-crystal X-ray diffraction. The {EuO(8)} coordination sphere in [NBu(4)][Eu(NTA)(4)] is best described as a distorted dodecahedron, where the metal ion is located at the 4-fold inversion axis with only one crystallographically independent NTA residue...

On a effectué une étude spectrophotométrique dans l'ultra-violet, des complexes formés par l'acide anthranildiacétique (ANDA) avec le scandium(III), l'yttrium(III) et le lanthane(III) qui a permis de doser ces éléments. On a établi que ces complexes possèdent la composition Me-ANDA = 1:1 et on a calculé leurs constantes d'instabilité apparente : K = 1,5 . 10(-6) pour le complexe Se-ANDA, K = 3,4 . 10(-6) pour Y-ANDA et K = 2,9 . 10(-6) pour La-ANDA. A spectrophotometric study of the complexes formed between anthranil-N,N-diacetic acid, ANDA, and scandium, yttrium and lanthanum, has led to the development of methods for the determination of these elements...

A series of organic-inorganic hybrid compounds, K2H7[{Ln(PW11O39)2}{Cu2(bpy)2(mu-ox)}].xH2O (Ln = La, x approximately = 18 (1); Ln = Pr, x approximately = 18(2); Ln = Eu, x approximately = 16(3); Ln = Gd, x approximately 22(4); Ln = Yb, x approximately = 19 (5); bpy = 2,2'-bipyridine and ox = oxalate), have been isolated by the conventional solution method. Single-crystal X-ray diffraction studies reveal that compounds 1-5 are isomorphic and consist of one-dimensional chains, which are constructed by alternating bis(undecatungstophosphate) lanthanates [Ln(PW11O39)2](11-) and dinuclear copper(II)-oxalate complexes [Cu2(bpy)2(mu-ox)]2+...

The authors report calculations of the intermolecular potential of mean force (PMF) in the case of the host-guest interaction. The host-guest system is defined by a water soluble calixarene and a cation. With an organic cation such as the tetramethylammonium cation, the calixarene forms an insertion complex, whereas with the Lanthane cation, the supramolecular assembly is an outer-sphere complex. The authors apply a modified free energy perturbation method and the force constraint technique to establish the PMF profiles as a function of the separation distance between the host and guest...

Spectrophotometric titrations revealed that stability of the quercetin/double stranded (ds) DNA or double stranded (ds) RNA non-covalent complexes is significantly higher compared to the quercetin/ss-RNA complexes. This observation can easily be correlated with the significantly larger aromatic surface of base pairs compared to single nucleobases, and it is in good agreement with other experimental data pointing toward intercalative binding mode of quercetin. Fluorescence increase of quercetin induced by ds-RNA is significantly stronger than observed for ds-DNA, offering usage of quercetin as the ds-RNA selective fluorescent probe...

The in vivo coordination structure of lanthanum ions interacting with chlorophyll-a of the fern Dicranopteris dichotoma grown in a rare earth minefield in southern China was determined by the extended x-ray absorption fine structure (EXAFS). The results show that lanthanum includes two porphyrin rings in its coordination sphere. It is postulated that the La-chlorophyll-a complex may have a bilayer structure. The analytical method may serve as a new tool to gain insight in the in vivo interactions of rare earth elements...

The subcellular localization of lanthane was studied using two microanalytic methods. 1.) The election microprobe method showed that lanthane is concentrated in the lysosomes of the hepatocytes and the spleen associated with phosphorus. 2.) The ion microanalysis showed that lanthane is selectively precipitated in the lysosomes of the enterocytes optical part. This mechanism of selective precipitation initially prevents the diffusion of this toxic element in the organism and then permits its elimination digestively after desquamation of enterocytes in apoptosis in the intestinal lumen...

Information provided in this article can be used for estimating the radiation dose associated with the use of thoriated tungsten electrodes in tungsten inert gas welding. Area and breathing zone concentrations of 232Th generated by welding and electrode sharpening along with particle size information; isotopic composition of electrodes from two domestic manufacturers and one European manufacturer; and process variables and estimates on the number of thoriated tungsten electrodes manufactured are presented. Past literature is reviewed and compared with the results of this study...