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  • 1
    ISSN: 1432-1459
    Keywords: Alzheimer's disease ; Apolipoprotein E ; Age at onset ; Relative risk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of the apolipoprotein E (apoE) genotype on the age at onset of Alzheimer's disease (AD) and the relative risk conferred by the apoE ε4 allele were studied in 91 patients and 69 healthy age-matched controls. According to the age of presentation, which varied from 44 to 95 years, subjects were divided into four groups. The inheritance of at least one ɛ4 allele was associated with a significant reduction of the age at onset by 7.7 years among patients who were 83 years or older when examined. A weaker inverse relationship between the ɛ4 allele and the age at onset was also observed among patients who were aged 44–63 years at presentation. The effect of the c4 allele was minimal or absent in the two intermediate age categories. The relative risk of AD conferred by the inheritance of at least one £4 allele showed no consistent age-related pattern. The overall risk expressed as an odds ratio was 5.0 (95% CI 2.4–10.5). With respect to the limitations of the study, we tentatively conclude (1) that the effect of the apoE ɛ4 allele on the age at onset is not restricted to AD patients of a particular age, in accordance with current hypotheses on the role of apoE gene products in the biology of AD; (2) that the relative risk of AD associated with the ɛ4 allele is not significantly modulated by age. Although the apoE ɛ4 allele is an important susceptibility factor for AD occurring in middle age as well as in later life, it is of limited value in routine clinical diagnosis and should not be used for predictive testing in asymptomatic individuals.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0044-2313
    Keywords: Rhenium tetrachloride chelate complexes ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chelate Complexes of Rhenium Tetrachloride. The Crystal Structures of ReCl4(DME) and ReCl4(DPPE) · TolanBright green crystals of ReCl4(DME) have been prepared by the reaction of rhenium pentachloride with dimethoxyethane (DME) in dichloromethane. ReCl4(DPPE) · tolan was obtained in form of red crystals by the reaction of the alkyne complex [ReCl4(Ph—C≡C—Ph)(POCl3)] with bis(diphenylphosphino)ethane (DPPE) in dichloromethane. The complexes were characterized by X-ray structure determinations.ReCl4(DME): Space group I42d, Z = 8, 829 observed unique reflexions, R = 0.022. Lattice dimensions at 19.5°C: a = b = 960.60(6), c = 2337.2(6) pm. The complex forms monomeric molecules with DME as chelating ligand; the Re—O bond lengths are 213.1 pm. The chlorine atoms, arranged in trans position to the chelating ligand, have slightly shorter Re—Cl bonds than the chlorine atoms in cis position (232,1 pm).ReCl4(DPPE) · tolan: Space group P21/n, Z = 4,4313 observed unique reflexions, R = 0.040. Lattice dimensions at -80°C: a = 1095.7(1), b = 1764.2(2), c = 1898.0(2) pm, β = 99.229(8)°. The compound consists in form of monomeric molecules [ReCl4(DPPE)] and diphenylacetylene molecules, which are incorporated in the lattice. The two phenyl rings of the tolan molecules are twisted towards each other along the C—C axis with a dihedral angle of 21°. The DPPE molecules are bonded to the rhenium atom in a chelating fashion with medium Re—P lengths of 250.4 pm. The chlorine atoms, arranged in trans position to this ligand, with Re—Cl bond lengths of 234.5 pm are slightly longer than the Re—Cl bonds in cis position with 232.3 pm.
    Notes: ReCl4(DME) wird in Form leuchtend grüner Kristalle durch Reaktion von Rheniumpentachlorid mit Dimethoxyethan (DME) in Dichlormethan hergestellt. ReCl4(DPPE) · Tolan erhielten wir als rote Kristalle bei der Reaktion des Alkinkomplexes [ReCl4(Ph—C≡C—Ph)(POCl3)] mit Bis(diphenylphosphino)ethan (DPPE) in Dichlormethan. Die Komplexe wurden durch röntgenographische Strukturanalysen charakterisiert.ReCl4(DME): Raumgruppe I42d, Z = 8, 829 beobachtete unabhängige Reflexe, R = 2,2%. Gitterkonstanten bei 19,5°C: a = b = 960,60(6); c = 2337,2(6) pm. Der Komplex bildet monomere Moleküle mit dem DME-Liganden als Chelat und Re—O-Abständen von 213,1 pm. Die hierzu trans-ständig angeordneten Chloratome haben mit 228,1 pm etwas kürzere Re—Cl-Bindungen als die cis-ständigen Cl-Atome (232,1 pm).ReCl4(DPPE) · Tolan: Raumgruppe P21/n, Z = 4, 4313 beobachtete, unabhängige Reflexe, R = 4,0%. Gitterkonstanten bei -80°C: a = 1095,7(1); b = 1764,2(2); c = 1898,0(2) pm, β = 99,229(8)°. Der Komplex bildet monomere Moleküle [ReCl4(DPPE)] und in das Gitter eingelagerte Diphenylacetylenmoleküle, deren Phenylringe einen Diederwinkel von 21° zueinander bilden. Die DPPE-Moleküle sind chelatartig am Rheniumatom gebunden mit Abständen Re—P von im Mittel 250,4 pm. Die hierzu trans-ständig angeordneten Chloratome sind mit Re—Cl—Abständen von 234,5 pm etwas länger als die cis-ständigen Re—Cl-Bindungen mit 232,3 pm.
    Additional Material: 5 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 500-506 
    ISSN: 0044-2313
    Keywords: Polytellurido Complexes of Zinc and Mercury ; Synthesis ; Crystal Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structures of the Polyellurido Complexes [K(15-Crown-5)2]2[MTe7] with M = Zn and HgThe title compounds were obtained in the presence of 15-crown 5 from solutions of zinc and mercury acetate, respectively, in DMF by addition of a solution of K2Te3 in DMF at 0°C (M = Zn) and -50°C (M = Hg). They form black crystal needles with metallic luster. Their crystal structures were determined by X-ray diffraction. The structures of [K(15-crown-5)2]2ZnTe7 and [K(15-crown-5)2]2HgTe7 show two-dimensional disorder as evidence by diffuse scattering. The averaged structures that were determined with the Bragg reflexions correspond to space group Pbcn and have very similar lattice parameters. Nevertheless, the structures differ. [HgTe7]2- ions consist of two condensed five membered rings. They are arranged to form strands in the c direction; within of one strand the ions have a definite orientation, but in different strands two different orientations occur randomly. A [ZnTe7]2- ion can be thought of consisting of a Zn2+ ion, a Te42- ion bonded in a chelate manner and a Te32- ion bonded with one terminal Te atom to the Zn2+. The [ZnTe7]2- ions are associated to strands in the c direction with two different strand orientations occuring randomly.
    Notes: Die Titelverbindungen entstehen aus Lösungen der Acetate von Zink bzw. Quecksilber in DMF bei Anwesenheit von 15-Krone-5 nach Zugabe einer Lösung von K2Te3 in DMF bei 0°C (M = Zn) bzw. -50°C (M = Hg). Die Verbindungen bilden schwarze, metallisch glänzende Kristallnadeln, die wir durch röntgenographische Strukturanalysen charakterisiert haben. Die Kristallstrukturen von [K(15-Krone-5)2]2[ZnTe7] und [K(15-Krone-5)2]2[HgTe7] sind zweidimensional fehlgeordnet, wie die entsprechende diffuse Streuung zeigt. Die Überlagerungsstrukturen, die mit Hilfe der Braggschen Reflexe bestimmt wurden, entsprechen bei beiden Verbindungen der Raumgruppe Pbcn bei sehr Ähnlichen Gitterparametern. Trotzdem unterscheiden sich die Strukturen. Die [HgTe7]2--Ionen bestehen aus zwei kondensierten Fünferringen. Sie sind zu Strängen längs c angeordnet, wobei sie innerhalb eines Stranges eine definierte Orientierung haben, aber von Strang zu Strang eine von zwei entgegengesetzten Orientierungen statistisch vorkommt. Ein [ZnTe7]2--Ion kann man sich aufgebaut denken aus einem Zn2+-Ion, einem chelatartig gebundenen Te42--Ion und einem Te32--Ion, das über ein terminales Te-Atom an das Zn2+ gebunden ist. Die [ZnTe7]2--Ionen sind zu Strängen längs c assoziiert, wobei statistisch zwei Strangorientierungen vorkommen.
    Additional Material: 4 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1607-1612 
    ISSN: 0044-2313
    Keywords: Indium polysulfido complexes ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structures of (PPh4)2[In(S4)(S6)Cl] and (PPh4)2[In(S4)Cl3]InCl and PPh4Cl yield (PPh4)2[In2Cl6] in acetonitrile. This reacts with Na2S4 in presence of PPh4Cl, forming (PPh4)2[In(S4)(S6)Cl]. Its crystal structure was determined by X-ray diffraction (R = 0.075, 2 282 observed reflexions). It is isotypic with (PPh4)2[In(S4)(S6)Br] and contains anions with trigonal-bipyramidal coordination of In, Cl occupying an axial position, and the S4 and S6 groups being bonded in a chelate manner. The reaction of (PPh4)2[In2Cl6] and sulfur in acetonitrile yielded (PPh4)2[InCl5] and (PPh4)2[In(S4)Cl3]. The crystal structure analysis of the latter (R = 0.072, 4 080 reflexions) revealed an anion with distorted trigonal-bipyramidal coordination of In, the S4 group occupying one axial and one equatorial position; the S4 group shows positional disorder.
    Notes: Aus InCl und PPh4Cl entsteht in Acetonitril (PPh4)2[In2Cl6]. Aus diesem wurde mit Na2S4 im Beisein von PPh4Cl (PPh4)2[In(S4)(S6)Cl] erhalten. Seine Kristallstruktur wurde mittels Röntgenbeugung bestimmt (R = 7,5%, 2 282 beobachtete Reflexe). Es kristallisiert isotyp zum (PPh4)2[In(S4)(S6)Br] und enthält Anionen mit trigonal-bipyramidaler Koordination des In; das Cl-Atom nimmt eine axiale Position ein und die S4- und S6-Gruppe ist jeweils chelatartig gebunden. Aus (PPh4)2[In2Cl6], PPh4Cl und Schwefel entstanden in Acetonitril (PPh4)2[InCl5] und (PPh4)2[In(S4)Cl3]. Nach der Kristallstruktur des letzteren (R = 7,2%, 4 080 Reflexe) ist im [In(S4)Cl3]2--Ion das In-Atom verzerrt trigonal-bipyramidal koordiniert, wobei die S4-Gruppe an eine axiale und eine equatoriale Position gebunden ist; die S4-Gruppe ist fehlgeordnet.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 541-545 
    ISSN: 0044-2313
    Keywords: Dimagnesium trimolybdate(IV) ; molybdenum oxide ; preparation ; crystal structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: η-Mo4O11 and Mg2Mo3O8: a New Way of Synthesis and Refinement of their Crystal StructuresMg2Mo3O8 was obtained by solid state reaction of MgI2 and MoO3 (1:1) at 200°C and subsequent crystallization at 800°C. Under the same conditions, ZnI2 and MoO3 only yielded rather impure Zn2Mo3O8; however, when ZnI2 or CdI2 and MoO3 were taken in a molar ratio of 1:2, well crystallized η-Mo4O11 was obtained. The known crystal structures of Mg2Mo3O8 and η-Mo4O11 were refined with new X-ray diffraction data (R = 0.030 and 0.059, respectively). The kind of twinning of monoclinic η-Mo4O11 is discussed.
    Notes: Durch Festkörperreaktion von MgI2 und MoO3 (1:1) bei 200°C und anschließender Kristallisation bei 800°C entsteht Mg2Mo3O8. Mit ZnI2 entsteht unter den gleichen Bedingungen nur stark verunreinigtes Zn2Mo3O8; beim Einsetzen von ZnI2 oder CdI2 und MoO3 im Molverhältnis von 1:2 wird dagegen gut kristallisiertes η-Mo4O11 erhalten. Die bekannten Kristallstrukturen von Mg3Mo8O8 und η-Mo4O11 wurden mit neuen Meßdaten verfeinert (R = 3,0 bzw. 5,9%). Die Art der Zwillingsbildung des monoklinen η-Mo4O11 wird diskutiert.
    Additional Material: 2 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 416-420 
    ISSN: 0044-2313
    Keywords: Nonaselenide ; Synthesis ; Crystal Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of the Nonaselenide [Sr(15-crown-5)2]Se9The title compound was prepared by the reaction of excess selenium with strontium diselenide in DMF in the presence of 15-crown-5. [Sr(15-crown-5)2]Se9 forms black crystals, which are soluble in DMF. They were characterized by FIR spectroscopy and by an X-ray structure determination.Space group P21/n, Z = 4, 2 381 observed unique reflections, R = 0.073. Lattice dimensions at 19°C: a = 1 228.7, b = 1 893.4, c = 1 575.7 pm, β = 99.15°. The compound consists of [Sr(15-crown-5)2]2+ ions in which the strontium ion is coordinated by the oxygen atoms of the crown ether molecules in a sandwich-like fashion, and of Se92- ions with a chain structure, which has a topolocical resemblance with the bicyclic ion Se102-.
    Notes: Die Titelverbindung entsteht durch Einwirkung von überschüssigem Selen auf Strontiumdiselenid in Dimethylformamid (DMF) in Gegenwart von 15-Krone-5. [Sr(15-Krone-5)2]Se9 bildet schwarze, in DMF leicht lösliche Kristalle, die durch das FIR-Spektrum und eine röntgenographische Strukturanalyse charakterisiert werden.Raumgruppe P21/n, Z = 4, 2 381 beobachtete unabhängige Reflexe, R = 0,073. Gitterabmessungen bei 19°C: a = 1 228,7; b = 1 893,4; c = 1 575,7 pm, β = 99,15°. Die Verbindung besteht aus [Sr(15-Krone-5)2]2+-Ionen, in denen das Strontiumion sandwichartig von den O-Atomen der beiden Kronenethermoleküle umgeben ist, und kettenförmigen Se92--Ionen, die topologische Verwandtschaft zu dem bicyclischen Se102--Ion aufweisen.
    Additional Material: 2 Ill.
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