Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
Add more filters










Database
Language
Publication year range
1.
Behav Res Methods ; 53(5): 1910-1922, 2021 10.
Article in English | MEDLINE | ID: mdl-33674990

ABSTRACT

Recent data collected on adult patients with vestibular loss (VL) tend to demonstrate possible cognitive impairments in visuospatial working memory, mental rotation, selective attention, and space orientation. However, the neuropsychological profile of children with VL remains largely under-investigated in the scientific literature. Although previous research has shown that children with VL may experience some degree of delayed motor development, it is not yet clear if VL could also lead to specific delayed cognitive development. In this study, we will present the development and validation of a new tablet-based computerized test battery (VSAD) that evaluates visuospatial working memory, mental rotation, selective attention, and space orientation abilities. Thirteen children with VL and 54 average-age matched healthy children performed the VSAD and classical paper-and-pencil neuropsychological tasks twice within a 1-month interval. Our results demonstrated a good concurrent validity with strong correlations between the visuospatial working memory, mental rotation, and space orientation tests of the VSAD and classical tasks. Test-retest reliability was also supported through good intra-class coefficients. However, the test of selective attention showed no concurrent validity with the matched classical task. The discriminant validity of the VSAD was partially supported for visuospatial working memory and mental rotation performance accuracy. The VSAD shows good concurrent validity and reliability for measuring visuospatial working memory, mental rotation, and space orientation in children with VL. Future studies are needed to extend discriminant validity with other populations.


Subject(s)
Spatial Navigation , Adult , Child , Cognition , Humans , Memory, Short-Term , Neuropsychological Tests , Reproducibility of Results
2.
Dalton Trans ; 40(15): 3914-26, 2011 Apr 21.
Article in English | MEDLINE | ID: mdl-21264387

ABSTRACT

We describe the synthesis, solid state and solution properties of two families of uranyl(VI) complexes that are ligated by neutral monodentate and anionic bidentate P=O, P=NH and As=O ligands bearing pendent phenyl chromophores. The uranyl(VI) ions in these complexes possess long-lived photoluminescent LMCT (3)Π(u) excited states, which can be exploited as a sensitive probe of electronic structure, bonding and aggregation behaviour in non-aqueous media. For a family of well defined complexes of given symmetry in trans-[UO(2)Cl(2)(L(2))] (L = Ph(3)PO (1), Ph(3)AsO (2) and Ph(3)PNH (3)), the emission spectral profiles in CH(2)Cl(2) are indicative of the strength of the donor atoms bound in the equatorial plane and the uranyl bond strength; the uranyl LMCT emission maxima are shifted to lower energy as the donor strength of L increases. The luminescence lifetimes in fluid solution mirror these observations (0.87-3.46 µs) and are particularly sensitive to vibrational and bimolecular deactivation. In a family of structurally well defined complexes of the related anion, tetraphenylimidodiphosphinate (TPIP), monometallic complexes, [UO(2)(TPIP)(thf)] (4), [UO(2)(TPIP)(Cy(3)PO)] 5), a bimetallic complex [UO(2)(TPIP)(2)](2) (6) and a previously known trimetallic complex, [UO(2)(TPIP)(2)](3) (7) can be isolated by variation of the synthetic procedure. Complex 7 differs from 6 as the central uranyl ion in 7 is orthogonally connected to the two peripheral ones via uranyl → uranium dative bonds. Each of these oligomers exhibits a characteristic optical fingerprint, where the emission maxima, the spectral shape and temporal decay profiles are unique for each structural form. Notably, excited state intermetallic quenching in the trimetallic complex 7 considerably reduces the luminescence lifetime with respect to the monometallic counterpart 5 (from 2.00 µs to 1.04 µs). This study demonstrates that time resolved and multi-parametric luminescence can be of value in ascertaining solution and structural forms of discrete uranyl(VI) complexes in non-aqueous solution.

3.
Inorg Chem ; 49(20): 9554-62, 2010 Oct 18.
Article in English | MEDLINE | ID: mdl-20839846

ABSTRACT

The reaction between Ph(3)PO dissolved in acetone and "PuO(2)Cl(2)" in dilute HCl resulted in the formation of [PuO(2)Cl(2)(Ph(3)PO)(2)]. Crystallographic characterization of the acetone solvate revealed the expected axial trans plutonyl dioxo, with trans Cl and Ph(3)PO in the equatorial plane. Spectroscopic analyses ((31)P NMR, (1)H NMR, and vis/nIR) indicate the presence of both cis and trans isomers in solution, with the trans isomer being more stable. Confirmation of the higher stability of the trans versus cis isomers for [AnO(2)Cl(2)(Ph(3)PO)(2)] (An = U and Pu) was obtained through quantum chemical computational analysis, which also reveals the Pu-O(TPPO) bond to be more ionic than the U-O(TPPO) bond. Slight variation in reaction conditions led to the crystallization of two further minor products, [PuO(2)(Ph(3)PO)(4)][ClO(4)](2) and cis-[PuCl(2)(Ph(3)PO)(4)], the latter complex revealing the potential for reduction to Pu(IV). In addition, the reaction of Ph(3)PNH with [PuO(2)Cl(2)(thf)(2)](2) in anhydrous conditions gave evidence for the formation of both cis- and trans-[PuO(2)Cl(2)(Ph(3)PNH)(2)] in solution (by (31)P NMR). However, the major reaction pathway involved protonation of the ligand with the crystallographic characterization of [Ph(3)PNH(2)](2)[PuO(2)Cl(4)]. We believe that HCl/SiMe(3)Cl carried through from the small scale preparation of [PuO(2)Cl(2)(thf)(2)](2) was the source of both protons and chlorides. The fact that this chemistry was significantly different from previous uranium studies, where cis-/trans-[UO(2)Cl(2)L(2)] (L = Ph(3)PO or Ph(3)PNH) were the only products observed, provides further evidence of the unique challenges and opportunities associated with the chemistry of plutonium.

4.
Acta Crystallogr C ; 65(Pt 5): o195-7, 2009 May.
Article in English | MEDLINE | ID: mdl-19407414

ABSTRACT

In the title compound, C(9)H(4)F(9)O(2)P, molecules are linked by a single O-H...O hydrogen bond into chains related to those in phenylphosphinic acid. There are short intramolecular F...P contacts.

5.
Chem Commun (Camb) ; (8): 917-9, 2009 Feb 28.
Article in English | MEDLINE | ID: mdl-19214315

ABSTRACT

The synthesis of [Np(VI)O(2)Cl(2)(thf)](n) offers the potential for more detailed exploration of neptunyl(vi) chemistry, while the synthesis of the mixed valence cluster complex [{Np(VI)O(2)Cl(2)}{Np(V)O(2)Cl(thf)(3)}(2)] allows molecular neptunyl(v) 'cation-cation' interactions to be probed.

6.
Inorg Chem ; 46(12): 4868-75, 2007 Jun 11.
Article in English | MEDLINE | ID: mdl-17506548

ABSTRACT

Phosphinimine ligands (Cy3PNH) readily react with UO2Cl2(THF)3 (THF=tetrahydrofuran) to give UO2Cl2(Cy3PNH)2, which contains strong U-N interactions and exists as cis and trans isomers in the solid and solution state. Solution NMR experiments and computational analysis both support the trans form as the major isomer in solution, although the cis isomer becomes more stabilized with an increase in the dielectric constant of the solvent. Mayer bond orders, energy decomposition analysis, and examination of the molecular orbitals and total electron densities support a more covalent bonding interaction in the U-NHPCy3 bond compared with the analogous bond of the related U-OPCy3 compounds.


Subject(s)
Organometallic Compounds/chemistry , Phosphines/chemistry , Uranium/chemistry , Ligands , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure , Stereoisomerism
7.
Inorg Chem ; 44(21): 7310-2, 2005 Oct 17.
Article in English | MEDLINE | ID: mdl-16212353

ABSTRACT

The first actinyl phosphinimine complexes have been synthesized and, in the case of uranium, exhibit strong U-N interactions. Competition reactions clearly demonstrate a surprising preference for R3P=NH ligands over R3P=O in the system [AnO2Cl2(R3PX)2] (An = U(VI), Np(VI); R = Ph, Cy; X = O, NH). Spectroscopic evidence for N-donor coordination to [NpO2]2+ in solution indicates chemical similarities to the [UO2]2+ moiety.

8.
Acta Crystallogr C ; 61(Pt 2): m74-5, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15695895

ABSTRACT

The title compound, [Pt2Br4(C6H15P)2], is a centrosymmetric dinuclear platinum(II) complex consisting of two square-planar platinum centres connected by two bridging Br atoms.

SELECTION OF CITATIONS
SEARCH DETAIL
...