Size-Dependent High-Pressure Behavior of Pure and Eu-Doped YO Nanoparticles: Insights from Experimental and Theoretical Investigations.

We report a joint high-pressure experimental and theoretical study of the structural, vibrational, and photoluminescent properties of pure and Eu-doped cubic YO nanoparticles with two very different average particle sizes. We compare the results of synchrotron X-ray diffraction, Raman scattering, and photoluminescence measurements in nanoparticles with ab initio density-functional simulations in bulk material with the aim to understand the influence of the average particle size on the properties of pure and doped YO nanoparticles under compression. We observe that the high-pressure phase behavior of YO nanoparticles depends on the average particle size, but in a different way to that previously reported.

Exploring the crystal structure and properties of ytterbium orthoantimonate under high pressure.

The crystal structure of YbSbO was determined from powder X-ray diffraction data using the Rietveld method. YbSbO is found to be monoclinic and isostructural to α-PrSbO. We have also tested the influence of pressure on the crystal structure up to 22 GPa by synchrotron powder X-ray diffraction.

Pressure-induced order-disorder transitions in β-InS: an experimental and theoretical study of structural and vibrational properties.

This joint experimental and theoretical study of the structural and vibrational properties of β-InS upon compression shows that this tetragonal defect spinel undergoes two reversible pressure-induced order-disorder transitions up to 20 GPa. We propose that the first high-pressure phase above 5.0 GPa has the cubic defect spinel structure of α-InS and the second high-pressure phase (ϕ-InS) above 10.

Structural, vibrational and electronic properties of α'-GaS under compression.

We report a joint experimental and theoretical study of the low-pressure phase of α'-GaS under compression. Theoretical ab initio calculations have been compared to X-ray diffraction and Raman scattering measurements under high pressure carried out up to 17.5 and 16.

Characterization and Decomposition of the Natural van der Waals SnSbTe under Compression.

High pressure X-ray diffraction, Raman scattering, and electrical measurements, together with theoretical calculations, which include the analysis of the topological electron density and electronic localization function, evidence the presence of an isostructural phase transition around 2 GPa, a Fermi resonance around 3.5 GPa, and a pressure-induced decomposition of SnSbTe into the high-pressure phases of its parent binary compounds (α-SbTe and SnTe) above 7 GPa. The internal polyhedral compressibility, the behavior of the Raman-active modes, the electrical behavior, and the nature of its different bonds under compression have been discussed and compared with their parent binary compounds and with related ternary materials.

Structural and Lattice-Dynamical Properties of TbO under Compression: A Comparative Study with Rare Earth and Related Sesquioxides.

We report a joint experimental and theoretical investigation of the high pressure structural and vibrational properties of terbium sesquioxide (TbO). Powder X-ray diffraction and Raman scattering measurements show that cubic 3̅ (C-type) TbO undergoes two phase transitions up to 25 GPa. We observe a first irreversible reconstructive transition to the monoclinic 2/ (B-type) phase at ∼7 GPa and a subsequent reversible displacive transition from the monoclinic to the trigonal 3̅1 (A-type) phase at ∼1 GPa.

Orpiment under compression: metavalent bonding at high pressure.

We report a joint experimental and theoretical study of the structural, vibrational, and electronic properties of layered monoclinic arsenic sulfide crystals (α-AsS), aka mineral orpiment, under compression. X-ray diffraction and Raman scattering measurements performed on orpiment samples at high pressure and combined with ab initio calculations have allowed us to determine the equation of state and the tentative assignment of the symmetry of many Raman-active modes of orpiment. From our results, we conclude that no first-order phase transition occurs up to 25 GPa at room temperature; however, compression leads to an isostructural phase transition above 20 GPa.

Randomized controlled trial of cognitive-motivational therapy program (PIPE) for the initial phase of schizophrenia: Maintenance of efficacy at 5-year follow up.

Aim: The main goal of this study was to evaluate the effectiveness of a cognitive motivational treatment program.

Method: A randomized, controlled, single-blind clinical trial was carried out. A total of 104 patients were recruited to take part in the trial, of whom ultimately 62 patients were allocated into two groups and finished the study.

High-pressure structural and vibrational properties of monazite-type BiPO, LaPO, CePO, and PrPO.

Monazite-type BiPO, LaPO, CePO, and PrPO have been studied under high pressure by ab initio simulations and Raman spectroscopy measurements in the pressure range of stability of the monazite structure. A good agreement between experimental and theoretical Raman-active mode frequencies and pressure coefficients has been found which has allowed us to discuss the nature of the Raman-active modes. Besides, calculations have provided us with information on how the crystal structure is modified by pressure.

Domiciliary intervention in psychosis: a systematic review.

Background: This theoretical study reviews the main findings and research on home-based treatment for psychosis. The principal purpose was to analyze the various types of home-based service and make recommendations for a service that would meet the needs of both first-episode and resistant patients. We compare the Early Intervention Service, which aims to reduce the range of untreated psychosis (DUP) with other types of home-care and similar interventions that have already been implemented: crisis resolution home teams (CRHTs), Open Dialogue Approach (ODA), social skills training (SST) and foster homes.

Pressure Impact on the Stability and Distortion of the Crystal Structure of CeScO.

The effects of high pressure on the crystal structure of orthorhombic (Pnma) perovskite-type cerium scandate were studied in situ under high pressure by means of synchrotron X-ray powder diffraction, using a diamond-anvil cell. We found that the perovskite-type crystal structure remains stable up to 40 GPa, the highest pressure reached in the experiments. The evolution of unit-cell parameters with pressure indicated an anisotropic compression.

High-pressure structural, elastic, and thermodynamic properties of zircon-type HoPO and TmPO.

Zircon-type holmium phosphate (HoPO) and thulium phosphate (TmPO) have been studied by single-crystal x-ray diffraction and ab initio calculations. We report on the influence of pressure on the crystal structure, and on the elastic and thermodynamic properties. The equation of state for both compounds is accurately determined.

High-Pressure Crystal Structure, Lattice Vibrations, and Band Structure of BiSbO4.

The high-pressure crystal structure, lattice-vibrations, and electronic band structure of BiSbO4 were studied by ab initio simulations. We also performed Raman spectroscopy, infrared spectroscopy, and diffuse-reflectance measurements, as well as synchrotron powder X-ray diffraction. High-pressure X-ray diffraction measurements show that the crystal structure of BiSbO4 remains stable up to at least 70 GPa, unlike other known MTO4-type ternary oxides.

Pressure-induced amorphization of YVO₄:Eu³⁺ nanoboxes.

A structural transformation from the zircon-type structure to an amorphous phase has been found in YVO4:Eu(3+) nanoboxes at high pressures above 12.7 GPa by means of x-ray diffraction measurements. However, the pair distribution function of the high-pressure phase shows that the local structure of the amorphous phase is similar to the scheelite-type YVO4.

Experimental and Theoretical Investigations on Structural and Vibrational Properties of Melilite-Type Sr2ZnGe2O7 at High Pressure and Delineation of a High-Pressure Monoclinic Phase.

We report a combined experimental and theoretical study of melilite-type germanate, Sr2ZnGe2O7, under compression. In situ high-pressure X-ray diffraction and Raman scattering measurements up to 22 GPa were complemented with first-principles theoretical calculations of structural and lattice dynamics properties. Our experiments show that the tetragonal structure of Sr2ZnGe2O7 at ambient conditions transforms reversibly to a monoclinic phase above 12.

Pressure effects on the vibrational properties of α-Bi(2)O(3): an experimental and theoretical study.

We report an experimental and theoretical high-pressure study of the vibrational properties of synthetic monoclinic bismuth oxide (α-Bi(2)O(3): ), also known as mineral bismite. The comparison of Raman scattering measurements and theoretical lattice-dynamics ab initio calculations is key to understanding the complex vibrational properties of bismite. On one hand, calculations help in the symmetry assignment of phonons and to discover the phonon interactions taking place in this low-symmetry compound, which shows considerable phonon anticrossings; and, on the other hand, measurements help to validate the accuracy of first-principles calculations relating to this compound.

Structural study of α-Bi2O3 under pressure.

An experimental and theoretical study of the structural properties of monoclinic bismuth oxide (α-Bi2O3) under high pressures is here reported. Both synthetic and mineral bismite powder samples have been compressed up to 45 GPa and their equations of state have been determined with angle-dispersive x-ray diffraction measurements. Experimental results have been also compared with theoretical calculations which suggest the possibility of several phase transitions below 10 GPa.

New polymorph of InVO4: a high-pressure structure with six-coordinated vanadium.

A new wolframite-type polymorph of InVO4 is identified under compression near 7 GPa by in situ high-pressure (HP) X-ray diffraction (XRD) and Raman spectroscopic investigations on the stable orthorhombic InVO4. The structural transition is accompanied by a large volume collapse (ΔV/V = -14%) and a drastic increase in bulk modulus (from 69 to 168 GPa). Both techniques also show the existence of a third phase coexisting with the low- and high-pressure phases in a limited pressure range close to the transition pressure.

Thermally activated cation ordering in ZnGa2Se4 single crystals studied by Raman scattering, optical absorption, and ab initio calculations.

Order-disorder phase transitions induced by thermal annealing have been studied in the ordered-vacancy compound ZnGa2Se4 by means of Raman scattering and optical absorption measurements. The partially disordered as-grown sample with tetragonal defect stannite (DS) structure and I4¯2m space group has been subjected to controlled heating and cooling cycles. In situ Raman scattering measurements carried out during the whole annealing cycle show that annealing the sample to 400 °C results in a cation ordering in the sample, leading to the crystallization of the ordered tetragonal defect chalcopyrite (DC) structure with I4¯ space group.

Compression of silver sulfide: X-ray diffraction measurements and total-energy calculations.

Angle-dispersive X-ray diffraction measurements have been performed in acanthite, Ag(2)S, up to 18 GPa in order to investigate its high-pressure structural behavior. They have been complemented by ab initio electronic structure calculations. From our experimental data, we have determined that two different high-pressure phase transitions take place at 5 and 10.

Lack of indinavir-associated nephrological complications in HIV-infected adults (predominantly women) with high indinavir plasma concentration in Abidjan, Côte d'Ivoire.

To report the tolerance of indinavir combined with ritonavir (IDV/r 800/100 mg) twice daily (bid) in sub-Saharan African HIV-infected adults. HAART-naives patients started zidovudine plus lamivudine plus IDV/r 800/100 mg bid. Follow-up included standardized documentation of morbidity, CD4(+) cell count, creatininemia, plasma HIV-1 RNA, and IDV minimal plasma concentration (C(min)) measurements at month 1 (M1), M3, and M6.

Production of oxidants by ion irradiation of water/carbon dioxide frozen mixtures.

We present new experimental results on the formation of oxidants, such as hydrogen peroxide, ozone, and carbonic acid, under ion irradiation of icy mixtures of water/carbon dioxide at different ratios and temperatures (16 and 80 K). Pure water ice layers and mixtures with carbon dioxide were irradiated by 200 keV He+ ions. We found that the CO(2)/H(2)O ratio progressively decreased to a value of about 0.

Haematological changes in adults receiving a zidovudine-containing HAART regimen in combination with cotrimoxazole in Côte d'Ivoire.

Objective: Neutropenia is the most frequent side effect of cotrimoxazole in sub-Saharan Africa. We estimated the incidence of haematological disorders during the first 6 months of a zidovudine-containing highly active antiretroviral therapy (HAART) regimen in sub-Saharan African adults receiving cotrimoxazole.

Methods: Prospective cohort study in Abidjan, with blood cell count measurement at baseline (HAART initiation), month 1, month 3 and month 6.