44 research outputs found
Structural single crystal, thermal analysis and vibrational studies of the new rubidium phosphate tellurate Rb2HPO4RbH2PO4·Te(OH)6
AbstractThe determination of the crystalline structure of rubidium phosphate tellurate Rb2HPO4RbH2PO4·Te(OH)6 [RbPTe] is performed from single crystal X-ray diffraction data. The title compound crystallizes in the monoclinic system P2. The unit cell parameters are as follows: a=7.9500(7)Å, b=6.3085(6)Å, c=9.5008(9)Å, β=109.783(4)°, Z=2 and V=448.37(7)Å3.The crystal structure is constituted from isolated (PO43-) tetrahedra and (TeO66-) octahedra and two nonequivalent Rb+ cations. Material cohesion is built of O–H⋯O bondings and ionic interactions.The new synthesized material has been characterized using the differential scanning calorimetry (DSC), thermal analysis [differential thermogravimetric analysis (TG), thermodifference analysis (DTA) and the mass spectrometric analysis], FT-IR and Raman techniques.Thermal analysis, in the temperature range of 300–900K, confirms that the decomposition of this material took place in two steps. The differential scanning calorimetry analysis shows three endothermic peaks at 451, 463 and 481K.The existence of anionic groups in the structure has been confirmed by IR and Raman spectroscopy in the frequency ranges 3000–600cm−1 and 1300–50cm−1, respectively
A new hybrid iron fluoride bipyridine with mixed valence: Fe2F5(2,2'-bipyridine)2H2O
Hydrothermal synthesis of iron fluoride compound, Fe2F5(2,2'-bipyridine)2H2O, and its characterization by single crystal X-ray diffraction is reported. The compound is found to crystallize in the triclinic space group . The monohydrate fluoroferrate of bipyridine is built up from Fe4F10N8 tetrahedron connected by eight nitrogen atoms of four 2,2'-bipyridine molecules and separated by H2O molecules. The main feature of this atomic arrangement is the coexistence of two oxidation states of iron cations and hybrid class II with 0-D dimensionality. Thermal and IR spectral analysis have been carried out for the title compound to confirm the hematite compound as residual and the presence of organic molecule , respectively. Magnetic characterization does not reveal any ferromagnetic component in the range of magnetic field from -20 kOe to 20 kOe at room temperature
Green and blue materials for the ceramic industry from pink MgCoxNi1-xSiO4 (0 ≤ x ≤ 1) solid solutions
In this study, MgCoxNi1-xSiO4 (0.0 ≤ x ≤ 1.0) solid solutions with an olivine structure were synthetized via the chemical coprecipitation method and materials with a smaller M(II) (M = Co, Ni) amount than Co2SiO4 and Ni2SiO4 compounds were obtained. At 1200 °C, the Co(II) and Ni(II) were randomly distributed in the MgCoxNi1-xSiO4 (0.0 ≤ x ≤ 1.0) solid solutions with the olivine structure, but the occupation of Co(II) and Ni(II) ions in M1 (4a) octahedral sites was obtained at a higher level than in M2 (4c) octahedral sites. The Mg(II) ions prefer the M2 sites. This preference explains the main contribution of the M1 sites in spectra of octahedral Co(II) ions and the M1-O and M2-O distances jointly explain the pink colour of the MgCoxNi1-xSiO4 (0.0 ≤ x ≤ 1.0) solid solutions, while the colour of Co2SiO4 is blue. Spectra can be interpreted as the sum of Ni(II) and Co(II) ions in octahedral sites. When these solid solutions are enamelled, the pink colouring changes to green or blue because of the presence of tetrahedral Co(II).Funding for open access charge: CRUE-Universitat Jaume
Structural Insights and Docking Analysis of Adamantane-Linked 1,2,4-Triazole Derivatives as Potential 11 -HSD1 Inhibitors
The solid-state structural analysis and docking studies of three adamantane-linked 1,2,4- triazole derivatives are presented. Crystal structure analyses revealed that compound 2 crystallizes in the triclinic P-1 space group, while compounds 1 and 3 crystallize in the same monoclinic P21/c space group. Since the only difference between them is the para substitution on the aryl group, the electronic nature of these NO2 and halogen groups seems to have no influence over the formation of the solid. However, a probable correlation with the size of the groups is not discarded due to the similar intermolecular disposition between the NO2/Cl substituted molecules. Despite the similarities, CE-B3LYP energy model calculations show that pairwise interaction energies vary between them, and therefore the total packing energy is affected. HOMO-LUMO calculated energies show that the NO2 group influences the reactivity properties characterizing the molecule as soft and with the best disposition to accept electrons. Further, in silico studies predicted that the compounds might be able to inhibit the 11 -HSD1 enzyme, which is implicated in obesity and diabetes. Self- and cross-docking experiments revealed that a number of non-native 11 -HSD1 inhibitors were able to accurately dock within the 11 -HSD1 X-ray structure 4C7J. The molecular docking of the adamantane-linked 1,2,4-triazoles have similar predicted binding affinity scores compared to the 4C7J native ligand 4YQ. However, they were unable to form interactions with key active site residues. Based on these docking results, a series of potentially improved compounds were designed using computer aided drug design tools. The docking results of the new compounds showed similar predicted 11 -HSD1 binding affinity scores as well as interactions to a known potent 11 -HSD1 inhibitor
Effectiveness of a cognitive behavioral intervention in patients with medically unexplained symptoms: cluster randomized trial
BACKGROUND: Medically unexplained symptoms are an important mental health problem in primary care and generate a high cost in health services.Cognitive behavioral therapy and psychodynamic therapy have proven effective in these patients. However, there are few studies on the effectiveness of psychosocial interventions by primary health care. The project aims to determine whether a cognitive-behavioral group intervention in patients with medically unexplained symptoms, is more effective than routine clinical practice to improve the quality of life measured by the SF-12 questionary at 12 month. METHODS/DESIGN: This study involves a community based cluster randomized trial in primary healthcare centres in Madrid (Spain). The number of patients required is 242 (121 in each arm), all between 18 and 65 of age with medically unexplained symptoms that had seeked medical attention in primary care at least 10 times during the previous year. The main outcome variable is the quality of life measured by the SF-12 questionnaire on Mental Healthcare. Secondary outcome variables include number of consultations, number of drug (prescriptions) and number of days of sick leave together with other prognosis and descriptive variables. Main effectiveness will be analyzed by comparing the percentage of patients that improve at least 4 points on the SF-12 questionnaire between intervention and control groups at 12 months. All statistical tests will be performed with intention to treat. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in this analysis. DISCUSSION: This study aims to provide more insight to address medically unexplained symptoms, highly prevalent in primary care, from a quantitative methodology. It involves intervention group conducted by previously trained nursing staff to diminish the progression to the chronicity of the symptoms, improve quality of life, and reduce frequency of medical consultations. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov, number NCT01484223 [http://ClinicalTrials.gov].S
A collaboratively derived environmental research agenda for Galapagos
Galápagos is one of the most pristine archipelagos in the world and its conservation relies upon research and sensible management. In recent decades both the interest in, and the needs of, the islands have increased, yet the funds and capacity for necessary research have remained limited. It has become, therefore, increasingly important to identify areas of priority research to assist decision-making in Galápagos conservation.
This study identified 50 questions considered priorities for future research and management. The exercise involved the collaboration of policy makers, practitioners and researchers from more than 30 different organisations. Initially, 360 people were consulted to generate 781 questions. An established process of preworkshop voting and three rounds to reduce and reword the questions, followed by a two-day workshop, was used to produce the final 50 questions. The most common issues raised by this list of questions were human population growth, climate change and the impact of invasive alien species. These results have already been used by a range of organisations and politicians and are expected to provide the basis for future research on the islands so that its sustainability may be enhanced.
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Ultralight vector dark matter search using data from the KAGRA O3GK run
Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM
A new hybrid iron fluoride bipyridine with mixed valence: Fe2F5(2,2'-bipyridine)2H2O
810-815Hydrothermal synthesis of iron fluoride compound, Fe2F5(2,2'-bipyridine)2H2O, and its characterization by single crystal X-ray diffraction is reported. The compound is found to crystallize in
the triclinic space group . The monohydrate fluoroferrate of bipyridine is built up from Fe4F10N8 tetrahedron connected by eight nitrogen atoms of four 2,2'-bipyridine molecules and separated by H2O molecules. The main feature of this atomic arrangement is the coexistence of two oxidation states of iron cations and hybrid class II with 0-D dimensionality. Thermal and IR spectral analysis have been carried out for the title compound to confirm the hematite compound as residual and the presence of organic molecule , respectively. Magnetic characterization does not reveal any ferromagnetic component in the range of magnetic field from -20 kOe to 20 kOe at room temperature
trans-[1,3-bis(2,4,6-trimethylphenyl)-imidazolidin-2-ylidene]dichlorido-(triphenylphosphine-kappa P)palladium(II)
WOS: 000247981200015PubMed ID: 17551189The title complex, [PdCl2(C21H26N2)(C18H15P)], shows slightly distorted square-planar coordination around the Pd-II metal centre. The Pd-C bond distance between the N-heterocyclic ligand and the metal atom is 2.028 (5) angstrom. The dihedral angle between the two trimethylphenyl ring planes is 36.9 (2)degrees