Influence of a co-substituted A-site on structural characteristics and ferroelectricity of (Pb, Ba, Ca)TiO3 complex perovskites: analysis of local-, medium- and long-range order

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental evidence of enhanced ferroelectricity in Ca doped BiFeO3

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Characterization and properties of elephant grass ashes as supplementary cementing material in pozzolan/Ca(OH)(2) pastes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production and characterization of natural rubber-Ca/P blends for biomedical purposes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Incorporation of Ca, P, and Si on bioactive coatings produced by plasma electrolytic oxidation: The role of electrolyte concentration and treatment duration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphology and properties of (Ba, Sr, Ca) titanates synthesized by microwave-assisted hydrothermal method

Ba1-xCaxTiO3, Ba1-xSrxTiO3 and Sr1-xCaxTiO3 (x = 0, 0.25, 0.50, 0.75 and 1) nanoparticles were synthesized using the microwave-assisted hydrothermal method. Samples were prepared for 40 minutes at 140°C under a pressure of 3 MPa using an adapted domestic microwave oven. The samples were characterized by X-Ray diffraction (XRD), scanning electron microscopy (FE-SEM), and Raman, photoluminescence (PL) and ultraviolet-visible (UV-Vis) spectroscopies. XRD data show that ceramic powders have crystalline phases associated with a short-range structural disorder. This structural disorder is confirmed by Raman spectral bands indicating multi-phonon processes and the presence of defects or impurities. Such defects account for a broad band in the photoluminescence spectrum in the green light (460 nm) region for all samples. Gap energy variation, obtained from UV-Vis spectra, suggest a non-uniform band structure of these titanates in accordance with the PL results. The morphology of each sample is changed with doping and varies from a spherical to cubic appearance for energy minimization.

Availability of nutrients, productive properties, and quality of sunflower ( L.) seeds in acid soils amended with different molar ratios between Ca and Mg

Liming is indispensable in acid soils for amending acidity; however, the technique may alter the cation balance in soil and, consequently, may limit the availability and uptake of nutrients. We aimed to evaluate different molar ratios between calcium (Ca) and magnesium (Mg) on the availability of soil nutrients and their influence on the productive properties of sunflower and seed quality. The experiment was carried out in a greenhouse under two types of contrasting soils and six molar combinations of CaCO3and MgCO3 in amendment of soil acidity to raise base saturation to 70%. After incubation, soil analysis was undertaken to verify the ratios obtained and nutrient availability. Morphological and production variables were analyzed at the end of the experiment, as well as accumulation of nutrients in the achenes and their physiological quality. In spite of equal base saturation between the types of soil, there were differences in the available contents of these cations. The increase in the Ca contents limited the Mg contents to the critical level of the sunflower. This result had a negative influence on the production properties of sunflower and physiological quality. In contrast, there was a compensation of the crop with greater accumulation of nutrients in the achenes under lower yield.

Covenanters of South Carolina Collection - Accession 208 - M92 (118)

The Covenanters of South Carolina Collections consists of a "Sketch of the Covenanters of Rocky Creek, South carolina About 1750 to 1840" by Miss Mary Elder, 1886 as dictated to her by her father Mr. Matthew Elder, Yorkville, SC. Also included is an undated genealogical sketch of William Stinson (Stevenson) (1752-1809) who was a covenanter from Rocky Creek, SC and a "History of Fishing Creek Presbyterian Church by Mrs. Frank Hicklin" that was written ca. 1958. The Fishing Creek Presbyterian Church was organized ca. 1752.

Computer simulation study of collective dynamics in the glass former Ca(NO3)(2)center dot 4H(2)O

Time correlation functions of current fluctuations were calculated by molecular dynamics (MD) simulations in order to investigate sound waves of high wavevectors in the glass-forming liquid Ca(NO3)(2)center dot 4H(2)O. Dispersion curves, omega(k), were obtained for longitudinal (LA) and transverse acoustic (TA) modes, and also for longitudinal optic (LO) modes. Spectra of LA modes calculated by MD simulations were modeled by a viscoelastic model within the memory function framework. The viscoelastic model is used to rationalize the change of slope taking place at k similar to 0.3 angstrom(-1) in the omega(k) curve of acoustic modes. For still larger wavevectors, mixing of acoustic and optic modes is observed. Partial time correlation functions of longitudinal mass currents were calculated separately for the ions and the water molecules. The wavevector dependence of excitation energies of the corresponding partial LA modes indicates the coexistence of a relatively stiff subsystem made of cations and anions, and a softer subsystem made of water molecules. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4751548]

A revision of species diversity in the Neotropical genus Oreobates (Anura: Strabomantidae), with the description of three new species from the Amazonian slopes of the Andes

We revisit species diversity within Oreobates (Anura: Strabomantidae) by combining molecular phylogenetic analyses of the 16S rRNA amphibian barcode fragment with the study of the external morphology of living and preserved specimens. Molecular and morphological evidence support the existence of 23 species within Oreobates, and three additional candidate species (Oreobates sp. [Ca JF809995], Oreobates sp. [Ca EU368903], Oreobates cruralis [Ca EU192295]). We describe and name three new species from the Andean humid montane forests of Departamento Cusco, southern Peru: O. amarakaeri New Species from Rio Nusinuscato and Rio Mabe, at elevations ranging from 670 to 1000 m in the Andean foothills; O. machiguenga, new species, from Rio Kimbiri (1350 m), a small tributary of the Apurimac River, in the western versant of Cordillera Vilcabamba; and O. gemcare, new species, from the Kosnipata Valley at elevations ranging from 2400 to 2800 m. The three new species are readily distinguished from all other Oreobates by at least one qualitative morphological character. Three species are transferred to Oreobates from three genera of Strabomantidae: Hypodactylus lundbergi, Pristimantis crepitans, and Phrynopus ayacucho (for which the advertisement call, coloration in life, and male characteristics are described for first time). Oreobates simmonsi is transferred to the genus Lynchius. Hylodes verrucosus is considered a junior synonym of Hylodes philippi. In addition, H. philippi is removed from the synonymy of O. quixensis and considered a nomem dubium within Hypodactylus. The inclusion of Phrynopus ayacucho in Oreobates extends the ecological range of the genus to the cold Andean puna. Oreobates is thus distributed from the Amazonian lowlands in southern Colombia to northern Argentina, reaching the Brazilian Atlantic dry forests in eastern Brazil, across an altitudinal range from ca. 100 to 3850 m.

Effect of Si addition on Ca- and P-impregnated implant surfaces with nanometer-scale roughness: an experimental study in dogs

Objectives: To investigate the effect of Si addition on a nanometer-scale roughness Ca and P implant surfaces in a canine tibia model by biomechanical and histomorphometric evaluations. Material and methods: The implant surfaces comprised a resorbable media CaP microblasted (control) and a CaP resorbable media + silica-boost microblasted (experimental) surfaces. Surfaces were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and optical interferometry (IFM) down to the nanometric level. The animal model involved the bilateral placement of control (n = 24) and experimental surface (n = 24) implants along the proximal tibiae of six dogs, remaining in vivo for 2 or 4 weeks. After euthanization, half of the specimens were torquedto- interface failure, and the other half was subjected to histomorphologic and bone-to-implant contact (BIC) evaluation. Torque and BIC statistical evaluation was performed by the Friedman test at 95% level of significance, and comparisons between groups was performed by the Dunn test. Results: IFM and SEM observations depicted comparable roughness parameters for both implant surfaces on the micrometer and nanometer scales. XPS analysis revealed similar chemical composition, except for the addition of Si on the experimental group. Torque-to-interface failure and BIC mean values showed no significant differences (P = 0.25 and 0.51, respectively) at both 2- and 4-week evaluation points for experimental and control groups. Early bone healing histomorphologic events were similar between groups. Conclusions: The experimental surface resulted in not significantly different biomechanical fixation and BIC relative to control. Both surfaces were biocompatible and osseoconductive.

Molecular characterization of a phytoplasma of group 16SrIX related to 'Ca. Phytoplasma phoenicium' in periwinkle in Brazil

Periwinkle (Catharanthus roseus), a tropical perennial plant, was found to be infected by a phytoplasma. Plants exhibiting virescence, phyllody and variegation symptoms were collected in the states of Minas Gerais and Sao Paulo, Brazil. The phytoplasma was transmitted by grafting from an infected periwinkle plant to healthy plants and by dodder to a citrus plant. Phytoplasma isolates from periwinkle plants from Brazil had the 16S rDNA gene sequenced and were classified in the 16SrIX group, subgroup A, belonging to the 'Candidatus P. phoenicium' species.

Evaluation of CA-125 and soluble CD-23 in patients with pelvic endometriosis: a case-control study

Objective: To evaluate serum concentrations of CA-125 and soluble CD-23 and to correlate them with clinical symptoms, localization and stage of pelvic endometriosis and histological classification of the disease. Methods: Blood samples were collected from 44 women with endometriosis and 58 without endometriosis, during the first three days (1st sample) and during the 7th, 8th and 9th day (2nd sample) of the menstrual cycle. Measurements of CA-125 and soluble CD-23 were performed by ELISA. Mann-Whitney U test was used for age, pain evaluations (visual analog scale) and biomarkers concentrations. Results: Serum levels Of CA-125 were higher in endometriosis patients when compared to the control group during both periods of the menstrual cycle evaluated in the study. This marker was also elevated in women with chronic pelvic pain, deep dyspareunia (2nd sample), dysmenorrhea (both samples) and painful defecation during the menstrual flow (2nd sample). CA-125 concentration was higher in advanced stages of the disease in both samples and also in women with ovarian endometrioma. Concerning CD-23, no statistically significant differences were observed between groups. Conclusion: The concentrations of CA-125 were higher in patients with endometriosis than in patients without the disease. No significantly differences were observed for soluble CD-23 levels between groups.

Evaluation of Inductively Coupled Plasma Mass Spectrometry for Determining Ca, Cu, Fe, Mg, Mn, Se and Zn in Bovine Semen Samples using a Simple Sample Dilution Method

A simple and fast method for the determination of Ca, Cu, Fe, Mg, Mn, Se and Zn in bovine semen by quadrupole inductively coupled plasma spectrometry (q-ICP-MS) is described. Prior to analysis, samples (200 mu L) were diluted 1:50 in a solution containing 0.01% v/v Triton (R) X-100 and 0.5% v/v nitric acid and directly analyzed by ICP-MS. The limits of detection of the method are 0.3, 0.03, 0.2, 0.04, 0.04, 0.03 and 0.03 mu g L-1 for Ca-44, Cu-63, Fe-57, Mg-24, Zn-64, Se-82 and Mn-55, respectively. For purposes of comparison and method validation, four ordinary bovine semen samples were directly analyzed by ICP-MS and by flame atomic absorption spectrometry (FAAS) or graphite furnace atomic absorption spectrometry (GF AAS), with no statistical difference between the techniques at the 95% level when applying the t-test. Then, the proposed method was applied in the determinations of Ca, Cu, Fe, Mg, Mn, Se and Zn in collected samples of bovine semen from different breeds, which are used in reproduction programs and artificial insemination.