A novel synthesis of CeO2 powder by using chemical bath (CB) as green method is presented. The process was completed by thermal annealing (TA) at 1000°C during 2 h. CeO2 growth was confirmed by: ...X-ray diffraction (XRD), UV–vis spectra, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and Raman spectra. By FTIR, bands associated with CO32−and OH− ions were identified, disappearing with the TA process. The X-ray diffraction (XRD) patterns of the as grown and CeO2 TA samples showed the reflection characteristic of CeO2 structure with a cubic symmetric pattern. By XRD diffractograms the grain size calculated were ∼2.7nm and ∼28.5nm for as-grown and CeO2 TA samples, respectively. The grain size of ∼2.7nm is the smallest among the reported values for CeO2. Absorbance of as-grown spectra showed three bands located at ∼382, ∼357 and ∼271nm while the CeO2 TA sample displayed only two bands at ∼271 and ∼320nm. Direct optical energy gap were Eg=4.4 eV and Eg=4.3 eV for as-grown and CeO2 TA samples, respectively, showing quantum size effect of CeO2 nanoparticles. Raman spectra indicated that the as-grown and CeO2 samples have the fluorite structure.
Resumen Caso clínico Varón de 70 años diagnosticado de distrofia foveomacular viteliforme del adulto (DFVA) que en el curso de su enfermedad presenta disminución brusca de visión en el ojo izquierdo ...coincidiendo con la aparición de una membrana neovascular oculta. Dada la localización yuxtafoveal de la membrana, se decidió tratar con ranibizumab intravítreo, siendo necesarias 2 inyecciones para lograr el cierre completo de la lesión neovascular. Discusión El uso de ranibizumab intravítreo puede ser una opción de tratamiento eficaz en la neovascularización coroidea secundaria a DFVA, y se precisan series de casos más amplias para poder confirmar esta observación.
Calcium hexaluminate (CaAl12O19) is the most alumina-rich intermediate compound of the CaO–Al2O3 system. The formation of this aluminate is produced by the reaction between calcium oxide and alumina. ...Intermediate compounds with lower alumina content (CaAl2O4, CaAl4O7,…) are formed during the synthesis of calcium hexaluminate with increasing temperature. With the aim to obtain dense and pure calcium hexaluminate by reaction sintering method using Spark Plasma Sintering (SPS) the variation of sintering parameters was studied. Final densities close to the theoretical and calcium hexaluminate formation rates over 93% were achieved by this method. Once the sintering parameters were optimized, a study of the flexural strength and the hardness of the samples were performed.
Holmium oxide (Ho2O3) nanocrystals were prepared through an uncomplicated precipitation technique applying Chemical Bath Deposition. The effect by the reaction temperature (∼20 °C and ∼90 °C samples) ...on the morphological, structural and some optical properties were investigated. Ho2O3 powder samples have been analyzed by applying SEM, FTIR, XRD and absorbance techniques. The crystalline morphology shows differences in grain boundaries as well as porosity and granular packaging. These crystalline materials have an acceptable stoichiometric balance. FTIR spectra show OH- and ions bands of different intensities, that are commonly incorporated in the surface and volume of these crystals. According to the XRD diffractograms, the crystalline cubic phase in both materials is identified. The grain size for each sample is located at range ∼4.06–21.35 nm and ∼21.15–35.35 nm respectively. The absorbance spectra investigated at UV–vis shows eleven absorption bands of different intensities located at ∼278, ∼287, ∼333, ∼345, ∼360, ∼415, ∼448, ∼472, ∼485, ∼535 and ∼645 cm−1 identified as Ho+3 electronic transitions occurring in the UV- Vis-region. The bandgap energies for each sample were Eg ∼4.95 eV, and Eg ∼4.85 eV respectively. The effect of the reaction temperature is manifested with the decrease in the grain size and carries with it the shifting of the Eg towards greater energy, which usually manifests itself in materials that have nanocrystals.
Stem canker of oilseed rape (canola, Brassica napus) is associated with a species complex of two closely related fungal species, Leptosphaeria maculans and L. biglobosa. Of these, L. maculans is the ...most damaging and develops gene-for-gene relationships with the host. Here, a wide scale analysis of the L. maculans - L. biglobosa species complex was performed throughout the American continent (23 locations from Chile to Canada) plus several locations in Western Australia for comparison purposes, based on a collection of 1132 isolates from infected tissues of a susceptible cultivar. Fungal species were discriminated on the basis of morphological, phytopathological and molecular criteria and showed that L. biglobosa was closely associated with L. maculans in most of the locations. Multiple gene phylogeny using sequences of ITS, actin and β-tubulin confirmed the prevalence of the L. biglobosa'canadensis' sub-clade in Canada, whereas up to three different sub-clades of L. biglobosa were found in Georgia (USA). Race structure of L. maculans was investigated using a combination of pathogenicity tests and PCR amplification of avirulence alleles AvrLm1, AvrLm4 and AvrLm6. Three contrasting situations were observed: (i) race structure in Ontario, Chile and Georgia was related to that of European and Western Australian populations, with a low race diversity; (ii) only one race was found in Mexico, and not found outside of this country; (iii) a large diversity of races was observed in central Canada (Manitoba, Alberta and Saskatchewan) with very specific features including maintenance of avirulence alleles absent from Europe, absence of the AvrLm7 allele common in Europe (or eastern Canada) and wide location-to-location variability.
We study the phase diagram of Fe1−qAlq alloys via the quenched site diluted spin-1 ferromagnetic Ising model by employing effective field theory. One suggests a new approach to exchange interaction ...between nearest neighbors of Fe that depends on the powers of the Al (q) instead of the linear dependence proposed in other papers. In such model we propose the same kind of the exchange interaction in which the iron–nickel alloys obtain an excellent theoretical description of the experimental data of the T–q phase diagram for all Al concentration q.
•We apply the quenched Ising model spin-1 to study the properties of Fe–Al.•We employ the EFT and suggest a new approach to ferromagnetic coupling.•The new probability distribution is considered.•The phase diagram is obtained for all values of q in T–q plane.
•Barium carbonate (BaCO3) nanocrystals were synthesized by Chemical Bath Deposition.•Thermal effects on morphology, dislocation density (δ), and crystalline phase, were studied.•Javelin-like, ...quasi-spherical, and rod-like nanostructures morphologies were obtained.•Chemical kinetic mechanism analysis of BaCo3 is presented.
Barium carbonate (BaCO3) nanocrystals were synthesized at ∼20 °C by Chemical Bath Deposition technique in the absence of additives. Chemical kinetic mechanism analysis is presented to understand the formation of the BaCO3 nanocrystal associated with the Ba2+ and CO32- ions. The BaCO3 nanocrystals were thermally annealing treated at ∼500 °C (BaCO3-TT) and the corresponding thermal effects on morphology, grain size, dislocation density (δ), and crystalline phase, were studied. We identified javelin-like, quasi-spherical, and rod-like complex nanostructures by Scanning Electron Microscopy (SEM). We found that the thermal annealing treatment produces a drastic change in morphology, presenting change to dendrite-like complex nanostructures. The FTIR spectra were recorded, both BaCO3 and BaCO3-TT exhibit the same frequency absorptions bands. Those bands at ∼855 cm−1, ∼693 cm−1, and ∼1090 cm-1 are assigned to out-of-plane bending vibrations of CO32- ion while the frequency absorption band at ∼1411 cm-1 is connected with the asymmetric stretching vibration of CO32- ion. BaCO3 powders have a rhombohedral crystalline phase, maintaining this crystalline phase even with thermal annealing treatment, confirming the thermal stability of this material. The calculated strain values ∼2.141 × 10-3 and ∼1.15 × 10-3, and the dislocation density ∼1.15 × 10-3 lines m-2 and ∼2.29 × 1015 lines m-2 justify the observed crystalline defects of BaCO3 and BaCO3-TT nanocrystals.
Physiological changes in elderly individuals (EI) can contribute to nutritional deterioration and comorbidities that reduce their quality of life. Factors such as diet can modulate some of these ...effects. The aim was to evaluate the functionality of foods added with Brosimum alicastrum Sw. seed flour in EI. EI (n = 23) living in nursing home conditions agreed to participate. A control stage was carried out (30 days) and subsequently, an intervention stage (30 days) was realized in which a muffin and a beverage, designed for EI, were added to the participants’ their usual diet. In both stages, anthropometric parameters, body composition, nutritional status, dietary intake, sarcopenic status, cognitive and affective states, biometric parameters, and total phenolic compounds (TPC), and antioxidant capacity in foods and plasma of EI were determined. The results showed that the consumption of the foods improved the energy intake and preserved the muscle reserves of the EI. The EI gained body weight (+1.1 kg), increased their protein (+18.6 g/day; 1.5 g/kg BW/day), dietary fiber (+13.4 g/day), iron (+4.4 mg/day), zinc (+1.8 mg/day), folic acid (+83.4 µg/day) consumption while reducing their cholesterol (−66 mg/day) and sodium (−319.5 mg/day) consumption. LDL-C lipoproteins reduced (14.8%) and urea (33.1%) and BUN (33.3%) increased. The TPC increased (7.8%) in the plasma, particularly in women (10.7%). The foods improve the EI nutritional status, and this has a cardiovascular protective effect that can benefit the health of the EI.
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