Unitarized hard-meson calculation of Kl3 form factors

K_l3 form factors are studied in the analytic hard-meson framework. The Gell-Mann-Oakes-Renner model for chiral SU(3) × SU(3) symmetry breaking is employed to determine the so called σ-terms and current divergences. PCAC is used for the π^? and K-mesons, and two-particle unitarity is used for the 1^? and 0⁺ channels. The results depend on the Kappa-meson mass. Results are presented for the slope of the divergence form factor λ₀, the ratio $\text{ξ =}\text{?}{}_{\mathrm{?}}\text{(0)}\text{?}{}_{\mathrm{+}}\text{(0)}$, and the width of the Kappa meson, for m_κ = 900 and 1100 MeV. It is found that the κ has a large width, and the prediction for λ₀ and ξ are in quantitative agreement with the recent experiments.     

Stainless steel supported NiS/CeS nanocomposite for significantly enhanced oxygen evolution reaction in alkaline media

Journal of Solid State Electrochemistry - The discovery of highly active and cost-effective materials capable of catalyzing the oxygen evolution reaction (OER) is essential for water splitting. In...     

Hierarchical C-N doped NiO with dual-head echinop flowers for ultrasensitive monitoring of epinephrine in human blood serum

Microchimica Acta - The authors describe nanoelectrodes based on the use of hierarchical carbon-nitrogen nanospheres and dual-head nickel oxide echinop flowers (CN@HDN) placed on indium tin oxide...     

Metal Nanoparticle–Microbe Interactions: Synthesis and Antimicrobial Effects

Metal nanoparticles (NPs), chalcogenides, and carbon quantum dots can be easily synthesized from whole microorganisms (fungi and bacteria) and cell-free sterile filtered spent medium. The particle size distribution and the biosynthesis time can be somewhat controlled through the biomass/metal solution ratio. The biosynthetic mechanism can be explained through the ion-reduction theory and UV photoconversion theory. Formation of biosynthetic NPs is part of the detoxification strategy employed by microorganisms, either in planktonic or biofilm form, to reduce the chemical toxicity of metal ions. In fact, most reports on NP biosynthesis show extracellular metal ion reduction. This is important for environmental and industrial applications, particularly in biofilms, as it allows in principle high biosynthetic rates. The antimicrobial and antifungal effect on biosynthetic NPs can be explained in terms of reactive oxygen species and can be enhanced by the capping agents attached to the NP during the biosynthesis process. Industrial applications of NP biosynthesis are still lagging, due to the difficulty of controlling NP size and low titer. Further, the environmental assessment of biosynthetic NPs has not yet been carried out. It is expected that further advancements in biosynthetic NP research will lead to applications, particularly in environmental biotechnology.     

Direct labeling of doxorubicin with technetium-99m: its optimization, characterization and quality control

Doxorubicin (DOX) is an anthracycline antineoplastic and one of the most potent and widely used drugs in clinical oncology. It is used in the treatment of a wide variety of cancers. The aim of this study was the direct labeling of DOX with ^99mTc; its optimization, characterization and quality control of the radiolabeled DOX. Labeling efficiency was determined by paper chromatography. More than 92% labeling was obtained at pH 6?C7, 10?C12???g stannous chloride and 200???g of DOX. The stability of ^99mTc?CDOX was studied up to 5?h. All the experiments were performed at room temperature (25±?2?°C). The characterization of the labeling compound was performed by HPLC and electrophoresis. Electrophoresis indicates that labeled DOX has no charge and HPLC shows single specie of labeled compound.     

Electronic, elastic, optical properties of rutile TiO2 under pressure: A DFT study

The electronic, elastic constants and optical properties of rutile TiO₂ have been investigated using first principle pseudopotential method within generalized gradient approximation (GGA) proposed by Perdew-Burke-Ernzerhof (PBE). The calculated volume, bulk modulus and pressure derivative of bulk modulus are in good agreement with previous experimental and computational results. An underestimated band gap (1.970 eV) along with the higher density of states and expanded energy bands around the fermi level is obtained. Calculated elastic constants satisfying the Born stability criteria suggest that rutile TiO₂ is mechanically stable under higher hydrostatic pressure. The acoustic wave speeds in [1 0 0], [0 1 0], [0 0 1], [1 1 0] and [45° to [1 0 0] and [0 0 1]] directions are predicted using the investigated elastic constants. The dielectric constant is identified with respect to electronic band structure and is utilized to derive the other optical properties like refractive index, energy loss function, reflectivity and absorption. The effect of hydrostatic pressure (0-70 GPa) is described for listed properties. Our investigated results are in good accord with the existing theoretical and experimental results.     

Kinetics of phase transition and thermal stability in Se80?x Te20Zn x (x?=?2, 4, 6, 8, and 10) glasses

Se_80?x Te₂₀Zn _x (x?=?2, 4, 6, 8, and 10) glasses have been prepared using conventional melt quenching technique. The kinetics of phase transformations (glass transition and crystallization) have been studied using differential scanning calorimetry (DSC) under non-isothermal condition at five different heating rates in these glasses. The activation energy of glass transition (E _t), activation energy of crystallization (E _c), Avrami exponent (n), dimensionality of growth (m), and frequency factor (K _o) have been investigated for the better understanding of growth mechanism using different theoretical models. The activation energy is found to be highly dependent on Zn concentration. The rate of crystallization is found to be lowest for Se₇₀Te₂₀Zn₁₀ glassy alloy. The thermal stability of these glasses has been investigated using various stability parameters. The values of these parameters were obtained using characteristic temperatures, such as glass transition temperature T _g, onset crystallization temperature T _c, and peak crystallization temperature T _p. In addition to this, enthalpy-released during crystallization has also been determined. The values of stability parameters show that the thermal stability increases with the increase in Zn concentration in the investigated glassy samples.     

Role of additive (Zn) incorporation on the glass/crystal thermodynamics and stability of Se80 − xTe20Znx (x = 2, 4, 6, 8 and 10) glassy alloys

Different thermodynamic parameters (quantities) of Se_80 − xTe₂₀Zn_x (x = 2, 4, 6, 8 and 10) glasses have been obtained from the phase transformation studies using Differential Scanning Calorimetry (DSC) under non-isothermal condition at five different heating rates (10-50 K/min). Specific heat measurements have been made to see the effect of Zn additive in Se-Te-Zn glasses which have further been utilized to evaluate various thermodynamic quantities such as entropy difference (ΔS), enthalpy difference (ΔH) and Gibbs free energy difference (ΔG) between the undercooled melt and the corresponding equilibrium solid phases as a function of temperature. The data obtained from different thermodynamic quantities have been used to determine the stability of these glasses. It has been found that the stability of the samples increases with the increase of Zinc (Zn) content in the investigated series of the glassy alloys.     

Development of extraction methods for speciation analysis of selenium in aqueous extracts of medicinal plants

Advanced extraction methods have been developed for direct speciation of dissolved inorganic and organic selenium (Se) species in aqueous extracts of medicinal plants (MPs). The inorganic species of Se (SeIV and SeVI) were separated from organic forms by adsorbing inorganic Se on alumina, while the organic Se was not retained. The retained inorganic Se species was eluted with 10 mL 0.2 M HCl. The total inorganic Se species was determined after prereduction of SeVI into SeIV with concentrated HCl. The SeIV in the eluent and total inorganic Se species were then complexed with diethyldithiocarbamate. The resultant complexes were entrapped in the nonionic surfactant Triton X-114. The total Se, organic Se, total inorganic Se, and SeIV species were determined by electrothermal atomic absorption spectrometry with a modifier. The SeVI concentration was obtained by subtracting SeIV from total inorganic Se contents. The main factors affecting the methodologies were investigated in detail. Under the optimized experimental conditions, the LOD for SeIV was 50 microg/L. Among dissolved inorganic and organic Se species in aqueous extracts of MPs, organic Se species were present in the range of 74-84%, SeIV 3.62-7.47%, and SeVI 12.4-18.57% of total Se contents.