Characterization of a new gel based on alanine–ninhydrin for possible use in radiation dosimetry

Ninhydrin reacts with alanine forming a Ruhemann’s purple (RP) compound. RP and chloral hydrate (CH) were introduced into gelatin to form a tissue equivalent RP gel for radiation dose measurements, 5–450 Gy. The gel color fades proportionally with the absorbed dose. Addition of CH to the gel improved its radiation sensitivity and fading. RP was analyzed by FTIR spectrometer and the gel by UV–Vis spectrophotometer at 404 and 572 nm. Dose–response is nearly temperature independent from 22 to 30 °C but it is a time dependent after irradiation. Uncertainty (2σ) in dose estimation is less than 6.0%.

     

Functional Itô calculus,path-dependence and the computation of Greeks

Dupire’s functional Itô calculus provides an alternative approach to the classical Malliavin calculus for the computation of sensitivities, also called Greeks, of path-dependent derivatives prices. In this paper, we introduce a measure of path-dependence of functionals within the functional Itô calculus framework. Namely, we consider the Lie bracket of the space and time functional derivatives, which we use to classify functionals accordingly to their degree of path-dependence. We then revisit the problem of efficient numerical computation of Greeks for path-dependent derivatives using integration by parts techniques. Special attention is paid to path-dependent functionals with zero Lie bracket, called locally weakly path-dependent functionals in our classification. Hence, we derive the weighted-expectation formulas for their Greeks. In the more general case of fully path-dependent functionals, we show that, equipped with the functional Itô calculus, we are able to analyze the effect of the Lie bracket on the computation of Greeks. Moreover, we are also able to consider the more general dynamics of path-dependent volatility. These were not achieved using Malliavin calculus.     

Dual anti-inflammatory and antiglycation propensities of a potentially novel class of functionalized fluoroquinolones

Promoted by elevated blood glucose concentrations in diabetes, glycation involves the nonenzymatic addition of reducing sugars and/or their reactive degradation products to amine groups on proteins. New synthetic approaches to 18 fluoroquinolones (FQs) have been developed on the basis of a promising antiglycation activity using 400μM methylglyoxal as the choice glucocytotoxicity concentration. Their anti-inflammatory and radical scavenging properties were elucidated in vitro. Intriguingly, FQs could exhibit an exceedingly more superior than or substantially comparable cytoprotection against methylglyoxal-induced carbonyl toxicity in RAW264.7 macrophages and antiglycation activity to aminoguanidine, as the reference compound. This kind of activity can suggestively be associated with the chelating properties possessed by the synthesized FQs as their DPPH radical scavenging activities proved to be significantly inferior to those of the reference compound, the ascorbic acid. The inhibitory bioactivities using the Griess assay were examined of the compounds against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Selectively, compounds R-2TCBA , R-4FACBA , R-3TCBA , and R-4CLACBA exerted an exceedingly remarkable and superior anti-inflammatory effects (P < .001 vs indomethacin IC₅₀ value of 101.07 ± 2.2 μM) while R-4TCBA and T-4BrACBA were moderately more efficacious than indomethacin. Compounds T-4CLACBA and R-4BrACBA displayed comparable activity with indomethacin. None of the tested compounds and indomethacin exerted any cytotoxicity against RAW 264.7 mouse macrophages. FQs possess potent duality of antiglycation–anti-inflammatory capacities and are devoid of undesirable side effects. FQs can, therefore, serve as scaffolds for the development and designing of new clinical deglycation and antiglycation therapeutic agents.     

Synthesis and properties of MoO3–V2O5–PbO glasses

Lead vanadate glasses of the system xMoO₃–50V₂O₅–(50-x)PbO (0 ≤ x ≤ 25 mol. %) were synthesized and studied by FTIR and ultrasonic spectroscopy and differential scanning calorimetry to investigate the role of MoO₃ content on their atomic structure. The elastic properties and Debye temperatures of the glasses were investigated using sound velocity measurements at 4 MHz. The activation energy for the glass transition was derived from the dependence of the glass-transition temperature (T_g ) on the heating rate. Similarly, the activation energy of the crystallization process was also determined. According to the IR analysis, the vibrations of the vanadate structural units are shifted towards higher wavenumbers on the formation of bridging oxygens. The change of density and molar volume with MoO₃ content reveals that the molybdinate units are less dense than the lead oxide units. The observed compositional dependence of the elastic moduli is interpreted in terms of the effect of MoO₃ on the coordination number of the vanadate units. A good correlation was observed between the experimentally determined elastic moduli and those computed according to the Makishima–Mackenzie model. It is assumed that MoO₃ plays the role of a glass former by increasing the activation energy for the glass transition and the activation energy for crystallization and by increasing both the thermal stability and the glass formation range of the vanadate glasses.     

Effect of WO3 on the glass transition and crystallization kinetics of borotellurite glasses

Tellurite glasses of the system xWO₃–75TeO₂–(25 ? x)B₂O₃ (0 ≤ x ≤ 25 mol. %) were prepared and studied by differential thermal analysis to explore the effect of WO₃ on their glass transition and crystallization kinetics. The crystallization kinetics was studied under non-isothermal conditions using the formal theory of transformations for heterogeneous nucleation. The crystallization results were analyzed and both the activation energy of the crystallization process and the crystallization mechanism characterized. The phases into which the glass crystallizes were identified by X-ray diffraction. Diffractograms of the transformed material indicate the presence of microcrystallites of α-tellurite, Te_0.95W_0.05O_2.05, Te₂W and B₂O₃ in the amorphous matrix.     

Radiation annealing of rapidly solidified Sn–6.7Sb–5.3Zn alloy by low-dose gamma ray

The radiation annealing of a rapidly solidified Sn–6.7Sb–5.3Zn (in atomic percent) melt-spun alloy was caused by low-dose gamma ray irradiation. This is observed from the increase in both the volume of unit cell and particle size of the Sn matrix, as revealed from X-ray diffraction analysis, and the decrease in the resistivity. The alloy was irradiated by gamma ray at doses 5, 10, 20, 40, 50, 60, 70, 80, and 100 Gy. The electrical resistivity was measured for the alloys subjected to these doses and it was found that the resistivity decreased by increasing the dose to a minimum value of 50 Gy and then increased by increasing the dose.     

Synthesis of methyl (5Z,8Z,10E,12E,14Z)-eicosapentaenoate

The first total synthesis of methyl (5Z,8Z,10E,12E,14Z)-eicosapentaenoate has been achieved in seven steps and in 16% overall yield. The synthesis confirmed the assigned structure of this polyunsaturated natural product.     

Synthesis and characterization of nano-silica gel aged under microwave radiation from white sandstone

Double perovskite La₂NiMnO₆ thin film was successfully prepared on (001)-oriented 0.7 wt% Nb-doped SrTiO₃ single crystal substrate by chemical solution deposition method. The microstructures as well as properties were investigated. The results show that the derived thin film is an admixture of Ni/Mn ordering, and two ferromagnetic transitions are observed with Curie temperatures of 289 and 110 K, respectively. A crossover from positive to negative magnetodielectric effect is observed near room temperature. The success preparation of La₂NiMnO₆ thin film by chemical solution deposition will provide a useful method to deposit double perovskite multiferroic thin films with low-cost.     

Synthesis and Spectral Properties of 4‐(2,5‐Dimethoxyphenylmethelene)‐2‐phenyl‐5‐oxazolone (DMPO)

An interesting flourophore, 4‐(2,5‐dimethoxyphenylmethelene)‐2‐phenyl‐5‐oxazolone (DMPO) was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5‐dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4‐(2,5‐dimethoxy‐phenylmethelene)‐2‐phenyl‐5‐oxazolone (DMPO) were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of molecules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B‐type class of Steven's Classification. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.