Classical and advanced chemical sciences
Different nickel oxide catalysts have been prepared by simple precipitation method using different nickel precursors and using surfactant sodium dodecyl sulfate (SDS) or without surfactant. The prepared catalysts have been characterized by using XRD and FT-IR. The particle sizes have been calculated by using the Scherrer equation. The nickel oxide catalyst prepared by using nickel acetate as precursor and surfactant SDS has shown less particle size as compared to other catalysts prepared by using other precursors. Also, nickel oxide catalyst prepared using nickel acetate precursor and surfactant SDS has shown higher catalytic activity for reduction of p-nitrophenol (PNP) to p-aminophenol (PAP) using sodium borohydride (NaBH4). Also, for the said reaction effect of concentration of p-nitrophenol on catalytic efficiency has been studied.
Keywords: nickel oxide; p-nitrophenol reduction; sodium dodecyl sulfate; p-aminophenol.
A considerable amount of work has been reported on isothermal annealing of pure alkali and alkaline earth metal nitrates. In the present work, initially, the eutectic of NaNO3-KNO3 was prepared by mixing NaNO3 (45%) and KNO3 (55%) fused at 225 0C and cooled naturally. The samples of a eutectic of NaNO3-KNO3 were irradiated in 60Co – gamma source. The radiation decomposition of the eutectic mixture takes place. Present work mainly deals with the study of isothermal annealing of radiation damage in a eutectic mixture of NaNO3-KNO3. This data has been analyzed by using conventional kinetics and the Waite model. Results of annealing show that a significant fraction of annealing obeys second order kinetics except in the initial short period. The energies of activation are calculated by two methods and are found to agree.
Keywords: annealing; kinetics; -irradiation; eutectic of NaNO3-KNO3.
A series of Rhodanine derivatives were synthesized by Knoevenagel condensation. All the synthesized compounds were tested for their in vitro anticancer activity against MCF-7 and BT-474 human breast cancer cell lines. All the synthesized compounds were characterized and screened for their antimicrobial activity against the bacterial and fungal strain. Majority of the compounds showed good to moderate anticancer and antimicrobial activity. Among these compounds, one showed promising activity against gram-positive bacteria B. subtilis and S. aureus when compared with ampicillin. Some of the most potent compounds possessed selective antimicrobial activity
Keywords: 2-thioxothiazolidin-4-one; Knoevenagel condensation; anticancer activity; antimicrobial activity.
Materials and environmental chemistry
Effect of toxic metal ions Cd(II) and Pb(II) on cyanobacterium (blue-green algae) Spirulina platensis intact cells have been studied with optical and differential scanning microcalorimetry (DSC) methods after 7.2 kGy 137Cs gamma irradiation and without irradiation. It is shown that the addition of metal ions causes a decrease in optical absorption spectra band intensities. In the case of irradiation, the absorption band intensity decreases higher than without irradiation. The binding constant of Pb(II) with Spirulina platensis is calculated for nutrition medium with pH 9.2. DSC data show that Cd(II) and Pb(II) ions do not change the integral heat of absorption (ΔHm) that equals to 24.6 J g-1. In the case of irradiation, the DSC melting curve profile changes significantly and ΔHm decreases two times, which indicates that 50 % of proteins are denaturated. The DSC method also gives a possibility to evaluate C-phycocyanin content from deconvoluted heat absorption peak at 50 °C, which equals to 35.5 %. In case of irradiated wet mass, sub-cultured wet mass, and wet mass re-irradiated with the same dose, contents of Spirulina platensis ingredients – C-phycocyanin, chlorophyll, and carotenoids – increase as a result of the simultaneous effect of the metal ions and irradiation.
Keywords: metal ions; γ-irradiation; Spirulina platensis; differential scanning microcalorimetry
The article deals with the modified method of “hot-wall” beam epitaxy for obtaining the strained lead selenide nanolayers over a wide range of growth rates and controlling their thickness. With detection of the two-stage growth of the layers, the layers with high deformations – tangential lattice constants, and hence with high “negative” pressure were formed. Observations of the shift of the optical spectrum in strained layers and the possibility of deep compensation of the concentration of current carriers when doping the layers with impurities with variable valence turned out to be interesting as well. Under high deformations, the texture of a tetragonal phase is formed. There appears a new level in the conduction band and hence additional absorption in the optical spectrum. The given specific features were first discovered in the physics and technology of IV–VI semiconductors, and they open new opportunities of using these semiconductors in IR optoelectronics.
Keywords: nanolayers; deformations; dislocations; supercriticality; “negative” pressure
Chemical and biological aspects of life
Cestrum nocturnum Linn. belongs to Solanaceae. It is commonly known as Raat rani, lady of night or night Jessamine have great medicinal value. The plant was extracted using conventional extraction as well as microwave-assisted extraction. The phytochemicals such as carbohydrate, proteins, amino acid, glycoside, phenolic compounds and tannins have been qualitatively determined. The physicochemical properties such as relative density, viscosity, surface tension and refractive index were determined. All features of microwave assisted extract were found to be higher than aqueous extract. UV-Vis and IR data were evaluated. The extracts were screened for biological activity and aqueous extract is found to be active against E. Coli, B. Subtilis, S. Typhi, S. Aureus, tuberculosis and malaria
Keywords: extraction; phytochemical analysis; antibacterial activity; Cestrum necturm
The radiotherapy is a complex procedure and involves understanding of the principles of medical physics, radiobiology, radiation safety, dosimetry, radiation treatment planning, simulation and interaction of radiation with other treatment modalities. Each step in the integrated process of RT needs quality control and quality assurance to prevent errors and to give high confidence that patients will receive the prescribed treatment correctly. A patient-specific quality assurance program has been developed to facilitate the clinical implementation of the intensity-modulated radiotherapy delivered using a micro‐multileaf collimator. The methodology includes several dosimetric tasks that are performed prior to the treatment of each patient. Film dosimeter is performed for each individual field and the multifield composite plan. Individual field measurements are performed at a depth of 5 cm in a water equivalent slab phantom. The heterogeneity inserts of phantom are 2 cm×2 cm×22 cm with absorption characteristics of water, brain, muscle, lung, breast, adipose tissue, bone, and liver.
Keywords: QA assurance and control; arc and map-check; oncology; breast and larynx patient; linear accelerator; external beam therapy, intensity-modulated-radiotherapy; volumetric-modulated-arc-therapy; dose distribution and measurement; dosimeters, c-index technique; two and three-dimensional plane