N-Hydroxysuccinamide functionalized iron oxide nanoparticles conjugated with 5-flurouracil for hyperthermic therapy of malignant liver cancer cells by DNA repair disruption.

Magnetized iron oxide nanoparticles are ideal materials for biological and biomedical applications due to their biocompatibility, super paramagnetic behavior, surface capability, and chemical stability. This research article is narrating the overview of methodologies of preparation, functionalization, characterization and applications of Fe3O4 nanoparticles. Super paramagnetic nanoparticles are studied for their hyperthermia properties. The proposed mechanism behind the hyperthermia was damaging the proteins responsible for DNA repair thereby, directly accelerating the DNA damages on cancer cells by increasing the temperature in the vicinity of the cancer cells. In this study, super paramagnetic iron oxide (Fe3O4) nanoparticles (SPIONs) and anti-cancer drug, 5-fluorouracil, functionalized with N-Hydroxysuccinimide organic molecules. A specific absorption rate at 351 nm can be achieved using UV analysis. The magnetic Fe3O4 nanoparticles had a cubic crystalline structure. FE-SEM(field emission scanning Electron microscopy) with EDAX(energy dispersive X-ray analysis) analysis shows that the size of the SPION was about 30-100 nm range and the percentage of chemical compositions was higher in the order of Fe, O, C. for particle size analysis, the SPION were positively charged derived at +9.9 mV and its conductivity is measured at 0.826 mS/cm. In-vitro anti-cancerous activity analysis in Hep-G2 cells (liver cancer cells) shows that the 5-fluorouracil functionalized SPIONs have higher inhibition rate than the bare Fe3O4 nanoparticles. The Fe3O4 nanoparticles were studied for their hyperthermic abilities at two different frequencies such as 3.05 × 106 kAm-1s-1 and 4.58 × 106 kAm-1s-1.The bare Fe3O4 at low magnetic field, 10 mg was required to raise the temperature above 42°- 45 °C and at high magnetic field, 6 mg was enough to raise the same temperature. The 5-fluorouracil functionalized Fe3O4 shows that at low magnetic field, 6 mg is required to raise the hyperthermia temperature and at high magnetic field, 3 mg is required to raise the temperature above 42°- 45 °C. the rate of heating and the temperature achieved with time can be tuned with concentrations as well as magnetic component present in the Fe3O4 nanoparticles. Beyond this concentration, the rate of cell death was observed to increase. The saturation and low residual magnetization were revealed by the magnetization analysis, making them well suited for clinical applications.

Effect of annealing on the luminescence properties of YVO4:Dy³âº phosphor on co-doping Pb²âº ions.

Pb(2+) co-doped YVO4:Dy(3+) phosphors have been synthesized at a relatively low temperature of 120°C via ethylene glycol route. The samples are further annealed at 500 and 900°C. The prepared samples were characterized by XRD, SEM, spectra energy dispersive analysis of X-ray (EDAX) and photoluminescence spectroscopy. XRD patterns of all samples are well indexed with single tetragonal phase of YVO4. The emission intensity of Dy(3+) is significantly enhanced on co-doping Pb(2+) ions. The highest emission is obtained at 7 at.% Pb(2+) for 900°C annealed samples. Both emission intensity and decay lifetime increases on annealing the samples from 500 to 900°C. On co-doping Pb(2+) into YVO4:Dy(3+) phosphors, the emission color falls near the white region and then shift towards yellow region on annealing from 500 to 900°C thereby indicating that annealing temperature play a role on tuning the color of the phosphors. As well as the emission color of the phosphors remain the same even on changing the excitation wavelengths from 280 nm, which would serve as potential phosphors for white emission in LED applications.

Kinetics and its accompanying thermodynamics studies on simultaneous complexation of heterobimetallic neodymium (III) with zinc (II) and L-tryptophan in aquated DMF using 4f-4f absorption spectra.

The 4f-4f absorption spectra of the simultaneous heterobimetallic complexation of trivalent neodymium ion with l-tryptophan and divalent zinc ion in aquated DMF (50%, v/v) at pH 6.0 was recorded at the time interval of 1h. From the observed absorption spectra, the values of intensity parameters such as oscillator strength (P) and Judd-Ofelt intensity (Tλ) parameters, kinetics and thermodynamics parameters were evaluated. The rate constant increases with an increase in the temperature along with the oscillator strengths and Judd-Ofelt intensity parameters. The positive values of the change in the standard enthalpy (ΔH°) and entropy (ΔS°) indicate that the complexation is endothermic. The negative values of the change in the standard free energy (ΔG°) in the range from 293.15 K to 308.15 K, indicate that the reaction occurs spontaneously and hence the formation of heterobimetallic complex in the solution is favored kinetically and thermodynamically.

Studies on the physico-chemical parameters in water of Keibul Lamjao National Park, Manipur, India.

A study on the physico- chemical parameters of Keibul Lamjao National Park (KLNP) on seasonal basis was carried out for parameters like temperature, pH, transparency, turbidity, dissolved oxygen, chloride, hardness, calcium and magnesium at six selected Stations. The temperature ranged from 10.4 to 28 degrees C showing subtropical nature. pH was consistent both spatially and temporally except at one Station where it was alkaline having value ranging from 6.9 to 7.26. There was a trend in dissolved oxygen to be more during cold season. Electrical conductivity ranged between 105.56 to 201 microS cm(-1). It was high during the dry season and low during rainy season. Transparency and turbidity values indicated that in most Stations water was clear and the two parameters were found to be negatively correlated (r = -0.381). Based on the hardness (41 to 78 mg l(-1)), water was soft. Significant negative correlation (r = -0.532) was found between rainfall and hardness. Calcium and magnesium ions were found to be below the prescribed value of WHO. These two parameters were found to be positively correlated with hardness. ANOVA showed a significant variation in the parameters recorded during winter and monsoon season.

Studies on the complexation of neodymium(III) ion with 1,2,4-1H-triazole and 1,2,3-benzotriazole in absence and presence of calcium(II) ion in aqueous and some selected different aquated organic solvents by an absorption spectroscopy involving 4f-4f transitions.

The absorption spectra of trivalent neodymium ion with 1,2,4-1H-triazole and 1,2,3-benzotriazole in absence and presence of calcium(II) ion in aqueous and some selected different aquated organic solvents have been recorded in the visible and near infrared regions. From the data available in the absorption spectra, various spectroscopic parameters such as Slator-Condon (F(k)), Lande spin-orbit coupling constant (ξ(4f)), nephelauxetic ratio (ß), bonding parameter (b(1/2)), percent covalency (δ), oscillator strength (P) and Judd-Ofelt intensity (T(λ)) parameters have been evaluated. The Judd-Ofelt intensity, T(λ) (λ=2, 4, 6) parameters are utilized in evaluating the P(cal) from various excited states of trivalent neodymium ions and ratifying as an inner sphere complexations.

Absorption spectroscopic probe to investigate the interaction between Nd(III) and calf-thymus DNA.

The interaction between Nd(III) and Calf Thymus DNA (CT-DNA) in physiological buffer (pH 7.4) has been studied using absorption spectroscopy involving 4f-4f transition spectra in different aquated organic solvents. Complexation with CT-DNA is indicated by the changes in absorption intensity following the subsequent changes in the oscillator strengths of different 4f-4f bands and Judd-Ofelt intensity (T(λ)) parameters. The other spectral parameters namely Slator-Condon (F(k)'s), nephelauxetic effect (ß), bonding (b(1/2)) and percent covalency (δ) parameters are computed to correlate with the binding of Nd(III) with DNA. The absorption spectra of Nd(III) exhibited hyperchromism and red shift in the presence of DNA. The binding constant, K(b) has been determined by absorption measurement. The relative viscosity of DNA decreased with the addition of Nd(III). Thermodynamic parameters have been calculated according to relevant absorption data and Van't Hoff equation. The characterisation of bonding mode has been studied in detail. The results suggested that the major interaction mode between Nd(III) and DNA was external electrostatic binding.

Computation of energy interaction parameters as well as electric dipole intensity parameters for the absorption spectral study of the interaction of Pr(III) with l-phenylalanine, l-glycine, l-alanine and l-aspartic acid in the presence and absence of Ca2+ in organic solvents.

Studying the absorption difference and comparative absorption spectra of the interaction of Pr(III) and Nd(III) with l-phenylalanine, l-glycine, l-alanine and l-aspartic acid in the presence and absence of Ca(2+) in organic solvents, various energy interaction parameters like Slater-Condon (F(K)), Racah (E(k)), Lande factor (xi(4f)), nephelauxetic ratio (beta), bonding (b(1/2)), percentage-covalency (delta) have been evaluated applying partial and multiple regression analysis. The values of oscillator strength (P) and Judd-Ofelt electric dipole intensity parameter T(lambda) (lambda = 2, 4, 6) for different 4f-4f transitions have been computed. On analysis of the variation of the various energy interaction parameters as well as the changes in the oscillator strength (P) and T(lambda) values reveal the mode of binding with different ligands.

Calculation of electric dipole intensity parameters of 4f-4f transitions of Pr(III) and glutathione reduced (GSH) complex in presence and absence of Zn(II).

Comparative absorption and spectral analysis of 4f-4f transitions of Pr(III) and glutathione reduced (GSH) complex in presence and absence of Zn(II) is carried out in different aquated organic solvents of CH3OH, CH3CN, DMF and dioxane and their equimolar mixtures at different pH (3.0, 4.0, 5.0 and 6.0). The values of experimentally calculated oscillator strengths (P) and computed values of Judd-Ofelt electric dipole intensity parameters, Tlambda (lambda=2, 4, 6) are discussed for different 4f-4f transitions in different experimental conditions. The changes in the values of oscillator strengths (P) and Tlambda parameters suggest the specific correlation between relative intensities, ligand structures and nature of interaction of Pr(III) with GSH in the presence and absence of Zn(II).

Calculation of electric dipole intensity parameter to explore some interaction between hard metal ions Pr(III) and Nd(III) with pi-electron density of butene-1,4 and butyne-1,4-diols in non-aqueous solutions: an absorption spectral study.

Pr(III) and Nd(III) are hard acceptors in HSAB (hard and soft acid base) sense and hence are known to exhibit practically a little affinity towards electrons. At the same time these metal ions show strong preference for oxygen donor chelating ligands. The ligands chosen for this study are structurally related diols, viz. butane-1,4, butene-1,4 and butyne-1,4-diols which form identical seven membered chelate ring by coordinating to metals in a bidentate manner through oxygen on 1 and 4 positions of the diol molecules. Complexation of these diols with Pr(III) and Nd(III) was carried out in DMF, CH3OH, CH3CN and their equimolar binary mixtures using comparative absorption spectrophotometry of 4f-4f transitions. The variation of oscillator strengths (P) of different 4f-4f bands as well as the magnitude and variation of Judd-Ofelt electric dipole intensity parameters (T lambda, lambda = 2, 4, 6) was discussed. They correlate the interaction between the metal 4f-orbitals of Pr(III) and Nd(III) with the pi-electron densities of the double and triple bonds present in butene-1,4 and butyne-1,4-diols, respectively. The value of empirical intensity parameter [T lambda(complex)/T lambda (aquo)] was calculated and its plot against oscillator strength (P) is drawn.

Comparison of energy interaction parameters for the complexation of Pr(III) with glutathione reduced (GSH) in absence and presence of Zn(II) in aqueous and aquated organic solvents using 4f-4f transition spectra as PROBE.

The coordination chemistry of glutathione reduced (GSH) is of great importance as it acts as excellent model system for the binding of metal ions. The GSH complexation with metal ions is involved in the toxicology of different metal ions. Its coordination behaviour for soft metal ions and hard metal ions is found different because of the structure of GSH and its different potential binding sites. In our work we have studied two chemically dissimilar metal ions viz. Pr(III), which prefer hard donor site like carboxylic groups and Zn(II) the soft metal ion which prefer peptide-NH and sulphydryl groups. The absorption difference and comparative absorption spectroscopy involving 4f-4f transitions of the heterobimetallic Complexation of GSH with Pr(III) and Zn(II) has been explored in aqueous and aquated organic solvents. The variation in the energy parameters like Slater-Condon (F(K)), Racah (E(K)) and Lande (xi(4f)), Nephelauxetic parameter (beta) and bonding parameter (b(1/2)) are computed to explain the nature of complexation.