Structural, photoluminescence, and optical characteristics of a Sm3+ -doped lead borate-strontium-tungsten glass system: Evaluation of Judd-Ofelt intensity parameters and radiative properties.

In this study, the melt quenching approach is used to synthesize a lead borate-strontium-based glass system doped with samarium ions. Modifications in the glass network structure arising from the addition of various concentrations of Sm3+ ions were investigated via Fourier transform infrared (FTIR) spectroscopy. FTIR analysis revealed B-O-B bridges, BO3 , and BO4 units are present. UV-vis-NIR spectroscopic measurement was performed to study the optical absorption spectra. Optical constants such as optical bandgap energies, refractive indices, and other related parameters were evaluated. The lifetime fluorescence decay was measured and ranged between 1.04 and 1.88 ns. The photoluminescence spectra in the range 500-750 nm revealed four transitions from the ground state 6 G5/2 to the excited states 6 H5/2 , 6 H7/2 , 6 H9/2 and 6 H11/2 and J-O theory was utilized to study these optical transitions for Sm3+ ions. Calculations of the oscillator strengths and J-O intensity parameters were performed and the obtained J-O parameters followed the sequence Ω4 > Ω6 > Ω2 . The ratio O/R indicated a high lattice asymmetry around the samarium ions. The values of lifetimes and branching ratios for the fabricated samples emphasized their suitability to be used in laser applications. The current glass samples are good candidates for orange and red emission devices.

The effect of immediate neoadjuvant electromotive instillation of mitomycin C with Bacillus Calmette-Guérin versus BCG alone in non-muscle-invasive bladder cancer: A randomized controlled trial.

PURPOSE: The clinical effect of neoadjuvant intravesical instillation of chemotherapy immediately before transurethral resection of bladder tumors (TURBT) has been a subject of recent research. The aim of this study was to assess the effect of immediate neoadjuvant electromotive instillation of mitomycin C before transurethral resection for patients with non-muscle-invasive urothelial bladder cancer. MATERIALS AND METHODS: Our study was a randomized clinical trial carried out on 50 patients diagnosed with non-muscle-invasive urothelial bladder cancer. Patients were classified into two groups: Group I consisted of 25 patients who received neoadjuvant electromotive drug administration of mitomycin C before TURBT and intravesical bacille Calmette-Guerin (BCG) per week for 6 weeks; Group II consisted of 25 patients who were treated with TURBT followed by intravesical BCG per week for 6 weeks alone (standard of care). Patients were followed up at 3, 6, 12, and 18 months by cystoscopy. RESULTS: Patients who received neoadjuvant electromotive drug administration of mitomycin C before TURBT in combination with BCG had a low recurrence rate compared with those who received BCG alone (12.0% vs. 48.0%, respectively; p=0.012) and a longer disease-free interval (88.0% vs. 52.0%, respectively; p=0.012). Four patients developed progression to muscle-invasive disease (16.0%) in the BCG alone group. However, this difference was not statistically significant (p=0.516). Regarding adverse effects, there were no statistically significant differences between the groups. CONCLUSIONS: Neoadjuvant intravesical electromotive drug administration of mitomycin C before TURBT is safe; reduces recurrence rates and enhances the disease-free interval compared with TURBT followed by BCG alone.

Biocompatible Water Soluble Polyacrylic Acid Coated CdSe/Cu Quantum Dot Conjugates for Biomolecule Detection.

Biocompatible polyacrylic acid functionalized CdSe/Cu quantum dot conjugates were synthesized to be used for biomolecules detection. The study results demonstrate the conjugation of the 2.5-3 nm QD with gram negative bacteria with a low detection limit of 28 cfu/ml. The photoluminescence (PL) intensity was correlated to bacterial count, cellular proteins and exopolysaccharides in the tested samples. Confocal Scanning Laser Microscopy (CSLM) images showed significant QD uptake within the cells, both cytoplasm and DNA were the predominant targeted biomolecules, higher fluorescent uptake was shown in gram negative bacteria than that observed for gram positive bacteria. Moreover, PL showed that there was a distinction between live and dead cells as well as gram negative and gram positive cells. Cell viability was not affected even after 6 days (100% viability) rendering it a non-toxic QD. The method is simple and is performed in a single step within approximately 10 min as compared to multi-step protocols for classical microbial count or fluorescent dye staining. All the above results indicate that the CdSe/Cu-PAA QDs are suitable for biomolecule detection, bio-labeling and bioimaging applications.

Spectroscopic analyses of the photocatalytic behavior of nano titanium dioxide.

Nano titanium dioxide TiO2 was synthesized using hydrolysis method then subjected to several characterizations. XRD revealed that the as-prepared sample is pure anatase phase and after calcinations at 500°C for 3 h the crystallinity has increased. The crystallite size calculated by Debye-Scherrer's formula is 8 nm. The HRTEM image shows an average size of about 9 nm, which is close to the XRD calculation from Scherrer's formula. PM3 semiempirical quantum mechanical calculations were conducted to present the electronic as well as thermal properties for TiO2. FTIR spectra between 800 and 400 cm(-1) are the verification for the lattice vibrations of anatase TiO2. The photo catalytic degradation of methylene blue (MB) was tested by the prepared nano TiO2. Results indicate that, the maximum degradation efficiency reached 94.4% after 120 min of UV irradiation. This increase in the degradation efficiency of TiO2 could be attributed to the reduction in particle size that enhanced the crystallinity as a result of heat treatment.