Tailoring graphene-oxide and reduced-graphene-oxide with NaNO3 and CaCl2 catalysts with enhanced photo-catalytic degradation of methylene blue dye

This study employed various experimental techniques to produce graphene oxide (GO) under different conditions, such as the inclusion or exclusion of NaNO3, and reduced graphene oxide (RGO) with or without the catalyst CaCl2. The procedure of decreasing RGO was carried out using the reducing agent NaBH4. Moreover, the prepared mixtures were utilized in the degradation process of methylene blue (MB) dye using photo-catalysis, with exposure to both ultraviolet (UV) light and sunlight. When exposed to UV and sunlight irradiation, WN-GO showed rapid and ecologically friendly breakdown of MB dye in comparison to N-GO. WN-GO exhibited exceptional adsorption capabilities, surpassing other tested materials like N-GO, WN-C-RGO and C-RGO. Although WN-C-RGO has demonstrated satisfactory performance in terms of photo-catalytic degradation, as the concentration-time graph of the MB dye revealed significant degradation, with a reduction of up to 90% and 62.5% under UV light and sunlight exposure, respectively. These results offer insightful information on the potential of graphene-based materials to address other environmental issues, particularly in the areas of water treatment.

Morphological analysis and grain size distribution of SnO2 nanoparticles via digital image processing across diverse calcination temperatures

This study presents a comprehensive image analysis of the SnO2 nanoparticles synthesised through calcination at diverse temperatures, which enables an estimation of grain size distribution (GSD) from field-emission scanning electron microscopy (FE-SEM) images. Even though FE-SEM images could provide us with a lot of information about sample differences, we can learn more and perform a more accurate analysis of them by using quantitative data obtained by our image processing application. The digital image processing techniques used in this research provide a detailed analysis of the nanoparticles' size and shape, enabling a deeper understanding of their unique characteristics. The results reveal the significant impact of calcination temperature on the morphology of the nanoparticles, with changes in grain size and grain size distribution observed at varying temperatures.

ESTIMATION OF ENTRANCE SURFACE AIR KERMA IN DIGITAL RADIOGRAPHIC EXAMINATIONS

PURPOSE

Contribution of radiation doses from medical X-ray examination to collective dose is significant. Unusually, high doses may increase the risk of stochastic effects of radiations. Therefore, radiation dose assessment was performed in 241 digital X-ray examinations in the study and was compared with published dose reference levels (DRLs).

METHODS

Entrance surface air kerma (ESAK) was calculated in chest PA, cervical AP/Lat, abdomen AP, lumbar AP/Lat and pelvis AP digital radiographic examinations (119 male and 122 female) following the International Atomic Energy Agency recommended protocol. Initially, 270 digital examinations were selected, reject analysis was performed and final 241 examinations were enrolled in the study for dose calculations. The exposure parameters and X-ray tube output were used for dose calculations. Effective doses were estimated with the help of conversion coefficients from ICRP 103.

RESULTS

Median ESAK (mGy) and associated effective doses obtained were cervical spine AP (1.30 mGy, 0.045 mSv), cervical spine Lat (0.25 mGy, 0.005 mSv), chest PA (0.11 mGy, 0.014 mSv), abdomen AP (0.90 mGy, 0.118 mSv), lumbar spine AP (1.52 mGy, 0.177 mSv), lumbar spine Lat (7.76 mGy, 0.209 mSv) and pelvis AP (0.82 mGy, 0.081 mSv). Results were compared with the studies of UK, Oman, India and Canada.

CONCLUSION

The calculated ESAK and effective dose values were less than or close to previously published literature except for cervical spine AP and lumbar spine Lat. The results reinforce the need for radiation protection optimization, improving examination techniques and appropriate use of automatic exposure control in digital radiography. ESAK values reported in this study could further contribute to establishing local DRLs, regional DRLs and national DRLs.

Photo-catalytic activity of Zn1-xMnxS nanocrystals synthesized by wet chemical technique

Polyvinyl pyrrolidone capped Zn1-xMnxS (0 ≤ x ≤ 0.1) nanocrystals have been synthesized using wet chemical co-precipitation method. Crystallographic and morphological characterization of the synthesized materials have been done using X-ray diffraction and transmission electron microscope. Crystallographic studies show the zinc blende crystals having average crystallite size approx. 3 nm, which is almost similar to the average particle size calculated from electron micrographs. Atomic absorption spectrometer has been used for qualitative and quantitative analysis of synthesized nanomaterials. Photo-catalytic activity has been studied using methylene blue dye as a test contaminant. Energy resolved luminescence spectra have been recorded for the detailed description of radiative and non-radiative recombination mechanisms. Photo-catalytic activity dependence on dopant concentration and luminescence quantum yield has been studied in detail.

Precision-cut tissue slices from transgenic mice as an in vitro toxicology system

In these experiments precision-cut tissue slices from two existing transgenic mouse strains, with transgenes that couple promoting or binding elements to a reporter protein, were used for determination of reporter induction. This approach combines the power of transgenic animals with the practicality of in vitro systems to investigate the biological impact of xenobiotics. Additionally, the normal cellular architecture and heterogeneity is retained in precision-cut tissue slices. Two transgenic mouse strains, one of which couples the promoting region of CYP 1A1 to beta-galactosidase, and another which couples two forward and two backward 12-O-tetradecanoyl phorbol-13-acetate (TPA) repeat elements (TRE) to luciferase (termed AP-1/luciferase), were used to determine the feasibility of this approach. Precision-cut kidney and liver slices from both transgenic strains remain viable as determined by slice K(+) ion content and LDH enzyme release. Liver slices harvested from the CYP 1A1/beta-galactosidase transgenic mice exhibit a 14-fold increase in beta-galactosidase activity when incubated with beta-napthoflavone for 24 h. Kidney and liver slices obtained from the AP-1/luciferase transgenic mice demonstrate induction of luciferase (up to 2.5-fold) when incubated with phorbol myristate acetate (PMA or TPA) up to 4 h. These data indicate that precision-cut tissue slices from transgenic mice offer a novel in vitro method for toxicity evaluation while maintaining normal cell heterogeneity.