Search Results (9)

As a toxic xenobiotic compound, the anthraquinone dye Remazol Brilliant Blue R (RBBR) poses a serious threat to aquatic ecosystems. In the present study, the ability of Trametes hirsuta to remove RBBR from the medium was investigated, and the role of adsorption by fungal mycelium and biodegradation by fungal enzymes was evaluated. It was shown that the whole fungal culture was able to remove up to 97% of the dye within the first four hours of incubation. Based on enzymatic activities in the culture broth, laccases were proposed to be the main enzymes contributing to RBBR degradation, and RT-qPCR measurements demonstrated an increase in transcription for the two laccase genes—lacA and lacB. Composite mycelial pellets of T. hirsuta with improved adsorption ability were prepared by adding activated carbon to the growth medium, and the induction of laccase activity by carbon was shown. For composite pellets, the RBBR decolorization degree was about 1.9 times higher at 1 h of incubation compared to carbon-free pellets. Hence, it was shown that using fungal mycelium pellets containing activated carbon can be an effective and economical method of dye removal. Full article

The presence of Methyl Orange, a hazardous organic compound typically found in industrial wastewater, presents a significant environmental challenge, necessitating the development of effective strategies for its removal to mitigate adverse impacts on aquatic ecosystems and human health. In this work, we utilized 60-watt continuous-wave (CW) and high-power CO₂ laser with 10.6 μm wavelength to synthesize Zinc Oxide nanoparticles (ZnO NPs) doped with 1% Cerium (Ce) as photocatalyst at standard laboratory conditions through Laser-Assisted Chemical Bath Synthesis (LACBS) technique. The synthesized nanostructures were thoroughly characterized using UV–vis spectroscopy, field-emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD) techniques. Subsequently, their efficiency in degrading Methyl Orange (MO) dye was evaluated under UV and sunlight irradiation. The findings revealed that the 1% Ce-doped ZnO sample exhibited enhanced photocatalytic efficiency under both UV and sunlight irradiation, as well as active adsorption capabilities in the absence of light. Notably, the most effective photodegradation performance was achieved under solar radiation, with an impressive 95% of MO dye degradation observed after just 90 min of exposure. Full article

Pure and Ni-doped (1%, 2%, and 3%) nanostructures were synthesized using a novel laser-assisted chemical bath synthesis (LACBS) technique. For the first time, LACBS was used to create a doping solution utilizing a 7 W blue laser with a 444.4 nm wavelength and a continuous beam. The Ni-doping concentration was varied by changing the amount of Ni precursor added. All samples were analyzed using XRD, SEM, EDX, FTIR, UV–Vis, and photocatalysis tests for photodegradation under blue laser illumination. XRD was used to confirm that the tested ZnO had a hexagonal wurtzite structure. The crystallite size decreased as the Ni-doping concentration rose. EDX experiments were conducted to analyze the elemental characteristics of the pure and Ni-doped (1%, 2%, and 3%) nanostructures. The existence of nanoscale hexagonal structures was confirmed through SEM studies. The band gap values of the pure and Ni-doped ZnO nanostructures decreased as the doping concentration increased. FTIR studies were conducted to examine the functional groups of the pure and doped samples. The produced materials exhibited excellent photocatalytic performance toward the degradation of MB organic dye, an example of a pollutant found in wastewater. Full article

Antimicrobial resistance poses a significant threat to global health, amplified by factors such as water scarcity and suboptimal hygienic practices. Addressing AMR effectively necessitates a comprehensive strategy encompassing enhanced access to potable water, developing innovative antibiotics, and exploring alternative treatment modalities, such as harnessing solar photocatalysis with zinc oxide nanoparticles for water purification and antimicrobial applications. The Laser-Assisted Chemical Bath Synthesis (LACBS) technique facilitates the fabrication of pure ZnO nanostructures, providing a potentially efficacious solution for mitigating pathogen proliferation and managing wastewater. The photocatalytic degradation of MB and MO dyes was investigated using blue laser light at 445 nm, and degradation rates were determined accordingly. Ag-doped ZnO nanostructures were characterized through X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The antimicrobial efficacy of LACBS-synthesized ZnO nanoparticles was assessed against C. albicans, S. aureus, B. subtilis, E. coli, and K. pneumoniae using the disc diffusion method, revealing 40 mm, 37 mm, 21 mm, 27 mm, and 45 mm inhibition zones at the highest concentration of doped-Ag (4.5%), respectively. These inhibition zones were measured in accordance with the guidelines established by the Clinical and Laboratory Standards Institute. X-ray diffraction patterns for ZnO, ZnOAg_(1.5%), ZnO:Ag_(3%), and ZnO:Ag_(4.5%) samples revealed variations in intensity and crystallinity. Scanning electron microscopy exposed morphological disparities among the nanostructures, while energy-dispersive X-ray spectroscopy verified their elemental compositions. UV-Vis absorption analyses inspected the optical band gaps, and Fourier-transform infrared spectra identified the stretching mode of metal-oxygen bonds. Under blue laser irradiation, Ag-doped ZnO exhibited enhanced photocatalytic activity during the photocatalytic degradation. These nanoparticles, synthesized via the cost-effective and straightforward LACBS method, benefit from silver doping that augments their electron-trapping properties and photocatalytic activity, thereby enabling efficient dye degradation. Consequently, Ag-doped ZnO nanoparticles hold promise as a potent solution for counteracting drug-resistant microorganisms and as an effective disinfectant. Full article

In this study, laser-assisted chemical bath synthesis (LACBS) was used to prepare pure and Ag-doped ZnO submicron structures using a simplified hydrothermal approach that did not require a catalyst. The photocatalytic degradation of Methylene Blue was investigated under blue laser irradiation (λ = 444.5 nm and I = 8000 lx). The doping concentration varied (2%, 4%, 6%, 8%, tando 10%) and was prepared by LACBS using a continuous blue laser (P = 7 W, λ = 444.5 nm) for the first time. XRD, FE-SEM, EDX, and UV-Vis investigated the characteristics of the samples produced by the LACBS. ZnO: Ag_(10%) submicron flowers are essential in rapid photodegradation under blue laser irradiation. The high surface area and catalytic activity of the prepared Ag-decorated ZnO are attributed to this improved photocatalytic activity. Using UV-visible spectroscopy, the photocatalytic efficiency was determined from the absorption spectra. The separation of photo-generated electron-hole pairs was facilitated, and the absorption edge of the hybrid submicron structures shifted into the visible spectrum region due to a combination of the Ag plasmonic effect and surface imperfections in ZnO. Effective visible light absorption was achieved via band-edge tuning, which increased the ZnO:Ag submicron structures’ ability to degrade dyes. Full article

Autophagy and apoptosis are two important regulatory mechanisms for how the body can respond to diseases. This study was designed to investigate the protective actions of vitamin E (Vit-E) and lactobacillus plantarum (Lac-B) against mercuric chloride (HgCl₂)-induced kidney injury. Thirty albino rats were divided into five groups: group 1 served as the normal group; rats in group 2 received high doses of HgCl₂; rats in groups 3, 4 and 5 were given Vit-E, Lac-B and the combination of Vit-E and Lac-B, respectively along with HgCl₂ for two weeks. HgCl₂ provoked renal injury, manifested by elevation in serum urea, urea nitrogen and creatinine. Kidney levels of oxidative stress and inflammation were markedly increased post HgCl₂ administration. Moreover, HgCl₂ significantly elevated the gene expression levels of VCAM-1 and cystatin C, while podocin was downregulated. Additionally, it markedly decreased the protein expression of Beclin-1 and Bcl-2. Histopathological examination revealed massive degeneration with congested blood vessels following HgCl₂ administration. Treatment with Vit-E or/and Lac-B restored the normal levels of the previously mentioned parameters, as well as improved the morphology of kidney tissues. Both Vit-E and Lac-B provided a protective effect against HgCl₂-induced kidney damage by regulating autophagy and apoptosis. Full article

At present, De Man, Rogosa and Sharpe (MRS) broth is the medium of choice for promoting bacteriocin production. However, this medium is expensive and not applicable for large-scale production. Therefore, a low-cost and high-efficiency culture medium for bacteriocin Lac-B23 production by Lactobacillus plantarum J23 was developed. First, the effects of the composition of MRS broth on bacteriocin Lac-B23 production and bacterial growth were researched by a one variable at a time approach. Then, a Plackett-Burman design was used to screen significant components for production. Finally, the steepest ascent and central composite designs were used to obtain an optimum medium. The final composition of the modified MRS was much simpler than MRS broth, and the modified MRS contained only glucose, yeast extract, dipotassium phosphate, manganese sulfate monohydrate, Tween 80 and sodium acetate anhydrous. The highest bacteriocin Lac-B23 production reached 2560 activity units (AU)/mL in the modified MRS, which is nine times higher than that in MRS broth (280 AU/mL). Meanwhile, the cost per liter of the modified MRS (8.56 Ren Min Bi (RMB)/L) is 34.70% the cost of MRS broth (13.11 RMB/L), and the cost per arbitrary units of bacteriocin Lac-B23 in the modified MRS is approximately fourteen times more convenient (3.34 RMB/10⁶ AU) than in the MRS broth (46.82 RMB/10⁶ AU). Full article

Dislocations play a crucial role in self-organization and strain relaxation mechanisms in SiGe heterostructures. In most cases, they should be avoided, and different strategies exist to exploit their nucleation properties in order to manipulate their position. In either case, detailed knowledge about their exact Burgers vectors and possible dislocation reactions are necessary to optimize the fabrication processes and the properties of SiGe materials. In this review a brief overview of the dislocation mechanisms in the SiGe system is given. The method of choice for dislocation characterization is transmission electron microscopy. In particular, the article provides a detailed introduction into large-angle convergent-beam electron diffraction, and gives an overview of different application examples of this method on SiGe structures and related systems. Full article

A resting cell system was developed for bacteriocin Lac-B23 production from Lactobacillus paracasei J23. The resting cell medium contained (g/L): Glucose 20, Sodium acetate 5.0, MnSO₄ 0.25 MgSO₄ 0.5, Ammoniumhydrogencitrate 1.0, KH₂PO₄ 1.0. The resting cell incubation time and temperature were 20 h and 37 °C and the effects of exogenous factors, including amino acids, glycerol, pyruvic acid, and α-ketoglutaric acid were investigated. Cys and Gly could stimulate the production of bacteriocin, while no stimulus effect was observed for Glu, Tyr and Ala. Glycerol and pyruvic acid increased bacteriocin production and the optimum concentrations were 1% and 30 g/L, respectively. Bacteriocin could act as an inducer of its own biosynthesis. These findings are of importance for the further study of bacteriocin biosynthesis regulation and for the improvement of bacteriocin production yields. Full article