Synthesis and characterization of Reishi mushroom-mediated green synthesis of silver nanoparticles for the biochemical applications

In recent years, the synthesis of nanoparticles via biological processes has attracted considerable attention. The use of plants and plant extracts is one of the most preferred methods for biological synthesis due to their rich biologically active metabolites. In this study, silver nanoparticles (Ag NPs) were synthesized using reishi mushroom (Ganoderma lucidum) extract. Different analytical techniques including X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis spectroscopy, and Fourier Transform Infrared Spectrophotometer (FTIR) were used for the characterization of Ag NPs. UV-vis spectrum exhibited a broad absorption peak between 400-460 nm which indicates the existence of Ag NPs. TEM images showed Ag NPs are spherical with a diameter range of 15-22 nm. In addition, it is shown that Ag NPs form a face-centered cubic structure according to XRD characterization technique. The antioxidant activity towards to 1-Diphenyl-2-picrylhydrazyl (DPPH) was also studied. The highest DPPH scavenging percentage was recorded as 76.45% at 250 mg/L. The DNA cleavage activity results indicated that the green Ag NPs caused single strain DNA cleavage activity for 30 and 60 min at 50 and 100 mg/L, respectively. The Ag NPs antimicrobial activity was also investigated and results recorded as minimum inhibition concentration (MIC). Ag NPs showed a strong antibacterial effect against gram-positive (S. aureus, E. hirae, B. cereus) and gram-negative (E. coli, P. aeruginosa, L. pneumophila subsp. Pneumophila) bacteria. Furthermore, Ag NPs have also been shown to have a high antifungal effect against C. albicans fungus.

Cytotoxic effects of platinum nanoparticles obtained from pomegranate extract by the green synthesis method on the MCF-7 cell line

The study utilizes monodisperse platinum nanoparticles (Pt NPs) biosynthesized from Punica granatum crusts as anti-tumor agents on the human breast cancer cell line, MCF-7. The obtained Pt NPs were fully characterized using the UV-vis spectrum (UV-vis), transmission electron microscopy (TEM), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transformation infrared spectroscopy (FTIR). Effectiveness of the Pt NPs was determined by cell viability, propidium iodide staining test, flow cytometry and comet tests on the MCF-7 cancer cell line. Cell survival percentage was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The biosynthesized monodisperse platinum nanoparticles inhibited MCF-7 proliferation with an IC₅₀ of 17.84 μg/ml after 48 h of incubation. Propidium iodide staining demonstrated that the monodisperse Pt NPs induced apoptosis by means of molecular DNA fragmentation.

Biological synthesis of silver nanoparticles using Rheum ribes and evaluation of their anticarcinogenic and antimicrobial potential: A novel approach in phytonanotechnology

This paper reports the anticarcinogenic and antimicrobial properties of silver nanoparticles (Ag NPs) obtained by green synthesis using the extract of Rheum ribes (R. ribes), a medicinal plant. For the synthesis of Ag NPs, the ethanolic extracts of R. ribes were used as a reducing as well as the stabilizing agent. For the characterization of Ag NPs, advanced analytical methods such as transmission electron microscopy (TEM), X-Ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV-vis spectrophotometry were performed. The synthesized Ag NPs obtained from R. ribes were evaluated as a cytotoxic agent against MDA-MB-231 breast carcinoma cell line. The IC₅₀ values of the nanoparticles were ranged from 165 to 99 μg/mL against MDA-MB 231 cell line for 24 h and 48 h, respectively. The results show that the use of Ag NPs at low concentrations show the toxic effect in the cancer cells. In addition, the results of experiments on gram-positive (Staphylococcus aureus (S. aureus), Methicillin-resistant Staphylococcus aureus (MRSA) and Bacillus subtilis (B. subtilis)) and gram-negative (Escherichia coli (E. coli)) bacteria showed that the Ag NPs had high antimicrobial activity. The results suggest that Ag NPs can be developed as potential anticancer and antibacterial agents.

Purification and characterization of glutathione S-transferase from blueberry fruits (Vaccinium arctostaphylos L.) and investigated of some pesticide inhibition effects on enzyme activity

Pesticides cause pollution by remaining in water, soil, fruits and vegetables for a long time and also reach human through the food chain. It was thought that some pesticides used in agriculture could adversely affect the antioxidant enzyme system and the minimum inhibition values were studied. glutathione s-transferase (GST), an important antioxidant enzyme, catalyzes the conjugation of glutathione with toxic metabolites. It was purified from the blueberry fruits. The purification of the enzyme was performed separately by affinity and gel filtration chromatography. The purity of the enzyme was determined by SDS-PAGE electrophoresis. Characterization studies were done for the enzyme. For this purpose, optimal pH, temperature, Km and Vmax values for GSH and CDNB were also determined for the enzyme as 7.2 in K-phosphate buffer, 50 °C, 1.0 M, 7.0 in K-phosphate buffer, 1.57 mM; 0.17 mM and 0.048 EU/mL, 0.0159 EU/mL, respectively. Additionally, inhibitory effects of some pesticides; dichlorvos, acetamiprid, cyhalothrin, haloxyfop-p-Methyl, 2,4 dichlorophenoxy acetic acid, cypermethrin, imidacloprid, fenoxaprop-p-ethyl, glyphosate isopropylamine salt were examined the enzyme activity in vitro by performing Lineweaver-Burk graphs and plotting activity % IC50 and Ki values were calculated for each of pesticides. All of the pesticides inhibited the GST enzyme at millimolar level. Pesticide showing the best inhibitory effect was found as dichlorvos. The Ki value which is the inhibition constant of this pesticide was 0.0175 ± 0.005.

The novel coronavirus 2019-nCoV: Its evolution and transmission into humans causing global COVID-19 pandemic

A novel coronavirus strain 2019-nCoV has caused a rapid global pandemic-COVID-19. Scientists have taken onto the task of characterizing this new virus and understanding how this virus has transmitted to humans. All preliminary studies have found some striking similarities between this new virus and the SARS-CoV that caused a similar kind of epidemic in 2002-2003. Through bioinformatics tools, a great deal of information has been gathered about the origin, evolution and zoonosis of this virus. We, in this review, report the symptoms, mode of transmission and available and putative treatments to tackle 2019-nCoV infections. We also comprehensively summarize all the information so far made available regarding the genome, evolution and zoonosis of this virus.

Highly monodispersed palladium-ruthenium alloy nanoparticles assembled on poly(N-vinyl-pyrrolidone) for dehydrocoupling of dimethylamine-borane: An experimental and density functional theory study

This study reports on one of the best heterogeneous catalysts for the dehydrogenation of dimethylamine-borane (DMAB). This new catalytic system consists of highly monodisperse Pd and Ru alloy nanoparticles supported by poly(N-vinyl-pyrrolidone) (PdRu@PVP). The prepared heterogeneous catalyst can be reproducibly formed using an ultrasonic reduction technique for DMAB dehydrogenation under mild conditions. For the characterization of PdRu@PVP nanomaterials, several spectroscopic and microscopic techniques were used. The prepared PdRu@PVP nanomaterials with an average particle size of 3.82 ± 1.10 nm provided an 808.03 h^-1 turnover frequency (TOF) in the dehydrogenation of DMAB and yielded 100% of the cyclic product (Me₂NBH₂)₂ under mild conditions. Furthermore, the activities of catalysts were investigated theoretically using DFT-B3LYP calculations. The theoretical results based on density functional theory were in favorable agreement with the experimental data.

Resistance, removal, and bioaccumulation of Ni (II) and Co (II) and their impacts on antioxidant enzymes of Anoxybacillus mongoliensis

In this study, it was hypothesis that A. mongoliensis could be used as bioindicator for Ni (II) and Co (II). Thus, Ni (II) and Co (II) resistance, removal, bioaccumulation, and the impacts of them on antioxidant enzyme systems of thermophilic Anoxybacillus mongoliensis were investigated in details. The bioaccumulation of Ni (II) and Co (II) on the cell membrane of thermophilic A. mongoliensis, variations on surface macrostructure and functionality by FT-IR and SEM, and determination of antioxidant enzyme activities were also tested. The highest bioaccumulation values of Co (II) and Ni (II) were detected as 102.0 mg metal/g of dry bacteria at 10 mg/L for the 12th h and 90.4 mg metal/g of dry bacteria for the 24th h, respectively, and the highest Ni (II) and Co (II) cell membrane bioaccumulation capacities of A. mongoliensis were determined as 268.5 and 274.9 mg metal/g wet membrane, respectively at the 24th h. In addition, increasing on SOD and CAT activities were observed on depend of concentration of Ni (II) and Co (II) with respect to control. The antioxidant enzyme activity results also indicated that A. mongoliensis might be used as a bioindicator for Ni (II) and Co (II) pollution in environmental water specimens.

Improving the sludge disintegration efficiency of sonication by combining with alkalization and thermal pre-treatment methods

One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization > sono-thermal pre-treatment > sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

Factors effecting natural course of egg allergy

Summary

Background. There is limited data about the natural course of egg allergy in the literature. We aimed to analyze the factors that can affect the tolerance or persistence of egg allergy. Methods. A total number of 126 IgE- mediated egg allergic patient who had data about tolerance gaining were included in the study. Demographic and laboratory data were recorded retrospectively. Kaplan-Meier curves was used for estimation of resolution and the factors related to resolution by Cox regression model. Results. Among 126 patients 81 (64.2%) had gained tolerance with a median survival time of 48 months (min 12- max 121). Tolerance was gained in 22.2% (28) of these patients in the first 2 years, in 46.8% (49) 2-6 years, 3.1% (4) between 7-12 years. In univariate analysis, no history of anaphylaxis (at initiation or during OFC) (Hazard ratio 2.193; 95%CI 1.309-3.674, p = 0.003), baseline sIgE level less than 8.2 (Hazard ratio 11.292; 95%CI 2.766-46.090, p = 0.001) and baseline egg SPT less than 11 mm (Hazard ratio 2.906; 95%CI 1.424-5.930, p = 0.003) were found to be related to earlier resolution of egg allergy. In multivariate analysis only anaphylaxis was significantly related to later resolution (Hazard ratio: 6.547; 95%CI 15.80-27.434, p = 0.01). Conclusions. Higher levels of egg sIgE, skin prick test induration and anaphylaxis at onset or during oral food challenge, can give hint about persistence of egg allergy.

Bi-doped BaBiO3 (x = 0%, 5%, 10%, 15%, and 20%) perovskite oxides by a sol-gel method: comprehensive biological assessment and RhB photodegradation

The BaBiO3 (BBO) perovskite oxide was prepared via a sol-gel method with different concentrations of Bi nitrate and examined as a photocatalyst for RhB degradation under sunlight, and its antioxidant and antibacterial activities were examined. X-ray diffraction (XRD) indicated the formation of a BaBiO3-BaCO3 (BBO-BCO) binary composite. For the degradation of RhB under solar radiation, high photocatalytic activity (73%) was observed. According to the antibacterial activity study, the addition of Bi enhanced the antibacterial activity of the resulting material against both Gram-positive and Gram-negative microorganisms. The Bi%-BBO (Bi 20%) inhibited 96.23% S. aureus. 10% Bi-BBO as an antioxidant agent had the most efficacious IC50 value of 2.50 mg mL-1. These results seem to suggest that BBO-BCO is a promising catalytic material with potential application in the fields of catalysis and medicine.