Search

Background: Around the world, poultry meat is a staple of everyday meals. However, chicken flesh is not always as healthy as it looks since it becomes contaminated by pollutants from the environment, especially heavy metals, which can bioaccumulate and magnify, and endanger human health., Aim: The current investigation set out to evaluate the degree of contamination in a subset of chicken samples and the potential risks to human health associated with the ingestion of chicken meat., Methods: Using atomic absorption spectroscopy, the heavy metal (lead, cadmium, and copper) contents of chicken samples were evaluated. To assess the residual content, 100 samples of chicken meat, 25 of each from the breast, thigh, gizzard, and liver were randomly selected from chicken butchers in Kafr El-Sheikh and El-Gharbia governorate in Egypt., Results: Lead had mean values of 0.27 ± 0.01, 0.34 ± 0.01, 0.55 ± 0.01, and 0.61 ± 0.02 (mg/kg ww), in the examined breast, thigh, gizzards, and liver, respectively. Cadmium, on the other hand, had mean levels (mg/kg ww) of 0.09 ± 0.01, 0.12 ± 0.01, 0.18 ± 0.01, and 0.25 ± 0.01 in the same samples, respectively. The copper residues had mean values (mg/kg ww) of 1.53 ± 0.14, 1.69 ± 0.16, 2.05 ± 0.17, and 2.71 ± 0.22, in the same samples, respectively., Conclusion: Further government efforts are required to reduce environmental pollution and enhance the quality of the El-Gharbia governorate to prevent the accumulation of heavy metals, even though the majority of the samples that were examined fell within the acceptable limits established by the Egyptian Organization for Standardization and Quality Control., Competing Interests: The authors declare that there is no conflict of interest.

Background: Nowadays veterinarians and poultry producers use antibiotics to increase growth rates, bird health, and feed efficiency, egg production, for preventative and therapeutic purposes, and to lessen the prevalence of poultry diseases. Most poultry producers have used a variety of antibiotics, either with or without veterinarian instruction. Although antibiotics are beneficial for the majority of their uses, their unauthorized use has resulted in residues accumulated in poultry products intended for human consumption which represents a serious risk to the general public that could be toxicological, microbiological, or immunological., Aim: This study aimed to the estimation of the residues of three major antimicrobials used in the intensive chicken-rearing systems in Egypt, namely Oxytetracycline (OTC), Gentamicin, and Ciprofloxacin. Moreover, the effect of cooking on such residues was investigated., Methods: A total of 100 chicken meat samples (breast, thigh, gizzard, liver, 25 each) were examined for detection of the aforementioned antimicrobials using the microbial inhibition assay and high-performance liquid chromatography (HPLC). Besides, samples containing the highest antimicrobial residues were examined for the effect of boiling for 30 minutes on such residues., Results: The obtained results revealed that 23%, 21%, and 17% of the examined samples were positive for OTC, gentamicin, and ciprofloxacin residues , respectively . Cooking (boiling) for 30 minutes showed a reduction of the antibiotic residue by 88.2%, 95.2%, and 31.3%, respectively., Conclusion: Antimicrobial residues were detected in the chicken meat parts retailed in Egypt. Cooking can reduce the antimicrobial residues at least in part., Competing Interests: The authors declare that there is no conflict of interest.

Consumers nowadays are becoming more aware of the importance of using only meat products containing safe and natural additives. Hence, using natural food additives for extending the shelf life of meat along with delaying microbial growth has become an urgent issue. Given the increasingly popular view of Moringa oleifera leaves as a traditional remedy and also the scarcity of published data concerning its antimicrobial effect against foodborne pathogens in meat and meat products, we designed the present study to investigate the antimicrobial effect of Moringa oleifera leaves aqueous extract (0.5%, 1%, and 2%) on ground beef during refrigerated storage at 4 °C for 18 days. MLE revealed potent antimicrobial properties against spoilage bacteria, such as aerobic plate count and Enterobacteriaceae count. MLE 2% showed a significant ( p < 0.01) reduction in the counts of E. coli O157:H7, Salmonella enterica serovar Typhimurium, and Staphylococcus aureus artificially inoculated to ground beef by 6.54, 5.35, and 5.40 log 10 CFU/g, respectively, compared to control, by the 18th day of storage. Moringa leaves extract (MLE) had no adverse effect on the overall acceptability and other sensory attributes; moreover, it induced a slight improvement in the tenderness and juiciness of treated ground beef, compared to the control. Therefore, MLE can be used as a healthy, natural, and safe preservative to increase meat products' safety, quality, and shelf stability during cold storage. A promising approach for using natural food additives rather than chemical preservatives could begin new frontiers in the food industry, as they are more safe and do not constitute health risks to consumers.

In this study, a high-density ZrN/ZrSi 2 composite reinforced with ZrO 2 as an inert phase was synthesized under vacuum starting with a Zr-Si 4 N 3 -ZrO 2 blend using combustion-synthesis methodology accompanied by compaction. The effects of ZrO 2 additions (10-30 wt%) and compression loads (117-327 MPa) on the microstructure, porosity and hardness of the samples were studied. The process was monitored using XRD, SEM, EDS, porosity, density and hardness measurements. Thermodynamic calculations of the effect of ZrO 2 addition on the combustion reaction were performed including the calculation of the adiabatic temperatures and the estimation of the fractions of the liquid phase. The addition of up to 20 wt% ZrO 2 improved the hardness and reduced the porosity of the samples. Using 20 wt% ZrO 2 , the sample porosity was reduced to 1.66 vol%, and the sample hardness was improved to 1165 ± 40.5 HV at 234 MPa.

In ferromagnetic semiconductors, the coupling of magnetic ordering with semiconductor character accelerates the quantum computing. The structural stability, Curie temperature (T c ), spin polarization, half magnetic ferromagnetism and transport properties of ZnX 2 Se 4 (X = Ti, V, Cr) chalcogenides for spintronic and thermoelectric applications are studied here by density functional theory (DFT). The highest value of T c is perceived for ZnCr 2 Se 4 . The band structures in both spin channels confirmed half metallic ferromagnetic behavior, which is approved by integer magnetic moments (2, 3, 4) μ B of Ti, V and Cr based spinels. The HM behavior is further measured by computing crystal field energy ΔE crystal , exchange energies Δ x ( d ), Δ x ( pd ) and exchange constants (N o α and N o β). The thermoelectric properties are addressed in terms of electrical conductivity, thermal conductivity, Seebeck coefficient and power factor in within a temperature range 0-400 K. The positive Seebeck coefficient shows p-type character and the PF is highest for ZnTi2Se4 (1.2 × 10 11 W/mK 2 ) among studied compounds.

Edible coatings have potential to decrease the postharvest losses of several horticultural commodities however; there is no systematic investigation focusing on fresh herbaceous aromatic plants such as basil. Herein, the effects of chitosan (CS), chitosan nanoparticles (CSNPs) and thyme volatile oil (TVO) loaded CSNPs (TVO-CSNPs) as edible coatings on preserving the quality of sweet basil leaves were investigated. All CS coatings considerably extended the shelf life and decreased the weight loss of basil leaves relative to the control. Using TVO-CSNPs showed 2.4-fold higher shelf life than the control. The loss in photosynthetic pigments and volatile oil content were significantly retarded by CS applications more so with TVO-CSNPs treatment. Contrary, treated leaves produced lower malondialdehyde (MDA) and H 2 O 2 and therefore retained the membrane functions compared to the control. All CS applications particularly with TVO-CSNPs considerably motivated the activities of catalase (CAT) and superoxide dismutase (SOD) enzymes and reduced the polyphenol oxidase (PPO) and lipoxyganase (LOX) activities relative to uncoated leaves. Overall, using TVO-CSNPs as an edible coating has a great potential in shelf life extension of basil leaves with satisfactory exterior and interior quality. Thus, it can be a promising approach to preserve the quality of fresh cut aromatic herbs., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Self-supported electrocatalysts are a new class of materials exhibiting high catalytic performance for various electrochemical processes and can be directly equipped in energy conversion devices. We present here, for the first time, sparse Au NPs self-supported on etched Ti (nanocarved Ti substrate self-supported with TiH 2 ) as promising catalysts for the electrochemical generation of hydrogen (H 2 ) in KOH solutions. Cleaned, as-polished Ti substrates were etched in highly concentrated sulfuric acid solutions without and with 0.1 M NH 4 F at room temperature for 15 min. These two etching processes yielded a thin layer of TiH 2 (the corrosion product of the etching process) self-supported on nanocarved Ti substrates with different morphologies. While F - -free etching process led to formation of parallel channels (average width: 200 nm), where each channel consists of an array of rounded cavities (average width: 150 nm), etching in the presence of F - yielded Ti surface carved with nanogrooves (average width: 100 nm) in parallel orientation. Au NPs were then grown in situ (self-supported) on such etched surfaces via immersion in a standard gold solution at room temperature without using stabilizers or reducing agents, producing Au NPs/TiH 2 /nanostructured Ti catalysts. These materials were characterized by scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), grazing incidence X-ray diffraction (GIXRD), and X-ray photoelectron spectroscopy (XPS). GIXRD confirmed the formation of Au 2 Ti phase, thus referring to strong chemical interaction between the supported Au NPs and the substrate surface (also evidenced from XPS) as well as a titanium hydride phase of chemical composition TiH 2 . Electrochemical measurements in 0.1 M KOH solution revealed outstanding hydrogen evolution reaction (HER) electrocatalytic activity for our synthesized catalysts, with Au NPs/TiH 2 /nanogrooved Ti catalyst being the best one among them. It exhibited fast kinetics for the HER with onset potentials as low as -22 mV vs. RHE, high exchange current density of 0.7 mA cm -2 , and a Tafel slope of 113 mV dec -1 . These HER electrochemical kinetic parameters are very close to those measured here for a commercial Pt/C catalyst (onset potential: -20 mV, Tafel slope: 110 mV dec -1 , and exchange current density: 0.75 mA cm -2 ). The high catalytic activity of these materials was attributed to the catalytic impacts of both TiH 2 phase and self-supported Au NPs (active sites for the catalytic reduction of water to H 2 ), in addition to their nanostructured features which provide a large-surface area for the HER.

In this paper, we demonstrated, for the first time, aluminum titania nanoparticle (Al-TiO2 NP) composites with variable amounts of TiO2 NPs as nonprecious active catalysts for the electrochemical generation of H2. These materials were synthesized by mixing desired amounts of hydrogen titanate nanotubes (TNTs), fabricated here by a cost-effective approach at moderate hydrothermal conditions, with aluminum powder (purity 99.7%; size 35 μm). The mixture was compacted under an applied uniaxial stress of 300 MPa followed by sintering at 500 °C for 1 h. After sintering had been completed, all TNTs were found to convert to TiO2 NPs (average particle size 15 nm). Finally, Al-xTiO2 NP nanocomposites (x = 1, 3, 5, and 10) were obtained and characterized by scanning electron microscopy/energy-dispersive X-ray, X-ray diffraction, and X-ray photoelectron spectroscopy. The hydrogen evolution reaction (HER) activity of these materials was studied in 0.5 M H2SO4 at 298 K using polarization and impedance measurements. The nanocomposite of chemical composition Al-5% TiO2 NPs showed the best catalytic performance for the HER, with an onset potential (EHER), a Tafel slope (βc), and an exchange current density (j0) of -100 mV (RHE), 59.8 mV decade(-1), and 0.14 mA cm(-2), respectively. This HER activity is not far from that of the commercial platinum/carbon catalyst (EHER = 0.0 mV, βc = 31 mV dec(-1), and j0 = 0.78 mA cm(-2)). The best catalyst also exhibited good stability after 10000 repetitive cycles with negligible loss in current.

This work aimed to characterize dust-fall samples collected from street's trees in Greater Cairo (GC), Egypt, and its surroundings by different spectroscopic techniques, namely; X-ray diffraction (XRD), attenuated total-reflection Fourier transform infrared (ATR-FTIR), particle-size analyzer, and scanning electron microscopy (SEM) combined with energy dispersive X-ray measurements. Samples were collected from 19 different locations inside and outside of GC. Quantitative phase analysis of the dust-fall samples was performed using the Rietveld method. Results showed that the most frequently observed phases in the dust-fall samples were calcite (CaCO3), dolomite (CaMg(CO3)2), gypsum (CaSO4·2H2O), and quartz (SiO2) with average concentrations of 39 ± 16, 8 ± 7, 22 ± 13, and 33 ± 14 wt%, respectively. The occurrence of these constituents referred to a combination of different anthropogenic and natural sources. The ATR-FTIR results are in good agreements with XRD data of the different observed phases. Based on the SEM and particle-size measurements, quantitative determination of the particle-size distribution was described. It was found that not only the large-sized particles are deposited but also the small-sized ones (PM10 and PM2.5). In addition, the particle size of the collected dust-fall samples varied from 0.1 to 200 µm with an average particle size of 17.36 µm; however, the particle size ranged from 2.5 to 40 µm predominated in all of the dust-fall samples.