Several fungal endophytes were isolated and screened for their ability to biosynthesize a variety of nanoparticles (NPs), as a potentially simple and eco-friendly method with low cost. Among these ...fungi, a promising isolate named ORG-1 was found able to synthesize five different NPs types: Co
3
O
4
NPs, CuONPs, Fe
3
O
4
NPs, NiONPs, and ZnONPs. The ORG-1 strain was identified as
Aspergillus terreus
according to the morphological and molecular studies. Synthesis of these NPs was initially monitored by UV–Vis spectroscopy and further characterized by Fourier transform infrared spectroscopy. X-ray diffraction patterns revealed their crystalline structure. Dynamic light scattering analysis was applied to study the particle size distribution and stability. Transmission electron microscope studies indicated the morphology of the synthesized NPs. Additionally, the biological activities of the in vitro antioxidant and antimicrobial potentials were evaluated. Co
3
O
4
NPs, CuONPs, Fe
3
O
4
NPs, NiONPs, and ZnONPs showed promising antioxidant activity with 50% inhibitory concentrations of 85.44, 96.74, 102.41, 87.41, and 108.67 μg mL
−1
, respectively. The synthesized NPs exhibited potent antimicrobial activities against several plant and human pathogens. To our knowledge, this is the first report on the use of one microbial strain for the synthesis of a variety of NPs. This study suggests endophytic fungi as new and alternate platforms with an exceptional potentiality for the synthesis of NPs with promising activities.
Key points
• Discovery of a promising endophytic fungus for synthesis of five different types of NPs
.
• Mycosynthesis and characterization of all the synthesized NPs were investigated
.
• The synthesized NPs showed promising antioxidant and antimicrobial activities
.
This cross-sectional survey aimed to identify aerobic bacteria, antimicrobial resistance, and multi-drug resistance profiles of bacteria isolated from different wound infections among a group of ...Egyptian patients.
Of 120 positive samples, 170 isolates were identified. Polymicrobial infections were determined in 55% of samples. The dominant Gram-positive isolated strains were Staphylococcus aureus, especially from wound infections because of accidents (71.8%). Piperacillin, methicillin, ampicillin/sulbactam, and amoxicillin/clavulanic acid were all highly resistant to S. aureus and Coagulase-negative Staphylococci. The prevalence of methicillin-resistant S. aureus in wound infections was 89.9%. S. aureus showed superior sensitivity to vancomycin (85.3%) and linezolid (81.3%). The highest prevalence of Gram-negative isolates was for Pseudomonas aeruginosa (40%), which was highly sensitive to ciprofloxacin (79.2%) and highly resistant to levofloxacin (83.3%). Several isolates revealed a multi-drug resistance profile (52.4%). The overall MDR rate of Gram-positive and Gram-negative isolates were 50% and 54.9%, respectively.
The prevalence of MRSA isolated from various wound infections and MDR is a warning issue in Upper Egypt. It should implement a health education strategy and hygiene measures to prevent the spread of wound infection-causing organisms in the community.
The protection mechanism of surface modified NPhE/TNC epoxy coating.
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•NPhE/TNC modifier was fabricated for improving the epoxy coating properties.•Salt spray accelerated corrosion ...test displayed a superior protective behavior for NPhE/TENC-E coating.•SEM survey confirmed the mitigation performance of modified NPhE/TNC coatings.•The proper acids and alkali resistance was offered for the modified 2.5% NPhE/TNC epoxy film.•TiO, TiOC and OTiO linkages with DGEBPA prohibited the transmission paths of aggressive species.
Nanocomposite modifiers reinforce the whole characteristics of epoxy coatings for different steel surface applications. To support this concept, sol-gel synthesized TiO2 nanoparticles (TNPs) were mixed with nonylphenol ethoxylate (NPhE) to form nonylphenol ethoxylate/TiO2 nanocomposite (NPhE/TNC) as a modifier for epoxy coating applied on the C-steel surface. TNPs were characterized by XRD, SEM and HR-TEM techniques. Various modified NPhE/TNC epoxy coating formulations with different loading levels (0.5, 1, 1.5, 2 and 2.5%) by weight were prepared. FT-IR spectra were used for characterizing of the formed nanocomposites. The anti-corrosion behavior of surface-modified NPhE/TNC coated films versus unmodified conventional epoxy was studied by salt spray accelerated corrosion test. The obtained results demonstrated a considerable improvement in the rust grade, blistering size and frequency, and adhesion strength of modified NPhE/TNC epoxy nanocomposite coated films and affirmed by SEM morphology survey. The impact resistances of unmodified and modified NPhE/TNC epoxy coatings were measured where the best impact resistance was recorded for NPhE/TENC-E coated film at 51 J. Acids and alkali chemical immersion test was performed to check the chemical immovability for the surface-modified NPhE/TNC coated films against conventional epoxy where NPhE/TENC-E coating showed the suitable immovability levels.
In drylands, groundwater is often the only perennial source of freshwater to sustain domestic water supplies and irrigation. Knowledge of the pathways and dynamics of groundwater discharge and ...recharge is, therefore, essential to inform sustainable and rational management of limited water resources. The lower valley of the Dallol Maouri in Niger represents a large fossil tributary (i.e. paleochannel) of the River Niger and drains groundwater regionally from the Iullemmeden Basin through coarse-grained Quaternary sediments. The objective of this paper is to quantify groundwater discharge within this paleochannel using piezometry and near-surface geophysics (TDEM: Time Domain Electromagnetics, MRS: Magnetic Resonance Sounding). TDEM and MRS experiments, conducted at 21 sites along 3 transects, show the thickness of the saturated Quaternary alluvium varies from 7 to 19 m with estimated effective porosities ranging from 18 to 38% and a hydraulic conductivity of 0.6–3 × 10
–3
m/s. Dense piezometric surveys along drainage channel reveal hydraulic gradients of 0.2–0.3‰ that generate Darcy fluxes of 1000–2000 m
3
/day (dry season, i.e. minimum value). Paleochannel discharge, which currently provides baseflow to the River Niger, is the focus of local demand to increase access to water for drinking, livestock watering, and supplementary irrigation.
Multi-functional action of PDMAS/TiO2 epoxy nanocomposite.
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•PDMAS/TiO2 nanocomposite was prepared and evaluated in steel epoxy coating.•Efficient protective and self-healing actions ...were offered by the modified PDMAS/TiO2 epoxy nanocomposite.•Mechanical resistance characteristics of the modified epoxy were investigated.•Solvent immersion trial was checked to affirm the chemical resistance of the modified coating.•UV immovability of the modified coating was attributed to TiO, TiOC OTiO, SiOSi and SiO linkages.
Nanocomposite coatings play a strategic role in the treatment of metal surfaces in the petroleum sector, especially steel oil transportation trucks, by providing novel materials exhibiting superior stability to various severe conditions. To confirm this concept, TiO2 nanoparticles (TNPs) were fabricated by a simple template-free sol-gel method and blended with poly-dimethylamino siloxane (PDMAS) to fabricate PDMAS/TiO2 nanocomposite acting as a multifunctional modifier for polyamine-cured epoxy coating. TNPs were characterized by TEM, XRD and DLS measurements. FTIR characteristic spectra were employed to affirm the formation of hybrid nanocomposite coating. The anti-corrosion performance of surface-modified PDMAS/TiO2 epoxy coated films versus unmodified conventional epoxy was investigated by salt spray accelerated corrosion test. Surface morphology combination (SEM/EDX) analysis and weight loss study confirmed that NT/PDMAS-E coated film manifested the best corrosion mitigation properties with a detected self-healing effect. The mechanical resistance characteristics of the coatings were studied by adhesion (pull-off and cross-cut), abrasion and bend coating strategies to emphasize their class strength and workability. The chemical durability was checked by water and solvent immersion tests. Finally, UV resistance test was performed to show the effect of fluorescent UV radiation on the checked epoxy coated films. The thermophysical and electrical properties were also investigated to offer the thermal and electrical conductivities of investigated coatings with increasing the loading level (%) by weight of the nanocomposite modifier via the coating layer. The obtained results illustrated the superior anti-corrosion, mechanical, chemical, electrical, thermal and UV resistance characteristics of the PDMAS/TiO2 epoxy hybrid nanocomposite coating.
By means of variational iteration method the solutions of Burger's equation and coupled Burger's equations are exactly obtained, comparison with the Adomian decomposition method is made, showing that ...the former is more effective than the later. In this paper, He's variational iteration method is introduced to overcome the difficulty arising in calculating Adomian polynomials.
The protection mechanism of NS/MCE-F3 and NS/MCE-F5 coatings.
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•Application of Schiff base metal complex/SiO2 epoxy hybrid nanocomposite coating on C-steel surface was ...investigated.•SEM and EDX combination survey was studied for anti-corrosion behavior evaluation.•Modified Cr(III) and Ni(II) complexes epoxy nanocomposite coatings manifested the best results.•Weight loss strategy affirmed protective behavior of the modified epoxy nanocomposite coatings.•The mechanical properties of coatings were studied by adhesion, bend, impact and abrasion resistance tests.
Implementation of Schiff base metal complex/SiO2 nanocomposite as a multifunctional modifier in steel epoxy coating represents a novel engineering issue for surface treatment technology. The present work investigates the application of epoxy coating modified with several metal (Co(II), Zr(IV), Ni(II), Cu(II) and Cr(III)) complexes of Schiff base versatile ligand namely p-Phenylamine-N(4-chloro salicylaldenemine) (HL), composited with SiO2 nanoparticles to enhance its protective behavior and mechanical resistance on the C-steel surface. Characterizations of silica nanoparticles were demonstrated by using transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive of X-rays (EDX) and X-ray diffraction analysis for integral clarification. FT-IR discriminatory spectra for polyamine cured blank unmodified conventional epoxy and surface modified HL and its metal complexes epoxy/SiO2 hybrid nanocomposite cured coatings were checked. The protective behavior of the investigated modified epoxy nanocomposite coatings against unmodified blank conventional epoxy on the steel surface was clarified by studying the surface morphology of the cured coated films after the immediate exposition to corrosive salt spray cabinet for 500 h and employing 5% NaCl aggressive solution. Modified cured Cr(III) and Ni(II) complex epoxy/SiO2 nanocomposite coated films (NS/MCE-F3 and NS/MCE-F5) manifested the minimum corrosion rate (CR) at 0.00063 mm/y and a superb protection efficiency (PE) recorded at 99.80%. The mechanical resistance properties of the nanocomposite coatings were examined by adhesion cross-cut, bend, impact, and abrasion (film stiffness) coating tests to underline their enforcement efficiency. NS/MCE-F3 and NS/MCE-F5 coated films boosted an outstanding mechanical resistance behavior on the C-steel surface in contrast with complete deterioration for blank conventional epoxy. The main reason for the superior anti-corrosion and mechanical performance properties observed in case of the nanocomposite coatings modified with Cr(III) and Ni(II) complexes may be attributed to the higher magnetic dipole moment of these complexes than the others in which enhances their electronegativity, cross-linking density and chemical bonding with the steel surface via the donor-acceptor interactions.
The extended tanh method with a computerized symbolic computation is used for constructing the travelling wave solutions of coupled nonlinear equations arising in physics. The obtained solutions ...include solitons, kinks and plane periodic solutions. The applied method will be used in further works to establish more entirely new solutions for other kinds of nonlinear evolution equations arising in physics.
In this study, the
exp
(
-
ϕ
(
ξ
)
)
-expansion function method is considered for solving two classes of space-time fractional partial differential equations of very special interest. The two ...classes, namely the higher dimensional Kadomtsev–Petviashvili and Boussinesq equations, have a wide range applications in different areas of complex nonlinear physics such as plasma physics, fluid dynamics and nonlinear optics. As a result, the
exp
(
-
ϕ
(
ξ
)
)
-expansion function method yields a different class of traveling solutions mapped to trigonometric functions, rational functions and hyperbolic functions. Also, the behavior of these solutions has been significantly affected by changing the values of fractional order where the obtained solutions go back to those obtained previously to the normal case, i.e.,
α
=
β
=
1
. Finally, our finding may be of wide relevance and helpful to better understand the main features and propagation of the nonlinear waves in fractal medium.
This paper deals with the solution of a third kind mixed integro-differential equation (MIDE) in displacement type in space L2−1,1×C0,T,T<1. The singular kernel is modified to take a logarithmic ...form, while the kernels of time are continuous and positive functions. Using the separation of variables technique, we have a system of Fredholm integral equations (FIEs) that can be transformed into an algebraic system after using orthogonal polynomials. In all the previous researchers’ works, the time periods were divided, and the mixed equation transformed into an algebraic system of FIEs. While when using the separation method, we are able to obtain FIE with time coefficients, and these functions are described as an integral operator in time. Thus, we can study the behavior of the solution with the time dimension in a broader and deeper than the previous one. Some examples are given and discussed to show the performance and efficiency of the proposed methods.
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