The ability of microorganisms to generate resistance outcompetes with the generation of new and efficient antibiotics. Therefore, it is critically required to develop novel antibiotic agents and ...treatments to control bacterial infections. Green synthesized metallic and metal oxide nanoparticles are considered as the potential means to target bacteria as an alternative to antibiotics. Nanoconjugates have also attracted attention because of their increased biological activity as compared to free antibiotics. In the present investigation, silver nanoparticles (AgNPs), zinc oxide nanoparticles (ZnO NPs), copper oxide nanoparticles (CuO NPs), and iron oxide nanoparticles (FeO NPs) have been synthesized by using leaf extract of Ricinus communis. Characterization of nanoparticles was done by using UV-Vis Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy Dispersive X-Ray Analyzer, X-ray Diffraction Analysis, and Dynamic Light Scattering Particle Size Analyzer. Interestingly, Streptomycin when combined with AgNPs, ZnO NPs, CuO NPs, and FeO NPs showed enhanced antibacterial activity against clinical isolates of S. aureus which suggested synergism between the nanoparticles and antibiotics. The highest enhanced antibacterial potential of Streptomycin was observed in conjugation with ZnO NPs (11 ± 0.5 mm) against S. aureus. Minimum inhibitory concentration of conjugates of AgNPs, ZnO NPs, CuO NPs, and FeO NPs with streptomycin against S. aureus was found to be 3.12, 2.5,10, and 12.5 μg/mL respectively. The considerable point of the present investigation is that S. aureus, which was resistant to streptomycin becomes highly susceptible to the same antibiotic when combined with nanoparticles. This particular observation opens up windows to mitigate the current crisis due to antibiotic resistance to combat antimicrobial infections efficiently.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This work reports the formation of polyacrylic acid (PAA)-zinc oxide (ZnO)-bromocresol purple (BCP), (PAA-ZnO@ (0.00-0.01) BCP wide-bandgap organic semiconductors deposited onto glass substrates via ...a sol-gel polymerization process. These semiconductor films were deposited on glass substrates using a spin coating and then dried at 60 °C. The PAA-ZnO film appeared to be of amorphous phase, and films loaded with BCP revealed semicrystalline behavior. The surface of the films exhibited adherence and extended grains. The hydrogen bonds formed between PAA-ZnO and the BCP dye within the PAA-ZnO@BCP films was performed using FTIR-spectroscopy. The prepared nanocomposites demonstrate an indirect band transition which is affected slightly by adding ZnO and BCP dye. Optical parameters such as the absorption coefficient, the refractive index, the dielectric constant, optical conductivity, optical depth, and optical electronegativity of the prepared nanocomposites were studied as functions of incident light energy (wavelength). The PAA carbonyl group n-π* transition and BCP aromatic ring π-π* transitions were detected at about 285 (for all samples) and 432 nm (for BCP loaded samples), respectively. The superior photoluminescence characteristics observed in the BCP/PAA-Zn films excited with a wavelength of 250 nm indicated the successful loading of the BCP dye during the self-aggregation of the PAA-Zn film.
Abstract
Talented di-phase ferrite/ferroelectric BaTi
0
.
7
Fe
0
.
3
O
3
@NiFe
2
O
4
(BFT@NFO) in oval nano-morphology was chemically synthesized using controlled sol–gel processes and calcined at ...600 °C. The effects of shielding using NiFe
2
O
4
(NFO) nanoparticles on the microstructure, phase transition, thermal, and relative permittivity of BaTi
0
.
7
Fe
0
.
3
O
3
(BTF) nano-perovskite were systematically explored. X-ray diffraction patterns and Full-Prof software exhibited the forming of the BaTi
2
Fe
4
O
11
hexagonal phase. TEM and SEM images demonstrated that the coating of BaTi0.
7
Fe
0
.
3
O
3
has been successfully controlled with exquisite nano-oval NiFe
2
O
4
shapes. The NFO shielding can significantly promote the thermal stability and the relative permittivity of BFT@NFO pero-magnetic nanocomposites and lowers the Curie temperature. Thermogravimetric and optical analysis were used to test the thermal stability and estimate the effective optical parameters. Magnetic studies showed a decrease in saturation magnetization of NiFe
2
O
4
NPs compared to their bulk system, which is attributed to surface spin disorder. Herein, characterization and the sensitive electrochemical sensor were constructed for the evaluation of peroxide oxidation detection using the chemically adjusted nano-ovals barium titanate-iron@nickel ferrite nanocomposites. Finally, The BFT@NFO exhibited excellent electrochemical properties which can be ascribed to this compound possessing two electrochemical active components and/or the nano-ovals structure of the particles which can further improve the electrochemistry through the possible oxidation states and the synergistic effect. The result advocates that when the BTF is shielded with NFO nanoparticles the thermal, dielectric, and electrochemical properties of nano-oval BaTi
0.7
Fe
0.3
O
3
@NiFe
2
O
4
nanocomposites can be synchronously developed. Thus, the production of ultrasensitive electrochemical nano-systems for the determination of hydrogen peroxide is of extensive significance.
Rhodamine B (RhB), as perilous contaminants vastly utilized in industrial purposes, has potential role in environmental pollution. In present study a series of nanocrystalline rare earth (Sm3+) ...substituted magnesium-zinc ferrite with composition Mg0.2Zn0.8SmxFe2-xO4; (0 ≤ x ≤ 0.2) (MZS), for RhB degradation, were scrutinized. The sharpness and prevalence of XRD peaks emphasize its nanocrystalline nature. The lattice constant (aexp) is found to increase from 8.3818 to 8.4215 Å; obeying Vegard’s law, with (311) peak shift from 2θ = 35.28ο to 34.32°. Bond dissociation energy of (Sm–O) is the reason for why the crystallite size (DWH) of MZS nanoferrites was increased by Sm/Fe substitution process; declaring an inverse relation between DWH and aexp values. Triple factors; magnetic moment of Sm/Fe cations in octahedral sites, crystallite size and porosity are responsible for the decrement behavior of saturation magnetization. The coercivity has a unique attitude; firstly exhibits a downward behavior and then an upward one. The dielectric parameters have unique behavior with Sm3+ substitution; firstly decrease (0.0 ≤ x ≤ 0.12) and then increases (0.12 ≤ x ≤ 0.2); governed by substitution ions, porosity and crystallite size effects. Nyquist plots have a distinct arc; meanwhile the second one is wholly unseen, due to one of two prospects. The optical energy gap has a special behavior; it has a blue shift from (1.74eV–2.06eV; for 0.0 ≤ x ≤ 0.12), and then a red shift from (2.06 eV–1.61 eV; for 0.12 ≤ x ≤ 0.2) by two justifications. The photo-decolorization efficiency of RhB over MZS photocatalysts is enhanced; (10.76%, 22.05%, 38.08%, 58.93%, 77.10% and 94.13% with increasing Sm3+ content, respectively) compared with its modest value 4.91% without addition. All these outcomes could provide insight into electronic devices besides photocatalyst for RhB removal by Mg0.2Zn0.8Sm0.2Fe1.8O4 ferrite nanoparticles.
•MZS nanoparticles have been synthesized by a combustion method.•Bond dissociation energy of (Sm–O) is the reason for the crystallite size behavior of MZS nanoferrites.•Triple factors; magnetic moment values, crystallite size and porosity are responsible for MS decrement.•Nyquist plots have a distinct arc; meanwhile the second one is wholly unseen, due to one of two prospects.•The photodegradation efficiency of RhB over MZS photocatalysts is enhanced.
A numerical simulation of magneto-hydrodynamic mixed convection flow and heat transfer of Cu-water nanofluid in a square cavity filled with a Darcian porous medium with a partial slip is numerically ...investigated. The left and right walls of the cavity are moving up with a constant speed in vertical direction, and the partial slip effect is considered along these walls. The top and bottom walls of the cavity are assumed to be adiabatic. The right vertical wall of the cavity is assumed to be kept at a lower temperature, while the left vertical wall is kept at a higher temperature. The developed equations of the mathematical model are nondimensionalized and then solved numerically subject to appropriate boundary conditions by the finite-volume method. A parametric study is performed and a set of graphical results is presented and discussed to demonstrate interesting features of the solution.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Recent investigations of a Greco-Roman site at Sais have provided well-preserved archaeobotanical remains within a pile of metal fragments. The remains are compared with comparable modern taxa. The ...morphology and anatomy are studied using Light microscope (LM), Environmental scanning electron microscope (ESEM) and X-ray computed tomography (CT). To investigate the preservation mode, Energy dispersive spectroscopy (EDS) analysis and elemental mapping are conducted. Results revealed that the archaeobotanical remains are exhibiting close affinity with modern juniper cones. Although, the studied archaeobotanical remains are buried for more than 2 millenniums, they underwent early stages of silicification and copper mineralization. These results are discussed in relation to other excavated objects in the find and to our knowledge and understanding of daily life in the Greco-Roman period.
In the current study, two molds, Aspergillus flavus (ACC# LC325160) and Penicillium chrysogenum (ACC# LC325162) were inoculated into two types of wood to be examined using scanning electron ...microscopy-energy dispersive X-ray (SEM-EDX) and computerized tomography (CT) scanning. Ficus sycomorus, a non-durable wood, and Tectona grandis, a durable wood, were the two wood blocks chosen, and they were inoculated with the two molds and incubated for 36 months at an ambient temperature of 27 ± 2 °C and 70 ± 5% relative humidity (RH). The surface and a 5-mm depth of inoculated wood blocks were histologically evaluated using SEM and CT images. The results showed that A. flavus and P. chrysogenum grew enormously on and inside of F. sycomorus wood blocks, but T. grandis wood displayed resistance to mold growth. The atomic percentages of C declined from 61.69% (control) to 59.33% in F. sycomorus wood samples inoculated with A. flavus while O increased from 37.81 to 39.59%. P. chrysogenum caused the C and O atomic percentages in F. sycomorus wood to drop to 58.43%, and 26.34%, respectively. C with atomic percentages in Teak wood's C content fell from 70.85 to 54.16%, and 40.89%, after being inoculated with A. flavus and P. chrysogenum. The O atomic percentage rose from 28.78 to 45.19% and 52.43%, when inoculated with A. flavus and P. chrysogenum, respectively. Depending on how durable each wood was, The examined fungi were able to attack the two distinct types of wood in various deterioration patterns. T. grandis wood overtaken by the two molds under study appears to be a useful material for a variety of uses.
Biofilm control by essential oil (EO) application has recently increased to preclude biofilm production on foods and environmental surfaces. In this work, the anti-biofilm effects of garlic and thyme ...essential oils using the minimum inhibitory concentration (MIC) method against
recovered from different abattoir samples were investigated along with the virulence genes (
and
genes), and the antimicrobial susceptibility profile of
.
as well. The obtained results revealed that
.
contaminated abattoir samples to varying degrees. The
gene was investigated in all isolates, whereas the
and
genes were observed in four and three isolates, respectively. Utilizing the disc diffusion method,
.
isolates demonstrated substantial resistance to most of the examined antibiotics with a high multiple antibiotic resistance index.
.
isolates demonstrated biofilm formation abilities to various degrees at varied temperatures levels (4 °C and 37 °C). In conclusion, the obtained samples from the research area are regarded as a potential
.
contamination source. Furthermore, garlic essential oil (GEO) has more potential to inhibit
.
biofilm at different sub-minimum inhibitory concentrations as compared to thyme essential oil (TEO). Therefore, these EOs are considered as potential natural antibacterial options that could be applied in food industry.
Crossbred photocatalysts with dielectric and magnetic are crucial by its vantage of being convenient in sundry applications. In this paper, lanthanum with large percentages doped zinc magnesium ...ferrite (Zn0.8Mg0.2LaxFe2-xO4) (ZML) nanoparticles with x ranging from 0.0 to 0.5 prepared via a combustion method. The spinel structure of ZML nanoparticles is asserted with further La3+ substitution. The lattice parameter is found to increase from 8.379 to 8.433 Å with a monotonic shift in diffraction peak (311) toward lower degree angles (2θ = 35.28ο to 34.0°). Williamson-Hall plots established increasing demeanor for crystallite size (28–49 nm) and lattice tensile strain for ZML nanoparticles. FE-SEM depicts spongy or carded wool-like structure with porous nature. EDX spectra revealed the presence of all chemical elements. HRTEM and SAED micrographs confirmed the nanosized polycrystalline nature of samples. The finger print ferrite FTIR absorption bands were obtained. The crystallite size role and magnetocrystalline anisotropy property of La3+ are the substantial reasons for the peculiar demeanor of coercivity. The increasing attitude of dielectric constant as well as conductivity and decreasing one for tangent loss are based on the effective role of porosity and crystallite size of samples. Tauc’s plots introduced direct allowed Eg for ZML nanoparticles with a red shift from (1.92 eV at x = 0.0–1.66 eV at x = 0.5); owing to three factors. The degradation efficiency of RhB over ZML photocatalyst is improved comparing with that of pure RhB reaches (84.43% for x = 0.5 in 270 min). The optimum features of the nanoferrite Zn0.8Mg0.2La0.5Fe1.5O4; high coercivity, dielectric constant, conductivity, photodegradation percentage, besides low loss and energy gap make it advisable for various applications as storage and high frequency devices and photocatalyst for disposing effluents from water.
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•Zn-Mg-La nanoparticles have been synthesized by a combustion method.•Crystallite size role and magnetocrystalline anisotropy of La3+ are the responsible for the peculiar coercivity demeanor.•The dielectric parameters behavior is based on the effective role of porosity and crystallite size.•The nanoferrite Zn0.8Mg0.2La0.5Fe1.5O4 indicated photocatalytic activity for the removal of rhodamine B dyes.•The optimum features of the nanoferrite Zn0.8Mg0.2La0.5Fe1.5O4 make it advisable for various applications.
In this study, TiO
2
nanoparticle (TiO
2
NP)-coated film was produced to protect manuscripts against microorganisms using ecofriendly benign materials. As a result, a simple method was created that ...uses poultice biofilm made of carboxymethyl cellulose (CMC) and Phytagel plant cell (PGP) loaded with TiO
2
NPs to preserve manuscripts against microbes in an environmentally responsible way. Three volumes (1, 2, 4 mL) of TiO
2
NPs were put into a biofilm combination to produce the poultices known as CMC/PGP/TiO
2
-1, CMC/PGP/TiO
2
-2, and CMC/PGP/TiO
2
-3. The synthesized TiO
2
NPs were nearly spherical in shape, small in size (98 nm), and stable (zeta potential value − 33 mV). The results showed that the unique deposition of TiO
2
NPs on the biofilm surface gave the produced films loaded with TiO
2
NPs a rough structure. The highest values of mechanical characteristics were determined to be in CMC/PGP/TiO
2
-1 with values of 25.4 g, 6.6 MPa, and 11.4%, for tensile strength, elongation at break, and tear strength, respectively. Based on molecular identification, the fungus
Aspergillus sydowii
and the bacterium
Nevskia terrae
, with accession numbers MG991624 and AB806800, respectively, were isolated and identified from an antiquated manuscript formed from cellulosic fibers. Before the experiments, the produced cotton paper samples were aged, and then, one group was infected for 6 months by
A. sydowii
and the second group with
N. terrae
. Following the preparation of a CMC/PGP biofilm loaded with various volumes of TiO
2
NPs, poultices were applied to infected cotton paper in order to clean it. The infected cotton paper was placed inside the sandwich-like poultices that were created. The poultice CMC/PGP/TiO
2
-2 demonstrated potential for preventing the growth of
A. sydowii
and
N. terrae
-infected cotton paper, when the fibers were saved, cleaned, and coated with CMC/PGP/TiO
2
-2 after absorbing the fungus and the bacterium and exhibiting exceptional antimicrobial activities. Finally, the novel biofilms have demonstrated their capacity to lessen microbial contamination of cotton paper. In order to generalize the usage of these poultices, it is also advised that they be produced on a large scale and tested on a variety of organic materials in the future.
Graphical Abstract
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