Vanadium substituted nickel ferrite nanoparticles (NPs), NiFe
2−x
V
x
O
4
(0.0 ≤ x ≤ 0.3) were prepared by sol–gel approach. The influence of calcination on the magnetic and optical properties of ...NiFe
2−x
V
x
O
4
(0.0 ≤ x ≤ 0.3) NPs were investigated deeply. The lattice parameters ‘a’ are almost constant with V-substitution for as-prepared and calcined samples. It was found that the calcination process both increased the crystallites size and removed the impurity phases in all products. The values of optical energy band gap, E
g
, are in range of 1.38–1.69 eV and 1.39–1.56 eV for as-prepared and calcined samples, respectively. The specific magnetic parameters such as saturation magnetization M
s
, remanence M
r
, coercivity H
c
, squareness ratio (SQR) and magnetic moment
n
B
were determined from magnetization versus applied field measurements. The various M(H) curves exhibit ferromagnetic behavior at room temperature and 10 K. A decrease in M
s
, M
r
and
n
B
values was observed with Vanadium substitution. However, an increase in H
c
value was observed. The obtained magnetic results are primarily resulted from the substitution of Fe ions with V ions that will weaken the A–B super-exchange interactions. Besides, the calcination step leads to an improvement in the various M
s
, M
r
and
n
B
parameters. This enhancement is due to the enlargement of crystallites size (or grains size) and the strengthening of the A–B exchange interactions caused by the calcination effect. Nevertheless, the enlargement in the crystallites size is followed by a reduction in H
c
values.
This study reports the preparation and characterization of nanocrystalline spinel powder of cubic copper ferrite nanoparticles (NPs) which have been fabricated via a cost-effective citrate sol–gel ...approach. The structural and morphological properties of the nanoparticles are analyzed by X-ray diffraction (XRD), Fourier transform spectroscopy (FT-IR), and scanning electron microscopy (SEM) whereas magnetic properties and Mössbauer analysis were performed using vibrating sample magnetometer (VSM) and Mössbauer spectra, respectively, and were characterized in detail. The empirical aim of this study is to perceive the transition phase of CuFe
2
O
4
as cubic symmetry which was confirmed by SEM images, and a couple of studies reported on the cubic structure of copper ferrite and discussed the magnetic properties. However, the present study gives the detailed information of the formation of cubic structure and magnetic behavior of the CuFe
2
O
4
cubic structure. X-ray diffraction measurements of resulting NPs show that the grain size of the particles is about 42.08 nm while SEM analysis showed that the particles have cubic nanostructured shapes with non-homogeneous sizes in around 80–100 nm. From
57
Fe, Mössbauer parameters consist of one superparamagnetic doublet and superposition of four sextets. VSM result shows the enhanced superparamagnetic nature of the CuFe
2
O
4
NPs.
The effects of Ce–Dy co-doping on the crystal structure, optical, dielectric, magnetic properties, and hyperfine interactions of Ni–Co spinel ferrite microspheres synthesized hydrothermally have been ...studied. A series of ferrites with the general formula Ni0.5Co0.5CexDyxFe2-2xO4 were synthesized with x values ranging from 0.00 to 0.10. The phase, crystallinity, and morphology of ferrite microspheres were analyzed by X-ray powder diffractometry (XRD), scanning and transmission electron microscopes (SEM and TEM), respectively. The structural analyses of the synthesized ferrite microspheres confirmed their high purity and cubic crystalline phase. The Diffuse reflectance spectroscopic (DRS) measurements were presented to calculate direct optical energy band gaps (Eg) and is found in the range 1.63 eV - 1.84 eV. 57Fe Mossbauer spectroscopy showed that the hyperfine magnetic field of tetrahedral (A) and octahedral (B) sites decreased with the substitution of Dy3+-Ce3+ ions that preferrentially occupy the B site. The impact of the rare-earth content (x) on the magnetic features of the prepared NiCo ferrite microspheres was investigated by analyzing M-H loops, which showed soft ferrimagnetism. The magnetic features illustrate a great impact of the incorporation of Ce3+-Dy3+ ions within the NiCo ferrite structure. The saturation magnetization (Ms), remanence (Mr), and coercivity (Hc) increased gradually with increasing Ce–Dy content. At x = 0.04, Ms, Mr, and Hc attain maximum values of about 31.2 emu/g, 11.5 emu/g, and 512.4 Oe, respectively. The Bohr magneton (nB) and magneto-crystalline anisotropy constant (Keff) were also determined and evaluated with correlation to other magnetic parameters. Further increase in Ce3+-Dy3+ content (i.e., x ≥ 0.06) was found to decrease Ms, Mr, and Hc values. The variations in magnetic parameters (Ms, Mr, and Hc) were largely caused by the surface spins effect, the variations in crystallite/particle size, the distribution of magnetic ions into the different sublattices, the evolutions of magneto-crystalline anisotropy, and the variations in the magnetic moment (nB). The squareness ratios were found to be lower than the predicted theoretical value of 0.5 for various samples, indicating that the prepared Ce–Dy substituted NiCo ferrite microspheres are composed of NPs with single-magnetic domain (SMD). Temperature and frequency-dependent electrical and dielectric measurements have been done to estimate the ac/dc conductivity, dielectric constant, and tangent loss values for all the samples. The ac conductivity measurements confirmed the power-law rules, largely dependent on Ce–Dy content. Impedance analysis stated that the conduction mechanisms in all samples are mainly due to the grains-grain boundaries. The dielectric constant of NiCo ferrite microspheres give rise to normal dielectric distribution, with the frequency depending strongly on the Ce–Dy content. The observed variation in tangential loss with frequency can be attributed to the conduction mechanism in ferrites, like Koop's phenomenological model.
Two new series of 5-(14
H
-dibenzo
a,j
xanthen-14-yl)furan-2-carbaldehydes and
α
-cyanostilbenes were synthesized in good yields. A one-pot reaction between 2-naphthol and furan-2,5-dicarbaldehyde ...led to the formation of the corresponding dibenzoxanthene derivative. The latter underwent Knoevenagel condensation with a variety of methylene active derivatives to afford the corresponding 5-(14
H
-dibenzo
a,j
xanthen-14-yl)furan-2-carbaldehydes. Knoevenagel condensation was also applied to synthesize a series of the α-cyanostilbenes bearing a variety of electron-withdrawing and electron-donating groups, utilizing 4-nitrophenylacetonitrile as a starting derivative to react with equimolar amounts of different aldehydes.
In this study, Co0.5Ni0.5Nd0.02Fe1.98O4 nanoparticles CoNiNd (NPs) were synthesized by combustion method linked with biosynthesis with and without different plant extracts such as Lavender, Ginger, ...Flax-Seed, Lemon Juice, Tragacanth Gum, and Dates Fruit. Co0.5Ni0.5Nd0.02Fe1.98O4 nanoparticles (NPs) with plant extracts (CoNiNd plant extracts) were analyzed by XRD, TEM and SEM methods. The structure of Co-Ni spinel ferrite was confirmed by XRD and the shape and the size of nanoparticles were examined via SEM and TEM and the size was found between 17 and 25 nm. The anti-cancer activity of NPs on cancer cells such as human colorectal carcinoma (HCT-116) and human cervical cells (Hela) were investigated. The cytotoxicity of was examined by MTT assay and followed by measuring the inhibitory concentration (IC50) values after 48 h treatments. The cell viability assay confirmed a decrease in the cancer cell viability post NPs treatments and showed dose-dependent inhibitory action. The treatments of CoNiNd (NPs) and CoNiNd plant extracts via Lavender plant extract showed most profound inhibitory action on both cancer cells than extracts other plant extracts. The IC50 values were for HCT-116 cells were found to be in range of 15.75–42.55 µg/mL and 13.44 to 35.65 µg/mL for HeLa cells. In contrast, the treatment of CoNiNd (NPs) and CoNiNd plant extracts showed inhibitory action but the percentage of inhibition was higher in HEK-293 cells. Our results showed that CoNiNd (NPs) and CoNiNd plant extracts possess potential application in the colon and cervical cancer treatments and we recommend molecular analysis of NPs mediated cancer cell death for future applications.
Clinical studies have shown that cigarette smoking is a dose-dependent and independent risk factor for acute pancreatitis. Cigarette smoke contains nicotine which can be converted to the potent ...receptor ligand and toxin, NNK 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Previously, we have shown that NNK induces premature activation of pancreatic zymogens in rats, an initiating event in pancreatitis, and this activation is prevented by pharmacologic inhibition of nicotinic acetylcholine receptors (nAChR). In this study, we determined whether NNK mediates pancreatitis through the α7 isoform of nAChR using α7nAChR knockout mice. PCR analysis confirmed expression of non-neuronal α7nAChR in C57BL/6 (WT) mouse and human acinar cells. NNK treatment stimulated trypsinogen activation in acini from WT but not α7nAChR-/- mice. NNK also stimulated trypsinogen activation in human acini. To further confirm these findings, WT and α7nAChR-/- mice were treated with NNK in vivo and markers of pancreatitis were measured. As observed in acini NNK treatment induced trypsinogen activation in WT but not α7nAChR-/- mice. NNK also induced other markers of pancreatitis including pancreatic edema, vacuolization and pyknotic nuclei in WT but not α7nAChR-/- animals. NNK treatment led to increased neutrophil infiltration, a marker of inflammation, in WT mice and to a significantly lesser extent in α7nAChR-/- mice. We also examined downstream targets of α7nAChR activation and found that calcium and PKC activation are involved down stream of NNK stimulation of α7nAChR. In this study we used genetic deletion of the α7nAChR to confirm our previous inhibitor studies that demonstrated NNK stimulates pancreatitis by activating this receptor. Lastly, we demonstrate that NNK can also stimulate zymogen activation in human acinar cells and thus may play a role in human disease.
The current study represents the synthesis and characterization of new pyrazoline, pyrazoline-thiazolinone, and pyrazoline-thiazole-based derivatives, using 1-(4-aminophenyl)-3-substituted ...phenylprop-2-en-1-ones as the key intermediate precursors. In order to decrease the reaction times and boost the yields of the target compounds, microwave irradiation at 80°C was utilized to synthesize the pyrazoline and thiazolinone derivatives. All the new analogues were subjected to antimicrobial evaluation against different gram-positive, gram-negative bacteria and the pathogenic yeast
Candida albicans
. In addition, the docking simulation study of the thiazolinone and the thiazole derivatives against VEGFR-2 kinase was carried out in comparison with the ligand sorafenib. The results confirmed that the pyrazoline-thiazole compounds represented good stability and fixation within the active site of VEGFR-2 and could be considered basic scaffolds for the discovery of new promising anticancer compounds.
Preparation of ZnO (Z) and ZnO/Zn(OH)
2
(Z/ZH) specimens was carried out practicing a hydrothermal method. Z/ZH specimens were furnished by distinctive mass% of silver (1.0, 3.0, and 5.0 mass%) ...utilizing photoassisted deposition regime and the attained decorated specimens were designated as (Ag1-Z/ZH, Ag3-Z/ZH, and Ag5-Z/ZH, respectively). Band-gap energy of Z makes it absorb in ultraviolet region whiles, Z/ZH and Ag-Z/ZH specimens possess band gaps that permit them to absorb in visible region. Modifying of Z/ZH specimens by Ag diminishes band-gap magnitude from 3.30 to 2.82 eV and, at the same time, reduces the speed by which electrons and holes may recombine. The photocatalytic actions of Z, Z/ZH, and Ag-Z/ZH were figured out beneath Vis light via nitrobenzene–aniline transformation. The complete and successful transformation could be achieved utilizing Ag3-Z/ZH photocatalyst with the charging of 1.2 g/l photocatalyst after 0.5 h from the beginning of the photocatalytic reaction. In addition, it was found that Ag3-Z/ZH photocatalyst could be reused five times conserving its stability.
Academic study of cloud computing is an emerging research field in Saudi Arabia. Saudi Arabia represents the largest economy in the Arab Gulf region, which makes it a potential market of cloud ...computing technologies. This cross-sectional exploratory empirical research is based on technology–organization–environment (TOE) framework, targeting higher education institutions. In this study, the factors that affect the cloud adoption by higher education institutions were identified and tested using SmartPLS software, a powerful statistical analysis tool for structural equation modeling. Three factors were found significant in this context. Relative advantage, complexity and data concern were the most significant factors. The model explained 47.9 % of the total adoption variance. The findings offer education institutions and cloud computing service providers with better understanding of factors affecting the adoption of cloud computing.
Microstructural and magnetic properties of BaFe12-xNbxO19 (0.0 ≤ x ≤ 0.1) nanohexaferrites (NHFs) have been investigated intensively in this work. The Ba NHFs are synthesized through sol-gel ...auto-combustion route. The formation of single phase Ba NHFs, in different samples are confirmed by XRD powder patterns, scanning electron microscopy and Fourier Transform Infrared spectroscopy. The magnetic properties of BaFe12-xNbxO19 (0.0 ≤ x ≤ 0.1) NHFs were performed at room and low temperatures and discussed in detail. The analysis of hysteresis loops divulged that the different products display hard ferromagnetic behavior at different temperatures. The deduced values of saturation magnetization (Ms), remanence (Mr), magneton number (nB) and magneto crystalline anisotropy constant (Keff) are reduced for lower Nb content and then increased with further increasing the Nb content, reaching a maximum values for BaFe11.9Nb0.1O19 (x = 0.1) nanohexaferrite. The coercivity (Hc) and intrinsic coercivity (Hci) are diminished for lower x and are comparable to that of pristine one for higher x. The squareness ratio (Mr/Ms) are fluctuating between 0.50 and 0.55, implying the uniaxial anisotropy for different BaFe12-xNbxO19 nanohexaferrite.
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