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1.
Pharmaceutics ; 16(5)2024 May 07.
Article in English | MEDLINE | ID: mdl-38794285

ABSTRACT

GW501516, also known by the name of cardarine, is a synthetic peroxisome-proliferator-activated receptor delta (PPR-δ) agonist agent developed for applications in the treatment of metabolic disorders and cardiovascular diseases. A broad polymorph screening in various solvents and mixtures was completed in order to explore its capabilities to grow polymorphs. The crystal structures of four polymorphs were elucidated using single-crystal X-ray diffraction, while one structure was solved via a powder X-ray diffraction method. The solid state features (nature of intermolecular interactions) were investigated by computational methods. The polymorphs were further investigated by thermal DSC analysis and X-ray diffraction on powders. From a pharmaceutical perspective, the stability and solubility of the polymorphs were analyzed as well.

2.
Molecules ; 28(20)2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37894658

ABSTRACT

Nandrolone (Estr-4-en-17ß-ol-3-one) is a derivative of testosterone and a naturally occurring anabolic-androgenic agent which belongs to the steroid group. Crystal structures of four short, medium and long esterified forms of nandrolone, including propionate, phenylpropionate, cypionate and undecanoate were determined using single-crystal X-ray diffraction. Crystal packing, supramolecular features and intermolecular interactions were described based on a quantitative and qualitative Hirshfeld surfaces analysis accompanied by evaluation of crystal energies and intermolecular interactions computation. Also, the solubility of the esters was investigated from a pharmaceutical perspective.

3.
Materials (Basel) ; 16(17)2023 Aug 24.
Article in English | MEDLINE | ID: mdl-37687501

ABSTRACT

Several forged 3-Polker coins have been reported in historical sources on the financial crisis that occurred between 1619 and 1623 at the start of the 30-year-long war. Supposedly, belligerent countries forged other countries' coins which were then used for external payments as a war strategy. Thus, a lot of 3-Polker coins (e.g., Sigismund-III-type) were forged, and the markets became flooded with poor currency. In the present day, these pre-modern forgeries are rare archeological findings. Only five forged 3-Polker coins randomly found in Transylvania were available for the current study. There are deeper implications of silver and tin in the forgery techniques that need to be considered. Thus, the forged 3-Polker coins were investigated via nondestructive methods: SEM microscopy coupled with EDS elemental spectroscopy for complex microstructural characterization and XRD for phase identification. Three distinct types of forgery methods were identified: the amalgam method is the first used for copper blank silvering (1620), and immersion in melted silver (1621) is the second one. Both methods were used to forge coins with proper legends and inscriptions. The third method is the tin plating of copper coins (with corrupted legend and altered design) (1622, 1623, and 1624). The EDS investigation revealed Hg traces inside the compact silver crusts for the first type and the elongated silver crystallites in the immersion direction, which are well-attached to the copper core for the second type. The third forgery type has a rich tin plating with the superficial formation of Cu6Sn5 compound that assures a good resistance of the coating layer. Therefore, this type should have been easily recognized as fake by traders, while the first two types require proper weighing and margin clipping to ensure their quality.

4.
Int J Mol Sci ; 24(18)2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37762121

ABSTRACT

The discovery of a new non-toxic metal complex with biological activity represents a very active area of research. Two Cu+2 complexes, [Cu4(L1)4(OH)4(DMF)2(H2O)] (C1) (HL1 = N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)-benzenesulfonamide) and [Cu(L2)2(phen)(H2O)] (C2) (HL2 = N-(5-(4-methylphenyl)-[1,3,4]-thiadiazole-2-yl)-naphtalenesulfonamide), with two new ligands were synthesized. The X-ray crystal structures of the complexes were determined. In both complexes, Cu+2 is five-coordinated, forming a CuN2O3 and CuN4O chromophore, respectively. The ligands act as monodentate, coordinating the metal ion through a single Nthiadiazole atom; for the two complexes, the molecules from the reaction medium (phenantroline, dimethylformamide and water) are also involved in the coordination of Cu+2. The complexes have a distorted square pyramidal square-planar geometry. The compounds were characterized by FT-IR and UV-Vis spectroscopy. Using the microdilution method, the antibacterial activity of the complexes was determined against four Gram-positive and two Gram-negative bacteria, with Gentamicin as the positive control. Cytotoxicity studies were carried out on two tumor cell lines (HeLa, DLD-1) and on a normal cell line (HFL1) using the MTT method and Cisplatin as a positive control. Flow cytometric assessment of apoptosis induced by the complexes on the three cell lines was also performed. Both complexes present in vitro biological activities but complex C2 is more active.

5.
Pharmaceuticals (Basel) ; 16(8)2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37630976

ABSTRACT

The present study aimed to develop 3D printed dosage forms, using custom-made filaments loaded with diclofenac sodium (DS). The printed tablets were developed by implementing a quality by design (QbD) approach. Filaments with adequate FDM 3D printing characteristics were produced via hot melt extrusion (HME). Their formulation included DS as active substance, polyvinyl alcohol (PVA) as a polymer, different types of plasticisers (mannitol, erythritol, isomalt, maltodextrin and PEG) and superdisintegrants (crospovidone and croscarmellose sodium). The physicochemical and mechanical properties of the extruded filaments were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD) and tensile measurements. In addition, cylindrical-shaped and tubular-shaped 3D dosage forms were printed, and their dissolution behaviour was assessed via various drug release kinetic models. DSC and XRD results demonstrated the amorphous dispersion of DS into the polymeric filaments. Moreover, the 3D printed tablets, regardless of their composition, exhibited a DS release of nearly 90% after 45 min at pH 6.8, while their release behaviour was effectively described by the Korsmeyer-Peppas model. Notably, the novel tube design, which was anticipated to increase the drug release rate, proved the opposite based on the in vitro dissolution study results. Additionally, the use of crospovidone increased DS release rate, whereas croscarmellose sodium decreased it.

6.
Materials (Basel) ; 16(7)2023 Mar 26.
Article in English | MEDLINE | ID: mdl-37048922

ABSTRACT

Methods for material investigation are powerful tools that allow specialists to elucidate important aspects regarding ancient artifacts such as the Roman amphorae deposits discovered at Potaissa Fortress in Turda, Romania. Archeological debate states that the deposit contained olive oil and wine amphorae, but no material evidence has been presented until now. The current research is focused on the most representative large amphora fragments found in the Potaissa deposit, with a significant amount of sediment on their walls, to give archeologists the material proof to elucidate their debate. Sediment was collected from each fragment and subjected to complex analysis. XRD investigation combined with cross-polarized light microscopy demonstrated mineral particles such as quartz, clay (muscovite and traces of biotite), and calcite. Quartz and calcite particles have a rounded shape and diameters in a range of 20-200 µm, and clay particles have a lamellar shape and dimensions from 1 to 20 µm, a fact confirmed by SEM microscopy. Sample 2 presented a large amount of amorphous phase followed by Samples 1 and 3, with a low amount of organic phase. FTIR investigation confirms organic phase presence owing to strong absorption bands regarding C-H, C=O, and O-H chemical bonds related to aliphatic compounds in Sample 2, and to some decayed wine residue in Samples 1 and 3. EDS elemental analysis was used for organic particle identification in the amphora sediments and to obtain a correlation with their microstructure. GC-MS investigation showed volatile compounds related to wine residue for Samples 1 and 3 and decomposed fats for Sample 2. Tartaric and malic acid were identified by HPLC in Samples 1 and 3, which are wine biomarkers. The correlation of all experimental results concludes with no doubt that Amphora 2 contained olive oil and Amphorae 1 and 3 contained wine in ancient times.

7.
Molecules ; 28(7)2023 Mar 30.
Article in English | MEDLINE | ID: mdl-37049860

ABSTRACT

Testosterone (17ß-Hydroxyandrost-4-en-3-one) is the primary male anabolic-androgenic steroid. The crystal structures of two medium and two long esterified forms of testosterone, including enanthate, cypionate, decanoate and undecanoate, were determined by X-ray single crystal diffraction. The samples were also characterized by powder X-ray diffraction, FT-IR spectroscopy and thermal analysis (DTA, TG). Crystal packings and supramolecular features were described. The analysis of structural features was accomplished by computational methods in terms of the type of intermolecular interactions, crystal energies and Hirshfeld surfaces analysis. From a pharmaceutical point of view, the solubility of compounds was investigated.

8.
Int J Mol Sci ; 24(8)2023 Apr 17.
Article in English | MEDLINE | ID: mdl-37108531

ABSTRACT

The aim of this study was to prepare and characterize the glasses made of x(Fe2O3∙V2O5)∙(100 - x)[P2O5∙CaO] with x ranging of 0-50%. The contribution of Fe2O3 and V2O5 amount on the structure of P2O5·CaO matrix was investigated. The vitreous materials were characterized by XRD (X-ray diffraction analysis), EPR (Electron Paramagnetic Resonance) spectroscopy, and magnetic susceptibility measurements. A hyperfine structure typical for isolated V4+ ions was noticed to all spectra containing low amount of V2O5. The XRD spectra show the amorphous nature of samples, apart x = 50%. An overlap of the EPR spectrum of a broad line without the hyperfine structure characteristic of clustered ions was observed with increasing V2O5 content. The results of magnetic susceptibility measurements explain the antiferromagnetic or ferromagnetic interactions expressed between the iron and vanadium ions in the investigated glass.


Subject(s)
Iron , Vanadium , Vanadium/chemistry , Calcium/chemistry , Calcium Phosphates/chemistry , Magnetic Phenomena , Glass/chemistry
9.
Pharmaceutics ; 15(2)2023 Feb 08.
Article in English | MEDLINE | ID: mdl-36839899

ABSTRACT

Mucoadhesive films loaded with doxycycline hyclate (Doxy Hyc), consisting of mixtures of hydroxypropylmethyl cellulose (HPMC) E3, K4 and polyacrylic acid (Carbopol 940), were prepared by casting method, aiming to design a formulation intended for application in the oral cavity. The obtained film formulations exhibited a Doxy Hyc content between 7.52 ± 0.42 and 7.83 ± 0.41%, which had adequate mechanical properties for application in the oral cavity and pH values in the tolerance range. The x-ray diffraction studies highlighted the amorphisation of Doxy Hyc in the preparation process and the antibiotic particles present on the surface of the films, identified in the TEM images, which ensured a burst release effect in the first 15 min of the in vitro dissolution studies, after which Doxy Hyc was released by diffusion, the data presenting a good correlation with the Peppas model, n < 0.5. The formulation F1, consisting of HPMC K4 combined with C940 in a ratio of 5:3, the most performing in vitro, was tested in vivo in experimentally-induced periodontitis and demonstrated its effectiveness in improving the clinical parameters and reducing the salivary levels of matrix metalloproteinase-8 (MMP-8). The prepared Doxy Hyc loaded mucoadhesive buccal film could be used as an adjuvant for the local treatment of periodontitis, ensuring prolonged release of the antibiotic after topical application.

10.
Polymers (Basel) ; 15(23)2023 Nov 21.
Article in English | MEDLINE | ID: mdl-38231889

ABSTRACT

Poly(tartaric acid) is a relatively recently described polymer that can be easily synthesized and scaled up from a readily available renewable material (tartaric acid). This article demonstrates its use in a green synthesis of gold nanoparticles, silver nanoparticles, copper particles, and magnetite nanoparticles. In this case poly(tartaric acid) acts both as a reductant and as a coating agent. To our knowledge this is the first green synthesis of several different types of nanoparticles using only one reagent (polytartrate) as both reductant and coating. The resulting particles were analyzed by XRD, TEM/SEM, EDX, FTIR, DLS, zeta-potential, XPS, and UV/VIS spectroscopy. Preliminary studies of the thermal behavior of mixtures of different types of particles with poly(tartaric acid) were also conducted. The obtained particles show different sizes depending on the material, and the coating allows for better dispersibility as well as potential further functionalization, making them potentially useful also for other applications, besides the inclusion in polymer composites.

11.
Materials (Basel) ; 15(21)2022 Oct 26.
Article in English | MEDLINE | ID: mdl-36363103

ABSTRACT

The present research is focused on the 3-Polker coins issued during 1619-1627 by Sigismund III Vasa, King of Poland. A major financial crisis took place at that time due to the 30-year War, which started in 1619. There are two theories among historians concerning the silver depreciation of these coins. The most common theory (generally accepted without proof) is that the later years of issue are depreciated below 60% Ag. The second theory is based on the medieval sources that indicate inflation during the years from 1621-1625, but the medieval source only refers to the inflation of the type of coins and does not mention the issuer. Therefore, in this study, we use modern investigation techniques and materials science methods to help historians elucidate the aforementioned aspects regarding the medieval period. The XRD investigation results are in good agreement with the SEM-EDX elemental analysis. The coins from 1619 and 1620 have high silver content, namely, 86.97% and 92.49%, which corresponds to good silver. The amount of Ag found in the coins from 1621-1625 issituated in the range of 63.2-74.6%. The silver titleis suddenly restored in 1626 at about 84.3% and is kept in a good range until the end of this decree under Sigismund III in 1627. In conclusion, the second theory was partly validated by our experimental results, certifying the currency depreciation during 1621-1625, but the silver title was not lower than 54.2%. Notably, even this depreciated silver title assures a good quality of the 3-Polker coins compared to similar coins issued in other countries that were copper-silver-plated. Therefore, the 3-Polker coins were preferably hoarded at that time.Small alterations in the mint mark's design were observed in all the depreciated coins compared to the good ones. This might be a sign for an expert to identify the depreciated coins, a fact which requires supplementary investigations. The silver title's restoration in 1626 also came with a complete change of the mintmark.

12.
Materials (Basel) ; 15(20)2022 Oct 17.
Article in English | MEDLINE | ID: mdl-36295310

ABSTRACT

Testosterone (17ß-hydroxyandrost-4-en-3-one) is the primary naturally occurring anabolic-androgenic steroid. The crystal structures of three short esterified forms of testosterone, including propionate, phenylpropionate, and isocaproate ester, were determined via single-crystal X-ray diffraction. Furthermore, all the samples were investigated using powder X-ray diffraction, and their structural features were described and evaluated in terms of crystal energies and Hirshfeld surfaces. They were also compared with the base form of testosterone (without ester) and the acetate ester. Moreover, from a pharmaceutical perspective, their solubility was evaluated and correlated with the length of the ester.

13.
Nanomaterials (Basel) ; 12(17)2022 Aug 30.
Article in English | MEDLINE | ID: mdl-36080044

ABSTRACT

In this study the adsorption and photodegradation capabilities of modified multi-walled carbon nanotubes (MWCNTs), using tartrazine as a model pollutant, is demonstrated. MWCNT-COOH/Fe3O4 and MWCNT-COOH/Fe3O4/NiO nanocomposites were prepared by precipitation of metal oxides in the presence of MWCNTs. Their properties were examined by X-ray diffraction in powder (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, synchrotron-based Scanning PhotoElectron Microscopy (SPEM), and Brunauer-Emmett-Teller (BET) analysis. It was found that the optimal adsorption conditions were pH 4 for MWCNT-COOH/Fe3O4 and pH 3 for MWCNT-COOH/Fe3O4/NiO, temperature 25 °C, adsorbent dose 1 g L-1, initial concentration of tartrazine 5 mg L-1 for MWCNT-COOH/Fe3O4 and 10 mg L-1 for MWCNT-COOH/Fe3O4/NiO and contact time 5 min for MWCNT-COOH/Fe3O4/NiO and 15 min for MWCNT-COOH/Fe3O4. Moreover, the predominant degradation process was elucidated simultaneously, with and without simulated sunlight irradiation, using thermal lens spectrometry (TLS) and UV-Vis absorption spectrophotometry. The results indicated the prevalence of the photodegradation mechanism over adsorption from the beginning of the degradation process.

14.
Acta Crystallogr C Struct Chem ; 78(Pt 5): 305-313, 2022 05 01.
Article in English | MEDLINE | ID: mdl-35510437

ABSTRACT

4-Chloro-17ß-hydroxy-17α-methylandrosta-1,4-dien-3-one (C20H27ClO2), known as turinabol, is a synthetic anabolic-androgenic agent which belongs to the steroid class. Recrystallization from various solvents was performed and the following new solid forms of turinabol were obtained: the hemihydrate (C20H27ClO2·0.5H2O), the anhydrous form (C20H27ClO2), the multicomponent acetic acid hydrate (2C20H27ClO2·C2H4O2·H2O) and the 2,2,2-trifluoroethanol hemisolvate (C20H27ClO2·0.5C2H3F3O). The absolute structures were determined by single-crystal X-ray diffraction. The starting hemihydrate form contains one turinabol molecule in the asymmetric unit, while the others contain two molecules in the asymmetric unit. Structural features were investigated in terms of the conformational analysis of the steroid skeleton rings and intermolecular interactions. The magnitudes, the nature of the crystal structure energies and the intermolecular interactions were also evaluated. Complexation with ß-cyclodextrin was performed and the obtained complex was investigated using powder X-ray diffraction, Fourier-transform infrared (FT-IR) spectroscopy and differential thermal analysis/thermogravimetric analysis (DTA/TGA).


Subject(s)
Steroids , beta-Cyclodextrins , Crystallography, X-Ray , Hydrogen Bonding , Spectroscopy, Fourier Transform Infrared , Steroids/chemistry , Testosterone/analogs & derivatives , X-Ray Diffraction
15.
Molecules ; 27(10)2022 May 23.
Article in English | MEDLINE | ID: mdl-35630815

ABSTRACT

Nowadays, the discovery of a new non-toxic metal complex with biological activity represents a very active area of research. Two Cu+2 complexes, [Cu(L1)2(H2O)3] (C1) (HL1= N-(5-(4-methylphenyl)-[1,3,4]-thiadiazole-2-yl)-naphtalenesulfonamide) and [Cu(L2)2(py)2(H2O)] (C2) (HL2= N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)-naphtalenesulfonamide), with two new ligands were synthesized. The X-ray crystal structures of the complexes were determined. In both complexes, Cu+2 is five-coordinated, forming a CuN2O3 and CuN4O chromophore, respectively. The ligands act as monodentate, coordinating the metal ion through a single Nthiadiazole atom; for the C2 complex, the molecules from the reaction medium (pyridine and water) are also involved in the coordination of Cu+2. The complexes have a distorted square pyramidal square-planar geometry. The compounds were characterized by FT-IR, electronic EPR spectroscopy, and magnetic methods. The nuclease activity studies confirm the complexes' capacity to cleave the DNA molecule. Using a xanthine-xanthine oxydase system, the SOD mimetic activity of the complexes was demonstrated. Cytotoxicity studies were carried out on two tumor cell lines (HeLa, WM35) and on a normal cell line (HFL1) using the MTT method, with cisplatin used as a positive control. The antibacterial activity of the complexes was investigated against two Gram-positive and two Gram-negative bacteria, and compared with Amoxicillin and Norfloxacin using the disk diffusion method. Both complexes showed in vitro biological activity but the C2 complex was more active. A lack of in vivo toxicity was demonstrated for the C2 complex by performing hepatic, renal, and hematological studies on Swiss mice.


Subject(s)
Antioxidants , Thiadiazoles , Animals , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Copper/chemistry , Ligands , Mice , Spectroscopy, Fourier Transform Infrared , Sulfanilamide , Sulfonamides/chemistry , Sulfonamides/pharmacology , Xanthines
16.
Materials (Basel) ; 15(9)2022 Apr 22.
Article in English | MEDLINE | ID: mdl-35591388

ABSTRACT

This study presents the correct processing of Co-Cr alloys as a method of preserving the properties of the materials as-cast, and therefore they can be safely placed in contact with the oral cavity tissues as resistance frameworks. The basic materials analyzed in this study were five commercial Co-Cr dental alloys with different components obtained in three processing steps. The analysis of the electrochemical behavior at the surface of the Co-Cr alloys was performed by electrochemical measurements: impedance spectroscopy (EIS), open circuit electrical potential (OCP), and linear polarization (LP). In terms of validation, all five alloys had a tendency to generate a stable oxide layer at the surface. After the measurements and the graphical representation, the alloy that had a higher percentage of tungsten (W) and iron (Fe) in composition showed a higher tendency of anodizing. After the application of the heat treatment, the disappearance of the hexagonal phase was observed, with the appearance of new phases of type (A,B)2O3 corresponding to some oxide compounds, such as Fe2O3, Cr2O3, (Cr,Fe)2O3, and CoMnO3. In conclusion, the processing of Co-Cr alloys by melting and casting in refractory molds remains a viable method that can support innovation, in the context of technology advance in recent years towards digitalization of the manufacturing process, i.e., the construction of prosthetic frameworks conducted by additive methods using Co-Cr powder alloy.

17.
Adv Sci (Weinh) ; 9(22): e2200924, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35619333

ABSTRACT

Sodium and iron make up the perfect combination for the growing demand for sustainable energy storage systems, given the natural abundance and sustainability of the two building block elements. However, most sodium-iron electrode chemistries are plagued by intrinsic low energy densities with continuous ongoing efforts to solve this. Herein, the chemical space of a series of (meta)stable, off-stoichiometric Fe-PO4 -F phases is analyzed. Some are found to display markedly improved electrochemical activity for sodium storage, as compared to the amorphous or thermodynamically stable phases of equivalent composition. The metastable crystalline Na1.2 Fe1.2 PO4 F0.6 delivers a reversible capacity of more than 140 mAh g-1 with an average discharge potential of 2.9 V (vs Na+ /Na0 ) resulting in a practical specific energy density of 400 Wh kg-1 (estimated at the material level), outperforming many developed Fe-PO4 analogs thus far, with further multiple possibilities to be explored toward improved energy storage metrics. Overall, this study unlocks the possibilities of off-stoichiometric Fe-PO4 -F cathode materials and reveals the importance to explore the oft-overlooked metastable or transient state materials for energy storage.

18.
Acta Crystallogr C Struct Chem ; 78(Pt 4): 240-249, 2022 04 01.
Article in English | MEDLINE | ID: mdl-35380127

ABSTRACT

Seven solvates of the angiotensin II receptor blocker agent olmesartan (C24H26N6O3), namely, the methanol (C24H26N6O3·CH4O), ethanol (C24H26N6O3·C2H6O), isopropanol (C24H26N6O3·C3H8O), isobutanol (C24H26N6O3·C4H10O), 2-ethoxyethanol (C24H26N6O3·C4H10O2), chloroform (C24H26N6O3·CHCl3) and acetonitrile (C24H26N6O3·C2H3N) solvates, were successfully obtained. The crystal structures were determined using the single-crystal X-ray diffraction technique and the structural features are described, each solvate containing one molecule of olmesartan and one of solvent in the asymmetric unit. The samples were also analyzed by powder X-ray diffraction. Total lattice energies and binding energies between the olmesartan and solvent molecules were evaluated, which can be partitioned into electrostatic, polarization, dispersion and repulsion components. Hirshfeld and fingerprint plot analysis was performed to highlight the intermolecular contacts. Hydrogen bonding and supramolecular arrangements were comparatively studied for the seven solvates.


Subject(s)
Tetrazoles , Crystallography, X-Ray , Hydrogen Bonding , Imidazoles , Models, Molecular
19.
Nanomaterials (Basel) ; 11(12)2021 Dec 16.
Article in English | MEDLINE | ID: mdl-34947760

ABSTRACT

The present work aims to follow the influence of TiO2 nanoparticles (TiO2 NPs) on bioactive compounds, the elemental content of wheat, and on wheat leaves' ultrastructure. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and transmission electron microscopy (TEM). The concentration of phenolic compounds, assimilation pigments, antioxidant capacity, elemental content, as well as the ultrastructural changes that may occur in the wheat plants grown in the presence or absence of TiO2 NPs were evaluated. In plants grown in the presence of TiO2 NPs, the amount of assimilating pigments and total polyphenols decreased compared to the control sample, while the antioxidant activity of plants grown in amended soil was higher than those grown in control soil. Following ultrastructural analysis, no significant changes were observed in the leaves of TiO2-treated plants. Application of TiO2 NPs to soil caused a significant reaction of the plant to stress conditions. This was revealed by the increase of antioxidant capacity and the decrease of chlorophyll, total polyphenols, and carotenoids. Besides, the application of TiO2 NPs led to significant positive (K, Zn, Br, and Mo) and negative (Na, Mn, Fe, As, Sr, Sb, and Ba) variation of content.

20.
Nanomaterials (Basel) ; 11(12)2021 Dec 20.
Article in English | MEDLINE | ID: mdl-34947806

ABSTRACT

The structure, morphology and magnetic properties of (Ni0.6Mn0.4Fe2O4)α(SiO2)100-α (α = 0-100%) nanocomposites (NCs) produced by sol-gel synthesis were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and vibrating sample magnetometry (VSM). At low calcination temperatures (300 °C), poorly crystallized Ni0.6Mn0.4Fe2O4, while at high calcination temperatures, well-crystallized Ni0.6Mn0.4Fe2O4 was obtained along with α-Fe2O3, quartz, cristobalite or iron silicate secondary phase, depending on the Ni0.6Mn0.4Fe2O4 content in the NCs. The average crystallite size increases from 2.6 to 74.5 nm with the increase of calcination temperature and ferrite content embedded in the SiO2 matrix. The saturation magnetization (Ms) enhances from 2.5 to 80.5 emu/g, the remanent magnetization (MR) from 0.68 to 12.6 emu/g and the coercive field (HC) from 126 to 260 Oe with increasing of Ni0.6Mn0.4Fe2O4 content in the NCs. The SiO2 matrix has a diamagnetic behavior with a minor ferromagnetic fraction, Ni0.6Mn0.4Fe2O4 embedded in SiO2 matrix displays superparamagnetic behavior, while unembedded Ni0.6Mn0.4Fe2O4 has a high-quality ferromagnetic behavior.

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