Magnetic nanoparticles based on Fe3O4 and their modifications of surface with therapeutic substances are of great interest, especially drug delivery for cancer therapy includes boron-neutron capture ...therapy. The results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane iron oxide nanoparticles are presented. Energy-dispersive X-ray analysis and Fourier transform infrared spectroscopy with attenuated total reflection (ATR) accessory confirmed change of nanoparticles elemental content after modification and formation of new bond between Fe3O4 and attached molecules. Scanning and transmission electron microscopy showed that Fe3O4 nanoparticles average size is 18.9 nm. Phase parameters were investigated by powder X-ray diffraction, Fe3O4 nanoparticles magnetic behavior was evaluated by Mössbauer spectroscopy. Chemical and colloidal stability was studied using simulated body fluid (phosphate buffer – PBS). Modified nanoparticles have excellent stability in PBS (pH = 7.4), characterized by X-ray diffraction, Mössbauer spectroscopy and dynamic light scattering. Fe3O4 biocompatibility was elucidated in-vitro using cultured mouse embryonic fibroblasts. The obtained results show the increasing of IC50 from 0.110 mg/ml for Fe3O4 to 0.405 mg/ml for Fe3O4-Carborane nanoparticles. Obtained data confirm biocompatibility and stability of synthesized nanoparticles and potential to use them in boron-neutron capture therapy.
•Fe3O4 nanoparticles (NPs) with 18.9 nm average size were synthesized and modified with APTMS.•NPs were characterized using FTIR, SEM, TEM, XRD, DLS, Mössbauer spectroscopy and VSM methods.•Modified NPs have excellent stability in simulated body fluid.•Carborane borate with 21 boron atoms was immobilized on NPs through the ionic interaction.•Synthesized modifed NPs are excellent candidates for using in boron-neutron capture therapy.
In the presence of different cations, reactions of SbBr63− and I2 result in a new family of diverse supramolecular 1D polyiodide‐bromoantimonate networks. The coordination number of Sb, as well as ...geometry of assembling {Ix}n− polyhalide units, can vary, resulting in unprecedented structural types. The nature of I⋅⋅⋅Br interactions was studied by DFT calculations; estimated energy values are 1.6–6.9 kcal mol−1. Some of the compounds showed strong photoconductivity in thin films, suggesting multiple feasible applications in optoelectronics and solar energy conversion.
Photoconductive metal‐polyhalide hybrids: In the presence of different cations, reactions of SbBr63− and I2 result in a family of polyiodide‐bromoantimonate networks. The coordination number of Sb, as well as geometry of assembling {BrxIy}n− polyhalide units, varies, resulting in unprecedented structural types. Some of the compounds showed strong photoconductivity in thin films, suggesting multiple feasible applications in optoelectronics and solar energy conversion.
•Poly-Si films were first fabricated using a-SiOx via the inverted-ALILE on glass substrates.•The presence of oxygen in the system suppressed the formation Si hillocks in the bottom layer of the ...annealed structure.•The presence of a-SiOx residual layer in the structure of annealed sample.•The bottom layer consists of Al, Si, and O atoms mixture with Si nanocrystallites inclusions.•The poly-Si formed had a preferred (1 1 1) crystal orientation and an average crystallite size of 4.5 µm.
A novel fabrication method of polycrystalline silicon (poly-Si) films by aluminum-induced crystallization of amorphous silicon suboxide (a-SiO0.2) material via the inverted aluminum-induced layer exchange (ALILE) mechanism on glass substrates is presented. The presence of oxygen in the system prevented the formation of columnar crystalline Si precipitates (hillocks) in the bottom layer of the structure even at a process temperature of 550 °C. At the same time, this layer, consisting of Al, Si, and O atoms, contained nanocrystalline Si inclusions and a layer of initial a-SiOx with a thickness of about 60 nm, which was called the “a-SiOx residual layer”. The poly-Si formed had a preferred (1 1 1) crystal orientation and an average crystallite size of 4.5 µm.
Magnetic Fe₃O₄ nanoparticles (NPs) and their surface modification with therapeutic substances are of great interest, especially drug delivery for cancer therapy, including boron-neutron capture ...therapy (BNCT). In this paper, we present the results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane (APTMS) iron oxide NPs. Fourier transform infrared spectroscopy with Attenuated total reflectance accessory (ATR-FTIR) and energy-dispersive X-ray analysis confirmed the change of the element content of NPs after modification and formation of new bonds between Fe₃O₄ NPs and the attached molecules. Transmission (TEM) and scanning electron microscopy (SEM) showed Fe₃O₄ NPs' average size of 18.9 nm. Phase parameters were studied by powder X-ray diffraction (XRD), and the magnetic behavior of Fe₃O₄ NPs was elucidated by Mössbauer spectroscopy. The colloidal and chemical stability of NPs was studied using simulated body fluid (phosphate buffer-PBS). Modified NPs have shown excellent stability in PBS (pH = 7.4), characterized by XRD, Mössbauer spectroscopy, and dynamic light scattering (DLS). Biocompatibility was evaluated in-vitro using cultured mouse embryonic fibroblasts (MEFs). The results show us an increasing of IC
from 0.110 mg/mL for Fe₃O₄ NPs to 0.405 mg/mL for Fe₃O₄-Carborane NPs. The obtained data confirm the biocompatibility and stability of synthesized NPs and the potential to use them in BNCT.
Garnet phosphor Y
3
Al
5
O
12
:Ce
3+
is prepared in the Y
2
O
3
–Al metal–CeO
2
ternary system by the solid-state reaction method in the air. For the first time, metal Al is used as a source of ...aluminum for the reaction instead of traditional oxide Al
2
O
3
. It is shown that the chemical reaction can be realized at lower temperatures and without use of special reducing atmosphere. The structural and spectroscopic properties of the prepared powder phosphor are very close to those earlier reported for the Y
3
Al
5
O
12
:Ce
3+
single crystal.
Three problems for a discrete analog of the Helmholtz equation are studied analytically using the plane wave decomposition and the Sommerfeld integral approach. They are: (1) the problem with a point ...source on an entire plane; (2) the problem of diffraction by a Dirichlet half-line; (3) the problem of diffraction by a Dirichlet right angle. It is shown that the total field can be represented as an integral of an algebraic function over a contour drawn on some manifold. The latter is a torus. As a result, explicit solutions are obtained in terms of recursive relations (for the Green’s function), algebraic functions (for the half-line problem), or elliptic functions (for the right angle problem).
•Three problems for a discrete analog of the Helmholtz equation are studied.•The problem with a point source on an entire plane is studied.•The problem of diffraction by a Dirichlet half-line is studied.•The problem of diffraction by a Dirichlet right angle is studied.•The plane wave decomposition and the Sommerfeld integral approach are applied.•The solution is obtained in terms of the algebraic functions.
•Ni nanotubes (NTs) were synthesized using template method.•Ni-Au NTs were obtained by gold electroless deposition in alkali media.•Substrates of Ni-Au NTs with different concentration on surface ...were fabricated.•SERS properties of Ni-Au NTs are identified by example of Rhodamine 6G.
The paper describes the synthesis of substrate for surface enhanced Raman spectroscopy (SERS) based on magnetic nickel nanotubes (Ni NTs). For the success application of Ni NTs in quantitative SERS analysis of organic molecules by the example of Rhodamine 6G (R6G), electroless deposition of gold (I) on Ni NTs in alkali media was performed. The purity and uniformity of the gold layer has been proven by methods of XRD, SEM-EDX, XPS and FTIR analysis. The magnetic properties of the obtained magnetic Ni-Au NTs measured by VMS did not change compared to the initial Ni nanotubes. The efficiency of substrates with Ni-Au NTs is determined by the optical properties of the substrate (the position of the plasmon resonance peak). The substrates with scattered nanotubes having a plasmon resonance position at 530 nm are the most effective for use in SERS when using a laser with a wavelength of 532 nm, as exemplified by the spectra of Radomin 6G. SERS analysis of R6G using Ni-Au NTs in concentration range from 10−3 to 10−8 led to average enhancement factor of 8∙105.
In this article, NiFe2O4 nanoparticles (NPs) were prepared by co-precipitation method with subsequent thermal annealing leading to obtainment NPs with average sizes of 78 nm. Structure and magnetic ...analysis were performed by X-ray diffraction, transmission electron microscopy, Mössbauer spectroscopy and vibrating sample magnetometry techniques. Stability of NiFe2O4 NPs was evaluated in PBS solution during 20 days. The toxicity of prepared NPs was evaluated in vitro using different cancer cell lines: HeLa (cervical cancer cell), PC-3 (prostate cancer cell). Fibroblasts like cells of L929 obtained from subcutaneous adipose tissue of mouse were used as normal cells. Results indicate successful synthesis of NiFe2O4 NPs that exhibit low cytotoxicity in concentration range from 1 to 100 μg/ml. Presented physical and biological results indicate the possibility of application investigated magnetic nanoparticles in hyperthermia, targeted drug delivery, magnetic resonance imaging or cell separation.
In this article, a novel method of simultaneous carborane- and gadolinium-containing compounds as efficient agents for neutron capture therapy (NCT) delivery via magnetic nanocarriers is presented. ...The presence of both Gd and B increases the efficiency of NCT and using nanocarriers enhances selectivity. These factors make NCT not only efficient, but also safe. Superparamagnetic Fe3O4 nanoparticles were treated with silane and then the polyelectrolytic layer was formed for further immobilization of NCT agents. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), ultraviolet–visible (UV-Vis) and Mössbauer spectroscopies, dynamic light scattering (DLS), scanning electron microscopy (SEM), vibrating-sample magnetometry (VSM) were applied for the characterization of the chemical and element composition, structure, morphology and magnetic properties of nanocarriers. The cytotoxicity effect was evaluated on different cell lines: BxPC-3, PC-3 MCF-7, HepG2 and L929, human skin fibroblasts as normal cells. average size of nanoparticles is 110 nm; magnetization at 1T and coercivity is 43.1 emu/g and 8.1, respectively; the amount of B is 0.077 mg/g and the amount of Gd is 0.632 mg/g. Successful immobilization of NCT agents, their low cytotoxicity against normal cells and selective cytotoxicity against cancer cells as well as the superparamagnetic properties of nanocarriers were confirmed by analyses above.
A Riemann surface of a dispersion diagram of a multilayer planar waveguide is studied. Structure of this surface is linked with the transient wave phenomena in the waveguide. A method is proposed to ...study the dispersion diagram. The method is constituted in introducing of an artificial parameter controlling the links between the layers of the waveguide. The strength of the links varies from the full isolation to the realistic physical contact. The dependence of the solution on the artificial parameter is analytical. Using this approach it is proven that the branch points of the Riemann surface can be listed as the crossing points of the branches of non-interacting layers. A numerical procedure of finding the branch points positions is described. An explanation of the types of waves corresponding to different parts of the Riemann surface of the dispersion diagram is given.
•Precursors in a three-layer acoustic waveguide are studied using an analytical continuation of the dispersion diagram.•The structure of the Riemann surface of the dispersion diagram is revealed.•A numerical procedure for finding the branch point of the dispersion diagram is proposed.
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