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Titanium oxide (TiO2) and oxynitride (N-TiO2) coatings can increase nitinol stents' cytocompatibility with endothelial cells. Methods of TiO2 and N-TiO2 sputtering and cytocompatibility assessments vary significantly among different research groups, making it difficult to compare results. The aim of this work was to develop an integral cytocompatibility index (ICI) and a decision tree algorithm (DTA) using the "EA.hy926 cell/TiO2 or N-TiO2 coating" model and to determine the optimal cytocompatible coating. Magnetron sputtering was performed in a reaction gas medium with various N2:O2 ratios and bias voltages. The samples' morphology was studied by scanning electron microscopy (SEM) and Raman spectroscopy. The cytocompatibility of the coatings was evaluated in terms of their cytotoxicity, adhesion, viability, and NO production. The ICI and DTA were developed to assess the cytocompatibility of the samples. Both algorithms demonstrated the best cytocompatibility for the sample sputtered at Ubias = 0 V and a gas ratio of N2:O2 = 2:1, in which the rutile phase dominated. The DTA provided more detailed information about the cytocompatibility, which depended on the sputtering mode, surface morphology, and crystalline phase. The proposed mathematical models relate the cytocompatibility and the studied physical characteristics. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is used for studying the composition of cell lipidome. However, the Raman approach suffers from limited distinguish power for different lipids. In recent years, isotopically labeled molecules are increasingly used to enhance the Raman resolution of similar compounds in biological samples. Here, we present Raman study of fully deuterated stearic acid (stearic‐d35), semi‐deuterated oleic acid (oleic d‐9), arachidonic acid with deuterated methine groups (arachidonic‐d8), and their hydrogenated analogs. Polarization properties and temperature dependences of CD stretching modes were investigated to reveal the capability of the isotopically shifted Raman peaks in molecular characterization. Sensitivity of Raman peaks to order–disorder transition corresponding was demonstrated for deuterated methine, methylene, and methyl groups. It was found that the isotopically shifted Raman peaks provide information about the orientation of deuterated Raman tags and their surroundings. Highlights: The assignments for Raman peaks at 1150 and 992 cm−1 of deuterated hydrocarbons are verified.Polarized Raman spectra for crystalline deuterated stearic acid are investigated.Polarization dependence of ═CD, CD2, and CD3 Raman peaks is studied.Temperature dependences for deuterated ═CD, CD2, and CD3 Raman peaks were measured.Sensitivity of ═CD, CD2, and CD3 modes to the phase transitions is analyzed. [ABSTRACT FROM AUTHOR]

Brillouin scattering by anisotropic Langmuir–Blodgett (LB) films is studied here. The films are composed of behenic acid doped with CdS and CuS nanocrystals distributed in the matrix of the behenic acid. The sound velocities along and perpendicular to the film surface are determined. The influence of nanocrystals on the LB film anisotropy and sound velocities is discussed. The Langmuir–Blodgett film composed of behenic acid molecules reveals anisotropic elastic properties for the sound waves propagated along and perpendicular to the film surface. Semiconductor nanocrystals embedded in the films reduce the anisotropy and change the elastic properties of the system. [ABSTRACT FROM AUTHOR]

Binary phospholipid bilayers composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine and 1,2-palmitoyl-sn-glycero-3-phosphocholine (DPPC) were studied by Raman spectroscopy and differential scanning calorimetry (DSC). We examined features in Raman scattering spectra that are sensitive to the lipid phase and, therefore, could indicate the phase coexistence. It was found that the low-frequency half-width of half-maximum (LHWHM) of the 2850 cm−1 Raman line, corresponding to the symmetric CH2 stretching vibrations, unequivocally reveals the coexisting phospholipids in ordered and disordered conformational states, which correspond to ordered and disordered phases coexistence, in the DPPC mole concentration range from 0.4 to 0.9. The phase coexistence in this concentration range was supported by the particular concentration behavior of the ratio between the intensities of the 2880 cm−1 antisymmetric CH2 vibration line and the 2850 cm−1 symmetric one. It was also shown that the spectral shape of the 1300 cm−1 Raman line, corresponding to the CH2 twisting vibrations, is a good indicator for the phase state and phase coexistence in the phospholipid bilayers. Comparison with the DSC curves confirmed that in the DPPC mole concentration range from 0.4 to 0.9, the two phase transition peaks are observed in DSC curve, those positions are independent of the DPPC concentration. The outcome of the study is the robust label-free contactless approach for the detection of the lipid phase separation, which can be realized with the micrometer resolution. [ABSTRACT FROM AUTHOR]

The Ba 2 Na 3 [B 3 O 6 ] 2 F single crystals of optical quality were grown. Raman, optical absorption and luminescence spectra of pure and neodymium-doped Ba 2 Na 3 [B 3 O 6 ] 2 F crystals were studied. Besides a broad band emission near 330 nm associated with native defects, the features related to 4f 3 →4f 3 transitions in the Nd 3+ ions were found both in absorption and luminescence. Ba 2 + replacement by Nd 3+ ion in the Ba 2 Na 3 [B 3 O 6 ] 2 F lattice was established to reduce the symmetry of oxygen surrounding. Na presence in the structure was found to facilitate the Rare Earth impurity incorporation, supposedly because of Na-assisted charge compensation. [ABSTRACT FROM AUTHOR]

K[AsW2O9], prepared by high-temperature solid-state reaction, is the first member of the arsenate–tungsten bronze family. The structure of K[AsW2O9] is based on a 3-dimensional (3D) oxotungstate–arsenate framework with the non-centrosymmetric P212121 space group, a=4.9747(3)Å, b=9.1780(8) Å, c=16.681(2) Å. The material was characterized using X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Raman and infrared (IR) spectroscopic techniques. The results of DSC demonstrate that this phase is stable up to 1076K. Second harmonic generation (SHG) measurements performed on a powder sample demonstrate noticeable (0.1 of LiIO3) non-linear optical (NLO) activity. [ABSTRACT FROM AUTHOR]

Cell-based therapies using corneal stromal stem cells (CSSC), corneal keratocytes, or a combination of both suppress corneal scarring. The number of quiescent keratocytes in the cornea is small; it is difficult to expand them in vitro in quantities suitable for transplantation. This study examined the therapeutic effect of corneal fibroblasts reversed into keratocytes (rCF) in a mouse model of mechanical corneal injury. The therapeutic effect of rCF was studied in vivo (slit lamp, optical coherence tomography) and ex vivo (transmission electron microscopy and immunofluorescence staining). Injection of rCF into the injured cornea was accompanied by recovery of corneal thickness, improvement of corneal transparency, reduction of type III collagen in the stroma, absence of myofibroblasts, and the improvement in the structural organization of collagen fibers. TEM results showed that 2 months after intrastromal injection of cells, there was a decrease in the fibril density and an increase in the fibril diameter and the average distance between collagen fibrils. The fibrils were well ordered and maintained the short-range order and the number of nearest-neighbor fibrils, although the averaged distance between them increased. Our results demonstrated that the cell therapy of rCF from ReLEx SMILe lenticules promotes the recovery of transparent corneal stroma after injury.

The phase relations in the subsolidus region of the Tl 2 MoO 4 -Bi 2 (MoO 4 ) 3 -Hf(MoO 4 ) 2 system were studied with the "intersecting cuts" method. The formation of the novel ternary molybdate Tl 5 BiHf(MoO 4 ) 6 is found in this ternary system. The compound has a phase transition at T pt = 731 K (Δ H = -3.15 J/g) and melts at T m = 871 K (Δ H = -41.71 J/g), as determined by a thermal analysis. Tl 5 BiHf(MoO 4 ) 6 single crystals were obtained by the spontaneous nucleation method. The crystal structure of Tl 5 BiHf(MoO 4 ) 6 was revealed by structure analysis methods. This molybdate crystallizes in the trigonal space group R 3̅ c with the unit cell parameters a = 10.6801(4) Å, c = 38.5518(14) Å, V = 3808.3(2) Å 3 , and Z = 6. The vibrational characteristics of Tl 5 BiHf(MoO 4 ) 6 were determined by Raman spectroscopy. The Tl 5 BiHf(MoO 4 ) 6 conductivity was measured at frequencies of 0.1, 1.0, and 10 kHz in the temperature range of 293-773 K; in this temperature range, the conductivity level was 10 -12 -10 -7 S/cm.