The Dosidicus gigas Collagen for Scaffold Preparation and Cell Cultivation: Mechanical and Physicochemical Properties, Morphology, Composition and Cell Viability.

Directed formation of the structure of the culture of living cells is the most important task of tissue engineering. New materials for 3D scaffolds of living tissue are critical for the mass adoption of regenerative medicine protocols. In this manuscript, we demonstrate the results of the molecular structure study of collagen from Dosidicus gigas and reveal the possibility of obtaining a thin membrane material. The collagen membrane is characterized by high flexibility and plasticity as well as mechanical strength. The technology of obtaining collagen scaffolds, as well as the results of studies of its mechanical properties, surface morphology, protein composition, and the process of cell proliferation on its surface, are shown in the given manuscript. The investigation of living tissue culture grown on the surface of a collagen scaffold by X-ray tomography on a synchrotron source made it possible to remodel the structure of the extracellular matrix. It was found that the scaffolds obtained from squid collagen are characterized by a high degree of fibril ordering and high surface roughness and provide efficient directed growth of the cell culture. The resulting material provides the formation of the extracellular matrix and is characterized by a short time to living tissue sorption.

Specific Features of Reactive Pulsed Laser Deposition of Solid Lubricating Nanocomposite Mo-S-C-H Thin-Film Coatings.

This work investigates the structure and chemical states of thin-film coatings obtained by pulsed laser codeposition of Mo and C in a reactive gas (H2S). The coatings were analysed for their prospective use as solid lubricating coatings for friction units operating in extreme conditions. Pulsed laser ablation of molybdenum and graphite targets was accompanied by the effective interaction of the deposited Mo and C layers with the reactive gas and the chemical states of Mo- and C-containing nanophases were interdependent. This had a negative effect on the tribological properties of Mo-S-C-H nanocomposite coatings obtained at H2S pressures of 9 and 18 Pa, which were optimal for obtaining MoS2 and MoS3 coatings, respectively. The best tribological properties were found for the Mo-S-C-H_5.5 coating formed at an H2S pressure of 5.5 Pa. At this pressure, the x = S/Mo ratio in the MoSx nanophase was slightly less than 2, and the a-C(S,H) nanophase contained ~8 at.% S and ~16 at.% H. The a-C(S,H) nanophase with this composition provided a low coefficient of friction (~0.03) at low ambient humidity and 22 °C. The nanophase composition in Mo-S-C-H_5.5 coating demonstrated fairly good antifriction properties and increased wear resistance even at -100 °C. For wet friction conditions, Mo-S-C-H nanocomposite coatings did not have significant advantages in reducing friction compared to the MoS2 and MoS3 coatings formed by reactive pulsed laser deposition.

Performance and Mechanism of Photoelectrocatalytic Activity of MoSx/WO3 Heterostructures Obtained by Reactive Pulsed Laser Deposition for Water Splitting.

This work studies the factors that affect the efficiency of the photoelectrochemical hydrogen evolution reaction (HER) using MoSx/WO3 nano-heterostructures obtained by reactive pulsed laser deposition (RPLD) on glass substrates covered with fluorinated tin oxide (FTO). Another focus of the research is the potential of MoSx nanofilms as a precursor for MoOz(S) nanofilms, which enhance the efficiency of the photo-activated oxygen evolution reaction (OER) using the MoOz(S)/WO3/FTO heterostructures. The nanocrystalline WO3 film was created by laser ablation of a W target in dry air at a substrate temperature of 420 °C. Amorphous MoSx nanofilms (2 ≤ x ≤ 12) were obtained by laser ablation of an Mo target in H2S gas of varied pressure at room temperature of the substrate. Studies of the energy band structures showed that for all MoSx/WO3/FTO samples, photo-activated HER in an acid solution proceeded through the Z-scheme. The highest photoelectrochemical HER efficiency (a photocurrent density ~1 mA/cm2 at a potential of ~0 V under Xe lamp illumination (~100 mW/cm2)) was found for porous MoS4.5 films containing the highest concentration of catalytically active sites attributed to S ligands. During the anodic posttreatment of porous MoSx nanofilms, MoOz(S) films with a narrow energy band gap were formed. The highest OER efficiency (a photocurrent density ~5.3 mA/cm2 at 1.6 V) was detected for MoOz(S)/WO3/FTO photoanodes that were prepared by posttreatment of the MoSx~3.2 precursor. The MoOz(S) film contributed to the effective photogeneration of electron-hole pairs that was followed by the transport of photoelectrons from MoOz(S) into the WO3 film and the effective participation of holes possessing strong oxidation ability in the OER on the surface of the MoOz(S) film.

Copper-Stabilized Si/Au Nanowhiskers for Advanced Nanoelectronic Applications.

We report here the growth and functional properties of silicon-based nanowhisker (NW) diodes produced by the vapor-liquid-solid process using a pulsed laser deposition technique. For the first time, we demonstrate that this method could be employed to control the size and shape of silicon NWs by using a two-component catalyst material (Au/Cu ≈ 60:1). During the NW growth, copper is distributed on the outer surface of the NW, whereas gold sticks as a droplet to its top. The length of NWs is defined by the total amount of copper in the catalyst alloy droplet. The measurements of the electrical transport properties revealed that in contact with the substrate, individual NWs demonstrate typical I-V diode characteristics. Our approach can become an important new tool in the design of novel electronic components.

Protective radiolucent aluminium oxide coatings for beryllium X-ray optics.

Beryllium, being one of the most transparent materials to X-ray radiation, has become the material of choice for X-ray optics instrumentation at synchrotron radiation sources and free-electron laser facilities. However, there are concerns due to its high toxicity and, consequently, there is a need for special safety regulations. The authors propose to apply protective coatings in order to seal off beryllium from the ambient atmosphere, thus preventing degradation processes providing additional protection for users and prolonging the service time of the optical elements. This paper presents durability test results for Be windows coated with atomic-layer-deposition alumina layers run at the European Synchrotron Radiation Facility. Expositions were performed under monochromatic, pink and white beams, establishing conditions that the samples could tolerate without radiation damage. X-ray treatment was implemented in various environments, i.e. vacuum, helium, nitrogen, argon and dry air at different pressures. Post-process analysis revealed their efficiency for monochromatic and pink beams.

A simple, rapid and high-throughput fluorescence polarization immunoassay for simultaneous detection of organophosphorus pesticides in vegetable and environmental water samples.

A simple, rapid and high-throughput fluorescent polarization immunoassay (FPIA) for simultaneous determination of organophosphorus pesticides (OPs) using a broad-specificity monoclonal antibody was developed. The effects of tracer structure, tracer concentration, antibody dilution, methanol content and matrix effect on FPIA performance were studied. The FPIA can detect 5 OPs simultaneously with a limit of detection below 10 ng mL(-1). The time required for the equilibrium of antibody-antigen interaction was less than 10 min. The recovery from spiked vegetable and environmental samples ranged from 71.3% to 126.8%, with the coefficient of variations ranging from 3.5% to 14.5%. The developed FPIA was applied to samples, followed by confirmation with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. The developed FPIA demonstrated good accuracy and reproducibility, and is suitable for rapid and high-throughput screening for OP contamination with high-efficiency and low cost.

Properties of silicon dioxide layers with embedded metal nanocrystals produced by oxidation of Si:Me mixture.

A two-dimensional layers of metal (Me) nanocrystals embedded in SiO2 were produced by pulsed laser deposition of uniformly mixed Si:Me film followed by its furnace oxidation and rapid thermal annealing. The kinetics of the film oxidation and the structural properties of the prepared samples were investigated by Rutherford backscattering spectrometry, and transmission electron microscopy, respectively. The electrical properties of the selected SiO2:Me nanocomposite films were evaluated by measuring C-V and I-V characteristics on a metal-oxide-semiconductor stack. It is found that Me segregation induced by Si:Me mixture oxidation results in the formation of a high density of Me and silicide nanocrystals in thin film SiO2 matrix. Strong evidence of oxidation temperature as well as impurity type effect on the charge storage in crystalline Me-nanodot layer is demonstrated by the hysteresis behavior of the high-frequency C-V curves.