Investigation of diamond biocompatible coatings for medical implants

Despite the advantages of diamond-like carbon fi lms that are used as wear-resistant coatings for implants, they may have a number of disadvantages such as the high level of internal tension, low adhesive durability and high sensitivity to environment conditions. These problems can be overcome by application of the new carbon nanocomposite coatings that can be deposited from C60 ionic beam. It was found that the proposed diamond-like nanocomposite coatings increase implant material resistance to electrochemical corrosion processes due to shift of its electrode potential to area of positive values, and also promote a complex of reparative and adaptation and compensatory reorganizations that will allow to accelerate processes of healing and postoperative adaptation of organism in zone of implant inputting.Незважаючи на переваги діамантоподібних вуглецевих покриттів, що використовуються в якості зносостійких захисних покриттів для імплантатів, вони можуть мати ряд недоліків, таких як високий рівень внутрішніх напружень, низька адгезійна міцність, висока чутливість до умов навколишнього середовища. Ці проблеми можуть бути подолані в разі застосування нових вуглецевих нанокомпозитних покриттів, нанесених з іонного пучка С60. Встановлено, що запропоновані діамантоподібні нанокомпозитні покриття підвищують опірність матеріалу імплантату до електрохімічних корозійних процесів за рахунок зміщення його електродного потенціалу в область позитивних значень, а також сприяють комплексу репаративних і адаптаційно-компенсаторних перебудов, що дозволить прискорити процеси загоєння та післяопераційної адаптації організму в зоні введення імплантату

Features of medical implant passivation using anodic oxide films

The passivation ability of metals from groups IV and V of the Periodic Table is considered. Anodic treatment is able to neutralize the increase of metal hardening when comminuting grains to nanometre sizes. The deposition of metal oxide film coatings on a cobalt–chromium alloy surface results in substantial passivation of its surface and prevents cobalt and chromium accumulation in bone tissues. The decrease of surface activity of titanium implants can be achieved both by cleaning the surface during vacuum annealing before oxidation and by the increase of the anodic oxide film thickness, which limits mass and charge transfer through the implant surface. Recommended titanium implant treatment regimens are vacuum annealing at 650 °C and anodic oxidation to attain an oxide thickness less or equal to 300 nm

Diamond biocompatible coatings for medical implants

New carbon (diamond-like) nanocomposite coatings deposited from a C60 ionic beam can be used as a wear-resistant protective coating for implants. It was found that these coatings enhance resistance to тelectrochemical corrosion processes due to a shift of the material’s electrode potential to a zone of positive values. They also promote a complex of reparative, adaptative and compensatory reorganization that accelerates the healing processes in the vicinity of the implant

Stimulation of calcium phosphate crystal formation by implant surfaces with electret properties

Oxide coatings with electret properties are investigated. The possibility of stimulation of the formation of calcium phosphate sediments near the electroactive surface is discussed. The exposure of implants with such coatings to solutions imitating blood plasma showed their high efficiency of biointegration due to activation of an exchange processes in living tissues by a negative superficial charge. The revealed effect amplifies with the growth of the thickness of the anodic oxide film

Properties of magnetron hydroxyapatite coatings deposited on oxidized substrates

Hydroxyapatite (HA) coating were formed on oxidized niobium surfaces by the highfrequency magnetron sputtering method using hydroxyapatite and tricalcium phosphate targets. The structure, substructure and mechanical properties of the Nb–Nb2O5–HA system were investigated by X-ray diffraction, atomic force microscopy and nanoindentation and the stress state was assessed. The synthesized hydroxyapatite film had the following characteristics: thermal expansion coefficient 10–5 K–1; modulus of elasticity 120 GPa; adhesive strength not less than 0.45 kg/mm2; density 2900 kg/m3. The stress magnitude in the metal oxide substrate was from 11 to 14 MPa after hydroxyapatite film deposition

Zeldovich flow on cosmic vacuum background: new exact nonlinear analytical solution

A new exact nonlinear Newtonian solution for a plane matter flow superimposed on the isotropic Hubble expansion is reported. The dynamical effect of cosmic vacuum is taken into account. The solution describes the evolution of nonlinear perturbations via gravitational instability of matter and the termination of the perturbation growth by anti-gravity of vacuum at the epoch of transition from matter domination to vacuum domination. On this basis, an `approximate' 3D solution is suggested as an analog of the Zeldovich ansatz.Comment: 9 pages, 1 figure

Non-fungible token: a promising digital tool for business

This paper presents a review of the current status and development trends of the non-fungible tokens’ technology (NFT), which are digital rights to unique objects recorded in the blockchain. The object of the study is the non-interchangeable token technology. The subject of the study is the fields of practical application of NFT. The method is an analytical review of scientific publications. The current state and socio-cultural sources of the NFT market related to works of art and media objects are analysed. The technological and legal problems preventing the wide spread of NFT in the business environment are identified. The prospects for the use of non-fungible tokens in the field of protection and commercialization of patent law objects are considered

High Resolution Infrared Spectroscopy in Support of Ozone Atmospheric Monitoring and Validation of the Potential Energy Function

The first part of this review is a brief reminder of general information concerning atmospheric ozone, particularly related to its formation, destruction, observations of its decrease in the stratosphere, and its increase in the troposphere as a result of anthropogenic actions and solutions. A few words are said about the abandonment of the Airbus project Alliance, which was expected to be the substitute of the supersonic Concorde. This project is over due to the theoretical evaluation of the impact of a fleet in the stratosphere and has been replaced by the A380, which is now operating. The largest part is devoted to calculations and observations of the transitions in the infrared range and their applications for the atmosphere based both on effective models (Hamiltonian, symmetry rules, and dipole moments) and ab initio calculations. The complementarities of the two approaches are clearly demonstrated, particularly for the creation of an exhaustive line list consisting of more than 300,000 lines reaching experimental accuracies (from 0.00004 to 0.001 cm−1) for positions and a sub percent for the intensities in the 10 microns region. This contributes to definitively resolving the issue of the observed discrepancies between line intensity data in different spectral regions: between the infrared and ultraviolet ranges, on the one hand, and between 10 and 5 microns on the other hand. The following section is devoted to the application of recent work to improve the knowledge about the behavior of potential function at high energies. A controversial issue related to the shape of the potential function in the transition state range near the dissociation is discussed. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The activities of S.M. and E.S. were supported by the Ministry of Science and Higher Education of the Russian Federation (V.E. Zuev Institute of Atmospheric Optics SB RAS); the work of S.M. was also supported by Ural Federal University