Effect of modified surface and architectonics of porous-permeable TiNi-based alloy scaffold on cellular biocompatibility

Cellular scaffolds based on porous biomaterials play an important role in the engineering of various tissues. Our porous-permeable cellular TiNi-based alloy scaffolds combine the advantages of metal structures, hardness, wear resistance and elasticity similar to that of human tissues. The aim of the research was the study on the change in the surface layer of samples from TiNi-based alloy and on the biotesting of modified samples with the 3H3 fibroblast line. Materials and methods: The biocompatibility of several samples of TiNi-based alloy scaffolds with an average pore size of 83,150,365 μm with modified (acid treatment) surface with 3H3 fibroblast line. Results. The porous-permeable cellular TiNi-based alloy scaffolds (average pore size = 150 μm) modified by treatment with solution of concentrated acids exhibited the highest biocompatibility with a fibroblast culture. It was shown that hemolysis of TiNi-based alloy samples, which are intact and treated with solution of concentrated acids, does not exceed 2 %. Direct cultivation of modified samples with fibroblast line in the cytotoxic test showed low cytotoxicity of the tested cells. The studies carried out using a scanning microscope showed that mesenchymal cells of bone marrow are attached in sufficient quantities to the microporous surface of the modified samples, which allows them to grow and proliferate in the pore space of TiNi-based alloy scaffolds and to cultivate tissue in vitro. Conclusion. Samples of scaffolds manufactured by the SHS-method and modified by treatment with concentrated solution of acids are technological and perspective biomaterial for their use as implantable clinically useful scaffolds

Combined transplantation of hepatocytes with mesenchimal stem cells of bone marrow on porous-permeable TiNi-based alloy scaffold

The aim of the research was to study of the therapeutic efficacy of combined transplantation of liver cells and mesenchymal stem cells of bone marrow (MSC) on TiNi-based alloy scaffolds of rats with chronic hepatitis. Materials and methods: Three groups of experiments were carried out on Wistar rats and intact rats (control) - I group; in the II group - chronic hepatitis; III group - cell-engineering designs with liver cells; in the IV group - cell-engineering designs with liver cells and BM MMSC. The activity of recovery processes was evaluated by using biochemical methods in dynamics on 10, 20, 30th days. Results. The optimal ratio of liver cells to MSC (5:1) was previously found in TiNi-based alloy scaffolds after transplantation and through co-cultivation of hepatocytes and MSC at different ratios. It was shown that recovery processes in the group with scaffolds transplanted into damaged livers were much more active if compared with those in the control group with chronic hepatitis. At the same time, in the group with combined transplantation on TiNi-based alloy scaffolds contributed to a more rapid normalization of liver enzyme indices compared with the group with transplantation of some hepatocytes on scaffolds. These data are confirmed by an increase in the life span of animals with combined hepatocytes and MSC transplantation on TiNi-based alloy scaffolds. Conclusions. A higher level and prolonged periods of liver regeneration during the transplantation of TiNi-based alloy scaffolds are due to the creation of biologically appropriate conditions for cells with certain ratio

The Interstellar Medium of Quiescent Galaxies and its Evolution With Time

We characterise the basic far-IR (FIR) properties and the gas mass fraction of massive ( ~ 11.0) quiescent galaxies (QGs) and explore how these evolve from z = 2.0 to the present day. We use robust, multi-wavelength (mid- to far-IR and sub-millimetre to radio) stacking ensembles of homogeneously selected and mass complete samples of log(M*/Msun) > 10.8 QGs. We find that the dust to stellar mass ratio (Md/M*) rises steeply as a function of redshift up to z~1.0 and then remains flat at least out to z = 2.0. Using Md as a proxy of gas mass (Mgas), we find a similar trend for the evolution of the gas mass fraction (fgas) with z > 1.0 QGs having fgas ~ 7.0% (for solar metallicity). This fgas is 3 - 10 times lower than that of normal star forming galaxies (SFGs) at their corresponding redshift but ~3 and ~10 times larger compared to that of z = 0.5 and local QGs. Furthermore, the inferred gas depletion time scales are comparable to that of local SFGs and systematically longer than that of main sequence galaxies at their corresponding redshifts. Our analysis also reveals that the average dust temperature (Td) of massive QGs remains roughly constant ( = 21.0 \pm 2.0K) at least out to z ~ 2.0 and is substantially colder (~ 10K) compared to that of z > 0 SFGs. This motivated us to construct and release a redshift-invariant template IR SED, that we use to make predictions for ALMA observations and to explore systematic effects in the Mgas estimates of massive, high-z QGs. Finally, we discuss how a simple model that considers progenitor-bias can effectively reproduce the observed evolution of Md/M* and fgas. Our results indicate universal initial interstellar medium conditions for quenched galaxies and a large degree of uniformity in their internal processes across cosmic time.Comment: Accepted for publication in A&

Origin and Distribution of Tick-Borne Encephalitis Virus Strains of the Siberian Subtype in the Middle Urals, the North-West of Russia and the Baltic Countries

Tick-borne encephalitis virus (TBEV) plays an important role in infectious human morbidity, particularly in Russia and the Middle Urals. The Siberian subtype of TBEV (S-TBEV) is dominant in the Middle Urals. Determining the origin of S-TBEV strains in this territory and also in the European part of Russia and the Baltic countries is very important for understanding the cause of its distribution. The surface glycoprotein E gene was partially sequenced in 165 S-TBEV isolates collected in the Middle Urals between 1966 and 2008. Nucleotide and amino acid sequence identity of the studied isolates is 94 and 97.4 %, respectively. Eighty per cent of them are represented by six clusters with identical amino acid sequences in the glycoprotein E fragment analysed. We have determined four types of isolate distribution in the explored territory: local, split, corridor and diffuse. The average rate of nucleotide substitutions per site year-1 is estimated to be 1.56×10-4. The age of the S-TBEV population was evaluated to be slightly less than 400 years. Phylogenetic analysis of the data and comparison with historical events indicate that the distribution of S-TBEV strains in the Middle Urals and the European part of Russia originated twice from different foci in western Siberia. This is related to the first land road into Siberia and the Trans-Siberian Way, which functioned at different times. The main reason for such rapid distribution of S-TBEV strains is the anthropogenic factor, i.e. human economic activity during the colonization of new territories in Siberia in the recent past. © 2009 SGM.We are indebted to Dr Irina Belyaeva (Royal Botanic Gardens, Kew, UK) and Dr Keith Chamberlain (Rothamsted Reseach, Harpenden, UK) for their help in preparing the manuscript. We thank Tatyana Pimenova and Boris Galishev for their help in tick collecting. This project was supported by the Russian Foundation of Fundamental Research (no. 07-04-96115)

Submillimetre compactness as a critical dimension to understand the main sequence of star-forming galaxies

We study the interstellar medium (ISM) properties as a function of the molecular gas size for 77 infrared-selected galaxies at z ∼ 1.3, having stellar masses 109.4 ≲ M⋆ ≲ 1012.0 M⊙ and star formation rates 12 ≲ SFRFIR ≲ 1000 M⊙ yr−1. Molecular gas sizes are measured on ALMA images that combine CO(2-1), CO(5-4), and underlying continuum observations, and include CO(4-3), CO(7-6) + [CI](3P2 − 3P1), [CI](3P1 − 3P0) observations for a subset of the sample. The ≳46 per cent of our galaxies have a compact molecular gas reservoir, and lie below the optical discs mass–size relation. Compact galaxies on and above the main sequence have higher CO excitation and star formation efficiency than galaxies with extended molecular gas reservoirs, as traced by CO(5-4)/CO(2-1) and CO(2-1)/LIR, SF ratios. Average CO + [CI] spectral line energy distributions indicate higher excitation in compacts relative to extended sources. Using CO(2-1) and dust masses as molecular gas mass tracers, and conversion factors tailored to their ISM conditions, we measure lower gas fractions in compact main-sequence galaxies compared to extended sources. We suggest that the submillimetre compactness, defined as the ratio between the molecular gas and the stellar size, is an unavoidable information to be used with the main sequence offset to describe the ISM properties of galaxies, at least above M⋆ ≥ 1010.6 M⊙, where our observations fully probe the main sequence scatter. Our results are consistent with mergers driving the gas in the nuclear regions, enhancing the CO excitation and star formation efficiency. Compact main-sequence galaxies are consistent with being an early post-starburst population following a merger-driven starburst episode, stressing the important role of mergers in the evolution of massive galaxies

Biocompatibility assessment of coatings obtained in argon and nitrogen atmospheres for TiNi materials

This work aims to study the cytocompatibility of protective coatings obtained in argon and nitrogen atmospheres on a TiNi surface. Particular attention is paid to comparing the interaction of cell culture with coatings and an uncoated TiNi sample, using for comparison the number of viable cells on the surface, the phase composition, structure, wettability, surface charge and topography. The Ti/Ni/Ti nanolaminate was deposited on a TiNi substrate by magnetron sputtering. Reaction annealing of Ti/Ni/Ti nanolaminate on a TiNi substrate, when heated to 900 ◦C in argon, leads to the formation of a dense two-layer coating 2.0–2.1 µm thick: layer I (TiO + Ti2N), layer II (Ti4Ni2 O(N)). Reaction annealing in nitrogen leads to the formation of a thin three-layer nanocoating 250 nm thick: I (TiO2 + TiN), II (Ti4Ni2N(O) + Ti3Ni4), III (TiN). The coating synthesized in nitrogen is more favorable for cell attachment and proliferation because of the moderately hydrophilic rough surface and mixed phase composition of titanium nitrides and oxides

The ALMA-ALPAKA survey I: high-resolution CO and [CI] kinematics of star-forming galaxies at z = 0.5-3.5

Spatially-resolved studies of the kinematics of galaxies provide crucial insights into their assembly and evolution, enabling to infer the properties of the dark matter halos, derive the impact of feedback on the ISM, characterize the outflow motions. To date, most of the kinematic studies at z=0.5-3.5 were obtained using emission lines tracing the warm, ionized gas. However, whether these provide an exhaustive or only a partial view of the dynamics of galaxies and of the properties of the ISM is still debated. Complementary insights on the cold gas kinematics are therefore needed. We present ALPAKA, a project aimed at gathering high-resolution observations of CO and [CI] emission lines of star-forming galaxies at z=0.5-3.5 from the ALMA public archive. With 147 hours of total integration time, ALPAKA assembles ~0.25'' observations for 28 star-forming galaxies, the largest sample with spatially-resolved cold gas kinematics as traced by either CO or [CI] at z>0.5. By combining multi-wavelength ancillary data, we derive the stellar masses ($M_{\star}$) and star-formation rates (SFR) for our targets, finding values of $M_{\star}\gtrsim 10^{10}$ M$_{\odot}$ and SFR of 10-3000 M$_{\odot}$/yr. A large fraction of ALPAKA galaxies (19/28) lie in overdense regions (clusters, groups, and protoclusters). We exploit the ALMA data to infer their dynamical state and we find that 19/28 ALPAKA galaxies are rotating disks, 2 are interacting systems, while for the remaining 7 sources the classification is uncertain. The disks have velocity dispersion values that are typically larger in the innermost regions than in the outskirts, with a median value for the entire disk sample of 35$^{+11}_{-9}$ km/s. Despite the bias of our sample towards galaxies hosting very energetic mechanisms, the ALPAKA disks have high ratios of ordered-to-random motion ($V/\sigma$) with a median value of 9$^{+7}_{-2}$.Comment: 35 pages, 23 figures, 5 tables; submitted to A&A. The data and the outputs of the kinematic analysis will be made available at https://alpaka-survey.github.io/index.html once the paper is accepted. Comments are welcom