Composition and toxicity of shrapnel in mine-explosive and fragmentation craniocerebral wounds compared to titanium implants: a pilot study

The feasibility of removing damaging fragments from the spine in gunshot and mine-blast injuries is assessed based on the data of their composition and cytotoxicity. Four damaging fragments removed from the spine and paravertebral tissues were analyzed. Elemental analysis was performed using a scanning electron microscope. The composition of the damaging fragments was studied using spectral analysis. The cytotoxicity of the medium with damaging fragments was evaluated using the methyl tetrazolium test, comparing to the control medium. Morphological changes in cells were assessed using optical light microscopy, comparing to the control. Elemental analysis showed that all studied fragments consisted of alloys of various metals and other chemical elements. During the first few weeks of incubation in a complete nutrient medium, metals underwent fairly active oxidation, producing an orange precipitate. During further incubation, the oxidation of metals continued quite intensively, leading to a change in the nutrient medium and reducing cell proliferation. Moreover, morphological examination showed that cells exposed to metal oxides were rounded, while control sample cells were elongated and spindle-shaped. The methyl tetrazolium test revealed high cytotoxicity of all the fragments studied. All fragments were found to release toxic metal oxides into the nutrient medium, significantly reducing cell viability, regardless of their elemental composition. To prevent complications associated with possible local and/or systemic toxicity of metal fragments, as well as early and late infections, it is recommended to remove projectiles to the maximum extent feasible.

In this study we report on the surface structure, distribution and isotopic composition of elements found on Ti cathodes before and after glow discharge in plasma, during which excess heat was produced. Irradiation was carried out with deuterium ions with a discharge voltage below 1000 volts, with a current of 10 to 20 mA. The analysis of the surface structure and of elemental composition of the Ti sample was carried out with a scanning electron microscope with Energy Dispersive X-ray Spectroscopy (EDS), which can detect impurities at concentrations as low as 0.2 atomic %. New metallic phase formation and newly present elements were revealed by the EDS method in several different, separate active spots on the cathode surface, with concentrations ranging from 0.3 % up to 10 or 20 % or more. Al, Mg, Br, Sr were found at ~0.3%, Rb ~0.4%, S ~1.0%, F ~10%, O>20%, Ni ~(0.3- 20)%, Cr ~1.4%, Fe ~4.0%, Sn (~0.4 to ~5.0) % were detected by this method after the experiment and were not in the as-received sample before the experiment. The basic changes are observed in places of microexplosions, micromeltings and structural inhomogeneities. Investigation of the isotopic composition was carried out by Thermal Ionization Mass Spectroscopy (TIMS). Additional elements in a thin surface layer were found by this method when analysis was performed at 1900ºC. The Ti cathode produced excess heat during glow discharge, estimated at 10 to 20 % above input power. This suggests that the heat was caused by the formation of the observed new elements. It is necessary to note that excess heat was created by the processes in a sample having weight of 0.7 gram in a device weighing 5 kg. At the same time thermal losses with the water cooling of anode, losses through a quartz wall of the discharge chamber and the losses in metal flanges were not taken into account. In the experiments with other cathode materials (including Mo, W and Zr) under the same experimental conditions, no excess heat was observed and thermal losses were roughly 40%.

Metal implants used in trauma surgeries are sometimes difficult to remove after the completion of the healing process due to the strong integration with the bone tissue. Periodic surface micro- and nanostructures can directly influence cell adhesion and differentiation on metallic implant materials. However, the fabrication of such structures with classical lithographic methods is too slow and cost-intensive to be of practical relevance. Therefore, we used laser beam interference ablation structuring to systematically generate periodic nanostructures on titanium and steel plates. The newly developed laser process uses a special grating interferometer in combination with an industrial laser scanner and ultrashort pulse laser source, allowing for fast, precise, and cost-effective modification of metal surfaces in a single step process. A total of 30 different periodic topologies reaching from linear over crossed to complex crossed nanostructures with varying depths were generated on steel and titanium plates and tested in bone cell culture. Reduced cell adhesion was found for four different structure types, while cell morphology was influenced by two different structures. Furthermore, we observed impaired osteogenic differentiation for three structures, indicating reduced bone formation around the implant. This efficient way of surface structuring in combination with new insights about its influence on bone cells could lead to newly designed implant surfaces for trauma surgeries with reduced adhesion, resulting in faster removal times, reduced operation times, and reduced complication rates.

Objective – to optimize of surgical approaches to damaged tissues of the head and methods of primary surgical treatment for gunshot non-penetrating gunshot craniocerebral injuries in accordance with the principles of comprehensive and single-stage surgical treatment accepted in military field surgery. Materials and methods. An analysis of the surgical treatment of 155 wounded people with non-penetrating gunshot wounds of the skull vault and brain for the period from 2014 to 2020 was carried out. Anatomical and morphological features of wound canals were studied depending on the traumatic agent. Variants of surgical approaches for the primary surgical treatment of non-penetrable gunshot wounds of the skull and brainwere developed based on the clinical X-ray and computed tomography characteristics of the affected head tissues. Results. The choice of surgical approaches depends on the nature of the wound canals (single fragment blind, multiple fragment blind, ball and fragment tangent) and the presence of concomitant epidural and subdural hematomas. Primary plasty of the skull defect with a titanium plate during primary surgical treatment is indicated for gunshot impenetrable craniocerebral injuries with a single fragmental blind wound channel. Such plastic surgery was performed in 33.5% of cases with a favorable postoperative course. Peculiarities of surgical approaches to damaged tissues of the head in case of single fragmentary, blind wound canal; with multiple blind fragmental wound canals, the adjacent wound canal and the sequence of their surgical treatment were established. Conclusions. Planning of surgical approaches to damaged tissues of the head in case of gunshot impenetrable craniocerebral wounds in modern local wars should be carried out taking into account clinical and computed tomography data. The high proportion of comprehensive and one-time early primary surgical treatments (92.9%) performed on the first day after the injury testifies to the high efficiency of the system of providing specialized medical care during the local war.

One of the most vulnerable issues in the technical protection of information is to obtain data via leakage through the opto-electronic channel.
 In this paper, studies of the protective capabilities of glass from laser sounding depending on its elemental composition were carried out using such indicators as the coefficients of reflection and absorption of the laser beam by the window glass.
 As a result of the work, an experimental installation based on a continuous solid-state laser was assembled.
 The study of the elemental composition of window glass, which is produced by modern industry, X-ray fluorescence method and the study of the coefficients of reflection and absorption of glass samples in the experimental setup showed that the studied window glass chemically belongs to quartz (silicate).
 All chemical elements involved in its formation can be divided into 3 groups: glass-forming, transitional, modifiers, which affects the optical properties of the studied glasses, as the elements used have different not only qualitative but also quantitative parameters.
 Absorption increases if the number of chemical elements that exhibit amphoteric and non-metallic properties and have (-charge) decreases, and increases if the number of chemical elements in the glass that exhibit the most alkaline, alkaline earth properties and in which the radius of cations (+ions) increases.
 Systematization of the elemental and quantitative composition of the studied window glass in accordance with the periods and groups of the periodic table of chemical elements, enabled the relationship between the electronic structure of chemical elements and the protective properties of glass

The development of biotechnological methods for producing medicinal plants, preserving the valuable elemental and chemical composition of the group, is one of the most important tasks of the pharmaceutical and food industries. The goal of this study was to investigate the elemental composition of regenerant I. sibirica in comparison with intact plants. We studied the biomass of leaves, rhizomes and roots of plants of regenerant I. sibirica varieties Cambridge and Sterh obtained by microclonal multiplication in Altai State University (Barnaul, Russia). The elemental composition was evaluated using atomic emission spectrometry (ICP-spectrometer Optima 7300 DV, PerkinElmer). The intensity and specificity of accumulation of chemical elements from culture media in organs of I. sibirica plants regenerated by tissue culture was studied. Energetic accumulation elements—K, Mg, Fe, Mn, Zn, Mo Cu, as well as a strong accumulation element Co— were determined based on obtained data. Calcium in the leaves of regenerant plants was defined as an energetic accumulation element, and in the roots and rhizomes as a strong accumulation element. In tissue culture, the two I. sibirica varieties Cambridge and Sterh accumulated chemical elements with the same intensity. Based on spectrometric analysis in I. sibirica biomass 24 chemical elements were identified and a series of preferential accumulation constructed: K > Ca > Mg > Fe > Al > Na > Mn > Zn > Sr > Ba > Ti > Cu > V > Pb > Ni > As > Mo > Co > Sb > Sn > Se > Cd > Ag > Be. Studies have shown that the qualitative composition of the elements found in regenerant and intact I. sibirica plants was identical, while the quantitative content differed significantly. We established that regenerant I. sibirica variety Cambridge were concentrators of manganese (leaves, roots and rhizomes). In the studied samples I. sibirica variety Cambridge, the concentration of heavy metals Pb, Cd and As did not exceed the permissible level for plant-based dietary supplements. The mercury content did not exceed the sensitivity threshold of the device. The possibility of using regenerant and intact I. sibirica plants as sources of various macro- and trace elements was demonstrated. The specificity of the accumulation of studied elements during in vitro cultivation of I. sibirica also should be considered.

We investigated the changes in cell morphology and elemental composition with varying iron nutritional status in four oceanic and two coastal isolates of the marine pennate diatom Pseudo‐nitzschia. When iron‐deficient, most isolates exhibited slower specific growth rates (m), reduced maximum photochemical yields (WM), and lower chlorophyll a (Chl a) contents than iron‐replete cultures. Iron‐deficient cells exhibited reduced cell volumes, primarily as the result of decreased valve transapical widths, which increased the valve aspect ratios. The increase in aspect ratios varied among isolates and was not correlated with the degree of growth limitation due to irondeficiency. In all Pseudo‐nitzschia isolates, the mean carbon (Ccell), nitrogen (Ncell), and silicon (Sicell) cell quotas of iron‐deficient cells decreased when compared to iron‐replete cells. Similarly, in five out of the six isolates, the mean C and N quotas normalized per unit cell volume (Cvol and Nvol) of iron‐deficient cells also decreased, but by a lesser extent. In contrast, there were no clear differences in the changes in the mean Si quotas normalized per unit cell surface area (Sisa). The Sicell:Ncell and Sicell : Ccell ratios (quotas normalized per cell) of iron‐deficient cells increased compared to iron‐replete conditions due to greater reductions in C and N cell quotas compared to Si cell quotas. This increase in the Sicell:Ncell ratio was proportional to the changes in the valve aspect ratios. Our results show that iron‐deficient Pseudo‐nitzschia cells acclimate to low iron concentrations by increasing their valve aspect ratios, thus reducing their cell volumes and increasing their surface area‐to‐volume (SA : V) ratios. These changes in cell morphology increase the Si‐containing valve surface area relative to the volume of the internal components, which may then influence the cellular elemental composition, in particular, the Si :N and Si :C ratios.

Research subject. Cyanobacteria and biogenic ultramicrostructures in stromatolites. Aim. Analysis of methods based on the systematization of stromatolites according to morphological characteristics, as well as the results obtained using these methods. Justification of the need to continue the study of stromatolites. Description of a method for detecting microbial residues in stromatolites, highlighting the main morphotypes and determining their composition. Discussion of the possibilities, advantages, and disadvantages of a new approach to studying biogenic ultramicrostructures in stromatolites, the reliability of the as-obtained data, and the specifics of their interpretation. Examples are provided to demonstrate the activity of which microorganisms resulted in the formation of a particular microstructure of stromatolites, forming the basis for their formal classification. The method described has been repeatedly tested by the author in the process of studying stromatolites and oncoliths of different ages; the results have been published in a number of leading journals. Materials and methods. Samples for analysis were collected primarily from Precambrian biogenic rocks in various regions of Russia. The study was conducted using scanning electron microscope. Specimens measuring approximately 20 × 20 mm were mechanically separated from the samples. Gold was deposited in a vacuum chamber. Organism remains in stromatolites and oncolites were identified using a TesScanMV-2300 scanning electron microscope. Their elemental composition was recorded using an EDS microanalyzer (INCA 200, Oxford Instruments), with a scan diameter of 1 μm and a polarized light scattering sensitivity of 0.001%. Results. Numerous fossilized remains of organisms in stromatolites are identified. Criteria for changes in their composition are established, including as a result of exposure to secondary processes. The role of the bacterial-algal community in the formation of textural and structural features of these rocks is discussed. The main morphotypes of biogenic ultramicrostructures in stromatolites are identified. The mandatory criteria for obtaining reliable data and their control by other methods are discussed. Further prospects for the study of organisms in biogenic structures are considered. Conclusions. The use of scanning electron microscope and the technique described by the author for the first time has made it possible to identify numerous microbial residues in stromatolites. Determination of their elemental composition and comparison of these data with the host rock facilitate monitoring the genesis of finds and obtaining useful additional information. The creation of a classification of stromatolite-forming microfossils and the analysis of the participation of organisms in the construction of textural and structural features of stromatolites will significantly expand the understanding of the formation features of these rocks and their age.

On-line analysis of CAL72 cells on two different titanium surfaces in a perfusion micro-bioreactor

The study of air-plasma treatment on corn starch/poly(ε-caprolactone) films

Durability of the optical plastic polycarbonate under modulated blue LED irradiation at different duty cycles

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With the continuous exploration of the special morphologies and properties of skin of some animals and plant leaf surfaces in the nature, new hydrophobic surfaces are developed through imitation of the observed surface effects. The aluminum alloy surface which is similar to multi-scale hierarchical structure surface of biomimetic rice leaf can be obtained by combining high speed wire electrical discharge machining (WEDM) method and electric brush-plating technique. The morphological feature was analyzed by scanning electron microscopy (SEM). The surface wettability of the sample was measured at ambient temperature using a contact angle measurement instrument and the SCA20 software by placing a 4 μ L pure distilled water droplet onto the surface of the sample. Three dimensional (3D) profile of the sample surface was obtained through confocal laser scanning microscopy (LSCM). The elemental composition was determined by X-ray diffraction (XRD) analysis in order to determine the phase composition on the sample surface. The regular submillimeter groove ridge structures were processed on the aluminum alloy surfaces by the method of high speed wire electrical discharge machining. And the hierarchical cauliflower-like structures which were consisted of micro-protrusions and submicro-grains were formed on the sample surfaces by electric brush-plating technique. The anisotropic functional surfaces and the superhydrophobic surfaces were achieved by the combination of the regular submillimeter groove ridge structures and hierarchical cauliflower-like structures. The research showed that the regular submillimeter groove ridge structures are similar to the surface morphology on rice leaf, and the hierarchical cauliflower-like structures are similar to the surface morphology on lotus leaf. The results showed that double scale (micro-submicro) microscopic structure obtained by electric brush-plating can play a key role on the hydrophobicity of the surface. The regular submillimeter groove ridge structure obtained by high speed wire electrical discharge machining further enlarged the hydrophobic properties of the direction of parallel groove. The sample surface showed excellent superhydrophobic properties, and the contact angle of the direction of parallel groove could reach up to 151°. The sample surface also showed different hydrophobic properties in the direction of the parallel groove and the direction ofthe vertical groove. Due to the existence of the edge structure make the two directions, and the two directions have different static wettability, which also led to the surface anisotropy. With the changing of electric brush-plating time, the trend of double and multi scale structure surface contact angle had large difference on the sample surface. The sample surface is fabricated without any chemical modification by combining high speed wire electrical discharge machining method with electric brush-plating technique. Although the application of the surface anisotropy and superhydrophobicity were not showed in other places, it is important for animals and plants in the nature. With the deepening of the study, this research will rise to certain guiding significance on the applications of combining the anisotropic functional materials with the superhydrophobic materials.

Our study reveals for the first time in a quantitative manner the differences in eggshell thickness and elemental composition between pigment spots and adjacent plain eggshell regions in bird species from three developmental modes, i.e. altricial (Great Reed Warbler Acrocephalus arundinaceus), semi-precocial (Black-headed Gull Chroicocephalus ridibundus, Mediterranean Gull Ichthyaetus melanocephalus, Sandwich Tern Thalasseus sandvicensis and Black Tern Chlidonias niger) and precocial species (Western Capercaillie Tetrao urogallus and Black Grouse Lyrurus tetrix). From a broader biological/biogeochemical perspective, our data broaden the knowledge in the heterogeneity of elemental composition between adjacent spotted-plain regions of eggshells, previously demonstrated in galliform birds, which differ in colour for many chemical elements. These differences, however, were distinctive of individual species and varied between chemical elements. There emerged a clear and consistent trend of higher elemental concentrations within pigment spots compared to plain eggshell regions, particularly in the case of five elements: C, Pb, Cu, Cr and Al. The most important and novel finding of our study is that even though the eggshells of gulls and terns (semi-precocial species) and of the passerine (altricial species) were thinner in the spotted regions (there was thus less shell material) compared with those of precocials (the eggshells being thicker eggshells at the spots), the spotted regions of all these eggs contained disproportionally higher concentrations of most major and minor chemical elements. Hence, this appears to be a general rule across all birds, regardless of the eggshell thickness in the spotted or plain regions and/or their developmental mode. In other words, this finding confirms that the thickness of the eggshell itself does not affect the concentrations of elements, and that the key issue related to this is the presence of one or more protoporphyrin layers along with the accompanying pool of chemical elements within the spotted eggshell region.

To perform complex morphological assessment of ALC in patients with ACCS. The study involved complex analysis of ALC that was removed due to ACCS in the pseudophakic eye in the setting of diabetes mellitus and past vitreoretinal surgery. The following examination methods were used: light-optical microscopy of ALC samples in the form of polychrome-colored semifine sections using optical microscope Leica DM-2500 (Germany), scanning microscopy of ALC surface with EVO LS10 (Carl Zeiss, Germany) microscope, analysis of chemical element composition and its variation of the ALC sample with energy-dispersive spectrometer Oxford X-Max50 (Oxford, UK). Light-optical microscopy showed altered state and plication of ALC induced by proliferation from inner surface of the fibrocellular tissue, which gradually thickens (up to 360 µm) towards center and causes reduction of anterior capsulotomy opening. Scanning electron microscopy revealed presence of tissue with uneven micro-relief and a porous three-dimensional structure uncharacteristic for capsule on the surface of ALC. Thickness of the fibrous deposition significantly exceeded the thickness of ALC. Evaluation of elemental composition of the fibrocellular tissue showed elevated concentration of sulfur and phosphorus, which indicates high activity of the regenerative process. In the observed case, the regenerative process was of substitute nature because an attempt to restore the lens was accompanied by formation of connective tissue structurally different from original. Complex assessment of an isolated ALC sample allowed revelation of the chain of pathological processes accompanying the development of ACCS.