•Electrochemical behavior of Ge nanowires in the temperature range from –40 to +20 o C is studied.•Formation of SEI on germanium nanowires was confirmed by IR spectra.•The activation energies of Rs, ...RSEI, and Rct are of 21.8, 24.1, and 36.5 kJ/mol, respectively.
Electrochemical impedance spectroscopy was used to study electrochemical lithium insertion into the electrodes based on germanium nanowires in a temperature range of +20 to −40 °C. Since such electrodes have a regular structure and do not contain binders and conductive additives, they are described by a relatively simple equivalent circuit including the electrolyte resistance (Rs), the resistance of the solid electrolyte film (RSEI) on the surface of germanium nanowires, the capacitance of the solid electrolyte film (CSEI), the charge transfer resistance (Rct), a constant phase element (CPE), reflecting the capacitance of the double layer, and the Warburg impedance (W), reflecting the diffusion of lithium in germanium. It is characteristic of the RSEI and Rct values to grow with an increase in the lithiation degree from 0.3 to 0.9, respectively, by 28% and 16%. A decrease in temperature leads to an increase in the values of Rs, RSEI, and Rct in accordance with the Arrhenius law with activation energies of 21.8, 24.1, and 36.5 kJ/mol, respectively. At the same time, the SEI capacity is independent of temperature.
Introduction.
Th e growing incidence of oropharyngeal cancer is driven by an increase in frequency of HPV-associated oropharyngeal cancer. Th e morbidity pattern of oropharyngeal cancer is ...area-specific.
Aim.
To analyze the oropharyngeal cancer diagnosis and treatment in the Republic of Bashkortostan for 2020.
Materials and methods.
Th e authors carried out a 2020 retrospective analysis of the diagnosis and treatment results of patients with oropharyngeal cancer. 79 patients were identified with this diagnosis. 84.8% (67/79) among them were males and 15.2% females (12/79). Th e mean age of the patients was 59.1 years. Th e site of primary tumor was on the oropharynx lateral wall in 37.8% cases (30/79), in the tongue root area — 24.1% (19/79), in the tonsils area — 17.7% (14/79), on the soft palate — 16.5% (13/79), on the oropharynx posterior wall — 3.8% (3/79).
Results.
Examination of tumor morphological types revealed squamous cell carcinoma (SCC) with various degrees of differentiation in 92.4% cases (73/79), adenocarcinoma of minor salivary gland — in 6.3% (5/79) and sarcoma in 1.2% (1/79). 57.5% of 73 patients with SCC (42/73) underwent protein (p16) immunohistochemistry, while 42.5% of the patients (31/73) did not. According to a surrogate marker for HPV, the following results were obtained for 42 patients: p16-positive in 23.8% cases (10/42), p16-negative in 76.2% (32/42). Stage distribution according to TNM-7: stage I — 11.4% (9/79), stage II — 17.7% (14/79), stage III — 36.7% (29/79), stage IV — 46.8% (37/79). Stage distribution according to TNM-8 (patients who underwent p16 immunohistochemistry): stage I — 11.9% (5/42), stage II — 23.8% (10/42), stage III — 19% (8/42), stage IV — 45.2% (19/42). In 2020, 72% of patients (57/79) received definitive treatment, 10.1% (8/79) — palliative care, 15.2% (12/79) — supportive care, and 2.5% (2/79) refused medical treatment.
Discussion.
Th e various types of radiation therapy were used as the main defi nitive treatment for patients with oropharyngeal cancer in 69.2% cases (45/65). Only 18.5% of patients (12/65) underwent surgery, 58.3% of which (7/12) received post-surgery radiation therapy.
Conclusion.
57.5% of patients (42/73) were detected with HPV status, 23.8% (10/42) revealed surrogate markers for HPV association. 69.2% of patients (45/65) received radiation therapy as the definitive treatment. 18.5% of patients (12/65) underwent surgery, 58.3% of which (7/12) received postsurgery radiation therapy.
Porous Ge layers of nanowires were formed by low energy (30 keV) Ag+ ion implantation of crystalline c-Ge substrate. Different radiation doses resulted in the formation of nanowires with various mean ...diameters. The obtained layers were studied by Raman spectroscopy using helium-neon and argon exciting lasers at wavelength of 633 and 488 nm respectively. It was demonstrated that implanted amorphous layers were locally crystallized by the lasers. The crystallization thresholds were found to be 3 kW/cm2 for helium-neon exciting laser and 1 kW/cm2 for argon exciting laser. The variation of thresholds is suggested to be due to the different light penetration depths at these wavelengths in Ge. The crystalline volume fraction was determined and reached maximum value of 6–7%, the divergence of which can be explained by the difference in the distribution of Ge nanowire diameters.
•The ion implantation of c-Ge led to formation of porous layers with Ge nanowires.•Lasers with different penetration depth were used during Raman study.•When the threshold intensity is exceeded, a nanocrystalline phase appears.•The crystalline phase volume fraction reaches 6–7%.•The threshold value for different wavelengths differs by 3 times.
We studied immunohistochemical and morphometric characteristics of the spermatogenic epithelium in rats against the background of peroral administration of nanoparticles containing titanium dioxide. ...Substantial degenerative changes in the spermatogenic epithelium were revealed: thinning, disorganization of layers, and detachment of sperm cells from the basement membrane. Immunohistochemical analysis revealed reduced proliferative activity and differentiation potential of epithelial cells, which was confirmed by changes in the expression of Ki-67 and c-kit markers. Our data attest to unfavorable effects of titanium dioxide nanoparticles on the structural and functional characteristics of the reproductive system in male rats leading to spermatogenesis disturbances.
In this work the reactive changes in rat hippocampus in response to intranasal administration of TiO
2
nanoparticles (NPs) have been studied. The immunohistochemistry of animal hippocampi has shown ...an increase in the sensitivity of vascular endotheliocytes and macroglia to the vascular endothelial growth factor (VEGF) in hippocampi of the experimental group. The expression of the glial fibrillary acidic protein (GFAP) has been found to enhance, suggesting the increment of the reactive astrocytes amount in the studied brain area under the action of TiO
2
NPs. According to the results of this research, we have deduced the compensatory reactions in hippocampus accompanied by astrocytic activation, processes of angiogenesis, and the impairment of neurogliar ratio under the action of TiO
2
NPs.
The conditions to obtain materials with elastic-viscous properties based on chitosan succinamide have been studied. A decreased polymer content and a transition from visco-elastic liquids to ...elastic-viscous systems were shown upon the addition of glycerol to an aqueous solution of chitosan succinamide. The systemic response, biological compatibility, and dynamics of bioresorbability of the obtained materials were studied during implantation in laboratory animals.
SUMMARY Using atomic force microscopy performed morphofunctional state analysis (morphometry, adhesion strength and stiffness of the membrane) of neutrophils in patients with chronic obstructive ...pulmonary disease, depending on the presence of pulmonary hypertension. In mode power spectroscopy performed quantification of elastic modulus (Young's modulus) and strength of a cell membrane adhesion of neutrophils. The study showed that in patients with chronic obstructive pulmonary disease with pulmonary hypertension observed neutrophil activation (reduction in cell size, cell nucleus, increasing the number and height of the granules in the cytoplasm), a significant increase in the stiffness of the membrane (increase in the Young modulus) and strength of adhesion of neutrophils compared with the control and COPD patients without pulmonary hypertension Keywords: chronic obstructive pulmonary disease, pulmonary hypertension, atomic force microscopy, neutrophils, morphometry, the stiffness of the membrane, the adhesive force.
Objectives.
To study the structure and biomechanical characteristics of blood neutrophils on the background of exposure to titanium dioxide nanoparticles.
Materials and methods.
Blood neutrophils ...from 20 essentially healthy donors of both sexes aged 20–22 years were studied in vitro before and after exposure to titanium dioxide nanoparticles. Atomic force microscopy was used to measure neutrophil diameter and height, and the biomechanical properties of neutrophils (roughness and rigidity) were also studied.
Results.
Exposure to titanium dioxide nanoparticles was followed by decreases in the diameter, increases in the height, and increases in the rigidity of neutrophils, as well as growth in surface roughness.
Conclusions.
Changes in the structural-functional properties of neutrophils provide evidence of the possible cytotoxic actions of titanium dioxide nanoparticles.
The effect of water-soluble polymer—chitosan succinamide—on surface activity of such commonly used surfactants as anionic sodium dodecylsulfate and nonionic TWEEN-80 is investigated. It is shown that ...the combined use of sodium dodecylsulfate and TWEEN-80 with chitosan succinamide increases the surface activity of the investigated surfactants. It is found that the association of chitosan succinamide with sodium dodecylsulfate or TWEEN-80 begins at concentrations an order of magnitude lower than the critical micelle concentration of studied surfactants. The fact of reduction in the dynamic viscosity of the solution of chitosan succinamide in the presence of both ionic and nonionic surfactants, apparently owing to the formation of polymer-colloid complexes, is revealed. The obtained systems have a stabilizing effect on the membrane of red blood cells in stringent hypotonic conditions, which may indicate a decrease in the adverse effect of surfactants on the skin.
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