The Bonebridge system – Our clinical experience /Case report/

Introduction: Bone conduction implants are a standard treatment option for patients with conductive or mixed, hearing loss. The Bonebridge system was introduced by MED-EL in 2012, and two years after its debut, it was used in more than 200 centers worldwide (6). For the first time the Bonebridge system was implanted in Bulgaria in 2015 by associated professor P. Rouev. The main audiological criteria for placement is conductive hearing loss, which is caused by atresia of the auditory canal or diseases of the middle ear with preserved bone conduction (below 45 dB), as well as unilateral hearing loss above 70 dB (contralateral hearing loss not more than 20 dB). The system does not penetrate the skin and consists of an internal part - an implant, which is placed completely under the skin, and an external part - a processor. The acoustic signal from the environment is transformed into mechanical vibrations that are transmitted to the mastoid bone. The expected results are an improved hearing threshold and better hearing in noisy environments.Methods: Our clinical experience with the Bonebridge system is based on three operated patients aged between 56 and 73 years. All three patients had evidence of bilateral conductive hearing loss. Here we present one of these cases.Results: Test results showed significant improvement in hearing sensitivity especially in frequencies round 1000 Hz.Conclusions: Bone conduction implants such as the Bonebridge system are an excellent treatment option for patients with bilateral conductive deafness. Bonebridge has good hearing results, relative simplicity, and low rate of complications. Experience has shown that the Bonebridge system is easy to use and highly reliable. The use of Bonebridge conduction implant system leads to a significant improvement in the quality of life

The subgroup identification problem for finitely presented groups

We introduce the subgroup identification problem, and show that there is a finitely presented group G for which it is unsolvable, and that it is uniformly solvable in the class of finitely presented locally Hopfian groups. This is done as an investigation into the difference between strong and weak effective coherence for finitely presented groups.Comment: 11 pages. This is the version submitted for publicatio

Morphology Influence on Wettability and Wetting Dynamics of ZnO Nanostructure Arrays

This study has been supported by internal research grant No. 14-95/2021/10 of Daugavpils University “Development of the Nanostructured Metal Oxide Coatings and Their Application in Optical Sensing for Heavy Metal Detection”.Changes in nanostructure morphology and size may result in very different surface wettability. In this research, the impact of different morphological parameters on the wetting dynamics of ZnO nanostructured layers is studied. Six different morphologies are chosen to determine the specific wetting processes of ZnO nanostructures: nanoneedles, small diameter rods, large diameter rods, nanotubes, nanoplates, and plain thin films. Wetting dynamics is investigated using conventional sessile drop technique and a novel approach based on electrochemical impedance spectroscopy. The results show that the surface of nanostructured ZnO thin films exhibits both hydrophilic and hydrophobic wetting behaviour, depending on nanostructure form, size, and orientation. ZnO nanostructure arrays are a promising platform for electrochemical and optical sensing in aqueous solutions. The full and effective use of the sensor working surface can be ensured only under the condition of complete wetting of the nanostructured layer. Therefore, it is important to take into account the peculiarities of the wetting process of a specific morphology of nanostructures. © 2022 V. Gerbreders et al., published by Sciendo.Institute of Solid State Physics, University of Latvia has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2

Recombinant Pseudomonas Vaccine: Technological Aspects of Obtaining and Evaluating Quality Indicators

For an aim to prevent Pseudomonas aeruginosa, a candidate recombinant vaccine has been developed. This vaccine – (RPV) was based on two protective proteins of P. aeruginosa: the outer membrane protein F (OprF) and the recombinant truncated form of the Exotoxin A (toxoid) that were adsorbed on the aluminum hydroxide. The optimal immunization schedule for mice included two intraperitoneal administrations with a two-week interval. RPV promoted to increase survival rates in challenged immunized mice and stimulated humoral and innate immune responses. During preclinical studies, we confirmed the immunogenicity of the vaccine that had not pyrogenicity, acute and chronic toxicity, allergenicity and immunotoxicity. Keywords: Pseudomonas aeruginosa, outer membrane protein F (OprF), toxoid, Pseudomonas Recombinant Vaccine (PRV

Non-Enzymatic Co3O4 Nanostructure-Based Electrochemical Sensor for H2O2 Detection

This article describes the synthesis of nanostructured cobalt oxide on iron wires and its application for the detection of hydrogen peroxide as working electrode for non-enzymatic electrochemical sensor. Cobalt oxide was obtained by the hydrothermal synthesis method using chloride and acetate anions. The resulting nanostructured coating obtained from the chloride precursor is a uniform homogeneous porous network of long nanofibers assembled into regular honeyсomb-like formations. In the case of an acetate precursor, instead of nanofibers, petal-like nanostructures assembled into honeycomb agglomerates are observed. The structure, surface, and composition of the obtained samples were studied using field-emission scanning electron microscopy along with energy-dispersive spectroscopy and X-ray diffractometry. The resultant nanostructured specimens were utilized to detect H2O2 electrochemically through cyclic voltammetry, differential pulse voltammetry, and i-t measurements. A comparative research has demonstrated that the nanostructures produced from the chloride precursor exhibit greater sensitivity to H2O2 and have a more appropriate morphology for designing a nanostructured sensor. A substantial linear correlation between the peak current and H2O2 concentration within the 20 to 1300 μM range was established. The Co3O4 electrode obtained exhibits a sensitivity of 505.11 μA·mM−1, and the electroactive surface area is calculated to be 4.684 cm2. Assuming a signal-to-noise ratio of 3, the calculated limit of detection is 1.05 μM. According to the interference study, the prevalent interfering agents, such as ascorbic acid, uric acid, NaCl, and glucose, do not influence the electrochemical reaction. The obtained results confirm that this sensor is suitable for working with complex analytes.The actual sample assessment demonstrated a recovery rate exceeding 95 %. --//-- This is an open access article Mizers, V., Gerbreders, V., Krasovska, M., Sledevskis, E., Mihailova, I., Ogurcovs, A., Bulanovs, A. and Gerbreders, A.. "Non-Enzymatic Co3O4 Nanostructure-Based Electrochemical Sensor for H2O2 Detection" Latvian Journal of Physics and Technical Sciences, vol.60, no.6, 2023, pp.63-84. https://doi.org/10.2478/lpts-2023-0037 published under the CC BY-NC-ND 4.0 licence.The research has been supported by ESF Project No. 8.2.2.0/20/I/003 “Strengthening of Professional Competence of Daugavpils University Academic Personnel of Strategic Specialization Branches 3rd Call”. The Institute of Solid State Physics, University of Latvia at the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2

Urban Soils: The Results Of The Study Of The Territory Of The City Of Ekaterinburg

In this article, we will consider the interesting, in our opinion, presented data of practitioners and scientists in terms of studying the formation and composition of urban soils, which is the most objective and stable indicator of man-made pollution, it clearly reflects the spread of pollutants and their actual distribution in the components of the urban environment. In this article, we have only shown the results of the analysis of the soils of g.For the period of the last 10 years, it is possible that for conclusions about the impact of the existing situation of the city territory on the entire environment, a more complete study of not only the chemical composition of soils, but also the impact of the economic mechanism of land management on the state of the city is necessary, the authors have not yet set themselves such a task. © Published under licence by IOP Publishing Ltd

Lease or easement for a forest plot for linear objects: An economic aspect

In this article, we will consider the interesting, in our opinion, presented data of practitioners and scientists in terms of the study of more cost-effective disposal of forest plots provided for linear objects on the lands of the forest fund of Russia. In our opinion, today it is quite relevant to resolve issues around the payment for the use of forest plots for linear objects for our country: granting the right to lease or establish an easement for the considered plots, as well as conducting forecast financial calculations of these options for the provision of land for 2020. In this article, we only showed forward-looking calculations on the example of the Ural Federal District, which has almost 10% of the country's forest land (almost 60% of the district's area), for conclusions about the damage to the budget due to lost revenue due to the choice of the form of granting forest plots, a more complete study of the economic mechanism of land management of the country is necessary, such a task the authors have not yet set themselves. © The Authors, published by EDP Sciences, 2021

Raman elastic geobarometry for anisotropic mineral inclusions

Elastic geobarometry for host-inclusion systems can provide new constraints to assess the pressure and temperature conditions attained during metamorphism. Current experimental approaches and theory are developed only for crystals immersed in a hydrostatic stress field, whereas inclusions experience deviatoric stress. We have developed a method to determine the strains in quartz inclusions from Raman spectroscopy using the concept of the phonon-mode Grüneisen tensor. We used ab initio Hartree-Fock/Density Functional Theory to calculate the wavenumbers of the Raman-active modes as a function of different strain conditions. Least-squares fits of the phonon-wavenumber shifts against strains have been used to obtain the components of the mode Grüneisen tensor of quartz (γm1 and γm3) that can be used to calculate the strains in inclusions directly from the measured Raman shifts. The concept is demonstrated with the example of a natural quartz inclusion in eclogitic garnet from Mir kimberlite and has been validated against direct X-ray diffraction measurement of the strains in the same inclusion