Approaches to the Modification of Perfluorosulfonic Acid Membranes.

Polymer ion-exchange membranes are featured in a variety of modern technologies including separation, concentration and purification of gases and liquids, chemical and electrochemical synthesis, and hydrogen power generation. In addition to transport properties, the strength, elasticity, and chemical stability of such materials are important characteristics for practical applications. Perfluorosulfonic acid (PFSA) membranes are characterized by an optimal combination of these properties.

Perfluorosulfonic Acid Membranes with Short and Long Side Chains and Their Use in Sensors for the Determination of Markers of Viral Diseases in Saliva.

The development of accessible express methods to determine markers of viral diseases in saliva is currently an actual problem. Novel cross-sensitive sensors based on Donnan potential with bio-comparable perfluorosulfonic acid membranes for the determination of salivary viral markers (-acetyl--methionine, -carnitine, and -lysine) were proposed. Membranes were formed by casting from dispersions of Nafion or Aquivion in -methyl-2-pyrollidone or in a mixture of isopropyl alcohol and water.

Potentiometric Sensor Arrays Based on Hybrid PFSA/CNTs Membranes for the Analysis of UV-Degraded Drugs.

The degradation of drugs is a substantial problem since it affects the safety and effectiveness of pharmaceutical products, as well as their influence on the environment. A novel system of three potentiometric cross-sensitive sensors (using the Donnan potential (DP) as an analytical signal) and a reference electrode was developed for the analysis of UV-degraded sulfacetamide drugs. The membranes for DP-sensors were prepared by a casting procedure from a dispersion of perfluorosulfonic acid (PFSA) polymer, containing carbon nanotubes (CNTs), whose surface was preliminarily modified with carboxyl, sulfonic acid, or (3-aminopropyl)trimethoxysilanol groups.

Correlation between Nafion Morphology in Various Dispersion Liquids and Properties of the Cast Membranes.

Nafion is a perfluorosulfonic acid polymer that is most commonly used in proton-exchange membrane fuel cells. The processes of pretreatment and formation of such membranes strongly affect their properties. In this work, dispersions of Nafion in various ionic forms and dispersing liquids (ethylene glycol, -dimethylformamide, -methyl-2-pyrrolidone and isopropyl alcohol-water mixtures in different ratios) were obtained and studied.

"Unshaved Intradermal Running Suture for Elective Cranial Neurovascular Surgeries".

Objective: In this paper, we analyze the experience and propose a method of incision and stitching of the postoperative scalp wound without shaving hair in elective neurosurgical interventions.

Methods: Between January 2021 and May 2022, 44 patients with various neurovascular pathologies were included in the study. The age of the patients varied from 28 to 58 years.

On the Properties of Nafion Membranes Recast from Dispersion in -Methyl-2-Pyrrolidone.

Perfluorosulfonic acid Nafion membranes are widely used as an electrolyte in electrolysis processes and in fuel cells. Changing the preparation and pretreatment conditions of Nafion membranes allows for the optimization of their properties. In this work, a Nafion-NMP membrane with a higher conductivity than the commercial Nafion 212 membrane (11.

Multisensory Systems Based on Perfluorosulfonic Acid Membranes Modified with Functionalized CNTs for Determination of Sulfamethoxazole and Trimethoprim in Pharmaceuticals.

Sulfamethoxazole and trimethoprim are synthetic bacteriostatic drugs. A potentiometric multisensory system for the analysis of sulfamethoxazole and trimethoprim combination drugs was developed. Perfluorosulfonic acid membranes containing functionalized CNTs were used as the sensor materials.

Keyhole surgery for giant basal brain tumors. Theoretical explanation with an example of trans-eyebrow subraorbital approach.

Background: Improvement of modern neurosurgical technology has given rise to keyhole surgery for a wide range of pathologies. Supraorbital trans-eyebrow approach has been described in detail for small tumors of anterior cranial fossa and suprasellar neoplasms. Can we use this small and less traumatic approach for a more complex tumor extending beyond the suprasellar region?

Objective: To analyze own experience of surgical treatment of large and giant parasellar tumors via supraorbital approach, to identify the principles of such operations, indications and possible limitations.

Trans-eyebrow supraorbital endoscope-assisted keyhole approach to suprasellar meningioma in pediatric patient: case report and literature review.

Background: Meningiomas are rather uncommon tumors in the pediatric population, differing significantly from those found in adults by their atypical location, higher rate of more malignant types, consequently higher risk of recurrence and a less favorable outcome. Even in children, suprasellar meningiomas without dural matrix are rare findings mimicking more common suprasellar lesions.

Case Presentation: Here we describe a case of a 12-year-old girl who presented with a rapidly progressing chiasmal syndrome and was diagnosed by MRI with an unusual suprasellar tumor that could not fit the diagnoses expected in a case of a parasellar mass in a child, similar to a craniopharyngioma or optic pathway glioma.

[Tubular retractors for transcranial approaches to intraaxial brain tumors in children].

Unlabelled: Reduction of surgical trauma associated with approach to deep brain structures including resection of tumors is an urgent direction in development of techniques and technology.

Objective: To analyze the efficacy and safety of tubular retractors in surgery of deep brain tumors in children.

Material And Methods: The study included 17 children with deep brain tumors who underwent surgery between 2020 and 2021.

Perfluorosulfonic Acid Membranes Thermally Treated and Modified by Dopants with Proton-Acceptor Properties for Asparaginate and Potassium Ions Determination in Pharmaceuticals.

The influence of incorporation of the dopants with proton-acceptor properties into perfluorosulfonic acid cation exchange membranes (MF-4SC and Nafion), and their treatment conditions on the characteristics of Donnan potential (DP)-sensors (analytical signal is the Donnan potential) in the aqueous solutions containing asparaginate and potassium ions in a wide pH range was investigated. A silica, surface modified by 3-aminopropyl and 3-(2-imidazolin-1-yl)-propyl groups, was used as the dopant. The membranes were subjected to mechanical deformation and thermal treatment at various relative humidities.

Non-woven bilayered biodegradable chitosan-gelatin-polylactide scaffold for bioengineering of tracheal epithelium.

Objectives: The conversion of tissue engineering into a routine clinical tool cannot be achieved without a deep understanding of the interaction between cells and scaffolds during the process of tissue formation in an artificial environment. Here, we have investigated the cultivation conditions and structural features of the biodegradable non-woven material in order to obtain a well-differentiated human airway epithelium.

Materials And Methods: The bilayered scaffold was fabricated by electrospinning technology.

Experimental animal model for assessment of tracheal epithelium regeneration.

Objectives/hypothesis: To develop an experimental model in rabbits for assessment of tracheal epithelium regeneration through application of either natural or artificial polymer scaffolds.

Study Design: First, we identified the size of full-thickness mucosal defect, which does not allow self-healing (a "critical defect"), thus representing an adequate experimental model for regenerative therapy of tracheal epithelium damage. Then, two methods of polymer scaffold fixation at the site of the epithelium defect were compared: suturing and fixation with a stent.

[PLGA mesh-collagen hybrid scaffold and tissue-engineered product in substitution urethroplasty: experimental validation].

Urethral strictures are a pressing issue in modern medicine. Substitution urethroplasty is considered one of the most effective treatment methods. However, despite the surgery showing good results, many problems remain unresolved, one being substitute material deficiency in extensive or recurrent strictures, as well as in cases requiring multistage surgeries, including those used to treat hypospadias.

[Influence of the MTHFR gene C677T polymorphism with physical performance and function of cardiovascular system in athletes].

The aim of the was to investigate the interrelation between MTHFR gene C677T polymorphism and morphometric echocardiography and physiologic parameters in male ski racers (n = 23). Genotyping was performed by RFLP. Echocardiography was performed by ultrasound scanner Nemio MX (Toshiba, Japan).

[Autonomous cardioneuropathy in patients with coronary heart disease].

This paper reports the results of an electron microscopic study of the sinoatrial node in deceased patients with CHD in whom high-resolution rhythmocardiography revealed autonomous cardioneuropathy. Non-specific morphological changes in pacemaker cells of the sinoatrial node (swelling and disintegration of mitochondria, incorporation of calcium and accumulation of lipofuscin in mitochondria) can be regarded as manifestations of ischemic insufficiency of cardiac tissue perfusion. The rhythmocardiograms of such patients showed signs of autonomous cardioneuropathy manifest as the sharply decreased amplitude of all vegetative waves.

[Autonomous pharmacodynamics of organic nitrates in patients with unstable angina].

The pharmacological test with the use of high-resolution rhythmocardiography for the analysis of cardiac rhythm variability associated with peripheral vegetative regulation of the synoatrial node was applied to study effects of a single dose of organic nitrates (nitroglycerin and mononitrate isosorbide) in 41 patients with unstable angina. Rhythmocardiograms were obtained before and after a morning sublingual dose of nitrates preceding intake of basal drugs. The results suggest negative action of nitrates on peripheral vegetative regulation of pacemaker activity of the synoatrial node.

[Free-radical processes in cardiomyopathy and concomitant vibration disease].

Progression from local vibration to cardiovascular pathology in patients with vibration disease is associated with remodeling cardiac and vascular tissues under effect of oxidative stress. Myocardium and nodular tissue are most vulnerable during development of occupational cardiopathy. Alteration of the heart rhythm wave structure is a predictor of remodeling.

Heart rate variability analysis at coronary artery disease and angina pectoris.

The purpose of this study was to present results of special examination and prospective observation of patients with coronary artery disease (CAD) and angina pectoris (AP) in practical cardiology. Except standard cardiological methods, we used high-resolution rhythmocardiography and apparatus-program complex for registration and analysis of the heart rate variability. There was an evaluation of the autonomic and humoral-metabolic regulative influences on pacemaker activity of the heart sinus node in 273 patients selected by criteria of including-excluding patients with CAD and AP.

[Occupational diseases-related autonomic system cardioneuropathy in Chelyabinsk region].

Cardiovascular diseases appear to be the most frequent complication and death cause in patients with various forms of occupational diseases. Autonomous nervous system could play significant role in genesis of those complications.

[Parameters of hypothalamo-pituitary-adrenal, thyroid and genital systems in patients with occupational allergic dermatosis].

The article deals with results obtained in studying parameters of hypthalamus-pituitary-adrenals, thyroid and genital systems. The studies revealed significant changes of both peripheral and central units in these systems. The authors present some clinical data obtained by endocrinologic and gynecologic examinations.

Possibilities of high-resolution HRV analysis.

Objective: The purpose of the study was to present the results of 15-year application in practical cardiology of the method of high-resolution registration and analysis of heart rate variability (HRV) for diagnosis of the cardiovascular pathology.

Methods: Database consists of more than 46 thousand cases with different cardiovascular diseases. Here are shown some peculiarities of the HRV analysis and perspective possibilities of the method, named rhythmocardiography.

[Dirofilariasis in the Volgograd region--a new disease in the region].

Due to the availability of factors whose reasons have not been studied so far for this area. Volgograd and Volgograd Region should be recognized to be a dirofilariasis-endemic zone. The lack of an actual system of prevention, as well as other objective and subjective factors are responsible for constantly increasing numbers of ill human beings and animals.