Structure and Biochemical Study of Nanocomposite Bioconstruction for Restoration of Bone-cartilaginous Defects

Porous and strong nanocomposite bioconstructions were formed by laser evaporation of an aqueous dispersion of carbon nanotubes in a protein matrix. The homogeneous dispersion was exposed to laser irradiation to create solid constructions. Continuous laser radiation with a wavelength of 970 nm and a power of 5-7 W was used. The porosity of nanocomposite bioconstructions was studied by the method of lowtemperature nitrogen porosimetry and X-ray microtomography, the tensile strength and relative elongation of bioconstructions were evaluated, and their biocompatibility was tested in vitro. It was found that with an increase of the carbon nanotube’s concentration, a slight decrease in strength (3-15 %), a decrease in the pore size (20- 40 %), and an increase in the degree of deformation (10-12 %) were observed. At the same time, the mechanical parameters of the bioconstructions met the requirements for the materials for the restoration of bone-cartilaginous defects. Using optical microscopy and the MTT-test, proliferative activity and structural features of bone tissue cells on the surface of nanocomposite bioconstructions were evaluated. Studies have shown no toxic or inhibitory effect on cells. The results of the studies can talk about the advantage of nanocomposite bioconstructions using as an implant material for improving the growth of biological cells and regenerating damaged biotissues. Keywords: Nanocomposites, laser radiation, mechanical properties, porosity, X-ray microtomography, biocompatibilit

Protracted fever after infliximab induction therapy in a patient with ulcerative colitis (clinical case)

Inflammatory bowel diseases (ulcerative colitis and Crohn’s disease) tend to increase in frequency and prevalence worldwide and lead to a significant reduction in quality of life with a complicated course. Intravenous administration of corticosteroids in acute severe ulcerative colitis is effective in 60–70 % of cases. Rescue therapy for patients with steroid‐refractory and steroid-dependence attacks is effective for reducing colectomy or colproctectomy and improves long-term treatment outcomes. Despite the proven efficacy of infliximab, limitations to the use of monoclonal antibodies are adverse reactions to the administration of genetically engineered biologic therapy (GEBT), both well-known and studied, and rare.The aim of the study. To analyze a case of an extremely rare and paradoxical incurable hyperergic reaction that occurred after using genetically engineered biological therapy with tumor necrosis factor alpha blockers in a patient suffering from ulcerative colitis.Materials and methods. We carried out the search in the PubMed, Embase, Scopus and Medline databases until November 1, 2022 using the following keywords: inflammatory bowel disease, ulcerative colitis (UC), anti-tumor necrosis factor α (antiTNFα), infliximab, fever, adverse events. In the scientific electronic library eLIBRARY, a search was made for Russian-language publications using similar queries in Russian. We analyzed the patient’s medical records from 03.06.2013 up to the present day; the patient signed an informed consent for the publication and discussion of the presented data.Conclusion. The widespread use of GEBT in the treatment of autoimmune and autoinflammatory diseases leads to the accumulation of both positive and negative experience of clinicians in real clinical practice. The officially described adverse events in the appointment of any drug suggest options for their prevention and treatment. Atypical manifestations or casuistic cases must be systematized for further fundamental pathophysiological studies

Periodic Pattern in the Residual-Velocity Field of OB Associations

An analysis of the residual-velocity field of OB associations within 3 kpc of the Sun has revealed periodic variations in the radial residual velocities along the Galactic radius vector with a typical scale length of lambda=2.0(+/-0.2) kpc and a mean amplitude of fR=7(+/-1) km/s. The fact that the radial residual velocities of almost all OB-associations in rich stellar-gas complexes are directed toward the Galactic center suggests that the solar neighborhood under consideration is within the corotation radius. The azimuthal-velocity field exhibits a distinct periodic pattern in the region 0<l<180 degrees, where the mean azimuthal-velocity amplitude is ft=6(+/-2) km/s. There is no periodic pattern of the azimuthal-velocity field in the region 180<l<360 degrees. The locations of the Cygnus arm, as well as the Perseus arm, inferred from an analysis of the radial- and azimuthal-velocity fields coincide. The periodic patterns of the residual-velocity fields of Cepheids and OB associations share many common features.Comment: 21 page

EPIDEMIOLOGICAL FEATURES OF MYASTHENIA GRAVIS

Aim. To assess the main epidemiological indicators of myasthenia gravis in various countries of the world, as well as in the territory of the Russian Federation.Materials and methods. Materials of publications on the study of epidemiological and population characteristics of myasthenia gravis of native and foreign authors are studied.Results. The indicator of the prevalence of myasthenia in the world varies from 0.5 to 20.0 per 100,000. The average primary morbidity of myasthenia gravis in the world is 0.53 per 100,000 population. The indicator varies from 0.17 to 2.13 per 100 thousand of the population.Conclusion. A fairly large range of epidemiological characteristics of myasthenia gravis in the world is revealed. The high prevalence of this pathology in the territory of the Russian Federation is established, which causes further interest in this type of research

The organisation of using videolaparoscopy in military field hospital in conditions of anti-terroristic operations in Easter Ukraine

Ministry of Defense, Kiyv, Military-Medical Clinical Centre of south region, Odessa, Military-Medical Clinical Centre of south region of Ukraine, Odessa, Odessa national medical university, Odessa, Military-Medical Clinical Center of South region, Odessa, Ukraine, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaBackground: Improvement of the medical support for injured in the region of anti-terroristic operation by using endovideo surgical techniques in the hospitals of the 2-3nd Echelon. Methods and materials: In June 2014 mobile military hospital was set up for providing qualified surgical help to warriors in the region of eastern Ukraine. 1460operations (62 laparoscopic) were carried out during first 9 months. Results: We use data of 23 patients suffered under abdomen and pelvis injuries: 18 had missile and gunshot wounds, 5 had closed traumas. Acute diseases of the abdomen cavity were diagnosed 39 patients. The penetrative character of shoot wound was excluded by 6 patients using the diagnostic laparoscopy. Out of 5 patients with closed traumas of abdomen, injuries of internal organs were identified in 2 cases, operations were finished laparoscopically. Suffering from urgent diseases of the abdomen cavity organs, 10 patients underwent the laparoscopic appendectomy for acute appendicitis; 2 persons - the laparoscopic diverticulectomy for Meckel’s diverticulitis; in 3 cases the ovarian apoplexy and haemoperitoneum were detected during the laparoscopy, the laparoscopic resection of ovarium was performed; 1 patient underwent laparoscopy for pancreonecrosis, 20 laparoscopic cholecystectomy for acute calculous cholecystitis; one laparoscopic cholecystectomy for cancer of the pancreas, obstructive jaundice; 2 patients had laparoscopic suturing of perforative ulcers in duodenum. Conclusion: Well-founded approaches of treatment and diagnosis of shoot wounds of abdomen and pelvis by using the video laparoscopic equipment in the field conditions (first time in the Ukrainian history) were performed. Application of the endovideo surgical technics allowed avoiding 20 useless laparotomies

Galactic Rotation Parameters from Data on Open Star Clusters

Currently available data on the field of velocities Vr, Vl, Vb for open star clusters are used to perform a kinematic analysis of various samples that differ by heliocentric distance, age, and membership in individual structures (the Orion, Carina--Sagittarius, and Perseus arms). Based on 375 clusters located within 5 kpc of the Sun with ages up to 1 Gyr, we have determined the Galactic rotation parameters Wo =-26.0+-0.3 km/s/kpc, W'o = 4.18+-0.17 km/s/kpc^2, W''o=-0.45+-0.06 km/s/kpc^3, the system contraction parameter K = -2.4+-0.1 km/s/kpc, and the parameters of the kinematic center Ro =7.4+-0.3 kpc and lo = 0+-1 degrees. The Galactocentric distance Ro in the model used has been found to depend significantly on the sample age. Thus, for example, it is 9.5+-0.7 kpc and 5.6+-0.3 kpc for the samples of young (50 Myr) clusters, respectively. Our study of the kinematics of young open star clusters in various spiral arms has shown that the kinematic parameters are similar to the parameters obtained from the entire sample for the Carina-Sagittarius and Perseus arms and differ significantly from them for the Orion arm. The contraction effect is shown to be typical of star clusters with various ages. It is most pronounced for clusters with a mean age of 100 Myr, with the contraction velocity being Kr = -4.3+-1.0 km/s.Comment: 14 pages, 4 figures, 2 table

Band spectra of rectangular graph superlattices

We consider rectangular graph superlattices of sides l1, l2 with the wavefunction coupling at the junctions either of the delta type, when they are continuous and the sum of their derivatives is proportional to the common value at the junction with a coupling constant alpha, or the "delta-prime-S" type with the roles of functions and derivatives reversed; the latter corresponds to the situations where the junctions are realized by complicated geometric scatterers. We show that the band spectra have a hidden fractal structure with respect to the ratio theta := l1/l2. If the latter is an irrational badly approximable by rationals, delta lattices have no gaps in the weak-coupling case. We show that there is a quantization for the asymptotic critical values of alpha at which new gap series open, and explain it in terms of number-theoretic properties of theta. We also show how the irregularity is manifested in terms of Fermi-surface dependence on energy, and possible localization properties under influence of an external electric field. KEYWORDS: Schroedinger operators, graphs, band spectra, fractals, quasiperiodic systems, number-theoretic properties, contact interactions, delta coupling, delta-prime coupling.Comment: 16 pages, LaTe

Antibiotic Dosing in Chronic Kidney Disease

Infectious process is an important cause of morbidity and mortality among patients with chronic kidney disease. Prescription of antibacterial drugs should take into account the pharmacokinetic parameters of the medicine and the individual characteristics of the patient. Adequate antibiotic dosing is crucial for positive treatment outcome and minimisation of side effects. The aim of the study was to analyse scientific literature on factors affecting the dosing of antibacterials in patients with chronic kidney disease. Since most antibacterial medicines are eliminated by the kidneys, a decrease in glomerular filtration rate or kidney function should be followed by the dose adjustment in order to prevent the medicine accumulation and reduce the risk of side effects. Antibiotic dosing in such patients should be accompanied by kidney function assessment and be adjusted to ensure effective and safe treatment, as well as prevention of bacterial resistance. The review provides data on the dosing of some antibiotic groups (beta-lactams, aminoglycosides, fluoroquinolones) at different creatinine clearance rates. Extrarenal excretion of medicines does not usually require the dose adjustment in patients with chronic kidney disease

Развитие электрохимических методов измерения скорости коррозии металлов научной школы профессора Л.И. Антропова

Розглянуто розвиток наукових основ електрохімічних методів визначення швидкості корозії металів, робота над якими започаткована під керівництвом видатного електрохіміка Л.І. Антропова та продовжується послідовниками його школи. Опрацьовано аспекти точності визначення швидкості корозії методом поляризаційного опору (Rp). Показано, що використання двохелектродної схеми істотно знижує похибку вимірювань Rp. Уточнені співвідношення для коефіцієнта пропорційності між Rp і швидкістю корозії з урахуванням структури подвійного електрохімічного шару та впливу специфічної адсорбції іонів, які перевірено експериментально. Виведено аналітичну залежність для визначення швидкості корозії за наявності великих поляризаційних ємностей. Розглянуто метод нелінійної подвійної поляризації для визначення кінетичних параметрів корозії за аналітичною формулою в системі з дифузійним або пасиваційним контролем, який не потребує застосування емпіричних коефіцієнтів. Описано новий неруйнівний метод на основі поляризаційного опору з використанням неполяризованих електродів. Показано приклади практичного застосування цього методу в дослідженнях корозійної стійкості зварного з’єднання. За дослідженнями характеру зміни поляризаційного опору в часі в сульфатній кислоті за наявності амінокислот і похідних гуанідину виведено кількісні співвідношення, які визначають зростання фазових плівок на поверхні металів залежно від часу експозиції та концентрації інгібітору.The development of scientific bases of electrochemical methods for the determination of the corrosion rate, which were originated under the guidance of outstanding electrochemists L.I. Antropov and continued by his followers’ school, was investigated. Accuracy aspects of the corrosion rate determination by polarization resistance (Rp) method were discussed. It was shown that application of the two-electrode cell significantly decreases Rp determination error. The relations for the proportionality constant between R p and corrosion rate accounting the electrochemical double layer structure and the influence of specific ion adsorption were improved and experimentally tested. Analytical dependence for corrosion rate determination in the presence of large polarization capacities was derived. A method of non-linear double polarization for the kinetic parameters of corrosion determination was discussed using analytical equation in systems with diffusion or passivation control without application of empirical coefficients. New non-destructive methods based on polarization resistance with application of non-polarizable electrodes were described. The examples of the practical application of this method in corrosion research of welded connection were shown. Quantitative relations for films growth on the metal surface at different exposure time and acid concentration were derived from time dependences of polarization resistance in sulfuric acid in the presence of aminoacids and guanidine derivatives.Рассмотрено развитие научных основ электрохимических методов определения скорости коррозии, работа над которыми была начата под руководством выдающегося электрохимика Л.И. Антропова и продолжается последователями его школы. Рассмотрены аспекты точности определения скорости коррозии методом поляризационного сопротивления (Rp). Показано, что использование двухэлектродной схемы существенно снижает погрешность измерений Rp. Уточнены соотношения для коэффициента пропорциональности между Rp и скоростью коррозии с учетом структуры двойного электрического слоя и влияния специфической адсорбции ионов, которые проверены экспериментально. Выведена аналитическая зависимость для определения скорости коррозии при наличии больших поляризационных емкостей. Представлен метод нелинейной двойной поляризации для определения кинетических параметров коррозии в системе с диффузионным или пассивационным контролем по аналитической формуле, который не требует использования эмпирических коэффициентов. Описан новый неразрушающий метод на основе поляризационного сопротивления с использованием неполяризуемых электродов. Показаны примеры практического применения этого метода в исследованиях коррозионной стойкости сварного шва. По результатам исследований характера изменения поляризационного сопротивления во времени в серной кислоте в присутствии аминокислот и производных гуанидина выведены количественные соотношения, которые определяют рост фазовых пленок на поверхности металла в зависимости от времени экспозиции и концентрации ингибитора