Use of biodegradable polycaprolactone matrix for filling bone defects (experimental study)

Background. There are unresolved issues in bone defect management associated with complications, invasiveness and long duration of treatment. The use of elastic implants made of bioactive biodegradable materials that take any form of defect could close many of them.The aim. To investigate features of reparative regeneration in filling bone defects with an elastic degradable implant made of polycaprolactone (PCL) with and without hydroxyapatite (HA).Materials and methods. The study was carried out on 10 adult mongrel dogs. A non-through cylindrical hole, 4 mm in diameter and 10 mm deep, was modeled in the upper third of the diaphysis of the tibia. The defects thus formed were filled with an elastic degradable implant made of polycaprolactone. In Group 1, HA was not added to polycaprolactone, while HA was added in dogs of Group 2. Radiographic and histological methods were used to study the results.Results. It was found that the tested materials did not cause toxic and allergic reactions, both local and general, during intravital observations and in post-mortem anatomical preparations. After 28 days in both series, the implant biodegraded and was replaced by bone tissue. The proportion of the bone component and the numerical density of microvessels in the defect zone in Group 2 were significantly higher than in Group 1.Conclusion. Elastic implants produced of polycaprolactone by electrospinning are biologically compatible, biodegradable and can be used to heal bone defects. Hydroxyapatite that was added stimulates the activity of osteogenesis

Optimizing the lithotripsy timing after drainage of the upper urinary tract in patients with urolithiasis and obstructive uropathy

Introduction. Timely unresolved upper urinary tract (UUT) obstruction in patients with infection can cause severe complications, such as sepsis, pyonephrosis and even death. There are no clear recommendations regarding the methods and timing of drainage. At the same time, this issue is still the subject of discussion in publications of recent years.Purpose of the study. To optimize the timing of lithotripsy after drainage of the UUT in patients with urolithiasis and obstructive uropathy (OU).Materials and methods. At the first stage, 90 patients with OU caused by the stone of the ureteropelvic junction underwent drainage of the UUT using a percutaneous nephrostomy. Subsequently, percutaneous nephrolithotripsy (PNLT) was performed at various times after drainage. The level of inflammatory markers (IL-8) and profibrotic factor (MCP-1) in the urine was determined. The calculated concentrations of urinary biomarkers were normalized by the level of urinary creatinine. Urine sampling for the analysis was carried out during and after the PCN placement (nephrostomy urine) 7 days later, and then once weekly before surgery. The coefficient K was calculated using a patented formula to evaluate the process of kidney remodeling. Urine sampling was performed for culture to determine the bacterial spectrum and antibiotic sensitivity.Results. The values of K ≤ 1.85 were observed in 11 patients of the group with OU (12.2%), K > 1.85 in 79 (87.8%) by day 21. The values of K ≤ 1.85 were achieved in 70 patients (88.6%) by day 28 and 4 patients (80.0%) by day 35. PNLT was performed on 21 days in patients with K ≤ 1.85 (11 patients), no complications were noted in the postoperative period., PNLT was performed in patients with K ≤ 1.85 (70 patients) by day 28, exacerbation of pyelonephritis and the development of chronic kidney disease were not noted. Six patients with values of K ˃ 1.85 underwent PNLT by day 28. In the postoperative period, all patients had an exacerbation of calculous pyelonephritis, 50% had a decrease in glomerular filtration rate within 3 months after surgery. The bacteria in urine were detected in 55 (61.0%) patients. Escherichia coli (63.0%), Proteus mirabilis (18.0%), Enterococcus faecalis (14.5%), Streptococcus haemolyticus (2.5%) were identified most often.Conclusion. The use of the developed remodeling index allows optimizing the surgery timing and minimizing the development of complications during the postoperative period. The presence of bacteria is associated with a long process of renal parenchymal remodeling

Changes of the body functions during long-term hypokinesia

Prolonged hypokinesis (100-170 days) studied in 2000 rats kept in cages limiting their mobility provoked considerable changes in the gaseous and energetic metabolism: an elevation of the total gaseous metabolism and of the rate of O2 requirement by the muscles (in the late periods of hypokinesis) and a change in the intensity of tissue respiration of the liver and myocardium. There also proved to be a reduction in the level of phosphorylation and separation of oxidative phosphorylation in the myocardium, liver, and partially in the skeletal muscle. Prolonged hypokinesia led to changes in tissue metabolism: a disturbance of development of the animals, a marked delay and an increase in the weight of the organism and the muscular system, and disturbances of the mineral and protein metabolism. Prolonged hypokinesis also lead to exhaustion of the hypothalamus-hypophysis-adrenal cortex system

ЭФФЕКТИВНОЕ ЖИВОТНОВОДСТВО – СТРАТЕГИЯ АГРАРНОЙ ПОЛИТИКИ БЕЛАРУСИ

Livestock breeding – is the most important branch of agriculture and the main source of funds for development of industrial and social base of agro-industrial complex of the country, which ensures food security. The animal husbandry is facing few priority tasks. The first – to have a competitive breeds of farm animals and poultry, the second – to implement efficient technologies for management, feeding and reproduction of animals, and the third – to ensure the biological safety the branch. Measures in the resent years aimed at increase of efficiency of animal breeding branches provided more than 7.45 million tons of milk, 1662 thousand tons of meat of livestock and poultry (body weight) for production in 2015 from all the categories of farms. In the whole in the country 730 kg of milk and 120 kg of meat was produced, calculated per capita. According to these indicators, as well as according to the amount of high-value food protein of animal origin produced (90–100 g per person a day) Belarus is among the most advanced countries along with Canada, the US and other. These volumes of livestock production ensure domestic requirements and export potential of the republic. More than 56 % of milk and 30 % of meat produced in the country is exported to external market. According to experts opinion, about 60–65 % of dairy products and 45 % of meat produced in the country will be exported in the near future. The article analyzes the modern state, main results, priorities and problems of containment of increase of productive traits of farm animals in Belarus. Ways to improve the competitiveness of the industry, as well as rates of livestock production growth in the future are presented.Животноводство – важнейшая отрасль сельского хозяйства и основной источник финансовых средств для развития производственной и социальной базы агропромышленного комплекса страны, которая обеспечивает продовольственную безопасность. Перед животноводством стоит несколько приоритетных задач. Первая - иметь конкурентоспособные породы сельскохозяйственных животных и птицы, вторая – внедрить эффективные технологии содержания, кормления и воспроизводства животных, третья – обеспечить биологическую безопасность отрасли. Осуществляемые в течение последних лет мероприятия по повышению эффективности ведения отраслей животноводства позволили обеспечить производство в 2015 г. всеми категориями хозяйств более 7,45 млн т молока, 1662 тыс. т мяса скота и птицы (в живом весе). В расчете на душу населения в целом по республике произведено 730 кг молока и 120 кг мяса. По этим показателям, а также по производству  высокоценного пищевого белка животного происхождения (90–100 г на человека в сутки) Беларусь входит в число самых передовых стран, таких как Канада, США и др. Эти объемы производства животноводческой продукции обеспечивают внутренние потребности республики и экспортный потенциал. Более 56 % произведенного в стране молока и около 30 % мяса поставляется на внешний рынок. По мнению экспертов, около 60–65 % молочной продукции и 45 % мяса, производимых в стране,в ближайшем будущем будут отправляться на экспорт. В статье анализируется  современное состояние, основные результаты, приоритетные направления развития и проблемы сдерживания повышения продуктивных качеств животных Беларуси. Приводятся пути повышения конкурентоспособности отрасли, а также темпы прироста производства продукции животноводства на перспективу

Commensurate-Incommensurate Phase Transitions for Multichain Quantum Spin Models: Exact Results

The behavior in an external magnetic field is studied for a wide class of multichain quantum spin models. It is shown that the magnetic field together with the interchain couplings cause commensurate-incommensurate phase transitions between the gapless phases in the ground state. The conformal limit of these models is studied and it is shown that the low-lying excitations for the incommensurate phases are not independent. A scenario for the transition from one to two space dimensions for the integrable multichain models is proposed. The similarities in the external field behavior for the quantum multichain spin models and a wide class of quantum field theories are discussed. The exponents for the gaps caused by relevant perturbations of the models are calculated.Comment: 23 pages, LaTeX, typos correcte

A sufficient criterion for integrability of stochastic many-body dynamics and quantum spin chains

We propose a dynamical matrix product ansatz describing the stochastic dynamics of two species of particles with excluded-volume interaction and the quantum mechanics of the associated quantum spin chains respectively. Analyzing consistency of the time-dependent algebra which is obtained from the action of the corresponding Markov generator, we obtain sufficient conditions on the hopping rates for identifing the integrable models. From the dynamical algebra we construct the quadratic algebra of Zamolodchikov type, associativity of which is a Yang Baxter equation. The Bethe ansatz equations for the spectra are obtained directly from the dynamical matrix product ansatz.Comment: 19 pages Late

The Bethe ansatz as a matrix product ansatz

The Bethe ansatz in its several formulations is the common tool for the exact solution of one dimensional quantum Hamiltonians. This ansatz asserts that the several eigenfunctions of the Hamiltonians are given in terms of a sum of permutations of plane waves. We present results that induce us to expect that, alternatively, the eigenfunctions of all the exact integrable quantum chains can also be expressed by a matrix product ansatz. In this ansatz the several components of the eigenfunctions are obtained through the algebraic properties of properly defined matrices. This ansatz allows an unified formulation of several exact integrable Hamiltonians. We show how to formulate this ansatz for a huge family of quantum chains like the anisotropic Heisenberg model, Fateev-Zamolodchikov model, Izergin-Korepin model, $t-J$ model, Hubbard model, etc.Comment: 4 pages and no figure

Measurement of J/psi to eta_c gamma at KEDR

We present a study of the inclusive photon spectra from 5.9 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c width and mass. Our preliminary results are: M(eta_c) = 2979.4+-1.5+-1.9 MeV, G(eta_c) = 27.8+-5.1+-3.3 MeV, B(J/psi to eta_c gamma) = (2.34+-0.15+-0.40)%.Comment: To be published in Proceedings of the PhiPsi09, Oct. 13-16, 2009, Beijing, Chin

Entanglement Entropy dynamics in Heisenberg chains

By means of the time-dependent density matrix renormalization group algorithm we study the zero-temperature dynamics of the Von Neumann entropy of a block of spins in a Heisenberg chain after a sudden quench in the anisotropy parameter. In the absence of any disorder the block entropy increases linearly with time and then saturates. We analyze the velocity of propagation of the entanglement as a function of the initial and final anisotropies and compare, wherever possible, our results with those obtained by means of Conformal Field Theory. In the disordered case we find a slower (logarithmic) evolution which may signals the onset of entanglement localization.Comment: 15 pages, 9 figure