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The results of the study of the length of the prenatal period of ontogenesis of 51 Ukrainian Red Dairy breed tribal cows are presented, and the relationship of this trait with the rate of growth of the organism in the postnatal period (at birth, at 6, 12 and 18 months) and dairy productivity for the first lactation are investigated. Also, at different stages of the prenatal period of ontogeny the dynamics of the mass of 66 fetus and some parenchymatous organs (liver, spleen, thymus) selected by anatomical preparation are determined. The aim of the research was to establish the possibility of predicting dairy productivity of Ukrainian Red Dairy breed cows over the length of the prenatal period and the effect of this period on the postnatal growth rate of the organism, and also to ascertain the existence of a regularity between the increase in fetus mass and the development of certain hemopoiesis organs at different stages of prenatal development. Laboratory animals were divided into three groups, depending on length of their prenatal period: less than 277 days-reduced (group I), 277-283 - medium (group II) and more than 283 days - extended period (group III). For 305 days of the first lactation, the advantage over milk yield, milk fat yield and milk protein belongs to animals with shortened duration of the prenatal period of ontogenesis in comparison with contemporaries who had an extended period with a statistically significant difference (P < 0.05). A further study in the short term may be a study of the relationship between the duration of the prenatal period and the rate of fetal growth with the subsequent forming of the physique, and in the long term turning into the study of the relationship between the duration of the prenatal period and the rate of fetal growth with a duration of productive use and lifelong productivity. [ABSTRACT FROM AUTHOR]

The effects of dispersed oxides Fe2O3, Cr2O3, α-PbO, β-PbO, PbO2, SiO2 on the processes of radical polymerization of styrene are studied. It is shown that the dispersed oxides affect the polymerization rate and the response of the thermal decomposition of radical initiators. Peroxides are adsorbed on the surface of mineral oxides and decomposed into free radicals. On the surface of SiO2 and Cr2O3, a heterolytic decomposition of peroxides takes place. The oxide introduced into the polymerization system reduces the molecular weight of the polymer that forms under these conditions. The degrees of grafting macromolecules to the surface of oxides were found. [ABSTRACT FROM AUTHOR]

We study the influence of temperature of a working medium and loading frequency on the contact fatigue of 20KhN3A and ShKh15 steels in oil and in a 3% NaCl aqueous solution. It is shown that, as the loading frequency increases, the contact fatigue of steels increases in a 3% NaCl aqueous solution but does not change in oil. At the same time, as temperature increases, the contact fatigue decreases in a 3% NaCl aqueous solution but remains almost constant in oil. It is shown that the outlined behaviors of the analyzed steels is explained by the action of the components of working media and their concentrations in the surface layers in the course of the tests. [ABSTRACT FROM AUTHOR]

The focus of this paper is to investigate the exact solutions of a diffusive susceptible‐infectious‐recovered (SIR) epidemic model, characterized by a nonlinear incidence. A four‐dimensional Lie point symmetry algebra is obtained for this model. We utilize the Lie symmetries to deduce the optimal system of one‐dimensional subalgebras. The reductions and group‐invariant solutions are obtained with the aid of these subalgebras. We also derive new group‐invariant solutions and reductions for the underlying model via subalgebras that are related to the optimal system by adjoint maps. We developed the diffusive susceptible‐infectious‐quarantined (SIQ) model with quarantine‐adjusted incidence function to understand the transmission dynamics of COVID‐19. [ABSTRACT FROM AUTHOR]

Among non-infectious diseases in humans and animals, iodine deficiency pathology is a significant problem worldwide due to its high prevalence and broad spectrum of clinical signs and consequences. Increasing anthropogenic pressure on the natural environment has led to an ecological crisis. The situation is complicated in the biogeochemical zones of Ukraine, where insufficient or excessive content of mobile forms of microelements in soils and water sources determines the biological reaction of local flora and fauna. In animals, this is manifested by endemic diseases, including hypothyroidism. Mineral elements, including iodine, are a structural material in the body of animals; they participate in the processes of digestion and absorption in the digestive tract, synthesis, splitting, and excretion of metabolic products, creating the necessary conditions for the normal functioning of enzymes, hormones, vitamins, stabilize acidic-alkaline balance and osmotic pressure. Of all the organs of the endocrine system, the thyroid gland is the most closely related to the environment since its structure and function largely depend on the supply of iodine from the outside. The authors describe in detail the role of synergists of iodine (selenium, iron, copper, zinc, cobalt) and antagonists, the imbalance of trace elements, the influence of ionizing radiation, and the nature of feeding. It is substantiated that the action of environmental elements and anthropogenic factors determines the appearance and risk of developing thyroid pathology in cows. The article presents materials from a complex study of the clinical course of iodine deficiency, as well as morphological and biochemical parameters of the blood of cows. The object of research is clinically healthy and sick animals – cattle. Diagnosis of thyroid pathology was carried out with the help of clinical and laboratory tests. The clinical examination of cows was carried out according to the generally accepted scheme, taking into account the results of the general condition and studies of individual organs and systems. The research was conducted in three districts of the Zhytomyr region (Korostenskyi, Narodytskyi, and Popilnianskyi). During the external examination of the animals, swelling in the intermaxillary space (Myxedema) was observed, which was found only in 5 out of 90 dairy cows (5.6 %), mainly from Narodytsky district (8.9 %), compared to 2.2 % in Korosten district. It was observed that goiter was established in only three cows out of 90 (3.35%); all were in Narodytsky district (6.7 %). Enophthalmos was detected in 24 out of 90 dairy cows (26.7 %), including 16 out of 45 cows (35.4 %) in the Narodytsky District, while this symptom was not detected in the Popilnya District dairy cows. It was established that the content of thyroxine in dairy cows of Narodytskyi and Korostensky districts ranged from 2.2 to 4.25 μg/100 ml (28.3–54.7 nmol/l), respectively, and was on average 3.4 ± 0.21 μg/100 ml (43.8 ± 2.70 nmol/l, in cows from the conditionally clean territory (Popelnyan district) – 5.3 ± 0.65 nmol/l. [ABSTRACT FROM AUTHOR]

The homeostasis of the whole organism and the analysis of hematological parameters in red deer (Cervus elaphus) play an essential role in comparative physiology for health assessment and disease diagnosis. The obtained blood results can be the basis for assessing the condition of wild deer populations with an existing clinical picture or characterize the nutritional status, habitat, or other stress factors, as the hematopoietic system is susceptible to any changes in the animal body. In the course of the research, it was found that the body weight of adult deer varied depending on the population. Female deer of the Latvian and Lithuanian crossbreeds and the Eastern European population had the highest weight. As for the males, the animals of the Hungarian population had a higher weight than the English population. A high level of growth intensity in the early postnatal period was characteristic of both young females (body weight gain was in the range of 44.8–45.8 kg) and males (42.6–44.12 kg). The analysis of hematological parameters confirmed that the number of red blood cells and hemoglobin content increased in the blood of animals of the English population under technological stress (by 5.6 and 4.4 %). Regarding individual populations, it was noted that under the same conditions of immobilization of animals (medication), the number of red blood cells in the blood of Latvian crossbred deer was 8.5 % higher than the English population. The hemoglobin content was 5.3 % lower, and the saturation of red blood cells with hemoglobin was 12.9 % lower. It was found that the hematological parameters of 3–4 month-old fawns (females and males) of the English population were characterized by relative stability. Against the background of a tendency to a higher number of red blood cells in females (by 12.8 %), the hemoglobin content was 3.3 % lower than in males. The number of leukocytes in the blood of females was slightly higher than that of males, although no significant deviations were noted in some forms of white blood cells. [ABSTRACT FROM AUTHOR]

The article presents the research results on the Development of manufacturing technology and the study of the stability of a solution for oral use based on carnitine hydrochloride, vitamins - E, B12, choline chloride, selenium, and zinc. "Devivit Carnitine" oral is used for the prevention of diseases of liver and muscle tissue metabolism in farm animals and poultry, nephrosis, myocarditis, prevention of stress (heat, transport, sound, food, postvaccination, etc.), and prevention of vitamin and hypovitaminosis. When developing the drug technology, experimentally obtained pharmaco-technological properties of active substances and excipients were taken into account. The technological process of preparing an oral solution consists of four technological stages: preparation of canisters for filling, preparation of the solution, filling containers with medicine and packaging. The stability and shelf life of "Devivit Carnitine" (solution for oral use) in plastic canisters were determined. It was established that the drug sample in plastic canisters was stable, according to all quality control methods indicators, during the entire period of the study. The shelf life of the medicinal product with carnitine hydrochloride, vitamins E and B12, choline chloride, selenium, and zinc is 12 months. In the future, a study of preclinical data is planned to verify whether the drug does not reveal a particular hazard for animals based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, carcinogenicity, and developmental toxicity. [ABSTRACT FROM AUTHOR]

This topic covers a wide range of aspects, including improving the genetic potential of animals through industrial crossbreeding, ensuring optimal housing conditions, and developing technologies for efficient use of the energy generated by these animals. Modern methods of industrial crossbreeding are determined by strategic plans to improve the genetic pool of animals to obtain more productive and disease-resistant offspring. Using advanced genetic technologies and modern breeding methods enhances product quality and ensures resistance to adverse factors. Considering the physiological needs of different breeds, providing appropriate nutrition and maintenance following current standards helps maintain high productivity and ensure the harmonious development of animals. In obtaining additional energy carriers, the latest technologies for using livestock waste in biogas, compost, and other energy resources are being studied. This contributes not only to the improvement of the environmental sustainability of farms but also to the use of internal resources for additional energy production. Summing up, modern approaches to the use of industrial crossing, housing conditions, and obtaining other energy carriers help solve complex tasks in animal husbandry, providing an optimal balance between productivity, efficiency, and environmental sustainability. It was established that the dynamics of live weight gains were more incredible in ½ Charolais steers when kept on deep litter, and on average up to 15 months, the average daily gains amounted to 947.9 g per day, and in purebreds under box keeping – 815.9 g; the absolute gains in live weight of purebred bulls of the Ukrainian black-spotted dairy breed, when kept in boxes for up to 15 months, reached 367.1 kg, which is 16.18 % less than that of ½ Charolais bulls when kept on deep bedding, with a probable difference of Р < 0.001. Innovative approaches to the use of the effect of heterosis and the conditions of keeping overrepair bulls in the production of beef have positive results, where ½ Charolais crossbreeds in conditions of keeping on deep bedding reach 453.9 kg by the age of 15 months, and their purebred counterparts – 406.7 kg, with a probable difference of P < 0.001. The results of the economic efficiency of the use of industrial crossbreeding, keeping conditions of purebred and crossbred bulls, show additional profits per head of 1,468.8 UAH ½ Charolais (maintenance on deep litter) and an increase in the level of profitability by 34.40 % compared to purebred Ukrainian black and white bulls dairy breed (maintenance boxing). [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Agricultural Research / Turkiye Tarimsal Arastirmalar Dergisi is the property of Siirt University, Faculty of Agriculture / Siirt Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Providing mankind with high-quality products of aquaculture is possible only by introduction of modern industrial technologies to fish farming, growing fish based on modern scientific achievements. Assessment of the ecotoxic situation and identification of impacts of various unfavourable factors of aquatic environment on aquatic organisms should be made through morphological studies of the organs that are first to encounter the impact. The study revealed species specifics of the morphology of the liver of the fishes of the Cyprinidae family – Prussian carp (Carassius gibelio), Eurasian carp (Cyprinus carpio), and bighead carp (Hypophthalmichthys nobilis), which vary by extent of the motor activity in the aquatic environment, nutrition, etc. We determined that during phylogenetic development of fish that grow in the aquatic environment, there occurs a certain restructuring of the liver: the adaptation to various living conditions were accompanied by changes in a number of parameters of macro- and microscopic architectonics of the liver. Cyprinus carpio and Carassius gibelio (omnivores) have a two-lobe liver, while Hypophthalmichthys nobilis (a herbivore) has a three-lobe liver. For C. carpio and H. nobilis, a characteristic feature of the liver was presence of the hepatopancreatitis (the liver and the pancreas, associated into a single organ), and in C. gibelio, they are differentiated into individual organs. A peculiarity of the microscopic structure of the liver of the Cyprinidae family is poorly developed interlobular connective tissue, and parenchyma of the liver lobule has a tubular structure as polyhedral, curved thick-walled tubules, the walls of which are hepatocytes. The greatest amounts of cytoplasm and karyoplasms were seen in C. gibelio, equaling respectively 12.98 ± 1.42 and 0.40 ± 0.02 µm³. The lowest volume of the indicated parameters was in C. carpio, particularly 2.97 ± 0.22 and 0.21 ± 0.01µm³, respectively. The lowest nuclear-cytoplasmic ratio was observed in hepatocytes of C. gibelio (0.0316 ± 0.0024). The conducted morphological studies at the levels of organs, tissues and cells can reveal how the fishes’ bodies adapt to particular living conditions and impacts of environmental factors. [ABSTRACT FROM AUTHOR]

The article is devoted to the development of ecological tourism in the agrarian territories of Ukraine, in particular, the creation of an organizational model of a living museum-ethno-farm, exhibits of which are productive gray cattle, whose herds a hundred years ago formed the basis of the economy disappearing. As objects of the tourist business, animals of the gray Ukrainian breed are beautiful to tourists: they have a beautiful appearance that is immediately memorable, have a calm, non-aggressive temperament, and have an excellent ability to get used to pastoral work. Today there are about a thousand animals of the aboriginal gray Ukrainian breed (in two state farms of Ukraine); this breed is recognized as a national heritage and has unique genetic and phenotypic qualities. The proposed model of a living open-air museum includes structural elements that allow creative use of local conditions of the modern Ukrainian village for the location of the ethno-farm and provide a vector of solutions to acute socio-cultural problems that will promote sustainable rural development: stop depopulation, expand to the history of their land, etc. The development of living museums-ethnofarms will reveal and use in the process of creative rethinking of folk traditions accumulated in previous generations invaluable qualities, namely: respect for rural labor and knowledge of the benefits of environmental management in environmental and social challenges. [ABSTRACT FROM AUTHOR]

The results of the production approval fully confirmed the high efficiency of introducing the feed additive "Butaselmevit-plus" into the compound feed for piglets. It was established that at the end of the piglet rearing period (at the age of 75 days), the average weight of one head in the experimental group was 32.6 kg, which is 1.1 kilograms or 3.5% higher (P < 0.05). Then their peers from the control group. During the period of rearing, the absolute increase in body weight in young animals of the experimental group was higher by 1.2 kg, or by 4.7 %, and the average daily weight gain by 21.8 g, or by 4.7 %, compared to similar indicators in piglets of the control group, and were 26.5 kg and 481.8 g, respectively. Among the numerous indicators determining the economic efficiency of production, the cost per unit of production is considered the most important. One of the reserves for reducing the cost of pig production is increasing young animals' productivity and preservation. The above results of the production inspection convincingly prove that using the feed additive "Butaselmevit-plus" in compound feed for piglets at the rate of 100 mg/kg of body weight increases their product qualities and, as a result, improves economic indicators. In the experimental group, the cost of 1 kg of live weight of piglets during rearing decreased by UAH 0.57, or 3.0 %, compared to the young of the control group and amounted to UAH 18.25. The cost of 1 kg of live weight gain in control and experimental groups was slightly higher (23.44 and 22.46 UAH, respectively), and the difference in favor of the latter was 4.2 %. The decrease in the unit cost of production in the experimental group was due to the increase in body weight and the survival of young pigs during the rearing period. The economic effect of using the feed additive "Butaselmevit-plus" as part of compound feed, calculated per 1 head of young pigs, was UAH 25.97 at the prices set for feed and feed additive in 2019. To increase the adaptability of piglets at an early age when weaning from the sow and to prevent the development of oxidative stress, for further maintenance during the period of rearing and fattening, it is recommended to use the feed additive "Butaselmevit-plus" in the amount of 100 mg/kg of body weight per day together with concentrates diet in the period from 21 to 40 days of age. [ABSTRACT FROM AUTHOR]

The research results on hematological indicators of males and females of the Ukrainian scaly breed of carp grown in the conditions of a fish farm in the Dnipropetrovsk region are given. In Ukraine, carp cultivation is becoming an increasingly popular method of commercial fish production. At the same time, the hydrochemical and temperature regimes of the reservoir have important practical significance for the average growth and development of fish since the intensity of respiration, metabolic processes, fish nutrition, motor activity, and resistance to various diseases depend on the chemical composition and temperature of the water. The process of formation of the hydrochemical composition of pond water occurs against the background of climatic changes. Therefore, control of temperature conditions and the physiological state of fish during carp cultivation is an important measure that ensures rational consumption of feed and high growth rates and, in the future, allows to plan of optimal cultivation technology. Therefore, the work aimed to investigate the hematological indicators of blood in males and females of the Ukrainian scaly breed of carp to control their physiological state in the conditions of the hydrochemical and temperature regime of the reservoir of the fish farm. It was established that the main hydrochemical parameters corresponded to the technological standards adopted in fish farming to cultivate carp fish. The hematological parameters of the blood of male and female carp were within the physiological norm. The determined blood composition is natural and characterizes changes in the body of fish according to the season, which reflects adaptation processes in the conditions of seasonal fluctuations in water temperature. Correlative relationships between carp blood's hematological parameters and their keeping temperature conditions were revealed. The pH of the medium (r = 0.28-0.34) has the most significant effect on hematological indicators of carp blood. A positive correlative relationship was established between water temperature and the level of hemoglobin, a color indicator, and the number of erythrocytes and leukocytes in the blood of fish, which was in the range of r = 0.21-0.26. There was a negative relationship between the water temperature indicator and the content of segmented nuclear neutrophils (r = 0.24). The variance analysis of the one-factor complex revealed a significant and most highly probable influence of the conditions of keeping carp on the hemoglobin content, the number of erythrocytes, leukocytes, and the color index of the carp's blood. The share of influence was from 56.14 to 76.90 %. The amplitude of water temperature is essential for favorable conditions for hydrophones and the formation of a natural feed base. In addition, the environment's temperature affects the speed of biological processes in fish. Therefore, the organization of carp feeding, considering scientifically based norms depending on the protein content in compound feed, water temperature, fish weight, and density of its landing, will contribute to ensuring high fish productivity and rational use of feed. [ABSTRACT FROM AUTHOR]

The relevance of this study is conditioned upon the need to improve the hygiene of milking cows by selecting detergents and disinfectants with different component compositions that ensure the quality and safety of dairy products. The purpose of this paper was to investigate the effectiveness of solutions of modern chlorine-containing and chlorine-free detergents and disinfectants on the test cultures of microorganisms, the sanitary and hygienic condition of the milking parlour, parts of milking equipment, and the skin of the udder teats of cows. The total number of bacteria was determined according to the requirements of DSTU ISO 15214:2007, by inoculating 1 cm³ of the test material on meat-peptone agar followed by incubation at an average temperature of 36°C for 24-48 h. Cultivation was performed in a thermostat at 37°C. After incubation, colonies of grown microorganisms were counted, and the number of colony-forming units was determined. Detergents and disinfectants "Chloramine B", "Sanalcalin" and "Neochlor" have a detrimental effect on the growth of test cultures of E. coli, S. aureus and P. aeruginosa. "Desmol" suppresses the growth of test cultures of E. coli and P. aeruginosa after 20 minutes. The number of colonies of microorganisms in the air of the milking parlour is minimal at the beginning and greatest at the end of milking. 0.5% solution has a detrimental effect on E. coli and S. aureus, and slightly affects the growth of Salmonella spp. At the same time, this product is effective against microbial contamination of the skin of the udder teats of cows for its use in pre-milking disinfection. During the treatment of milking equipment with a 0.5% "Gralan Gel" solution, the total bacterial inoculation of the milking gum is reduced by 94.1%, the collector -- by 98.4%, the milk hose -- by 96.5%, the tank of the milking machine -- by 97.4% compared to the indicators before processing the milking equipment with detergents and disinfectants. According to the results of the study, the best efficiency in reducing the general bacterial contamination of milking equipment, the harmful effect on opportunistic microflora and microbial contamination of the skin of the udders of cows when used in pre-milking disinfection at milk production enterprises shows a 0.5% solution of the alkaline detergent and disinfectant "Gralan Gel". Thus, it is advisable to use a 0.5% solution of alkaline detergent and disinfectant "Gralan Gel" for producers of cow's raw milk to reduce the total bacterial contamination of milking equipment and cow udders [ABSTRACT FROM AUTHOR]

The study investigates the potential for takaful operators to collaborate with the government by using drones to identify victims in the event of a mass disaster. It is critical to emphasise that takaful operators are not part of the government agencies involved in the search and rescue (S&R) operations. Nevertheless, takaful operators are part of the critical chain in the risk management process because they are the parties that will issue compensation to victims if they are takaful participants (policyholders). Through semi-structured interviews, feedback on this issue was gathered from key informants who are experts in their fields. This study included 21 key informants: first responders to an emergency or disaster from Malaysian government agencies, forensic experts, takaful association, drone practitioners (including drone pilots, Vice President (VP) of drone consultation services, and the owner of a drone company), actuarial expert, Shariah experts, regulators (representatives from the central bank), takaful participants, and accounting expert. Findings indicate that the benefits of using drones to the takaful operators are undisputable. Yet, the associated costs of using the device are the main concerns to the industry players. The middle path is to have joint funds between the takaful industry and the government to pool the funds for the national disaster management agency to employ drones for DVI needs in the event of a disaster. Thus, the findings of this study will be useful to the government and takaful association when developing future policy and guidelines for the takaful industry. Furthermore, this research adds to the body of knowledge and provides a better understanding of the subject. [ABSTRACT FROM AUTHOR]

In this work, four well known time Fractional Partial Differential Equations (FPDEs) namely, time Fractional Fornberg-Whitham Equation (FFWE), time Fractional KdV Equation (FKdVE), time Fractional Convection-Diffusion Equation (FCDE) and time Fractional BBMBurger Equation (FBBMBE) are solved numerically through Fractional Wave Variable Transformation (FWVT) and Successive Differentiation Method (SDM). By using the FWVT, = ,x ¡ vt® ¡(® + 1), these FPDEs are converted into an Ordinary Differential Equation (ODE). Then SDM is applied on thus formed ODE to produce their Taylor series. A comparison of obtained numerical series at ® = 1 with the exact solution is presented to prove the accuracy of this technique as well as graphical illustrations for different values of ®. SDM along with fractional wave variable transformation proves to be an adequate and accurate method for obtaining numerical solutions of FPDEs. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum seria Zootechnica is the property of West Pomeranian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lie symmetry classification of the diffusive Lotka-Volterra system with time-dependent coefficients in the case of a single space variable is studied. A set of such symmetries in an explicit form is constructed. A nontrivial ansatz reducing the Lotka-Volterra system with correctly-specified coefficients to the system of ordinary differential equations (ODEs) and an example of the exact solution with a biological interpretation are found. [ABSTRACT FROM AUTHOR]

The nonlinear mathematical model for solute and fluid transport induced by the osmotic pressure of glucose and albumin with the dependence of several parameters on the hydrostatic pressure is described. In particular, the fractional space available for macromolecules (albumin was used as a typical example) and fractional fluid void volume were assumed to be different functions of hydrostatic pressure. In order to find non-uniform steady-state solutions analytically, some mathematical restrictions on the model parameters were applied. Exact formulae (involving hypergeometric functions) for the density of fluid flux from blood to tissue and the fluid flux across tissues were constructed. In order to justify the applicability of the analytical results obtained, a wide range of numerical simulations were performed. It was found that the analytical formulae can describe with good approximation the fluid and solute transport (especially the rate of ultrafiltration) for a wide range of values of the model parameters. [ABSTRACT FROM AUTHOR]

Clinical and animal studies suggest that peritoneal absorption of fluid and protein from dialysate to peritoneal tissue, and to blood and lymph circulation, occurs concomitantly with opposite flows of fluid and protein, i.e., from blood to dialysate. However, until now a theoretical explanation of this phenomenon has been lacking. A two-phase distributed model is proposed to explain the bidirectional, concomitant transport of fluid, albumin and glucose through the peritoneal transport system (PTS) during peritoneal dialysis. The interstitium of this tissue is described as an expandable two-phase structure with phase F (water-rich, colloid-poor region) and phase C (water-poor, colloid-rich region) with fluid and solute exchange between them. A low fraction of phase F is assumed in the intact tissue, which can be significantly increased under the influence of hydrostatic pressure and tissue hydration. The capillary wall is described using the three-pore model, and the conditions in the peritoneal cavity are assumed commencing 3 min after the infusion of glucose 3.86% dialysis fluid. Computer simulations demonstrate that peritoneal absorption of fluid into the tissue, which occurs via phase F at the rate of 1.8 ml/min, increases substantially the interstitial pressure and tissue hydration in both phases close to the peritoneal cavity, whereas the glucose-induced ultrafiltration from blood occurs via phase C at the rate of 15 ml/min. The proposed model delineating the phenomenon of concomitant bidirectional transport through PTS is based on a two-phase structure of the interstitium and provides results in agreement with clinical and experimental data. [ABSTRACT FROM AUTHOR]

Superfine FeOOH powder in an aerosol state with a particle size of about 3 nm has been studied in the processes of reactive adsorption and photocatalytic oxidation of acetone and diethyl sulfide vapors in air. The aerosol (5 g) is sprayed with a Helmholtz resonator placed into the center of a 100-L plastic chamber. Spraying is completed in 2 min, and the aerosol settles down within a time of less than 5 min. Rapid partial adsorption of acetone and diethyl sulfide on aerosol nanoparticles with characteristic times of 1 and 1.3 min, respectively, has been observed. FeOOH exhibits no photocatalytic activity with respect to acetone oxidation. Diethyl sulfide is oxidized with the formation of acetaldehyde as an intermediate product and CO and CO as the final products. [ABSTRACT FROM AUTHOR]

A mathematical model for fluid and solute transport in peritoneal dialysis is constructed. The model is based on a three-component nonlinear system of two-dimensional partial differential equations for fluid, glucose and albumin transport with the relevant boundary and initial conditions. Our aim is to model ultrafiltration of water combined with inflow of glucose to the tissue and removal of albumin from the body during dialysis, by finding the spatial distributions of glucose and albumin concentrations as well as hydrostatic pressure. The model is developed in one spatial dimension approximation, and a governing equation for each of the variables is derived from physical principles. Under some assumptions the model can be simplified to obtain exact formulae for spatially non-uniform steady-state solutions. As a result, the exact formulae for fluid fluxes from blood to the tissue and across the tissue are constructed, together with two linear autonomous ODEs for glucose and albumin concentrations in the tissue. The obtained analytical results are checked for their applicability for the description of fluid-glucose-albumin transport during peritoneal dialysis. [ABSTRACT FROM AUTHOR]

The aim of this study was to simulate clinically observed intraperitoneal kinetics of dialysis fluid volume and solute concentrations during peritoneal dialysis. We were also interested in analyzing relationships between processes in the peritoneal cavity and processes occurring in the peritoneal tissue and microcirculation. A spatially distributed model was formulated for the combined description of volume and solute mass balances in the peritoneal cavity and flows across the interstitium and the capillary wall. Tissue local parameters were assumed dependent on the interstitial hydration and vasodilatation induced by glucose. The model was fitted to the average volume and solute concentration profiles from dwell studies in 40 clinically stable patients on chronic ambulatory peritoneal dialysis using a 3.86% glucose dialysis solution. The model was able to describe the clinical data with high accuracy. An increase in the local interstitial pressure and tissue hydration within the distance of 2.5 mm from the peritoneal surface of the tissue was observed. The penetration of glucose into the tissue and removal of urea, creatinine, and sodium from the tissue were restricted to a layer located within 2 mm from the peritoneal surface. The initial decline of sodium concentration (sodium dip) was observed not only in intraperitoneal fluid but also in the tissue. The distributed model can provide a precise description of the relationship between changes in the peritoneal tissue and intraperitoneal dialysate volume and solute concentration kinetics. Computer simulations suggest that only a thin layer of the tissue within 2-3 mm from the peritoneal surface participates in the exchange of fluid and small solutes between the intraperitoneal dialysate and blood. [ABSTRACT FROM AUTHOR]

Waniewski J, Stachowska-Pietka J, Flessner MF. Distributed modeling of osmotically driven fluid transport in peritoneal dialysis: theoretical and computational investigations. Am J Physiol Heart Circ Physiol 296: H1960-H1968, 2009. First published March 27, 2009; doi: 10.1152/ajpheart.0012 1.2009.-Based on a distributed model of peritoneal transport, in the present report, a mathematical theory is presented to explain how the osmotic agent in the peritoneal dialysis solution that penetrates tissue induces osmotically driven flux out of the tissue. The relationships between phenomenological transport parameters (hyrdraulic permeability and reflection coefficient) and the respective specific transport parameters for the tissue and the capillary wall are separately described. Closed formulas for steady-state flux across the peritoneal surface and for hydrostatic pressure at the opposite surface are obtained using an approximate description of the concentration profile of the osmotic agent within the tissue by exponential function. A case of experimental study with mannitol as the osmotic agent in the rat abdominal wall is shown to be well described by our theory and computer simulations and to validate the applied approximation. Furthermore, clinical dialysis with glucose as the osmotic agent is analyzed, and the effective transport rates and parameters are derived from the description of the tissue and capillary wall. [ABSTRACT FROM AUTHOR]

The calculation of the heats of combustion ΔH°c and formation ΔH°f of organic molecules at standard conditions is presented using a commonly applicable computer algorithm based on the group-additivity method. This work is a continuation and extension of an earlier publication. The method rests on the complete breakdown of the molecules into their constituting atoms, these being further characterized by their immediate neighbor atoms. The group contributions are calculated by means of a fast Gauss–Seidel fitting calculus using the experimental data of 5030 molecules from literature. The applicability of this method has been tested by a subsequent ten-fold cross-validation procedure, which confirmed the extraordinary accuracy of the prediction of ΔH°c with a correlation coefficient R2 and a cross-validated correlation coefficient Q2 of 1, a standard deviation σ of 18.12 kJ/mol, a cross-validated standard deviation S of 19.16 kJ/mol, and a mean absolute deviation of 0.4%. The heat of formation ΔH°f has been calculated from ΔH°c using the standard enthalpies of combustion for the elements, yielding a correlation coefficient R2 for ΔH°f of 0.9979 and a corresponding standard deviation σ of 18.14 kJ/mol. [ABSTRACT FROM AUTHOR]

The diffusive Lotka–Volterra system arising in an enormous number of mathematical models in biology, physics, ecology, chemistry and society is under study. New Q-conditional (nonclassical) symmetries are derived and applied to search for exact solutions in an explicit form. A family of exact solutions is examined in detail in order to provide an application for describing the competition of two species in population dynamics. The results obtained are compared with those published earlier as well. [ABSTRACT FROM AUTHOR]

1. The enantioselectivity of the sulphation of racemic terbutaline by phenolsulphotransferases was examined in vitro using cytosol from human livers (n = 3) and [35S]-3′-phosphoadenosine-5′-phosphosulphate (PAP35S) as the sulphate donor. 2. The radioactive sulphate conjugate formed was isolated by h.p.l.c. and its enantiomers were separated intact by h.p.l.c. after chiral derivatization. 3. Sulphation of racemic terbutaline occurred with the same apparent Km value for both enantiomers (270 microM). The extent of sulphation of the (+)- enantiomer was double that of the (-)-enantiomer, solely due to a difference in their apparent Vmax values. 4. Sulphation of racemic prenalterol, a structural analogue of terbutaline, also showed a two- fold preference for the (+)-enantiomer. 5. These findings suggest that enantioselective sulphate conjugation of chiral phenolic sympathomimetic amine drugs may lead to enantioselective pharmacokinetics that should be considered in the clinical use of these drugs. [ABSTRACT FROM AUTHOR]

1. Xamoterol is a cardioselective beta-adrenoceptor partial agonist which may have a role in the management of cardiac failure. Excretion is mainly by the renal route. 2. The kinetics of a single 200 mg oral dose of xamoterol were studied in eight elderly (age 67-82 years) volunteers, eight young (age 21-43 years) volunteers; eight patients with mild to moderate cardiac failure and eight age and sex matched controls. 3. Elderly volunteers had a significantly longer time to reach peak concentration (mean +/- s.e. mean 2.1 +/- 0.2 vs 1.1 +/- 0.1 h) and elimination half-life time (27.0 +/- 2.8 vs 16.4 +/- 3.1 h) compared with young volunteers. The renal clearance of xamoterol was lower in the elderly (115 +/- 12 vs 185 +/- 19 ml min-1) and showed a significant correlation with creatinine clearance (r = 0.85, P less than 0.001). 4. There was no significant difference in any of the pharmacokinetic parameters measured in patients with cardiac failure compared with healthy age and sex matched controls. 5. These results suggest that the maintenance dose of xamoterol could be reduced in elderly patients in relation to impairment of renal function. [ABSTRACT FROM AUTHOR]

The known three-component reaction–diffusion system modeling competition and co-existence of different language speakers is under study. A modification of this system is proposed, which is examined by the Lie symmetry method; furthermore, exact solutions in the form of traveling fronts are constructed and their properties are identified. Plots of the traveling fronts are presented and the relevant interpretation describing the language shift that has occurred in Ukraine during the Soviet times is suggested. [ABSTRACT FROM AUTHOR]

This review is devoted to search for Lie and Q-conditional (nonclassical) symmetries and exact solutions of a class of reaction-diffusion-convection equations with exponential nonlinearities. A complete Lie symmetry classification of the class is derived via two different algorithms in order to show that the result depends essentially on the type of equivalence transformations used for the classification. Moreover, a complete description of Q-conditional symmetries for PDEs from the class in question is also presented. It is shown that all the well-known results for reaction-diffusion equations with exponential nonlinearities follow as particular cases from the results derived for this class of reaction-diffusion-convection equations. The symmetries obtained for constructing exact solutions of the relevant equations are successfully applied. The exact solutions are compared with those found by means of different techniques. Finally, an application of the exact solutions for solving boundary-value problems arising in population dynamics is presented. [ABSTRACT FROM AUTHOR]