Polyelectrolyte substrate coating for controlling biofilm growth at solid–air interface

Because bacteria–surface interactions play a decisive role in bacteria adhesion and biofilm spreading, it is essential to understand how biofilms respond to surface properties to develop effective strategies to combat them. Polyelectrolyte coating is a simple and efficient way of controlling surface charge and energy. Using polyelectrolytes of various types, with different molecular weights and polyelectrolyte solutions of various pH provides a unique approach to investigate the interactions between biofilms and their substrate. Here, the formation of Escherichia coli biofilms at a solid–air interface is explored, whereby charge and interfacial energy are tuned using polyelectrolyte coatings on the surface. Cationic coatings are observed to limit biofilm spreading, which remain more confined when using high molecular weight polycations. Interestingly, biofilm surface densities are higher on polycationic surfaces despite their well-studied bactericidal properties. Furthermore, the degree of polyelectrolyte protonation also appears to have an influence on biofilm spreading on polycation-coated substrates. Finally, altering the interplay between biomass production and surface forces with polyelectrolyte coatings is shown to affect biofilm 3D architecture. Thereby, it is demonstrated that biofilm growth and spreading on a hydrogel substrate can be tuned from confined to expanded, simply by coating the surface using available polyelectrolytes

Development of the energy efficient residential low-rise house concept for the Ural region

In the article the problem of energy-efficient construction in Russia is considered. The energy-saving technologies and renewable energy sources acceptable in construction in the Ural region analysis is carried out. Main reasons of the irrational consumption of thermal energy are highlighted and the strategy of the energy-efficient construction development in the Urals is described. As a result of the research, a conceptual project of an individual residential house was developed. © Published under licence by IOP Publishing Ltd

Adaptation problems experienced by international students in aspect of quality management

Regulation and problems of adaptation are considered in research in aspect of high-quality management. The object of research is foreign students. Adaptation challenges a person's sense of well-being. Research defines satisfaction as a global assessment of quality of human life. This assessment is based on criteria of the person. systems; in these conditions the development of effective mechanisms of adaptation in the unstable external environment is possible on the assumption of use of co-evolutionary - innovative processes. The recommendations about the creation on the basis of these processes of effective mechanisms of adaptation of social systems to instability conditions are developed. On the basis of a systematic approach in the article explores innovative models of behavior as a way of effective adaptation of social systems in an unstable environment, based on the principle of co-evolutionary innovation. It is shown that the modern period is characterized by the growth of the dynamics and complexity of the interaction of social systems; in these conditions, the development of effective adaptation mechanisms in an unstable environment can be provided the use of evolutionary processes and innovation. To evaluate the potential use of evolutionary processes and innovation to create effective mechanisms for the adaptation of social systems in an unstable environment

Structure and Crystallographic Texture Changes of Ferritic Martensitic Steel Resulting from Thermal Creep and Ageing Tests

Thermal ageing (650 and 700∘C during 1000, 7000 or 13300 h) and creep (700∘C, 50 MPa) tests of tubes made from ferritic-martensitic steels EK181 and ChS139 were carried out. With the aid of X-ray techniques the investigation of crystallographic texture and structure condition after tests was conducted. Thermal ageing provides substructure enhancement. With the increase of ageing time one can note the decrease of microhardness and X-ray peaks broadening, which indicates inner elastic microstress relaxation. It was revealed that changes of crystallographic texture in the rupture area of steel ChS139 tube after creep test is similar to those after uniaxial tensile test at room temeprature. This indicates the similarity of the mechanisms ofgrain reorientation for creep and tension. Recrystallization occurs in steel EK181 during creep test at temperature 700∘C leading to formation of recrystallization texture. This results in faster failure of steel EK181 (2486 h before rupture) in comparison with steel ChS139 (3426 h)

The daily arterial stiffness profile in rheumatoid arthritis patients with and without hypertension

Patients with rheumatoid arthritis (RA) have an increased risk for cardiovascular diseases. To determine their daily arterial stiffness (AS) as an indicator of cardiovascular risk is of unquestionable interest.Objective: to evaluate the features of daily AS in RA patients with or without hypertension.Patients and methods. Twenty-four hour AS monitoring (24-h ASM) was done in 75 women with a valid diagnosis of RA. The patients were randomized into 3 groups: 1) 39 RA patients with hypertension; 2) 24 RA patients without hypertension; 3) 12 RA patients with masked hypertension. A comparison group consisted of 30 hypertensive patients without RA and a control group included 22 apparently healthy women who were age-matched with the patients with RA and those from the comparison group. 24-h ASM readings were studied using a BPlab device with Vasotens software (Russia).Results. All the patients with RA were found to have higher 24-h ASM readings than the controls; and, in the presence of hypertension, these changes were even more pronounced. Group 1 was noted to have higher ambulatory AS index than the comparison group; more than 70% of the patients in Group 2 were observed tohave increased aortic pulse wave velocity when reducing to a blood pressure (BP) of 100 mm Hg. The patients in Groups 1 and 2 had increases in augmentation index, in the latter normalized for a heart rate of 75 beats/min, in the propagation time of a reflected wave when reducing to a BP of 100 mm Hg, and in AS index at night. The patients with RA showed an association between daily AS and major cardiovascular risk factors (hypertension, age, body mass index, menopause duration), RA-specific risk factors (RA duration, erythrocyte sedimentation rate, and C-reactive protein), and psychoemotional status. Conclusion. 24-h ASM revealed that the patients with RA had higher vascular wall stiffness than the individuals in the comparison and control groups. Taking into consideration the pronounced changes in AS not only during the daytime, but also during the night, it is appropriate to perform daily monitoring in patients with RA in order to obtain more objective data

Structure-Sensitive Mechanism of Nanographene Failure

The response of a nanographene sheet to external stresses is considered in terms of a mechanochemical reaction. The quantum chemical realization of the approach is based on a coordinate-of-reaction concept for the purpose of introducing a mechanochemical internal coordinate (MIC) that specifies a deformational mode. The related force of response is calculated as the energy gradient along the MIC, while the atomic configuration is optimized over all of the other coordinates under the MIC constant-pitch elongation. The approach is applied to the benzene molecule and (5, 5) nanographene. A drastic anisotropy in the microscopic behavior of both objects under elongation along a MIC has been observed when the MIC is oriented either along or normally to the C-C bonds chain. Both the anisotropy and high stiffness of the nanographene originate at the response of the benzenoid unit to stress.Comment: 19 pages, 7 figures 1 tabl

Quality of life and health utility index in type 2 diabetes mellitus patients with various forms of hypoglycemia receiving basal-bolus insulin therapy

Analysis of the results of observational program «Quality of life, symptoms of hypoglycemia and treatment satisfaction in patients with type 2 diabetes receiving basal-bolus insulin therapy» are presented. One thousand patients with type 2 diabetes mellitus (DM2) from ten regions of Russia were included in the above program. The quality of life of DM2 patients with different forms of hypoglycemia on insulin therapy and their distribution according to the grades of quality of life impairment were studied; the health utility index ( Ut) for various forms of hypoglycemia was determined. Quality of life in DM2 patients with hypoglycemia was lower than in those without hypoglycemia. Patients with severe and nocturnal hypoglycemia episodes recorded the expressed disturbances in quality of life; the majority of patients in this group had critical or severe quality of life impairment. On the basis of real-world practice data, the values of health utility index for patients with and without hypoglycemia were determined. The obtained values of health utility index can be used to calculate QALY in pharmacoeconomic analysis

Этиологическая структура лептоспир, циркулирующих в популяциях сельскохозяйственных животных в Якутии

It is necessary to know the etiological structure of diseases in each region of the country that affects a particular animal species for successful prevention and diagnosis of natural focal diseases, in particular leptospirosis. In this paper, the authors presented research materials on the distribution and etiological structure of pathogenic leptospirosis circulating in the populations of farm animals in Yakutia. Currently, 8 unfavorable points for animal leptospirosis have been registered in Yakutia: two cattle and six horses. A comparative analysis of the etiological structure of leptospirosis in agricultural animals (cattle, horses) testifies to the diversity of leptospira serological groups circulating in the republic. Thus 7 serogroups are registered in cattle, among which the leptospira serogroups Icterohaemorrahagiae (36.0%) and Grippotyphosa (27.1%) dominate. Infection of animals averages 3.2%, in the central zone, where about 63% of the total livestock in the region is concentrated, the level of infection of livestock in the districts of the zone ranges from 0.14 to 8.58%. The highest infection rate of animals is observed in Gorny (8.58%), Namsky (2.26%), and Yakutsk (1.35%) regions. In this zone, circulation of 6 leptospira serogroups is recorded: Grippotyphosa (30.8%), Icterohaemorrahagiae (29.0%) and Tarassovi (27.1%), to a lesser extent Canicola (7.5%), Pomona (3.7%) and Sejroe (1.9%). It should be noted that no Leptospira Hebdomadis were found in cattle in the Central Zone. In Yakut horses, 6 serogroups were identified, among which the leptospira serogroups Hebdomadis (31.5%) and Tarassovi (28.7%) dominate. In the Central zone, where the main number of horses in the region (61.1%) is concentrated the infection rate of animals is an average of 3.2%. The level of infection of horses in the districts of the zone ranges from 0.15 to 8.62%. The highest infection rate of horses is recorded in the horse breeding farms of Gorny (8.62%), Kobyaisky (8.59%), Tattinsky (6.17%), and Churapchinsky (5.74%) districts. It should be noted that L. Pomona does not occur in horses.Для успешной профилактики и диагностики природно-очаговых заболеваний, в частности лептоспироза, необходимо знание этиологической структуры заболевания в каждом регионе страны, поражающего тот или иной вид животных. В данной работе представлены материалы исследований по особенностям распространения и этиологической структуре патогенных лептоспир, циркулирующих в популяциях сельскохозяйственных животных Якутии. В настоящее время на территории Якутии зарегистрировано всего 8 неблагополучных пунктов по лептоспирозу животных: крупного рогатого скота – 2, лошадей – 6. Проведенный сравнительный анализ этиологической структуры лептоспироза сельскохозяйственных животных (крупный рогатый скот, лошади) свидетельствует о разнообразии циркулирующих на территории республики серологических групп лептоспир. Так, у крупного рогатого скота регистрируются 7 серогрупп, среди которых доминируют серогруппы лептоспир Icterohaemorrahagiae (36,0%) и Grippotyphosa (27,1%). В Центральной зоне, где сосредоточено около 63% всего поголовья в регионе, инфицированность животных составляет в среднем 3,2%. Уровень инфицированности скота по районам зоны колеблется от 0,14 до 8,58%. Наиболее высокая инфицированность животных отмечается в Горном (8,58%), Намском (2,26%) и Якутском (1,35%) районах. В этой зоне регистрируется циркуляция 6 серогрупп лептоспир: Grippotyphosa (30,8%), Icterohaemorrahagiae (29,0%) и Tarassovi (27,1%), в меньшей степени Canicola (7,5%), Pomona (3,7%) и Sejroe (1,9%). Следует отметить, что в Центральной зоне у крупного рогатого скота не обнаружены лептоспиры Hebdomadis. У якутских лошадей выявлено 6 серогрупп, среди которых доминируют серогруппы лептоспир Hebdomadis (31,5%) и Tarassovi (28,7%). В Центральной зоне, где сосредоточено основное поголовье лошадей в регионе (61,1%), инфицированность животных составляет в среднем 3,2%. Уровень инфицированности лошадей по районам зоны колеблется от 0,15 до 8,62%. Наиболее высокая инфицированность лошадей регистрируется в коневодческих хозяйствах Горного (8,62%), Кобяйского (8,59%), Таттинского (6,17%) и Чурапчинского (5,74%) районов. Следует отметить, что у лошадей не встречается L. pomona