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

Pharmacoeconomic analysis of use the oral hypoglycemic agents in patients with type 2 diabetes mellitus according to a real clinical practice

We aimed to conduct cost-utility analysis of two different regimens of the oral hypoglycemic therapy in 2 type diabetes mellitus (DM2). Methods. In the whole, 229 patients with DM2, receiving vildagliptin add-on to metformin (group 1) or sulphonylureas add-on to metformin (group 2) were enrolled in the study. Cost-utility ratio (CUR) was identified as a ratio of difference in total costs of treatment in the groups and difference in QALY in corresponding groups. The overall costs included direct costs of treatment as well as costs for treating of DM2 complications (severe hypoglycemia) and the costs related to the loss of GDP due to severe hypoglycemia events. Health utility value was evaluated for each patient on the basis of SF-6D questionnaire. Pharmacoeconomic expediency of treatment regimen was estimated by means of comparing the CUR and wiliness-to-pay ratio (WTP) for Russian Federation (RF). Results. The health utility value was higher in group 1 as compared to group 2: 0,757 vs 0,70 (p>0,05). The overall costs for treating one patient in group 1 during a year were 28 637,34 rubles, in group 2 - 10 231,55 rubles. CUR amounted 328 674,82 rubles and it was 4.4 times lower than upper border of WTP ratio in RF (1 457 400 rub.). Conclusion. The innovation treatment regimen with vildagliptin add-on to metformin is beneficial and may be considered as economically reasonable alternative to traditional treatment regimen with sulphonylureas add-on to metformin for DM2 patients in RF