Damage Accumulation Phenomena in Multilayer (TiAlCrSiY)N/(TiAlCr)N, Monolayer (TiAlCrSiY)N Coatings and Silicon upon Deformation by Cyclic Nanoindentation.

The micromechanism of the low-cycle fatigue of mono- and multilayer PVD coatings on cutting tools was investigated. Multilayer nanolaminate (TiAlCrSiY)N/(TiAlCr)N and monolayer (TiAlCrSiY)N PVD coatings were deposited on the cemented carbide ball nose end mills. Low-cycle fatigue resistance was studied using the cyclic nanoindentation technique. The obtained results were compared with the behaviour of the polycrystalline silicon reference sample. The fractal analysis of time-resolved curves for indenter penetration depth demonstrated regularities of damage accumulation in the coatings at the early stage of wear. The difference in low-cycle fatigue of the brittle silicon and nitride wear-resistant coatings is shown. It is demonstrated that when distinguished from the single layer (TiAlCrSiY)N coating, the nucleation and growth of microcracks in the multilayer (TiAlCrSiY)N/(TiAlCr)N coating is accompanied by acts of microplastic deformation providing a higher fracture toughness of the multilayer nanolaminate (TiAlCrSiY)N/(TiAlCr)N.

BACTERIAL CONTAMINATION AND METHODS OF DECONTAMINATION OF BASES COMPLETE REMOVABLE PROSTHESES DURING THE APPLICATION OF ADHESIVE MATERIALS.

It turned out that the permanent microbiota of surfaces of acrylic bases of complete removable plastic dentures (CRPD) characterized by several features: the presence of aerobic (7) and anaerobic (10) species. Qualitative and quantitative compositions of microbiocenosis in orthopedic treatment stages have been changed. The revealed patterns require further study in the context of the improvement of decolonization of acrylic bases in the stages of orthopedic treatment by CRPD. Deactivation of acrylic bases of CRPD significantly affects the species composition of microbiota, reduces the quantitative parameters of bacterial contamination. The purpose of our work was determination of bacterial contamination of acrylic bases of CRPD in stages of their clinical exploitation and study of changes in the quantitative composition of the acrylic bases microbiota of CRPD under different decontamination modes. Smears from the inner surface of the acrylic base were stained with Gram and microscopic and seeded on blood agar, Endo agar, Chistovich, Saburo. Species belonging to the micro-organisms were identified by the LAHEMA test system and were determined in colonies forming units (CFUs). These data indicate accumulation under the acrylic base in the course of clinical operation of certain types of microbiota, which requires improvement of the methods of their decontamination. We studied the change in the quantitative and specific composition of the microbiota (bacterial contamination) of acrylic bases CRPD under different modes ("A", "B"). Patients in group "A" used the Sideex solution - a two-component system consisting of a liquid component (glutaraldehyde solution) and a powdery activator, mixed before use to obtain a working activated solution. The liquid component is a clear, colorless solution with a specific odor, which is a 2.2-2.7% aqueous solution of glutaraldehyde, which is an active ingredient, pH=3.0 - 4.5. Powdery activator is a pale-yellow powder containing alkaline components, a corrosion inhibitor, and a dye. The activated working solution is a fluorescent green solution with a specific odor and containing 2.2-2.7% glutaraldehyde; pH=8.2-9.2. (Great Britain). Preparation of the activated solution: a powder-activator is added to the container containing the liquid component (avoiding losses). Cleaning is carried out by the method of full immersion of the prosthesis in solution, with a thickness of the drug over it not less than 1 cm. The dentures are soused in solution for 15 minutes, then thorough washing in the same solution for 1-3 minutes. Sideex activated solution is used for sterilization and disinfection of metal, glass, polymeric (plastic, rubber, etc.) medical products. The dentures of patients from group "B" are decontaminated with 0.2% solution of chlorhexidine bigluconate. The dentures were placed in the solution overnight for 14 days, changing the solution every two days. The decontamination of acrylic bases of CRPD should be considered mode "B" as more effective because of the significant decrease in the species composition of the microbiota (the qualitative indicator of reduction of microbial contamination was 72.0%). It is substantiated that decontamination of acrylic bases of CRPD with mode "A" has a small effect on the species composition of the microbiota, although it significantly (p<0.05) reduces quantitative indicators of microbial contamination. Regarding "B" mode, the species composition of aerobes from 31 lgCFU/ml to 8.7 lgCFU/ml and anaerobes from 42.7 lgCFU/ml to 14.6 lgCFU/ml was considered more effective.

Endemic and panglobal genetic groups, and divergence of host-associated forms in worldwide collections of the wheat leaf rust fungus Puccinia triticina as determined by genotyping by sequencing.

The wheat leaf rust fungus, Puccinia triticina, is found in the major wheat growing regions of the world and is a leading cause of yield loss in wheat. Populations of P. triticina are highly variable for virulence to resistance genes in wheat and adapt quickly to resistance genes in wheat cultivars. The objectives of this study were to determine the genetic relatedness of worldwide collections of P. triticina using restriction site associated genotyping by sequencing. A total of 558 isolates of P. triticina from wheat producing regions in North America, South America, Europe, the Middle East, Ethiopia, Russia, Pakistan, Central Asia, China, New Zealand, and South Africa were characterized at 6745 single nucleotide loci. Isolates were also tested for virulence to 20 near-isogenic lines that differ for leaf rust resistance genes. Populations that were geographically proximal were also more closely related for genotypes. In addition, groups of isolates within regions that varied for genotype were similar to groups from other regions, which indicated past and recent migration across regions. Isolates from tetraploid durum wheat in five different regions were highly related with distinct genotypes compared to isolates from hexaploid common wheat. Based on a molecular clock, isolates from durum wheat found only in Ethiopia were the first to diverge from a common ancestor form of P. triticina that is found on the wild wheat relative Aegilops speltoides, followed by the divergence of isolates found worldwide that are virulent to durum wheat, and then by isolates found on common wheat.

Benchmarking of several material constitutive models for tribology, wear, and other mechanical deformation simulations of Ti6Al4V.

Use of an alpha-beta (multiphase HCP-BCC) titanium alloy, Ti6Al4V, is ubiquitous in a wide range of engineering applications. The previous decade of finite element analysis research on various titanium alloys for numerous biomedical applications especially in the field of orthopedics has led to the development of more than half a dozen material constitutive models, with no comparison available between them. Part of this problem stems from the complexity of developing a vectorised user-defined material subroutine (VUMAT) and the different conditions (strain rate, temperature and composition of material) in which these models are experimentally informed. This paper examines the extant literature to review these models and provides quantitative benchmarking against the tabulated material model and a power law model of Ti6Al4V taking the test case of a uniaxial tensile and cutting simulation.

Multilocus Genotypes of the Wheat Leaf Rust Fungus Puccinia triticina in Worldwide Regions Indicate Past and Current Long-Distance Migration.

Many plant pathogenic fungi have a global distribution across diverse ecological zones and agricultural production systems. Puccinia triticina, the wheat leaf rust fungus, is a major pathogen in many wheat production areas of the world. The objective of this research was to determine the genetic relatedness of P. triticina in different worldwide regions. A total of 831 single-uredinial isolates collected from 11 regions were characterized for multilocus genotype at 23 simple sequence repeat loci and for virulence to 20 lines of wheat with single genes for leaf rust resistance. A total of 424 multilocus genotypes and 497 virulence phenotypes were found. All populations had high heterozygosity and significant correlation between virulence and molecular variation, which indicated clonal reproduction. The populations from North America and South America, Central Asia and Russia, and the Middle East and Europe were closely related for multilocus genotypes and many individual isolates from other continental regions were closely related. Twenty-seven multilocus genotypes were found in more than one continental region, and 13 of these had isolates with identical virulence phenotypes. The wide geographic distribution of identical and highly related multilocus genotypes of P. triticina indicated past and more recent migration events facilitated by the spread of clonally produced urediniospores.

Is exponential gravity a viable description for the whole cosmological history?

Here we analyse a particular type of F(R) gravity, the so-called exponential gravity which includes an exponential function of the Ricci scalar in the action. Such a term represents a correction to the usual Hilbert-Einstein action. By using Supernovae Ia, Barionic Acoustic Oscillations, Cosmic Microwave Background and H(z) data, the free parameters of the model are well constrained. The results show that such corrections to General Relativity become important at cosmological scales and at late times, providing an alternative to the dark energy problem. In addition, the fits do not determine any significant difference statistically with respect to the [Formula: see text]CDM model. Finally, such model is extended to include the inflationary epoch in the same gravitational Lagrangian. As shown in the paper, the additional terms can reproduce the inflationary epoch and satisfy the constraints from Planck data.

[New aspects of Helicobacter pylori infection: Association with metabolic disturbances]. / Novye aspekty piloricheskoi khelikobakternoi infektsii: sviaz' s metabolicheskimi narusheniiami.

The review is devoted to the analysis of the literature on the possible association of Helicobacter pylori infection with type 2 diabetes mellitus, metabolic syndrome and its supposed mechanisms.

[Socio-economic aspects of epidemiology of helicobateriosis].

There are considered special social and economic aspects of the epidemiology of Helicobacter pylori. These aspects acquired the particular importance for the last time due to the fact that the provision of the people with pure water has been becoming the focus of the attention of geopolitical and socio-economic interests in a number of countries. The availability ofpure drinking water serves a marker of the socio-economic state of the territory and the population living there. In Russia where different climatic conditions are deposited by considerable regional differences in the conditions of communal services caused both by various level of the socio-economic development of the territory, the supplementation with pure drinking water serves as the social determinant of the ecological conditions of the population's life. This particularly has impact on the unfeasible technical state of the water distribution systems, microorganism ecology of which can substantially affect public health. The performed by authors a specialized screening ofpresented at the official web site of the joint-stock company «Mosvodokanal¼ current data concerning the quality of drinking water consumed by 2500 Moscovites, tested for the Helicobacter pylori infection revealed no deviations from the sanitary standards in the water received by the consumers. Along with that, the comparison of the map documents of the distribution of the Helicobacter pylori infection in Moscow with the distribution of citizens' complaints of the decline of the quality of tap water has revealed a territorial fastening of the high values of the population infection rate of n^ylori and the urban sites with the greatest number of complaints. In the microbial ecology of water-distribution systems there are tightly aligned problems of their epidemiological safety, technical state and economic damage caused by corrosion as a result of microbiotic activity. In contrast to acute bacterial and viral infections which are deemed of the greatest importance when assessing the sanitary condition of water sources and water-distribution systems, the consequences of infection with H. pylori may not be manifestedfor a long time but some years later they may be manifested as serious chronic diseases (from gastritis to adenocarcinoma of the stomach and a wide range of extraintestinal pathologies), which causes great social and economic losses. Thus, the socio-economic aspect of the epidemiology of helicobacteriosis includes at least two components: the technic - the maintenance of the feasible technic and sanitary state of the water distribution systems and the medico-social - expenditures for screening and treatment of infected patients. In total they are an inseparable part of the prevention of socially-important diseases in the public health system.

Liposomes loaded with hydrophilic magnetite nanoparticles: Preparation and application as contrast agents for magnetic resonance imaging.

Magnetic fluid-loaded liposomes (MFLs) were fabricated using magnetite nanoparticles (MNPs) and natural phospholipids via the thin film hydration method followed by extrusion. The size distribution and composition of MFLs were studied using dynamic light scattering and spectrophotometry. The effective ranges of magnetite concentration in MNPs hydrosol and MFLs for contrasting at both T2 and T1 relaxation were determined. On T2 weighted images, the MFLs effectively increased the contrast if compared with MNPs hydrosol, while on T1 weighted images, MNPs hydrosol contrasting was more efficient than that of MFLs. In vivo magnetic resonance imaging (MRI) contrasting properties of MFLs and their effects on tumor and normal tissues morphology, were investigated in rats with transplanted renal cell carcinoma upon intratumoral administration of MFLs. No significant morphological changes in rat internal organs upon intratumoral injection of MFLs were detected, suggesting that the liposomes are relatively safe and can be used as the potential contrasting agents for MRI.

[Prevalence and routes of transmission of pyloric Helicobacter infection. II. Transmission infection from an external source (literature review)].

AIM OF THE STUDY: On the available reports to assess the possibility of the infection with pyloric Helicobacter (H.pylori) from external sources--via contaminated food and water. BASIC CONCEPTS: H. pylori was established to be unable to multiply in dairy and other products, but under favorable conditions, can survive in the limited time. There are obtained epidemiological data about the feedback between the prevalence of H. pylori infection in the region and the availability of safe water. There was recorded ability of bacteria to survive for a short time in water in bacillary virulent form. In different water sources in different countries there was found H. pylori coccal form. CONCLUSION: H. pylori ability to survive in the commonly used product supports the hypothesis that contaminated food (tank-human) may serve as a conductor of infection. The literature data testify to the possibility and importance of the waterway for H. pylori infection transmission that changes the approaches to prophylaxis and the prevention of associated with it diseases.

Genetic Analysis of Resistance to Leaf Rust and Yellow Rust in Spring Wheat Cultivar Kenya Kongoni.

The Kenyan wheat (Triticum aestivum L.) 'Kenya Kongoni' exhibits high levels of adult plant resistance (APR) to leaf rust (LR) and yellow rust (YR). We determined the genomic regions associated with LR and YR resistance in a population of 148 recombinant inbred lines generated from a cross between 'Avocet-YrA' and Kenya Kongoni. Field experiments to characterize APR to LR and YR were conducted in four and two Mexican or Uruguayan environments, respectively. A linkage map was constructed with 438 diversity arrays technology and 16 simple-sequence repeat markers by JoinMap 4.1 software. Genetic analyses showed that resistance to both rusts was determined by four to five APR genes, including Lr46/Yr29 and Sr2/Lr27/Yr30. Quantitative trait loci (QTL) analysis indicated that pleiotropic APR loci QYLr.cim-1BL corresponding to Lr46/Yr29 and QYLr.cim-7BL that is a putative novel QTL accounted for 5 to 57% and 12 to 35% of the phenotypic variation for resistance to LR and YR, respectively. These loci, in combination with another three LR QTL and two YR QTL, respectively, conferred high levels of resistance to both LR and YR in wheat under Mexican and Uruguayan environments. Among other detected QTL, QLr.cim-1DS, QLr.cim-2BL, and QYLr.icm-7BL may be new loci for APR to both rusts in common wheat.

Surface chemistry of thiomalic acid adsorption on planar gold and gold nanoparticles.

The self-assembly of thiomalic acid (TMA) on Au(111) and on preformed Au nanoparticles (AuNPs) protected by weak ligands has been studied by X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Results show that TMA is adsorbed on the Au(111) surface as thiolate species with a small amount of atomic sulfur (∼10%) and a surface coverage lower than that found for alkanethiols due to steric factors. The amount of atomic sulfur markedly increases when the TMA is adsorbed on AuNPs by the ligand exchange method. We propose that the atomic sulfur is produced as a consequence of C-S bond cleavage, a process that is more favorable at defective sites of the AuNPs surface. The bond scission is also assisted by the presence of the electron-withdrawing carboxy moiety in the α-position relative to the C-S bond. Moreover, the high local concentration of positively charged species increases the stability of the negatively charged leaving group, leading to a higher amount of coadsorbed atomic sulfur. Our results demonstrate that the terminal functionalities of thiols are conditioning factors in the final structure and composition of the adlayers.

[Prevention of pyloric H. pylori infection is the actual problem of modern preventive health care].

In the article there are presented data on the high prevalence of Helicobacter pylori (H. pylori) infection in Russia and its consequences, including the development of gastric cancer. There is presented the evidence of possible transmission of H. pylori with water previously underestimated. There is substantiated the necessity of preventing infection, which should include the informing of the population, compliance with hygiene standards and widespread availability of safe water.

[Prevalence and transmission pathways of the pyloric Helicobacter infection. Transmission from person to person (literature review)].

The purpose of review: analysis of the available in the literature data about the possible kinds and pathways of transmission of pyloric Helicobacter infection from person to person. Knowledge of these data is necessary for its prevention. Subjects--available literature, mainly English-language articles. There were separated two modes of transmission of Helicobacter pylori: vertical--the spread of infection from older to younger and horizontal--by contact between persons outside of the family. Basis statements. There is abundant evidence confirming the gastro-oral, oral-oral and fecal-oral transmission of H. pylori. To prevent the transmission of infection from person to person and the development of related diseases an essential measure is elibiotics.

[The study of spatial distribution of Helicobacter pylori infection rate in able-bodied population of Moscow in the course of medical examination of the manufacturing contingents].

UNLABELLED: Numerous studies have shown that Helicobacter pylori (H. pylori) is a leading etiologic factor in the development of chronic atrophic gastritis, one gastric ulcer and duodenal ulcer and gastric cancer. Effective prevention of gastroduodenal pathology requires the right information about its prevalence in the population and risk factors. The most reliable information can be obtained during medical examination of the able-bodied population, which provides in-depth clinical examination of contingents with the identification of asymptomatic pathology, detection of risk groups, the substantiation ofprophylactic measures and tracking their efficacy. MATERIAL AND METHODS: During the clinical examination of the manufacturing contingents there was performed a study of the presence of infection Helicobacter pylori (H. pylori) in 2414 people aged 19 to 74 years. For more details on the presence of gastroduodenal pathology 991 people were examined with the use of clinical methods and interviews. The aggregation of information presented in the form of estimates for its geocoding and mapping has been made. Cluster analysis was performed. RESULTS: H. pylori infection was diagnosed in 2,182 people accounting for 90.4% out of 2414 examined cases. Infections occurred equally in males--91.7% and females--89.6%. The risk of development of gastroduodenal pathology in individuals infected with H. pylori is 4.4 times greater than the risk in seronegative individuals (95%, confidence interval 1.9-6.4). Cluster analysis revealed a statistically significant clusters for the strata with a prevalence of 100% (X2 = 45.5204) and below 50% of infection rate (X2 = 7.36). It is in prospect to analyze in more detail the data relating to these areas in order to identify the factors contributing to the different degree of infection rate of residents, including the assessment of drinking water.

Performance of culture media for the isolation and identification of Staphylococcus aureus from bovine mastitis.

Rapid isolation and identification of pathogens is a major goal of diagnostic microbiology. In order to isolate and identify Staphylococcus aureus, a number of authors have used a variety of selective and/or differential culture media. However, to date, there are no reports comparing the efficacy of selective and differential culture media for S. aureus isolation from bovine mastitis cases using the 16S rRNA (rrs) gene sequence as a gold standard test. In the present study, we evaluated the efficacy of four selective and/or differential culture media for the isolation of S. aureus from milk samples collected from cows suffering from bovine mastitis. Four hundred and forty isolates were obtained using salt-mannitol agar (SMA, Bioxon), Staphylococcus-110 agar (S110, Bioxon), CHROMAgar Staph aureus (CSA, BD-BBL) and sheep's blood agar (SBA, BD-BBL). All bacterial isolates were identified by their typical colony morphology in the respective media, by secondary tests (for coagulase and ß-haemolysis) and by partial 16S rRNA (rrs) gene sequencing as a gold standard test. Sensitivity, positive predictive and negative predictive values were higher for SMA (86.96, 52.63 and 95.95%, respectively) compared with S110 (70.00, 23.73 and 90.91%, respectively), CSA (69.23, 28.13 and 95.74%, respectively) and SBA (68.75, 37.93 and 89.58%, respectively) while specificity values were similar for all media. Data indicated that the use of culture media for S. aureus isolation combined with determination of coagulase activity and haemolysis as secondary tests improved accuracy of the identification and was in accordance with rrs gene sequence-analysis compared with the use of the culture media alone.

Hierarchical adaptive nanostructured PVD coatings for extreme tribological applications: the quest for nonequilibrium states and emergent behavior.

Adaptive wear-resistant coatings produced by physical vapor deposition (PVD) are a relatively new generation of coatings which are attracting attention in the development of nanostructured materials for extreme tribological applications. An excellent example of such extreme operating conditions is high performance machining of hard-to-cut materials. The adaptive characteristics of such coatings develop fully during interaction with the severe environment. Modern adaptive coatings could be regarded as hierarchical surface-engineered nanostructural materials. They exhibit dynamic hierarchy on two major structural scales: (a) nanoscale surface layers of protective tribofilms generated during friction and (b) an underlying nano/microscaled layer. The tribofilms are responsible for some critical nanoscale effects that strongly impact the wear resistance of adaptive coatings. A new direction in nanomaterial research is discussed: compositional and microstructural optimization of the dynamically regenerating nanoscaled tribofilms on the surface of the adaptive coatings during friction. In this review we demonstrate the correlation between the microstructure, physical, chemical and micromechanical properties of hard coatings in their dynamic interaction (adaptation) with environment and the involvement of complex natural processes associated with self-organization during friction. Major physical, chemical and mechanical characteristics of the adaptive coating, which play a significant role in its operating properties, such as enhanced mass transfer, and the ability of the layer to provide dissipation and accumulation of frictional energy during operation are presented as well. Strategies for adaptive nanostructural coating design that enhance beneficial natural processes are outlined. The coatings exhibit emergent behavior during operation when their improved features work as a whole. In this way, as higher-ordered systems, they achieve multifunctionality and high wear resistance under extreme tribological conditions.

Why can tiAicrsiYN-based adaptive coatings deliver exceptional performance under extreme frictional conditions?

Adaptive TiAlCrSiYN-based coatings show promise under the extreme tribological conditions of dry ultra-high-speed (500-700 m min-1) machining of hardened tool steels. During high speed machining, protective sapphire and mullite-like tribo-films form on the surface of TiAlCrSiYN-based coatings resulting in beneficial heat-redistribution in the cutting zone. XRD and HRTEM data show that the tribo-films act as a thermal barrier creating a strong thermal gradient. The data are consistent with the temperature decreasing from approximately 1100-1200 degrees C at the outer surface to approximately 600 degrees C at the tribo-film/coating interface. The mechanical properties of the multilayer TiAICrSiYN/TiA1CrN coating were measured by high temperature nanoindentation. It retains relatively high hardness (21 GPa) at 600 degrees C. The nanomechanical properties of the underlying coating layer provide a stable low wear environment for the tribo-films to form and regenerate so it can sustain high temperatures under operation (600 degrees C). This combination of characteristics explains the high wear resistance of the multilayer TiAlCrSiYN/TiAICrN coating under extreme operating conditions. TiAlCrSiYN and TiAlCrN monolayer coatings have a less effective combination of adaptability and mechanical characteristics and therefore lower tool life. The microstructural reasons for different optimum hardness and plasticity between monolayer and multilayer coatings are discussed.

[To the problem of evaluation of public health: screening for gastroduodenal pathology on the example of atrophic gastritis in mass medical examination of the population].

Assessment of health status of the population - the most important issue in preventive medicine. The objective of this work - to determine the possibility of nonendoscopic screening for gastroduodenal pathology, by the example of atrophic gastritis, in mass medical examinations of working residents in Moscow. Minimally invasive diagnostic test system GastroPanel ("Biohit", Finland) has been used. It allows with the ELISA method to determine both serum indicators of the function of the stomach -pepsinogen 1, gastrin 17 and the presence of H. pylori infection. 758 persons have been examined. The performed study confirms the possibility with the use of a set of mentioned indicators to identify individuals suspected for the presence of gastroduodenal disorders, especially atrophic gastritis, recognized as a precancerous condition. The use in preventive medicine complex diagnostic system, firstly, will make assessment of the health of the population more correct, increase the effectiveness of preventive measures and quality of life, and secondly, will contribute to the diagnosis of diseases of the stomach and duodenum in the early stages.

[Epidemiological characteristics of Helicobacter pylori infection in Moscow].

The authors studied the prevalence and a number of epidemiological features of Helicobacter pylori (Hp) infection in Moscow. A prophylactic medical examination revealed the infection in 863 working residents of the megapolis. A mini-invasive study was used. Enzyme immunoassay was carried out to determine serum IgG antibodies against Hp. The authors' questionnaire was used in 634 interviews. There was an extremely high incidence (88%) of Hp infection. The prevalence of the infection was found to be related to age, social status (social position, educational level), living conditions (shared or hostel habitation, no sewerage system), contact with waste waters. No association was found between the rate of the infection and the examinees' gender, the intake of raw Moscow tap drinking water, and the contact with domestic animals. Moscow was rated among the cities with a high prevalence of Hp infection. The study revealed a number of epidemiological features of the infection in the megapolis, a knowledge of which is required to elaborate measures for its prophylaxis and the prevention of its associated diseases.