Experimental Tests of Discrete Strengthened Elements of Machine-Building Structures

Computer simulation and bench tests of components and full-scale structures of internal combustion engine are performed in order to evaluate discrete and continual strengthening technology. The contact pressure distributions, friction coefficients, wear, roughness and hardness of the contacting surfaces of the tested machine parts were determined. The numerical characteristics that determine the effectiveness of such combined strengthening method are established. Conceptual fundamentals of discrete continual strengthening have been developed. Positive effects in the “load – contact – friction – wear” chain were found due to the proposed strengthening method. The positive effect of the coordination of micro and macroscale processes and states of loaded parts, which are strengthened by the discrete and continuous method, is also established. It is confirmed that the entire set of tribo-mechanical characteristics is improved with such strengthening, in contrast to traditional methods, an application of which results in improvement in some characteristics at the cost of the others

The Extracellular Matrix Component Psl Provides Fast-Acting Antibiotic Defense in Pseudomonas aeruginosa Biofilms

Bacteria within biofilms secrete and surround themselves with an extracellular matrix, which serves as a first line of defense against antibiotic attack. Polysaccharides constitute major elements of the biofilm matrix and are implied in surface adhesion and biofilm organization, but their contributions to the resistance properties of biofilms remain largely elusive. Using a combination of static and continuous-flow biofilm experiments we show that Psl, one major polysaccharide in the Pseudomonas aeruginosa biofilm matrix, provides a generic first line of defense toward antibiotics with diverse biochemical properties during the initial stages of biofilm development. Furthermore, we show with mixed-strain experiments that antibiotic-sensitive “non-producing” cells lacking Psl can gain tolerance by integrating into Psl-containing biofilms. However, non-producers dilute the protective capacity of the matrix and hence, excessive incorporation can result in the collapse of resistance of the entire community. Our data also reveal that Psl mediated protection is extendible to E. coli and S. aureus in co-culture biofilms. Together, our study shows that Psl represents a critical first bottleneck to the antibiotic attack of a biofilm community early in biofilm development.National Institutes of Health (U.S.). National Institute of Environmental Health Sciences (Training Grant in Toxicology 5 T32 ES7020-37

Influenza vaccination for immunocompromised patients: systematic review and meta-analysis from a public health policy perspective.

Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events

Compositional and structural analysis of iron doped X-cut lithium niobate crystals

We present a systematic study on the correlation between the compositional and structural properties of iron doped X-cut lithium niobate crystals doped by the thermal diffusion of thin iron film deposited via radio frequency (RF) sputtering varying the preparation conditions. The iron concentration profiles measured by using secondary ion mass spectrometry were properly fitted to determine the iron diffusion coefficients and the activation energy of the diffusion process. High resolution X-ray diffraction technique was used to study the crystalline quality of the doped region and to estimate the strain induced by the dopant incorporation. Depending on the preparation condition compressive and tensile strains were found in the diffused region

Compositional and structural analysis of iron doped X-cut lithium niobate crystals

We present a systematic study on the correlation between the compositional and structural properties of iron doped X-cut lithium niobate crystals doped by the thermal diffusion of thin iron film deposited via radio frequency (RF) sputtering varying the preparation conditions. The iron concentration profiles measured by using secondary ion mass spectrometry were properly fitted to determine the iron diffusion coefficients and the activation energy of the diffusion process. High resolution X-ray diffraction technique was used to study the crystalline quality of the doped region and to estimate the strain induced by the dopant incorporation. Depending on the preparation condition compressive and tensile strains were found in the diffused region