Synthesis and evaluation of N,N-dibutylundecenamide as new eco-friendly plasticizer for polyvinyl chloride

Journal of Materials Science - Tertiary fatty amide, namely N,N-dibutylundecenamide (DBUA), has been synthesized and evaluated as potential plasticizer for polyvinyl chloride (PVC). Homogeneous...     

The Antiadhesive Strategy in Crohn′s Disease: Orally Active Mannosides to Decolonize Pathogenic Escherichia coli from the Gut

Blocking the adherence of bacteria to cells is an attractive complementary approach to current antibiotic treatments, which are faced with increasing resistance. This strategy has been particularly studied in the context of urinary tract infections (UTIs), in which the adhesion of pathogenic Escherichia coli strains to uroepithelial cells is prevented by blocking the FimH adhesin expressed at the tips of bacteria organelles called fimbriae. Recently, we extended the antiadhesive concept, showing that potent FimH antagonists can block the attachment of adherent‐invasive E. coli (AIEC) colonizing the intestinal mucosa of patients with Crohn′s disease (CD). In this work, we designed a small library of analogues of heptyl mannoside (HM), a previously identified nanomolar FimH inhibitor, but one that displays poor antiadhesive effects in vivo. The anomeric oxygen atom was replaced by a sulfur or a methylene group to prevent hydrolysis by intestinal glycosidases, and chemical groups were attached at the end of the alkyl tail. Importantly, a lead compound was shown to reduce AIEC levels in the feces and in the colonic and ileal mucosa after oral administration (10 mg kg^?1) in a transgenic mouse model of CD. The compound showed a low bioavailability, preferable in this instance, thus suggesting the possibility of setting up an innovative antiadhesive therapy, based on the water‐soluble and non‐cytotoxic FimH antagonists developed here, for the CD subpopulation in which AIEC plays a key role.     

Trypsinization-dependent cell labeling with fluorescent nanoparticles

Trypsin is often used to detach adhered cell subculture from a substrate. However, the proteolytic activity of trypsin may harm cells by cleaving the cell membrane proteins. The present study shows that cellular uptake of fluorescent nanoparticles is remarkably increased within 24 h after trypsinization. These results highlight the trypsin-induced protein digestion, provoking leaky cell plasma membrane which leads to the strongly enhanced cellular uptake of the nanoparticles. To prevent this effect, one should expose cells to the nanoparticle (NP)-based fluorescent labels at least 48 h after trypsinization.     

Submerged-arc hardfacing large components with a composite strip electrode

Results of investigations and development of the highly productive technology of submerged-arc large components with a composite strip electrode are presented. It is shown that selecting the optimum dimensions of the composite strip electrode and the welding conditions ensures high quality of formation of the bead in depositing the sub-layer and the wear-resisting layer.     

Numerical analysis of the components of the three-dimensional non-singular stress field at a mixed-type crack tip

A program was developed that allows one to automate the process of calculating the three-dimensional stress field at a mixed-type crack tip within the ANSYS software. The calculation results are given for the stress intensity factors and components of the non-singular T-stress for the disk model with an inclined crack under compression with a varying thickness of the sample and an approximately constant parameter of mixing of the types of stress (I + II). We note the significant influence of the thickness of the sample on the nonsingular T _zz -stress when the value of the T _xx stress changes negligibly.     

Dynamic characteristics of the mockup of the fuel assembly in coolant flow

During exploitation, fuel assemblies are subjected to vibration loads caused by vibrations of intracase devices, pressure pulsations, acoustic waves, and turbulent flow of the coolant. Vibrations of the fuel assembly can be the cause of damage to its details, particularly, fuel elements and spacer lattices, because of their wear. Therefore, one requirement for the project of the fuel assembly of AES-2006 reactor installations is vibration strength and resistance throughout the service life of the fuel assembly in the reactor. The vibration strength and fuel assembly strength are substantiated by computational-experimental methods using the results of the experimental modal analysis of the full-scale mockup for verification.     

Wear dynamics of fragments in the lower part of a fuel assembly with unattached rods

The dynamic characteristics and wear of unattached fuel rods in the lower supporting lattice are investigated. The vibrational eigenfrequencies and dynamic rigidity of the fuel rods in different configurations are determined. The vibrational wear at contact between the fuel rods and the spacing elements is studied.