Rate-dependent elastic hysteresis during the peeling of pressure sensitive adhesives

PSA can undergo fibrillation and large strain, which leads to hysteretic dissipation at debonding. The resulting high adherence energy has a non trivial dependence on both the peeling angle and on the large strain rheology of the adhesive.

Nano-Machining Polishing Method on Metal Materials

Ice desk can realize the polishing on the metal material. Ice desk polishing can decrease the surface. Ice desk polishing can get ideal polishing result on LY12 aluminum alloy, which is nonferrous metal and unsuitable for traditional grinding and polishing. Under micro-loading or zero-loading, when the two faces are in sliding friction and the interval of boundary interface decreases to the degree that molecular force can make its function, the main reason removing the metal surface materials is lattice relaxing, structure splitting, surface energy and adherence energy in the interface. Crystal structure, surface crystal orientation, surface bias-gathering effect, adsorbs effect etc. is all have influences on the surface roughness of the metal material.

Identification of Streptococcus pneumoniae genes specifically induced in mouse lung tissues

To identify Streptococcus pneumoniae genes expressed specifically during infections, a selection system based on the in vivo expression technology (IVET) was established. galU, which is critical for capsular polysaccharide biosynthesis, and lacZY encoding β-galactosidase were employed as dual reporter genes to screen in-vivo-induced (ivi) genes of S. pneumoniae. The galU-deficient mutant of S. pneumoniae is incapable of utilizing galactose, thus failing to synthesize capsular polysaccharide, and therefore loses its ability to survive in the host. A promoter-trap library was constructed in S. pneumoniae, which was used to infect BALB/c mice in an intranostril model. Those strains recovered from lung tissue of mice and exhibiting a white colony phenotype on tryptic soy agar containing X-gal (5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside) were collected and identificated. A total of 15 unique sequences were obtained through in vivo screening. The ivi genes of S. pneumoniae are involved in many processes, such as colonization and adherence, energy metabolism, nutrient substance transport, transcription regulation, DNA metabolism, and cell wall synthesis. There are some hypothetical proteins whose functions are not clear. This novel IVET is a useful tool for identifying ivi genes in S. pneumoniae.