Anti-VIM monoclonal antibody, clone 6E8

GH4586 is a nickel-based wrought superalloy developed by China, and features high Ti, W, Mo and low Al. However, it is easy to form whit spot (WP) defects within the disk components manufactured from the GH4586 ingot with a diameter of 508 mm produced by double vacuum melting method. In present work, the macro- and micro-structural characteristics, as well as the element distribution of WP defect were systematically studied. Special attention was focused on the effects of WP on mechanical properties. Hardness, tensile properties and fracture morphology of normal and defective areas were investigated for comparison. In addition, the formation mechanism and control method of WP defects were investigated based on the thermodynamic calculation and solidification simulation, respectively. In order to analyze its dendritic segregation and second phase precipitation in the solidification process, solidification phase diagram and thermodynamic equilibrium phase diagram of GH4586 alloy were calculated with JmatPro software. To study the forming mechanism of WP, the solidification process of vacuum introduction melting (VIM) GH4586 ingots was simulated with Procast software. Results show that the WP defects within GH4586 components are dendritic WP which exhibits dendritic pattern on the macro level. While on micro level, it is the precipitate clusters which consisted of MC carbides, M 6C carbides and large incoherent.' phase. Due to the clusters' inherent rigid and fragile characteristics, the tensile strength and ductility of the alloy are significantly reduced. Therefore, the WP defects are harmful to the mechanical properties of the GH4586 disk significantly. The WP defects must be avoided during the forging process. Since excessive internal stress and shrinkage cavities form during the solidification process of large VIM GH4586 ingots, chips fall into molten pool easily if the VIM ingots are employed as vacuum arc remelting (VAR) electrode, and then give birth to WP defects within the final forging components. Therefore, it is the effective method for avoiding WP defects by improving the quality of VAR electrode and optimizing the VAR process.

Pseudomonas aeruginosa is considered an opportunistic pathogen, causing a wide variety of infections in compromised hosts, also frequently develops multi-resistance to antibiotics and can colonize various habitats, including water systems. The main aim of this study was to investigate antibiotics susceptibility pattern, genotypic diversity and detection of resistence genes in P. aeruginosa isolates from clinical and aquatic environment sources. Of the 220 P. aeruginosa isolates examined, 48 were clinical isolates and 172 isolates from wastewater and freshwater. Susceptibility to eight antimicrobial agents was carried out by disk diffusion method. Clinical and environmental isolates were screened for the presence of the genes encoding bla(KPC-2), bla(CTX-M-9), bla(PER-1), bla(OXA-10), bla(IMP-1), bla(VIM-2) and bla(ampC) by polymerase chain reaction (PCR). Isolates were examined with PCR-SSCP analysis of partial DNAr 16S sequence. Isolates were mainly resistant to cefoxitin. Multidrug-resistant P. aeruginosa (MDRPA) strains were found in 70% and 90.3% of the clinical and environmental isolates, respectively. The prevalence rates of a-lactamase genes were recorded (bla(KPC-2) 41.3%, bla(VIM-2) 36.8%, bla(IMP-1) 13.6%, bla(CTX-M-9) 10.9% and bla(ampC) 10.5%,). The PCR-SSCP analysis showed three conformational patterns. All clinical isolates and most environmental isolates were grouped into a single cluster. In this study, we found that P. aeruginosa strains recovered from city water systems must be considered potential reservoir for ESBL genes, especially blaKPC-2 and blaVIM-2.