Search

In this paper, we study universal sums of triangular numbers and squares. Specifically, we prove that a sum of triangular numbers and squares is universal if and only if it represents 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 10 , 13 , 14 , 15 , 18 , 19 , 20 , 23 , 27 , 28 , 34 , 41 , 47 , and 48. [ABSTRACT FROM AUTHOR]

The current sorbents used to remove Cr (VI) from electroplating wastewater are faced with some challenges including the difficulty in separating, regenerating, and safely disposing of adsorbed Cr species. To address these challenges, CuS x /TiO 2 was developed to recover Cr (VI) from electroplating wastewater. CuS x /TiO 2 had superior performance in removing Cr (VI), with the rate and capacity of approximately 9.36 mg g−1 h−1 and 68.8 mg g−1 at initial pH 4.0, respectively. Additionally, Cu2+ released from CuS x /TiO 2 during Cr (VI) removal would come back to its external surface as the Cu(OH) 2 precipitate at initial pH 4.0, which helped to prevent the generation of secondary pollution. The Cu(OH) 2 precipitate would be decomposed into CuO x after calcination, which would then be transformed back into CuS x by re-sulfuration for regeneration. Hence, CuS x showed a magical induction effect on Cr (VI) recovery, and Cr (VI) from electroplating wastewater might be gradually enriched as Cr 2 O 3 in the sandwich between CuS x and TiO 2 through multiple regenerations and removals, which could be considered as a chromium ore resource for industrial applications when the amount of enriched Cr 2 O 3 reached more than 30 wt%. Overall, CuS x /TiO 2 showed great potential as a promising sorbent for Cr (VI) removal from electroplating wastewater. [Display omitted] • CuS x exhibits superior performance in removing Cr (VI), which outperforms common FeS x. • CuS x /TiO 2 can be recycled for Cr (VI) removal after regeneration. • CuS x shows a magical induction effect on Cr (VI) recovery. • CuS x /TiO 2 is a promising sorbent for Cr (VI) removal from electroplating wastewater. [ABSTRACT FROM AUTHOR]

Methicillin-resistant S. aureus (MRSA) has attracted more and more attention in recent years, especially in burn medical centers. Here we conducted a 5-year period study to evaluate the MRSA infection in our burn center. The staphylococcal chromosomal cassette mec ( SCCmec ) typing, antimicrobials susceptibility and virulence profiles were also performed among the MRSA isolates. Of the 259 S. aureus isolates, 239 (92.28%) isolates were identified as MRSA. A decreased trend of MRSA isolation rate over time was found ( P = 0.0063). Majority of MRSA isolates in our center belonged to SCCmec type III (230/239, 96.23%). Antimicrobials susceptibility tests of the MRSA isolates revealed significantly decreased resistance to clindamycin ( P = 0.0183), and increased resistance to chloramphenicol ( P = 0.0020) and minocycline ( P < 0.0001) over time. Trimethoprim/sulfamethoxazole, clindamycin, vancomycin, teicoplanin and linezolid were suggested to be good choice for MRSA infection in our center. Virulence factors profiling showed that most of MRSA isolates in our center carried the virulence factor pattern of cna - clfA - clfB - eno - fib - icaA - icaD - sea - psmα - lukED - hlg - hlgv - hla - hld (214/239, 89.54%). In conclusion, our study suggests that MRSA infection is serious in our burn center, but presented decreased trend over time. Most of MRSA isolates in our center presented the same virulence factor profile. More attention should be attached to nosocomial infection in burn medical center. Antimicrobials susceptibility changing over time was observed. Antimicrobials susceptibility monitoring is necessary and helps to select appropriate drugs against MRSA infections. [ABSTRACT FROM AUTHOR]