Lithiation of carbamates followed by borylation provides a powerful method for the homologation of boron reagents. However, when applied to hindered systems (secondary carbamates with tBu-boronic esters) for the construction of two quaternary centers, this methodology fails. Instead, using mixed boranes (tBuBMe2), the synthesis of adjacent quaternary stereogenic centers with full stereocontrol ...

results of total 60 s. aureus isolates, 51 (85%) were mrsa, and of 60 cons, 7 (11.66%) were mrcons. the results showed that the mic of chlorhexidine for all 120 isolates was 1-16 μg/ml. 15 (12.5%) isolates carried qaca/b gene, 26 (21.7%) carried qacc gene, and 38 (31.7%) carried smr gene. conclusions maintenance of mrsa isolates in the attendance of low amounts of antiseptics could result in th...

Derivatization of peptides as quaternary ammonium salts (QAS) is a promising method for sensitive detection by electrospray ionization tandem mass spectrometry (Cydzik et al. J. Pept. Sci. 2011, 17, 445-453). The peptides derivatized by QAS at their N-termini undergo fragmentation according to the two competing mechanisms - charge remote (ChR) and charge directed (ChD). The absence of mobile pr...

In this paper, we propose multicode multiple-input multiple-output (MIMO) systems with quaternary low correlation zone (LCZ) and zero correlation zone (ZCZ) sequences as spreading codes. Quaternary LCZ and ZCZ sequences have very low correlation values when the time shifts of correlation function are within the predetermined correlation zone and thus the multiuser or multipath interference can ...

Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of the eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane li...

MCCULLOCH, E. C. 1947 The real and apparent bactericidal efficiencies of quaternary ammonium compounds. J. Bacteriol., 53: 370. MCCULLOCH, E. C., HAUGE, S., AND MIGAKI, H. 1948 The role of disinfectants in veterinary medicine. II. A critical evaluation of the quaternary ammonium compounds. J. Am. Vet. Med. Assoc., 112: 283-290. STUART, L. S. 1947 N.A.I.D.M.-U.S.D.A. report on quaternary ammoniu...

Asymmetric preparation of all-carbon quaternary stereocenters is an important goal. Despite advances in formation of highly enantioenriched products with quaternary stereocenters proximal to a functional group, methods to install quaternary stereocenters isolated from functional groups are limited. Transition metal catalysis offers a potential solution, but prior cross couplings are limited to ...

Although infections with NonTuberculous Mycobacteria have become less common in AIDS patients, they are important opportunistic infections after surgical procedures, likely because they are ubiquitous and not efficiently killed by many commonly used disinfectants. In Venezuela there have recently been many non-tuberculous mycobacteria soft tissue infections after minor surgical procedures, some...