Impact of Penicillin Allergy-Based Alternative Antibiotics on the Risk of Postoperative Central Nervous System Infection: A Retrospective Cohort Study.

Background: Central nervous system (CNS) infection is one of the most serious complications after neurosurgery. This study aimed to analyze the effect of penicillin allergy (PA) and alternative prophylactic antibiotics on risk of postoperative CNS infection in patients undergoing neurosurgery.

Methods: Data of patients who underwent neurosurgical procedures from January 2015 to December 2021 were analyzed retrospectively.

[Nitrate Source Identification and Nitrification-denitrification at the Sediment-water Interface].

Identifying nitrate sources and its transformation mechanisms are important for nitrate pollution control in surface water. The columnar core sediment samples in West Lake were taken in different seasons. The transformation of nitrogen at the sediment-water interface was studied using nitrogen and oxygen isotopes, stable isotope analysis in R (SIAR) and acetylene inhibition method in the West Lake, Hangzhou.

Mechanistic Studies of Azaphilic versus Carbophilic Activation by Gold(I) in the Gold/Palladium Dual-Catalyzed Rearrangement of Alkenyl Vinyl Aziridines.

A vinyl aziridine activation strategy cocatalyzed by palladium(0) and a gold(I) Lewis acid has been developed. This rearrangement installs a C-C and a C-N bond in one synthetic step to form pyrrolizidine and indolizidine products. Two proposed mechanistic roles for the gold cocatalyst were considered: (1) carbophilic gold catalysis or (2) azaphilic gold catalysis.

Organogold reactivity with palladium, nickel, and rhodium: transmetalation, cross-coupling, and dual catalysis.

Using two transition metals to simultaneously catalyze a reaction can offer distinct opportunities for reactivity and selectivity when compared to using single-metal catalyst systems. Creating dual transition metal catalytic systems is complicated, however, by challenges in predicting compatible reactivities and designing turnover pathways for both metals. In this Account, we describe our development of dual-metal catalysis reactions involving gold and a second transition metal.

Catalyzed catalysis using carbophilic Lewis acidic gold and Lewis basic palladium: synthesis of substituted butenolides and isocoumarins.

A new strategy for gold and palladium dual-catalytic reactivity and turnover, called catalyzed catalysis, enhanced the synthetic usefulness of vinylgold intermediates by providing dual-catalytic carbon-carbon cross-coupling as an alternative to protodemetalation. This protocol enabled the synthesis of substituted butenolides and isocoumarins from allyl esters. Kinetic and spectroscopic experiments support a mechanism in which the Lewis acidic gold complex catalyzes both an initial rearrangement step and a subsequent Lewis basic palladium oxidative-addition step.

Diastereoselective and enantioselective Rh(I)-catalyzed additions of arylboronic acids to N-tert-butanesulfinyl and N-diphenylphosphinoyl aldimines.

Two new Rh(I)-catalyzed methods for the synthesis of chiral alpha-branched amines via addition of arylboronic acids to N-tert-butanesulfinyl and N-diphenylphosphinoyl imines have been developed. The syntheses are more functional group tolerant than alternative methods utilizing Grignard or organolithium reagents, and the imine activating groups used are easily removed. These methods are both high-yielding (70-97% yield) and very selective (>93:7 dr and 88-94% ee).