A weighing method for measuring nitrous oxide leakage from hospital manifold-pipeline networks.

Nitrous oxide is a potent greenhouse gas and ozone-depleting agent with a long atmospheric lifetime. Several previous reports indicate that over half of supplied nitrous oxide is wasted from leaking manifold-pipeline systems infrastructure prior to patient use, and that remediating leaks can have significant environmental benefits. We describe an accurate, simple and cost-effective cylinder weighing method to quantify nitrous oxide leak from the manifold-pipeline network at our tertiary non-obstetric facility.

Catalytic asymmetric diaziridination.

The first catalytic enantio- and diastereoselective synthesis of diaziridines is presented. Aziridination of N-tosyl aldimines applying modified hydroxylamine under asymmetric phase-transfer catalysis furnished optically active diaziridines. The diaziridines are formed as a single diastereomer in up to 96% ee, containing two orthogonal N-protecting groups, which can be deprotected selectively.

Structure-activity relationship studies of strigolactone-related molecules for branching inhibition in garden pea: molecule design for shoot branching.

Initially known for their role in the rhizosphere in stimulating the seed germination of parasitic weeds such as the Striga and Orobanche species, and later as host recognition signals for arbuscular mycorrhizal fungi, strigolactones (SLs) were recently rediscovered as a new class of plant hormones involved in the control of shoot branching in plants. Herein, we report the synthesis of new SL analogs and, to our knowledge, the first study of SL structure-activity relationships for their hormonal activity in garden pea (Pisum sativum). Comparisons with their action for the germination of broomrape (Phelipanche ramosa) are also presented.