Carbon monoxide binding to iron porphyrins

The carbon monoxide affinities of iron complexes of meso-tetra (α,α,α,α-o-pivalamidophenyl)porphyrin (the "picket fence" porphyrin) and of a "picket fence" porphyrin derivative with an appended axial base have been measured in solution and compared with the CO affinities of various hemoproteins. The model complexes bind CO with much greater affinity than normal hemoproteins; the role of the steric bulk of distal residues in lowering the CO affinities of the hemoproteins is discussed. The significance of this lowered CO affinity is described with regard to endogenous CO. A discussion of mutant hemoglobins lacking distal residues that sterically inhibit the binding of CO is presented. The use of pressure units versus concentration units in equilibrium expressions is analyzed

Three toxic gases meet in the mitochondria

Public service fleets offer an attractive option for introducing renewable fuels and alternative technologies on a large scale, which allow for the reduction of both greenhouse gas emissions and exhaust air pollutants. This paper ex amines the use of biomethane (bio-CNG) and compressed natural gas (CNG) for part of the bus fleet in Dublin. Dublin is typical of many international urban centres with a large bus fleet; therefore the results detailed in this paper could be applied to other urban bus fleets. The emissions produced from the 2008 fleet based at one of the city?s seven bus depots were compared to use of new diesel and bio-CNG buses, which were modelled using COPERT 4, a road transport emissions model developed by the European Commission. The optimum feedstock for bio-CNG production in Ireland was investigated, as well as the quantity of feedstock needed to produce t he required bio-CNG to fuel the bus fleet examined. The merits of producing bio-CNG in Ireland were analysed in order to determine the best policy. As expected the results showed a substantial decrease in all exhaust emissions from the use of bio-CNG buses compared the 2008 fleet. Grass silage was chosen as the optimum feedstock for production of bio-CNG in Ireland, and it was calculated using a sensitivity analysis that 1,349 ha is the land take needed to produce the grass silage for bio-CNG required to run the bus fleet examined

Principles and Applications of Organotransition Metal Chemistry

Oxford715 p.: illus.; 23 c

Naturally dangerous : supprising facts about food, health, and the environtment

This book connects observations from our everyday lives to the scientific principles tha texplain them. You will find information on organic and commercial foods, natural herbs, modern medicine, the environment, DNA testing, and much more

Electrocatalytic four-electron reduction of dioxygen by indium porphyrins adsorbed on graphite

11Nsciescopu

Cofacial porphyrin dimers containing intramolecular metal-metal bonds

11Nsci