Computer modelling has been used to investigate the effect of direct transfer of metabolites between consecutive enzymes (channelling) on the free concentrations of the channelled metabolites. When a channelled intermediate cannot participate in any other reactions, any increase in channelling tends to increase its free concentration, albeit very slightly, unless the increase in net flux brough...

FREQUENTLY CITED THEORETICAL framework for the conduct of monetary policy consists of a policy instrument, an intermediate policy target and a long-run policy objective. The policy instrument is a lever which the central bank can manipulate to achieve its intermediate target. Possible choices for the policy instrument include the quantity of bank reserves, the monetary base (hank reserves plus ...

Consumers’uncertainty regarding their future needs generates demand for options to utilize different products. Such options are commonly sold in the form of insurance. A prime example for option demand presents in health care markets and other repair markets. This work studies two-dimensional spatial competition between medical providers who choose their geographical location and medical-care s...

The Breslow catalytic cycle describing the benzoin condensation promoted by N-heterocyclic carbenes (NHC) as proposed in the late 1950s has since then been tried by generations of physical organic chemists. Emphasis has been laid on proofing the existence of an enaminol like structure (Breslow intermediate) that explains the observed umpolung of an otherwise electrophilic aldehyde. The present ...

Superoxide reductase is a nonheme iron metalloenzyme that detoxifies superoxide anion radicals O(2)(•-) in some microorganisms. Its catalytic mechanism was previously proposed to involve a single ferric iron (hydro)peroxo intermediate, which is protonated to form the reaction product H(2)O(2). Here, we show by pulse radiolysis that the mutation of the well-conserved lysine 48 into isoleucine in...

this guide to the identification of iranian freshwater snails has been prepared with aim of helping individuals involved in field work, but who have had no specialized training in taxonomy to differentiate snail specimens which they collect to certain groups by means of simple identification key. the guide pays special attention to the principal snail groups which transmit human schistosomiasis...

background and aims: infectious bursal disease (ibd) is an acute contagious viral disease of birds worldwide. the causative virus induces a persistent immune suppression following destroy b lymphocytes precursors in bursal lymphoid follicles. vaccination is the main strategy for prevention of the disease in commercial poultry industry. materials and methods: to produce a live vaccine against th...

This paper discusses the requirements on product model presentations that are suitable for reuse. The aim is to define promising directions for future research by recognizing how the characteristics of reuse entities vary at the different stages of the product life-cycle. Reuse entities are roughly categorized into three types of presentation entities: macroscopic principles for the early stage...

A novel sedimentary transformation product of chlorophyll, purpurin-7 phytyl ester, has been identi®ed by atmospheric pressure chemical ionisation liquid chromatography mass-spectrometry in sediments from Lake Baikal, Russia, Loch Ness and Priest Pot, UK. This product of oxidative transformation is an intermediate on the transformation pathway leading to sedimentary aetioporphyrins and its occu...

A nine-step synthesis of trans 4-cyclohexyl-L-proline has been developed on a laboratory scale. The product is an intermediate in the preparation of fosinopril--an effective hypotensive drug. The total yield of the synthesis was 25%. The final product was 99.7% pure. Analytical methods were developed for each step of the synthesis (HPLC, TLC, IR, 1H-NMR, 13C-NMR, GC-MS, [alpha]D).