Understanding substrate substituent effects to improve catalytic efficiency in the SABRE hyperpolarisation process

The use of parahydrogen based hyperpolarisation in NMR is becoming more widespread due to the rapidly expanding range of target molecules and low-cost of parahydrogen production. Hyperpolarisation via SABRE catalysis employs a metal complex to transfer polarisation from parahydrogen into a substrate whilst they are bound. In this paper we present a quantitative study of substrate–iridium ligation effects by reference to the substrates 4-chloropyridine (A), 4-pyridinecarboxaldehyde methyl hemiacetal (B), 4-methylpyridine (C) and 4-methoxypyridine (D), and evaluate the role they play in the SABRE catalysis. Substrates whose substituents enable stronger associations yield slower substrate dissociation rates (kd). A series of variable temperature studies link these exchange rates to optimal SABRE performance and reveal the critical impact of NMR relaxation times (T1). Longer catalyst residence times are shown to result in shorter substrate T1 values in solution as binding to iridium promotes relaxation thereby not only reducing SABRE efficiency but decreasing the overall level of achieved hyperpolarisation. Based on these data, a route to achieve more optimal SABRE performance is defined

Cancer survival in New South Wales, Australia: socioeconomic disparities remain despite overall improvements

Background\ud \ud Disparities in cancer survival by socioeconomic status have been reported previously in Australia. We investigated whether those disparities have changed over time.\ud Methods\ud \ud We used population-based cancer registry data for 377,493 patients diagnosed with one of 10 major cancers in New South Wales (NSW), Australia. Patients were assigned to an area-based measure of socioeconomic status. Five-year relative survival was estimated for each socioeconomic quintile in each ‘at risk’ period (1996–2000 and 2004–2008) for the 10 individual cancers. Poisson-regression modelling was used to adjust for several prognostic factors. The relative excess risk of death by socioeconomic quintile derived from this modelling was compared over time.\ud Results\ud \ud Although survival increased over time for most individual cancers, Poisson-regression models indicated that socioeconomic disparities continued to exist in the recent period. Significant socioeconomic disparities were observed for stomach, colorectal, liver, lung, breast and prostate cancer in 1996–2000 and remained so for 2004–2008, while significant disparities emerged for cervical and uterus cancer in 2004–2008 (although the interaction between period and socioeconomic status was not significant). About 13.4 % of deaths attributable to a diagnosis of cancer could have been postponed if this socioeconomic disparity was eliminated.\ud Conclusion\ud \ud While recent health and social policies in NSW have accompanied an increase in cancer survival overall, they have not been associated with a reduction in socioeconomic inequalities

Supplemental Iodide for Preterm Infants and Developmental Outcomes at 2 Years:an RCT

Background The recommendation for enteral iodide intake for preterm infants is 30–40 μg/kg/day and 1μg/kg/day for parenteral intake. Preterm infants are vulnerable to iodide insufficiency and thyroid dysfunction. The hypothesis tested whether, compared to placebo, iodide supplementation of preterm infants improves neurodevelopment. Methods A randomized controlled trial of iodide supplementation versus placebo in infants <31 weeks’ gestation. Trial solutions (sodium iodide or sodium chloride; dose 30μg/kg/day) were given within 42 hours of birth to the equivalent of 34 weeks’ gestation. The only exclusion criterion was maternal iodide exposure during pregnancy or delivery. Whole blood levels of thyroxine, thyrotropin and thyroid binding globulin were measured on four specific postnatal days. The primary outcome was neurodevelopmental status at two years’ of age, measured using the Bayley-III scales. The primary analyses are by intention-to-treat and data are presented also for survivors. Results 1,273 infants (637 intervention, 636 placebo) were recruited from 21 UK neonatal units. 131 infants died, and neurodevelopmental assessments were undertaken in 498 iodide and 499 placebo supplemented infants. There were no significant differences between the intervention and placebo groups in the primary outcome: mean difference Cognitive score, -0.34, 95% confidence interval (CI) -2.57 to 1.89; Motor composite score, 0.21, 95% CI -2.23 to 2.65; Language composite score, -0.05, 95%CI -2.48 to 2.39. There was evidence of weak interaction between iodide supplementation and hypothyroxinemic status in the Language composite score and one subtest score. Conclusions Overall iodide supplementation provided no benefit to neurodevelopment measured at 2 years of age

Standard electrode potentials involving radicals in aqueous solution: inorganic radicals

Inorganic radicals, such as superoxide and hydroxyl, play an important role in biology. Their tendency to oxidize or to reduce other compounds has been studied by pulse radiolysis; electrode potentials can be derived when equilibrium is established with a well-known reference compound. An IUPAC Task Group has evaluated the literature and produced the recommended standard electrode potentials for such couples as (O2/O2·-), (HO·, H+/H2O), (O3/O3·-), (Cl2/Cl2·-), (Br2·-/2Br-), (NO2·/NO2-), and (CO3·-/CO32-

Australia\u27s health 1994 : the fourth biennial report of the Australian Institute of Health and Welfare

Australia\u27s Health is the most comprehensive and authoritative source of national information on health in Australia. Australia\u27s Health is published mid-year in even-numbered years and provides national statistics and related information that form a record of health status, service provision and expenditure in Australia

Australia\u27s health 2002 : the eighth biennial report of the Australian Institute of Health and Welfare

Australia\u27s Health 2002 is the eighth biennial health report of the Australian Institute of Health and Welfare. It is the nation\u27s authoritative source of information on patterns of health and illness, determinants of health, the supply and use of health services, and health service costs and performance. Australia\u27s Health 2002 is an essential reference and information resource for all Australians with an interest in health