Investigation of hydrogen induced fluorescence in C60 and its potential use in luminescence down shifting applications

Herein the photophysical properties of hydrogenated fullerenes (fulleranes) synthesized by direct hydrogenation utilizing hydrogen pressure (100 bar) and elevated temperatures (350 °C) are compared to the fulleranes C₆₀H₁₈ and C₆₀H₃₆ synthesized by amine reduction and the Birch reduction, respectively. Through spectroscopic measurements and density functional theory (DFT) calculations of the HOMO-LUMO gaps of C₆₀H_x (0 ≤ x ≤ 60), we show that hydrogenation significantly affects the electronic structure of C₆₀ by decreasing conjugation and increasing sp³ hybridization. This results in a blue shift of the emission maximum as the number of hydrogen atoms attached to C₆₀ increases. Correlations in the emission spectra of C₆₀H_x produced by direct hydrogenation and by chemical methods also support the hypothesis of the formation of C₆₀H₁₈ and C₆₀H₃₆ during direct hydrogenation with emission maxima of 435 and 550 nm respectively. We also demonstrate that photophysical tunability, stability, and solubility of C₆₀H_x in a variety of organic solvents make them easily adaptable for application as luminescent down-shifters in heads-up displays, light-emitting diodes, and luminescent solar concentrators. The utilizization of carbon based materials in these applications can potentially offer advantages over commonly utilized transition metal based quantum dot chromophores. We therefore propose that the controlled modification of C₆₀ provides an excellent platform for evaluating how individual chemical and structural changes affect the photophysical properties of a well-defined carbon nanostructure.

Clinical effectiveness and cost-effectiveness of foot orthoses for people with established rheumatoid arthritis: an exploratory clinical trial

OBJECTIVES

Foot orthoses are commonly prescribed as an intervention for people with rheumatoid arthritis (RA). Data relating to the cost-effectiveness of foot orthoses in people with RA are limited. The aim was to evaluate the clinical and cost-effectiveness of two types of foot orthoses in people with established RA.

METHOD

A single-blind randomized controlled trial was undertaken to compare custom-made foot orthoses (CMFOs) and simple insoles (SIs) in 41 people with established RA. The Foot Function Index (FFI) was used to measure foot pain, disability, and functional limitation. Costs were estimated from the perspective of the UK National Health Service (NHS), societal (patient and family) perspective, and secondary care resource use in terms of the intervention and staff time. Effects were assessed in terms of health gain expressed as quality-adjusted life years (QALYs).

RESULTS

At baseline, 20 participants received a CMFO and 21 participants received an SI. After 16 weeks foot pain improved in both the CMFOs (p = 0.000) and the SIs (p < 0.01). However, disability scores improved for CMFOs (p < 0.001) but not for SIs (p = 0.40). The cost-effectiveness results demonstrated no difference in cost between the arms (CMFOs: £159.10; SIs: £79.10; p = 0.35), with the CMFOs being less effective in terms of cost per QALY gain (p < 0.001).

CONCLUSIONS

In people with established RA, semi-rigid customized foot orthoses can improve pain and disability scores in comparison to simple insoles. From a cost-effectiveness perspective, the customized foot orthoses were far more expensive to manufacture, with no significant cost per QALY gain.

Technical innovation changes standard radiographic protocols in veterinary medicine: is it necessary to obtain two dorsoproximal-palmarodistal oblique views of the equine foot when using computerised radiography systems?

Since the 1950s, veterinary practitioners have included two separate dorsoproximal-palmarodistal oblique (DPr-PaDiO) radiographs as part of a standard series of the equine foot. One image is obtained to visualise the distal phalanx and the other to visualise the navicular bone. However, rapid development of computed radiography and digital radiography and their post-processing capabilities could mean that this practice is no longer required. The aim of this study was to determine differences in perceived image quality between DPr-PaDiO radiographs that were acquired with a computerised radiography system with exposures, centring and collimation recommended for the navicular bone versus images acquired for the distal phalanx but were subsequently manipulated post-acquisition to highlight the navicular bone. Thirty images were presented to four clinicians for quality assessment and graded using a 1-3 scale (1=textbook quality, 2=diagnostic quality, 3=non-diagnostic image). No significant difference in diagnostic quality was found between the original navicular bone images and the manipulated distal phalanx images. This finding suggests that a single DPr-PaDiO image of the distal phalanx is sufficient for an equine foot radiographic series, with appropriate post-processing and manipulation. This change in protocol will result in reduced radiographic study time and decreased patient/personnel radiation exposure.

Limits to sustained energy intake XXIV: impact of suckling behaviour on the body temperatures of lactating female mice

The objective of this study was to investigate the potential causes of high body temperature (Tb) during lactation in mice as a putative limit on energy intake. In particular we explored whether or not offspring contributed to heat retention in mothers while suckling. Tb and physical activity were monitored in 26 female MF1 mice using intraperitoneally implanted transmitters. In addition, maternal behaviour was scored each minute for 8 h d(-1) throughout lactation. Mothers that raised larger litters tended to have higher Tb while nursing inside nests (P < 0.05), suggesting that nursing offspring may have influenced heat retention. However, Tb during nursing was not higher than that recorded during other behaviours. In addition, the highest Tb during the observation period was not measured during nursing behaviour. Finally, there was no indication that mothers discontinued suckling because of a progressive rise in their Tb while suckling. Tb throughout lactation was correlated with daily increases in energy intake. Chronic hyperthermia during lactation was not caused by increased heat retention due to surrounding offspring. Other factors, like metabolic heat produced as a by-product of milk production or energy intake may be more important factors. Heat dissipation limits are probably not a phenomenon restricted to lactation.

Trust: The Missing Dimension in the Food Retail Transition in Thailand

Thailand has experienced dramatic growth of large national and international modern food retailers, such as supermarkets, hypermarkets and convenience stores in large cities and regional centres in the last two decades. Nevertheless, Thai consumers continue to purchase perishables (fruits, vegetables and animal products) from fresh markets (wet markets, talat sot) contradicting predictions from analysts that modern food retail chains will rapidly replace fresh markets as the preferred venue for purchasing all types of foods. This paper examines trust in food retail systems as an under-explored dimension lying behind the continued patronage by Thais of fresh markets to purchase perishable items. It derives from a research program commenced in 2005 that includes fieldwork visits, interviews and questionnaires. In the context of the Thai food retail transition, we propose that trust affects relationships between consumers and (1) individual fresh market-based vendors, (2) the food products sold at fresh markets and (3) the food retail system more broadly. If fresh markets can be maintained in the face of sustained pressure from modern national and international food retailers, Thais will continue to use them. Meanwhile, trust is a relatively unrecognised dimension that is supporting the continued existence of traditional food retail formats.

Venous thromboembolism rates in patients undergoing major hip and knee joint surgery at Waitemata District Health Board: a retrospective audit

BACKGROUND/AIM

Symptomatic venous thromboembolism (VTE) complicates approximately 4% of major orthopaedic surgical procedures performed without thromboprophylaxis. Randomised clinical trials demonstrate primary thromboprophylaxis reduces VTE rates to <1%, with low rates of clinically important bleeding, using low molecular weight heparin (LMWH), oral FXa inhibitors or thrombin inhibitors. We reviewed the rates of VTE in patients undergoing major hip/knee joint surgery at Waitemata District Health Board (WDHB).

METHODS

Cases of VTE within 90 days of orthopaedic surgery were identified by retrospective audit of data from the haematology VTE database. The number of major hip/knee joint surgeries at WDHB from January 2006 to December 2010 was obtained from clinical coding data.

RESULTS

The cumulative incidence of VTE within 90 days of surgery was 3.29%. The median time from surgery to diagnosis was 7 days. Deep vein thrombosis comprised 75% of cases, 77.6% distal and 23.2% proximal. Pulmonary embolism comprised 26.5% of VTE; 47.7% had right heart strain on computed tomography/echocardiography. Hip fracture surgery comprised one-third of patients. Of patients developing VTE, 85.5% had chemical thromboprophylaxis - aspirin 73%, LMWH 20 mg 16%, LMWH 40 mg 16%, therapeutic LMWH 3%, unfractionated heparin twice daily 1%, and warfarin 4%; 75.6% received mechanical prophylaxis, while 4% of patients received no prophylaxis.

CONCLUSION

VTE incidence after major hip/knee joint surgery at WDHB is high, with pulmonary embolism comprising almost one-third of all VTE in this study, indicating the prophylaxis given is suboptimal. Implementation of appropriate, extended duration prophylaxis as per evidence-based guidelines is required to reduce these rates.

Climate change, food systems and population health risks in their eco-social context

The establishment of ecological public health as crucial to modern public health is overdue. While the basic concepts have been gestating for decades, receptivity within broader public health has been limited. This position is changing, not least as the population-level impacts of climate change and, more broadly, of limits to growth are emerging from theory and forecasting into daily reality. This paper describes several key elements of ecological public health thinking. These include the 'environmental' risks to human health (often systemic and disruptive, rather than local and toxic) posed by climate change and other forms of adverse global environmental change. Closer recognition of the links between social and environmental factors has been urged--an 'eco-social' approach--and, relatedly, for greater co-operation between social and natural sciences. The authors revisit critics of capitalism who foresaw the global capture and transformation of ecosystems for material human ends, and their resultant despoliation. The perennial call within public health to reduce vulnerability by lessening poverty is more important than ever, given the multifactored threat to the health of the poor which is anticipated, assuming no radical strategies to alleviate these pressures. But enhanced health security for the poor requires more than the reconfiguring of social determinants; it also requires, as the overarching frame, ecological public health.

The art and science of chronic disease management come together in a lifestyle-focused approach to primary care

Changes in patterns of living result in changes in the nature and causes of disease. The industrial revolution of the late 18th century, and the technological revolution of the late 20th century are cases in point. The former was associated with a decline in infectious diseases; the latter with an increase in lifestyle and environmentally induced chronic diseases . Health practices are typically modified to deal with such changes, hence the recent rise in interest in lifestyle-oriented forms of clinical practice.