Aromatic dioxygenases: Molecular biocatalysis and applications

Aromatic dioxygenases have been found to catalyse single and tandem oxidation reactions of conjugated polyenes. Rational selection and design of dioxygenases, allied to substrate shape, size and substitution pattern, has been used to control regiochemistry and stereochemistry during the oxygenation process. The resulting enantiopure bioproducts have been increasingly utilised as precursors for new and alternative routes in chiral synthesis.

Resting energy expenditure in non-ventilated, non-sedated patients recovering from serious traumatic brain injury: Comparison of prediction equations with indirect calorimetry values

Background & aims: Little is known about energy requirements in brain injured (TBI) patients, despite evidence suggesting adequate nutritional support can improve clinical outcomes. The study aim was to compare predicted energy requirements with measured resting energy expenditure (REE) values, in patients recovering from TBI.

Methods: Indirect calorimetry (IC) was used to measure REE in 45 patients with TBI. Predicted energy requirements were determined using FAO/WHO/UNU and Harris–Benedict (HB) equations. Bland– Altman and regression analysis were used for analysis.

Results: One-hundred and sixty-seven successful measurements were recorded in patients with TBI. At an individual level, both equations predicted REE poorly. The mean of the differences of standardised areas of measured REE and FAO/WHO/UNU was near zero (9 kcal) but the variation in both directions was substantial (range 591 to þ573 kcal). Similarly, the differences of areas of measured REE and HB demonstrated a mean of 1.9 kcal and range 568 to þ571 kcal. Glasgow coma score, patient status, weight and body temperature were signi?cant predictors of measured REE (p < 0.001; R²⁼ 0.47).

Conclusions: Clinical equations are poor predictors of measured REE in patients with TBI. The variability in REE is substantial. Clinicians should be aware of the limitations of prediction equations when estimating energy requirements in TBI patients.

Control of the thickness of mesoporous titania films for application in multiphase catalytic microreactors

A new method of sol-gel polymer template synthesis of mesoporous catalytic thin films has been proposed which allows controlling the chemical nature of the film, the porosity, thickness and loading with an active species. The mesoporous films with a long-order structure can be obtained in a narrow range of surfactant-to-metal precursor molar ratios from 0.006 to 0.009. The catalytic film thickness was varied from 300 to 1000 nm while providing a uniform catalyst distribution with a desired catalyst loading (1 wt. % Au nanoparticles) throughout the film. The films were characterized by TEM, SEM, ethanol adsorption and contact angle measurements. The calcination of the as-synthesized films at 573 K reduced Ti4+ sites to Ti3+. A 300 nm thick Au-containing film showed an initial TOF of 1.4 s(-1) and a selectivity towards unsaturated alcohols as high as 90% in the hydrogenation of citral. Thicker films demonstrated a high selectivity towards the saturated aldehyde (above 55%) and a lower intrinsic catalytic activity (initial TOF of 0.7-0.9 s(-1)) in the absence of internal diffusion limitations.

Monoclonal antibody development for acrylamide-adducted human haemoglobin; A biomarker of dietary acrylamide exposure

The spontaneous formation of the neurotoxic carcinogen acrylamide in a wide range of cooked foods has recently been discovered, leading to dietary exposure estimates of 30.8 mu g of acrylamide day(-1) for an average 77 kg human male. This is considerably higher than the European legal limit of acrylamide in drinking water, which is approximately 0.2 mu g of acrylamide person(-1) day(-1). A recent study of 62,573 women over 11.3 years has observed an increased risk of postmenopausal endometrial and ovarian cancer (but not breast cancer) with increasing dietary acrylamide intake, demonstrating significant risk to human health. As individual acrylamide exposure is affected by dietary habits, cooking methods, and cigarette consumption; accurate extrapolation from estimated dietary exposure is extremely difficult. Quantifying biomarkers of acrylamide exposure therefore remains the most effective means of rapidly determining individual exposure to acrylamide, and correlating exposure with lifestyle choices. Current methodologies for the analysis of blood biomarkers of acrylamide are focused on expensive, slower chromatographic techniques such as GC and LC coupled to mass spectrometry. This paper describes the first successful development of two monoclonal antibodies specific to acrylamide-adducted haemoglobin (IC50 of 94 ng ml(-1) and 198 ng ml(-1)), that are suitable for use in a high-throughput biomarker immunoassay to determine individual acrylamide exposure. Further development of acrylamide-haemoglobin standards with defined levels of acrylamide adduction will enable a fully quantitative assay, and allow sensitivity comparisons with alternative chromatographic methods of analysis. (C) 2008 Elsevier B.V. All rights reserved.

Modulated wave packets and envelope solitary structures in complex plasmas

A theoretical study is presented of the nonlinear amplitude modulation of waves propagating in unmagnetized plasmas contaminated by charged dust particles. Distinct well-known dusty plasma modes are explicitly considered, namely, the dust-acoustic wave, the dust-ion acoustic wave, and transverse dust-lattice waves. Using a multiple-scale technique, a nonlinear Schrodinger-type equation is derived, describing the evolution of the wave amplitude. A stability analysis reveals the possibility for modulational instability to occur, possibly leading to the formation of different types of envelope-localized excitations (solitary waves), under conditions which depend on the wave dispersion laws and intrinsic dusty plasma parameters.

A method to reconstruct patient-specific proximal femur surface models from planar pre-operative radiographs

Three-dimensional reconstruction from volumetric medical images (e.g. CT, MRI) is a well-established technology used in patient-specific modelling. However, there are many cases where only 2D (planar) images may be available, e.g. if radiation dose must be limited or if retrospective data is being used from periods when 3D data was not available. This study aims to address such cases by proposing an automated method to create 3D surface models from planar radiographs. The method consists of (i) contour extraction from the radiograph using an Active Contour (Snake) algorithm, (ii) selection of a closest matching 3D model from a library of generic models, and (iii) warping the selected generic model to improve correlation with the extracted contour.

This method proved to be fully automated, rapid and robust on a given set of radiographs. Measured mean surface distance error values were low when comparing models reconstructed from matching pairs of CT scans and planar X-rays (2.57–3.74 mm) and within ranges of similar studies. Benefits of the method are that it requires a single radiographic image to perform the surface reconstruction task and it is fully automated. Mechanical simulations of loaded bone with different levels of reconstruction accuracy showed that an error in predicted strain fields grows proportionally to the error level in geometric precision. In conclusion, models generated by the proposed technique are deemed acceptable to perform realistic patient-specific simulations when 3D data sources are unavailable.

How resource quality differentially affects motivation and ability to fight in hermit crabs

Contesting animals typically gather information about the resource value and that information affects fight motivation. However, it is possible that particular resource characteristics alter the ability to fight independently of the motivation. Using hermit crabs, we investigate how the resource in terms of shell quality affects both motivation and ability to fight. These crabs fight for shells, but those shells have to be carried and may impose physiological costs that impede fight vigour. We find that the shell has different effects on motivation and ability. Potential attackers in very small shells were highly motivated to attack but, rather than having enhanced ability, unexpectedly quickly fatigued and subsequently were not more successful in the fights than were crabs in larger shells. We also examined whether defending crabs could gather information about the attacker's shell from the vigour of the attack. Defending crabs gave up quickly when a potential gain had been assessed, indicating that such information had been gathered. However, there was no indication that this could be owing to the activity of the attacker and the information is probably gathered via visual assessment of the shell.

Social Accounting Research as If The World Matters: An essay in postalgia and a new absurdism

This essay is intended as a self-reflective, auto-critique of the ‘social accounting community’. The essay is directed at the academic community of accountants concerned with social accounting. This `community' is predominantly concerned with English language accounting journals and is preoccupied with the social and environmental practices of the larger private sector organisations. The essay is motivated by a concern over our responsibilities as academics in a world in crisis and a concern that social accounting is losing its energy and revolutionary zeal. This community's social accounting endeavours have taken place in almost complete ignorance of the activities and developments in non accounting communities and, in particular, developments in the public and third sectors. The essay reaches out to the public and third sector work and literature as an illustration of one of the ways in which ‘our’ social accounting can try to prevent itself from becoming moribund.

Use of NMR metabolomic plasma profiling methodologies to identify illicit growth-promoting administrations

Detection of growth-promoter use in animal production systems still proves to be an analytical challenge despite years of activity in the field. This study reports on the capability of NMR metabolomic profiling techniques to discriminate between plasma samples obtained from cattle treated with different groups of growth-promoting hormones (dexamethasone, prednisolone, oestradiol) based on recorded metabolite profiles. Two methods of NMR analysis were investigated—a Carr–Purcell–Meiboom–Gill (CPMG)-pulse sequence technique and a conventional 1H NMR method using pre-extracted plasma. Using the CPMG method, 17 distinct metabolites could be identified from the spectra. 1H NMR analysis of extracted plasma facilitated identification of 23 metabolites—six more than the alternative method and all within the aromatic region. Multivariate statistical analysis of acquired data from both forms of NMR analysis separated the plasma metabolite profiles into distinct sample cluster sets representative of the different animal study groups. Samples from both sets of corticosteroid-treated animals—dexamethasone and prednisolone—were found to be clustered relatively closely and had similar alterations to identified metabolite panels. Distinctive metabolite profiles, different from those observed within plasma from corticosteroid-treated animal plasma, were observed in oestradiol-treated animals and samples from these animals formed a cluster spatially isolated from control animal plasma samples. These findings suggest the potential use of NMR methodologies of plasma metabolite analysis as a high-throughput screening technique to aid detection of growth promoter use.