The effect of temperature and strain rate on the deformation behaviour, structure development and properties of biaxially stretched PET-clay nanocomposites.

The inclusion of a synthetic fluoromica clay in PET affects its processability via biaxial stretching and stretching temperature (95 °C and 102 °C) and strain rate (1 s-1 and 2 s-1) influence the structuring and properties of the stretched material. The inclusion of clay has little effect on the temperature operating window for the PET–clay but it has a major effect on deformation behaviour which will necessitate the use of much higher forming forces during processing. The strain hardening behaviour of both the filled and unfilled materials is well correlated with tensile strength and tensile modulus. Increasing the stretching temperature to reduce stretching forces has a detrimental effect on clay exfoliation, mechanical and O2 barrier properties. Increasing strain rate has a lesser effect on the strain hardening behaviour of the PET–clay compared with the pure PET and this is attributed to possible adiabatic heating in the PET–clay sample at the higher strain rate. The Halpin–Tsai model is shown to accurately predict the modulus enhancement of the PET–clay materials when a modified particle modulus rather than nominal clay modulus is used.

Complete Genome Sequence of Propionibacterium acnes Type IB Strain 6609

Propionibacterium acnes is an anaerobic Gram-positive bacterium that forms part of the normal human cutaneous microbiota and is thought to play a central role in acne vulgaris, a chronic inflammatory disease of the pilosebaceous unit (I. Kurokawa et al., Exp. Dermatol. 18:821-832, 2009). Here we present the whole genome sequence of P. acnes type IB strain 6609, which was recovered from a skin sample from a woman with no recorded acne history and is thus considered a nonpathogenic strain (I. Nagy, Microbes Infect. 8:2195-2205, 2006).

Epidemiology of Adolescent Rugby Injuries: A Systematic Review

OBJECTIVE: Despite recent increases in the volume of research in professional rugby union, there is little consensus on the epidemiology of injury in adolescent players. We undertook a systematic review to determine the incidence, severity, and nature of injury in adolescent rugby union players.

DATA SOURCES: In April 2009, we performed a computerized literature search on PubMed, Embase, and Cochrane Controlled Trials Register (via Ovid). Population-specific and patient-specific search terms were combined in the form of MEDLINE subject headings and key words (wound$ and injur$, rugby, adolescent$). These were supplemented with related-citation searches on PubMed and bibliographic tracking of primary and review articles.

STUDY SELECTION: Prospective epidemiologic studies in adolescent rugby union players.

DATA SYNTHESIS: A total of 15 studies were included, and the data were analyzed descriptively. Two independent reviewers extracted key study characteristics regarding the incidence, severity, and nature of injuries and the methodologic design.

CONCLUSIONS: Wide variations existed in the injury definitions and data collection procedures. The incidence of injury necessitating medical attention varied with the definition, from 27.5 to 129.8 injuries per 1000 match hours. The incidence of time-loss injury (>7 days) ranged from 0.96 to 1.6 per 1000 playing hours and from 11.4/1000 match hours (>1 day) to 12-22/1000 match hours (missed games). The highest incidence of concussion was 3.3/1000 playing hours. No catastrophic injuries were reported. The head and neck, upper limb, and lower limb were all common sites of injury, and trends were noted toward greater time loss due to upper limb fractures or dislocations and knee ligament injuries. Increasing age, the early part of the playing season, and the tackle situation were most closely associated with injury. Future injury-surveillance studies in rugby union must follow consensus guidelines to facilitate interstudy comparisons and provide further clarification as to where injury-prevention strategies should be focused.

Purification and characterization of a novel naphthalene dioxygenase from Rhodococcus sp strain NCIMB12038

We report here the characterization of the catalytic component (ISPNAR) of a new naphthalene dioxygenase from Rhodococcus sp. strain NCIMB12038. The genes encoding the two subunits of ISPNAR are not homologous to their previously characterized counterparts in Pseudomonas. The deduced amino acid sequences have only 33 and 29% identity with the corresponding subunits in Pseudomonas putida NCIB 9816-4, for which the tertiary structure has been reported.