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BACKGROUND Paediatric localized scleroderma (LS) can negatively impact health-related quality of life (HRQoL) by causing skin fibrosis, abnormal limb development, disfigurement, and side-effects from immunosuppressive treatment. Studies to date have rarely included qualitative data gathered directly from paediatric patients with LS. OBJECTIVES To assess the impact of LS on HRQoL among affected youth and their caregivers using qualitative description. METHODS Youth with all subtypes of LS and their caregivers were purposively sampled to participate in age-appropriate focus groups (younger children, early adolescents, adolescents). Each group started with a drawing exercise followed by in-depth discussion of topics including skin symptoms (e.g. itch, pain, tightness), functional impairment, physical appearance, family and peer relationships, and treatment burden. Focus groups were transcribed verbatim and co-coded, with adjudication of differentially applied codes. The study findings were triangulated via comparison with adult reports and published literature. RESULTS Eleven youth aged 9-16 years and 16 caregivers participated in three focus groups each. Major identified areas of impact included uncomfortable skin symptoms, physical functioning limitations, extracutaneous manifestations, body image, bullying and teasing, unwanted questioning from others, and treatment side-effects and burden. CONCLUSIONS This is the first qualitative study of HRQoL in LS to include all major LS subtypes. We identified domains of HRQoL impacted by LS, some of which replicate earlier findings and some of which were novel. As impact also changed with developmental stage, our findings support the need for ongoing, formal evaluation of HRQoL in children and adolescents with LS. What is already known about this topic? Paediatric localized scleroderma (LS) negatively impacts health-related quality of life (HRQoL) via skin fibrosis, musculoskeletal and other extracutaneous manifestations from the disease process, and side-effects of systemic immunosuppression. The full impact of LS and its treatment on HRQoL is incompletely understood, with only one published qualitative study of youth with LS, which was limited to facial involvement. There are no qualitative studies of HRQoL in other LS subtypes to date. What does this study add? This is the first qualitative evaluation of HRQoL in youth with LS inclusive of all disease subtypes. Our study confirms that LS affects HRQoL across multiple distinct domains, including uncomfortable skin sensations, impacts on body image, bullying and teasing from peers, unwanted intrusive questioning, physical limitations, extracutaneous manifestations and high treatment burden. These results indicate the need for ongoing clinical assessment of paediatric patients in these domains. What are the clinical implications of the work? These results support the need to care for patients with LS holistically by synthesizing cutaneous, musculoskeletal and extracutaneous disease assessments with multidimensional evaluation of psychosocial impact and adverse effects of treatments. The development of an LS-specific HRQoL measure would advance such efforts.

Changes in undergraduate medical training mean that students have direct patient contact from an early stage of their training. This study aimed to assess the knowledge of third-year medical students at the University of Birmingham Medical School, UK on infection control policy and procedures. A semi-structured questionnaire was distributed to medical students. Out of 322 students, 156 returned completed questionnaires (48%). Results showed that 58% of medical students did not know the correct indications for using alcoholic hand gel, 35% did not know the correct use of gloves, and 50% did not know the exclusion period after an episode of diarrhoea and vomiting. Sixty-four percent of medical students reported formal teaching on hand hygiene, 12% reported informal teaching, 19% reported both types of teaching and 5% reported no hand hygiene teaching at all. Forty-nine percent of medical students thought that there was insufficient emphasis on infection control in their course. These results raised concerns about medical students' knowledge about infection control. The University is currently reviewing the need for a more structured model for the teaching and assessment of infection control.

The essential oil of Melaleuca alternifolia (tea tree) exhibits broad-spectrum antimicrobial activity. Its mode of action against the Gram-negative bacterium Escherichia coli AG100, the Gram-positive bacterium Staphylococcus aureus NCTC 8325, and the yeast Candida albicans has been investigated using a range of methods. We report that exposing these organisms to minimum inhibitory and minimum bactericidal/fungicidal concentrations of tea tree oil inhibited respiration and increased the permeability of bacterial cytoplasmic and yeast plasma membranes as indicated by uptake of propidium iodide. In the case of E. coli and Staph. aureus, tea tree oil also caused potassium ion leakage. Differences in the susceptibility of the test organisms to tea tree oil were also observed and these are interpreted in terms of variations in the rate of monoterpene penetration through cell wall and cell membrane structures. The ability of tea tree oil to disrupt the permeability barrier of cell membrane structures and the accompanying loss of chemiosmotic control is the most likely source of its lethal action at minimum inhibitory levels.

An analysis is presented of a new horn antenna, fabricated by a novel micromachining technique, that uses crystallographic etching of silicon and ultraviolet lithography of an ultra-thick photoresist (SU-8). The horn was found to have low cross-polarized field levels and a predicted Gaussian coupling efficiency of 92.5%. The horn shape is governed by the crystal planes of the silicon substrate and the thickness of the photoresist and has up to four independent design parameters that allow a wide range of antenna patterns. A design for the horn that yields symmetric beam patterns was investigated by computer analysis, microwave scale modeling, and measurements of a micromachined horn at 585 GHz. The major features of the 585-GHz beam patterns agree well with the computer-generated and scaled beam patterns. We have thus demonstrated a new micromachinable horn that has great potential for integration into array structures.

A new microdilution method has been developed for determining the minimum inhibitory concentration (MIC) of oil-based compounds. The redox dye resazurin was used to determine the MIC of a sample of the essential oil of Melaleuca alternifolia (tea tree) for a range of Gram-positive and -negative bacteria. Use of 0.15% (w/v) agar as a stabilizer overcame the problem of adequate contact between the oil and the test bacteria and obviated the need to employ a chemical emulsifier. A rapid version of the assay was also developed for use as a screening method. A comparison of visual and photometric reading of the microtitre plates showed that results could be assessed without instrumentation; moreover, if the rapid assay format was used, rigorous asepsis was not necessary. Accuracy of the resazurin method was confirmed by plate counting from microwells and MIC values were compared with results obtained using an agar dilution assay. The MIC results obtained by the resazurin method were slightly lower than those obtained by agar dilution.

Terahertz waveguide components can now be realised using a variety of methods. The size and geometry of waveguide at terahertz frequencies ideally lends itself to fabrication via a number of micromachining techniques. The use of micromachining allows the realisation of waveguide components that cannot be fabricated via conventional machining at these frequencies. Conventional machining should not, however, be overlooked. Corrugated feedhorns operating at 3 THz have been realised using ultra high precision machining techniques. To date it has not been possible to realise the corrugated horn structure via lithographic micromachining. This paper discusses the relative merits fabrication techniques, highlighting any or weakness that is relevant to terahertz waveguide fabrication.

Aims: This study compared the antimicrobial activity of Melaleuca alternifolia (tea tree) oil with that of some of its components, both individually and in two-component combinations. Methods and Results: Minimum inhibitory concentration and time-kill assays revealed that terpinen-4-ol, the principal active component of tea tree oil, was more active on its own than when present in tea tree oil. Combinations of terpinen-4-ol and either γ-terpinene or p-cymene produced similar activities to tea tree oil. Concentration-dependent reductions in terpinen-4-ol activity and solubility also occurred in the presence of γ-terpinene. Conclusions: Non-oxygenated terpenes in tea tree oil appear to reduce terpinen-4-ol efficacy by lowering its aqueous solubility. Significance and Impact of the Study: These findings explain why tea tree oil can be less active in vitro than terpinen-4-ol alone and further suggest that the presence of a non-aqueous phase in tea tree oil formulations may limit the microbial availability of its active components.

Pseudomonas aeruginosa is less susceptible to the antimicrobial properties of tea tree oil than many bacteria and its tolerance is considered to be due to its outer membrane. Polymyxin B nonapeptide (PMBN), which has no antibacterial action, was used to permeabilize the outer membrane. The addition of PMBN to Ps. aeruginosa NCTC 6749 markedly increased this organism's susceptibility to tea tree oil and to its normally inert hydrocarbons, p-cymene and gamma-terpinene.