ADding negative pRESSure to improve healING (the DRESSING trial): a RCT protocol

Introduction Obese women are more likely to develop a surgical site infection (SSI) following caesarean section (CS) than non-obese women. Negative pressure wound therapy (NPWT) is increasingly being used to reduce SSI with limited evidence for its effectiveness. Objectives To determine the clinical and cost-effectiveness of using NPWT in obese women having elective and semiurgent CS. Methods and analysis A multisite, superiority parallel pragmatic randomised controlled trial with an economic evaluation. Women with a body mass index (BMI) of ≥30, booked for elective and semiurgent CS at 4 Australian acute care hospitals will be targeted. A total of 2090 women will be enrolled. A centralised randomisation service will be used with participants block randomised to either NPWT or standard surgical dressings in a 1:1 ratio, stratified by hospital. The primary outcome is SSI; secondary outcomes include type of SSI, length of stay, readmission, wound complications and health-related quality of life. Economic outcomes include direct healthcare costs and cost-effectiveness, which will be evaluated using incremental cost per quality-adjusted life year gained. Data will be collected at baseline, and participants followed up on the second postoperative day and weekly from the day of surgery for 4 weeks. Outcome assessors will be masked to allocation. The primary statistical analysis will be based on intention-to-treat. Ethics and dissemination Ethics approval has been obtained from the ethics committees of the participating hospitals and universities. The findings of the trial will be disseminated through peer-reviewed journals, national and international conference presentations

Microstructural and environmental effects on stress corrosion and corrosion fatigue of 7075 aluminum alloy

The design and development of high performance structural materials requires a thorough understanding of the relationship between environment, mechanical stresses, microstructure, and properties. The corrosion and fatigue behavior of aluminum alloys is greatly influenced by environment and precipitate structure. A comprehensive, mechanistic understanding of the role of environment on cyclic fatigue of Al alloys is needed. The relationship between environmental and mechanical effects is not well understood. The driving force at the crack tip is clearly a combination of chemical and mechanical processes operating together. A synergy between these processes is also present. In this talk, the role of moisture on stress corrosion and corrosion-fatigue of 7075 Al alloy will be presented. Rolled 7075 Al alloy was heat-treated to underaged, peak-aged, and overaged conditions. To investigate the effects of corrosion and fatigue on peak-aged 7075 aluminum alloy, corroded samples were tested via in situ x-Ray tomography. The samples were mechanically polished, then soaked in covered 3.5 wt.% NaCl for fifteen days to allow for significant corrosion to occur. Then, they were fatigue tested in situ in 3.5 wt.% NaCl using synchrotron x-ray tomography to analyze the fatigue crack initiation and growth characteristics. Hydrogen bubbles were observed between the sample and the fluid upon crack initiation, indicating chemical changes in the sample during in situ corrosion fatigue. The effect of oxide layers forming during corrosion and 2nd phase inclusions, on fatigue initiation and propagation, will be discussed. The microstructure and morphology of the fracture surfaces were examined by scanning electron microscopy (SEM) and correlated with the crack growth behavior. The crack initiation, growth, and damage were also quantified by sophisticated three dimensional (3D) in situ x-ray synchrotron tomography technique. This technique provided interesting insights into the onset of crack initiation and growt

Malignant salivary gland tumours: Can fast neutron therapy results point the way to carbon ion therapy?

BACKGROUND AND PURPOSE: To evaluate the outcome of malignant salivary gland tumours treated with neutron therapy to assess the potential for other high linear energy transfer (LET) beams. MATERIALS AND METHODS: Neutrons at iThemba LABS are produced by the reaction of 66 MeV protons on a beryllium target. A median dose 20.4 Gy, in 12 fractions in 4 weeks or 15 fractions in 5 weeks, was given to 335 patients with 176 irresectable, 104 macroscopically residual and 55 unresected tumours. RESULTS: Locoregional control was 60.6% at 5 years and 39.1% at 10 years and DSS was 66.8% and 53.7% at 5 and 10 years respectively. In the univariate analysis T4, >4 cm, high grade, squamous carcinoma, unresected and irresectable tumours, and positive nodes were significantly worse for LRC. In the multivariate analysis tumours >6 cm, squamous carcinoma, irresectable tumours and nodes were significantly worse for LRC. Tumours >6 cm, high grade, squamous carcinoma and nodes were significantly worse for DSS. Neither LRC nor DSS was influenced by age, sex, site, dose, fractionation or for initial or recurrent disease. CONCLUSIONS: Neutron therapy appears to be the treatment of choice for macroscopically incompletely excised and irresectable salivary gland tumours with improved survival rates. Further improvement may be achieved with other high LET modalities with a superior dose profile, such as carbon ions.Web of Scienc

4D microstructural and electrochemical characterization of dissimilar metal corrosion in naval structural Joints

Dissimilar metal corrosion in aircraft and naval structures has proven to be a persistent challenge. Decades of research in the area have shown that such complex contact surfaces are subject to a combination of corrosive environments and mechanical loads. Hence, this multi-faceted problem must be understood from electrochemical, microstructural and mechanical standpoints to comprehensively understand corrosion damage in these systems. Please click Additional Files below to see the full abstract

In situ three-dimensional study of corrosion fatigue crack initiation and growth of corroded 7075 aluminum alloys

Corrosion fatigue crack initiation in aluminum alloys can have significant effects on part life. An improved understanding of the mechanisms governing corrosion and corrosion fatigue damage of Al alloys is necessary. Alloy design and environmental chemistry have significant effects on corrosion fatigue crack initiation and growth. Influential alloy design features include alloy chemistry, precipitate structure, and grain structure. Environmental factors such as environmental chemistry and preexisting corrosion damage can also effect the corrosion fatigue behavior of the alloys. To investigate the effects of environment and precipitate size on corrosion fatigue of aluminum alloys, the in situ corrosion fatigue testing of corroded peak-aged and overaged 7075 Al alloys in 3.5 wt% NaCl solution will be presented. For this study, rolled 7075 Al alloy was heat-treated to peak-aged, overaged, and highly overaged conditions. The samples were machined, mechanically polished, masked, and then soaked in 3.5 wt.% NaCl solution for fifteen days to yield significant corrosion damage in a region of interest. The corroded specimens were fatigue tested in situ in 3.5 wt.% NaCl using synchrotron X-ray tomography to gain three dimensional information regarding fatigue crack initiation and growth characteristics. Hydrogen bubbles were observed within the crack during propagation, indicating chemical changes in the sample during corrosion fatigue. The crack initiation, growth, and bubble evolution were quantified and discussed. A relationship was observed between the bubble volume and crack surface area as the test progressed, which suggested an effect from stress at the crack tip. Ultimately, this in situ study provided new insights regarding the localized processes occurring during the corrosion fatigue cracking of aluminum alloys which previous post-mortem and two dimensional studies were unable to discover

Cost-effectiveness analysis alongside a pilot study of prophylactic negative pressure wound therapy

Background Negative pressure wound therapy (NPWT) is increasingly used prophylactically following surgery despite limited evidence of clinical or cost-effectiveness. Objective To evaluate whether NPWT is cost-effective compared to standard care, for the prevention of surgical site infection (SSI) in obese women undergoing elective caesarean section, and inform development of a larger trial. Methods An economic evaluation was conducted alongside a pilot randomised controlled trial at one Australian hospital, in which women were randomised to NPWT (n\ua0=\ua044) or standard care (n\ua0=\ua043). A public health care provider perspective and time horizon to four weeks post-discharge was adopted. Cost-effectiveness assessment was based on incremental cost per SSI prevented and per quality-adjusted life year (QALY) gained. Results Patients receiving NPWT each received health care costing AU$5887 (±1038) and reported 0.069 (±0.010) QALYs compared to AU$5754 (±1484) and 0.066 (±0.010) QALYs for patients receiving standard care. NPWT may be slightly more costly and more effective than standard care, with estimated incremental cost-effectiveness ratios (ICERs) of AU$1347 (95$41,873) per SSI prevented and AU$42,340 (95$884,019) per QALY gained. However, there was considerable uncertainty around these estimates. Conclusions NPWT may be cost-effective in the prophylactic treatment of surgical wounds following elective caesarean section in obese women. Larger trials could clarify the cost-effectiveness of NPWT as a prophylactic treatment for SSI. Sensitive capture of QALYs and cost offsets will be important given the high level of uncertainty around the point estimate cost-effectiveness ratio which was close to conventional thresholds. Australian and New Zealand trial registration number ACTRN12612000171819

Symmetric dithiodigalactoside: strategic combination of binding studies and detection of selectivity between a plant toxin and human lectins

Thioglycosides offer the advantage over O-glycosides to be resistant to hydrolysis. Based on initial evidence of this recognition ability for glycosyldisulfides by screening dynamic combinatorial libraries, we have now systematically studied dithiodigalactoside on a plant toxin (Viscum album agglutinin) and five human lectins (adhesion/growth-regulatory galectins with medical relevance e.g. in tumor progression and spread). Inhibition assays with surface-presented neoglycoprotein and in solution monitored by saturation transfer difference NMR spectroscopy, flanked by epitope mapping, as well as isothermal titration calorimetry revealed binding properties to VAA (Ka: 1560 ± 20 M-1). They were reflected by the structural model and the affinity on the level of toxin-exposed cells. In comparison, galectins were considerably less reactive, with intrafamily grading down to very minor reactivity for tandem-repeat-type galectins, as quantitated by radioassays for both domains of galectin-4. Model building indicated contact formation to be restricted to only one galactose moiety, in contrast to thiodigalactoside. The tested lycosyldisulfide exhibits selectivity between the plant toxin and the tested human lectins, and also between these proteins. Therefore, glycosyldisulfides have potential as chemical platform for inhibitor design

Measuring Statistical Isotropy of CMB Anisotropy

The statistical expectation values of the temperature fluctuations and polarization of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We investigate the statistical isotropy (SI) of the CMB maps recently measured by the Wilkinson Microwave Anisotropy Probe (WMAP) using the bipolar spherical harmonic formalism proposed in Hajian & Souradeep 2003 for CMB temperature anisotropy and extended to CMB polarization in Basak, Hajian & Souradeep 2006. The Bipolar Power Spectrum (BiPS) had been measured for the full sky CMB anisotropy maps of the first year WMAP data and now for the recently released three years of WMAP data. We also introduce and measure directional sensitive reduced Bipolar coefficients on the three year WMAP ILC map. Consistent with our published results from first year WMAP data we have no evidence for violation of statistical isotropy on large angular scales. Preliminary analysis of the recently released first WMAP polarization maps, however, indicate significant violation of SI even when the foreground contaminated regions are masked out. Further work is required to confirm a possible cosmic origin and rule out the (more likely) origin in observational artifact such as foreground residuals at high galactic latitude.Comment: 12 pages, 3 figures; Proceedings of the Fundamental Physics With CMB workshop, UC Irvine, March 23-25, 2006, to be published in New Astronomy Review

Gravity modelling along CROP04 seismic profile

The processing and interpretation of seismic lines, together with the analysis of surficial geological data and hydrocarbon wells data, are powerful tools for the investigation of crust structures. Nevertheless, for depths exceeding that portion of crust usually investigated for commercial purposes, only geophysical data are generally available (among the others: NVR seismic from CROP project, DSS data, magnetic data, gravity data). In this context, the possibility of comparing two independent geophysical data sets, such as data from seismic exploration (CROP Project) and gravimetric analysis (Bouguer anomalies), is of particular interest for investigations into the deeper crust portion. In the present work gravity data modelling was used to study deep crust, constraints being provided by WARR data and by reflection seismic data obtained along the CROP04 profile that crosses the Southern Apennines (Italy) from Agropoli (SW) to Barletta (NE). A preliminary interpretation has been made of the regional gravity anomaly trend in deep crust in Southern Italy; the role of this anomaly trend as an independent constraint for the geological interpretation of the CROP04 seismic line is discussed