Aortopexy for the management of paediatric tracheomalacia - the Alder Hey experience.

BACKGROUND: Whilst aortopexy is an accepted and established procedure, there remains considerable heterogeneity within the literature, with inconsistencies in both the approach taken and the technique employed. Furthermore, limited data exist on both patient selection and long-term outcomes. This study aimed to report the experience of managing severe tracheomalacia by way of aortopexy in a large UK paediatric centre. METHOD: A retrospective case note review was conducted. Mean follow up was five years. RESULTS: Twenty-five patients underwent aortopexy for severe tracheomalacia caused by external vascular compression. Acute life-threatening events precipitated investigation in 72 per cent of cases. Twenty-one patients initially presented to ENT services for investigation, which comprised upper airway endoscopy and imaging with computed tomography angiography. Post-operatively, the majority of patients demonstrated complete resolution of symptoms and were discharged from all associated services. Only four patients required a tracheostomy. CONCLUSION: Aortopexy offers an effective method of treating severe tracheomalacia due to vascular compression.

The European roadmap towards fusion electricity.

The European roadmap to the realization of fusion electricity breaks the quest into eight missions. For each mission, it reviews the current status of research, identifies open issues, and proposes a research and development programme. ITER is the key facility on the roadmap as it is expected to achieve most of the important milestones on the path to fusion power. The Fusion Roadmap is tightly connected to the ITER schedule and the vast majority of resources in fusion research are presently dedicated to ITER and its accompanying experiments. Parallel to the ITER exploitation in the 2030s, the construction of the demonstration power plant DEMO needs to be prepared. DEMO will for the first time supply fusion electricity to the grid and it will have a self-sufficient fuel cycle. The design, construction and operation of DEMO require full involvement of industry to ensure that, after a successful DEMO operation, industry can take responsibility for commercial fusion power. The European fusion roadmap provides a coherent path towards the fusion power plant, and it proposes in an integrated way to find solutions for all challenges that still need to be addressed. This article is part of a discussion meeting issue 'Fusion energy using tokamaks: can development be accelerated?'

Prevalence and management of recurrent respiratory papillomatosis (RRP) in the UK: cross-sectional study.

OBJECTIVES: To estimate the number of patients with recurrent respiratory papillomatosis currently managed in secondary and tertiary health care in the UK and the frequency of its treatment with radiofrequency cold ablation (Coblation™ ). DESIGN: Cross-sectional survey of ENT consultants in the UK with validation using Hospital Episode Statistics (HES) inpatient data. SETTING: Online survey. PARTICIPANTS: ENT consultants in the UK. MAIN OUTCOME MEASURES: Number of recurrent respiratory papillomatosis patients currently managed in acute care in the UK and frequency of use of Coblation. RESULTS: A total of 283 ENT consultants from 128 UK NHS healthcare trusts and health boards completed the online survey. Responses were received from 86% of surveyed organisations, and an estimated 45% of all ENT consultants in UK. The estimated number of recurrent respiratory papillomatosis patients from the cross-sectional survey was 918 (at August 2015) which included 730 patients in England. The number of recurrent respiratory papillomatosis patients in England estimated from Hospital Episode Statistics (2014/15 financial year) was up to 741. A total of 42 Coblation procedures conducted in the UK were identified from the cross-sectional survey; 36 were conducted in England compared with 34 identified from Hospital Episode Statistics. CONCLUSIONS: The numbers of recurrent respiratory papillomatosis patients and Coblation procedures identified in England from a cross-sectional survey and Hospital Episode Statistics were in broad agreement. Our study estimated 1.42 recurrent respiratory papillomatosis patients per 100 000 in the general UK population. We also estimated that Coblation procedures accounted for 3% of interventional treatments conducted in the UK recurrent respiratory papillomatosis population.

Image quality method as a possible way of in situ monitoring of in-vessel mirrors in a fusion reactor.

The plasma-facing (first) mirrors in ITER will be subject to sputtering and/or contamination with rates that will depend on the precise mirror locations. The resulting influence of both these factors can reduce the mirror reflectance (R) and worsen the transmitted image quality (IQ). This implies that monitoring the mirror quality in situ is an actual desire, and the present work is an attempt towards a solution. The method we propose is able to elucidate the reason for degradation of the mirror reflectance: sputtering by charge exchange atoms or deposition of contaminated layers. In case of deposition of contaminants, the mirror can be cleaned in situ, but a rough mirror (due to sputtering) cannot be used anymore and has to be replaced. To demonstrate the feasibility of the IQ method, it was applied to mirror specimens coated with carbon film in laboratory conditions and to mirrors coated with contaminants during exposure in fusion devices (TRIAM-1M and Tore Supra), as well as to mirrors of different materials exposed to sputtering by plasma ions in the DSM-2 plasma stand (in IPP NSC KIPT).

Does primary indication for tonsillectomy influence post-tonsillectomy haemorrhage rates in children?

INTRODUCTION: A significant risk in tonsillectomy that causes concern to surgeon and patient is post-tonsillectomy bleed. Secondary haemorrhage is mainly post-operative bleed presenting at or 24h after surgery. Classical teaching indicates infection as the cause. There are not enough published data to evaluate the post-tonsillectomy bleed rates in patients operated for obstructive sleep apnoea versus recurrent tonsillitis. We suspected secondary bleed rates to be higher in patients with recurrent tonsillitis. METHODS: A retrospective review of case-notes of patients presenting to Accident & Emergency department within 4 weeks of tonsillectomy or adeno-tonsillectomy was performed. 568 patients presented with post-operative complications over the 5-year period 2008-2013. Of these, 222 presented with post-operative secondary bleed. Electronic case records were used to identify indication of operation and matched with coding data. These coded data were also used to identify number of operations and primary indications over the 5-year period. RESULTS: The proportion of OSA patients receiving tonsillectomy or adenotonsillectomy surgery increased over the 5-year period. Secondary haemorrhage rate for recurrent tonsillitis surgery was around 4.9% and for OSA surgery was around 15.6%. Comparison of recurrent tonsillitis against OSA for post-operative bleed showed a relative risk of 0.31 (CI 0.24-0.41). The incidence of bleeding mirrored primary indication for each year. CONCLUSION: The bleed rate for OSA was unexpectedly higher than for recurrent tonsillitis. The primary indication for tonsillectomy affects secondary bleeding rate.

Dual array 3D electron cyclotron emission imaging at ASDEX Upgrade.

In a major upgrade, the (2D) electron cyclotron emission imaging diagnostic (ECEI) at ASDEX Upgrade has been equipped with a second detector array, observing a different toroidal position in the plasma, to enable quasi-3D measurements of the electron temperature. The new system will measure a total of 288 channels, in two 2D arrays, toroidally separated by 40 cm. The two detector arrays observe the plasma through the same vacuum window, both under a slight toroidal angle. The majority of the field lines are observed by both arrays simultaneously, thereby enabling a direct measurement of the 3D properties of plasma instabilities like edge localized mode filaments.

Pre-operative overnight pulse oximetry to predict high dependency unit intervention in children undergoing adenotonsillectomy for obstructive sleep apnoea.

Background: Post-operative high dependency unit beds are often requested for patients undergoing adenotonsillectomy for obstructive sleep apnoea. This study evaluated the utilisation of high dependency unit beds for such cases at our institution, a paediatric tertiary referral centre. Method: A retrospective case note review of patients admitted to the high dependency unit following adenotonsillar surgery for obstructive sleep apnoea, over a two-year period, was performed. Results: Sixty-six cases were identified. Thirty-nine patients underwent pre-operative overnight pulse oximetry; of these, 30 patients had desaturations noted. Seventeen patients had significant post-operative desaturations. These were predicted in all 11 patients who had undergone pre-operative pulse oximetry. The remaining six had not undergone pre-operative pulse oximetry. Nineteen patients required high dependency unit care; eight had experienced post-operative desaturations. Conclusion: High dependency unit care may be required following adenotonsillectomy for obstructive sleep apnoea. In this study, pre-operative overnight pulse oximetry had 100 per cent sensitivity in predicting post-operative desaturations, and may therefore aid the appropriate utilisation of high dependency unit beds for patients undergoing adenotonsillectomy for obstructive sleep apnoea.

Parents' experiences and views of caring for a child with a tracheostomy: a literature review.

OBJECTIVES: To review the published/reported experiences and views of parents' whose child has had a tracheostomy. To date, no review has focused specifically on parents' experiences and views of having a child with a tracheostomy. METHODS: MEDLINE, CINAHL, PsycINFO and Embase were systematically searched from 1990 to 2012 and a review of reference lists was conducted. The review draws on articles where parents' views of caring for their child's tracheostomy were either the sole focus of the research or where parental views of caring for their child's tracheostomy have been sought as a subsidiary aim. Studies relating to the aims of the review were examined using quality appraisal tools and in line with criteria for inclusion of studies. Studies were excluded if findings were about adults, studies that only focused on children's or sibling's views were not based on empirical work (e.g. literature reviews or expert commentary) or were not published in the English language. Findings were summarised under thematic headings. RESULTS: The systematic database search identified 442 citations of which 10 were eligible for inclusion in the review. Of those 10 studies six were quantitative and four qualitative. Only one paper published qualitative data specifically on parents' experiences about their tracheotomised child. The three main themes identified were parents' experiences of caregiving, their social experiences and experiences of service delivery of having a child with a tracheostomy. Although parents encountered emotional and social challenges, some positive responses to these challenges were reported. CONCLUSION: This review identifies a lack of qualitative research on parents' views of having a child with a tracheostomy. Issues surrounding parental management of tracheostomy require further investigation. This review has identified the need to elicit parents' longitudinal experiences of having a child with a tracheostomy.

Appearance and dynamics of helical flux tubes under electron cyclotron resonance heating in the core of KSTAR plasmas.

Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n=1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n=1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two current-carrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.

Advanced Thomson scattering system for high-flux linear plasma generator.

An advanced Thomson scattering system has been built for a linear plasma generator for plasma surface interaction studies. The Thomson scattering system is based on a Nd:YAG laser operating at the second harmonic and a detection branch featuring a high etendue (f/3) transmission grating spectrometer equipped with an intensified charged coupled device camera. The system is able to measure electron density (n(e)) and temperature (T(e)) profiles close to the output of the plasma source and, at a distance of 1.25 m, just in front of a target. The detection system enables to measure 50 spatial channels of about 2 mm each, along a laser chord of 95 mm. By summing a total of 30 laser pulses (0.6 J, 10 Hz), an observational error of 3% in n(e) and 6% in T(e) (at n(e) = 9.4 × 10(18) m(-3)) can be obtained. Single pulse Thomson scattering measurements can be performed with the same accuracy for n(e) > 2.8 × 10(20) m(-3). The minimum measurable density and temperature are n(e) < 1 × 10(17) m(-3) and T(e) < 0.07 eV, respectively. In addition, using the Rayleigh peak, superimposed on the Thomson scattered spectrum, the neutral density (n(0)) of the plasma can be measured with an accuracy of 25% (at n(0) = 1 × 10(20) m(-3)). In this report, the performance of the Thomson scattering system will be shown along with unprecedented accurate Thomson-Rayleigh scattering measurements on a low-temperature argon plasma expansion into a low-pressure background.

Two-dimensional visualization of growth and burst of the edge-localized filaments in KSTAR H-mode plasmas.

The filamentary nature and dynamics of edge-localized modes (ELMs) in the KSTAR high-confinement mode plasmas have been visualized in 2D via electron cyclotron emission imaging. The ELM filaments rotating with a net poloidal velocity are observed to evolve in three distinctive stages: initial linear growth, interim quasisteady state, and final crash. The crash is initiated by a narrow fingerlike perturbation growing radially from a poloidally elongated filament. The filament bursts through this finger, leading to fast and collective heat convection from the edge region into the scrape-off layer, i.e., ELM crash.

Intermediate frequency band digitized high dynamic range radiometer system for plasma diagnostics and real-time Tokamak control.

An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototype system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.

The HPV16 E6 binding protein Tip-1 interacts with ARHGEF16, which activates Cdc42.

BACKGROUND: Guanidine exchange factor (GEF)-catalysed activation of Rho proteins such as Cdc42 has been shown to have a crucial role in cellular transformation, malignant progression and invasion. We have previously shown that the HPV16 E6 oncoprotein binds to the PDZ domain protein Tax-interacting-protein 1 (Tip-1) and we now report identification and functional analysis of a novel Tip-1 binding GEF. METHODS: Yeast two-hybrid, in vitro pull-down, site-directed mutagenesis, semiquantitative PCR, co-immunoprecipitation and western blotting were used to identify/confirm novel Tip-1 binding partners and analyse cellular expression levels. In vitro kinetic analyses of recombinant proteins, siRNA gene silencing and in cell assays were used to measure Rho protein activation. RESULTS: Tax-interacting-protein 1 was shown to interact with ARHGEF16 by its carboxyl PDZ binding motif. Levels of ARHGEF16 were increased in transformed and immortalised cells expressing ectopic HPV16 E6 and Cdc42 was co-immunoprecipitated by ARHGEF16 in the presence of high-risk HPV E6. In vitro kinetic analysis confirmed that recombinant ARHGEF16 activates Cdc42 and this was increased by the addition of recombinant Tip-1 and E6. Cells expressing HPV16 E6 had higher levels of Cdc42 activation, which was decreased by siRNA silencing of either Tip-1 or ARHGEF16. CONCLUSION: These data suggest that HPV16 E6, Tip-1 and ARHGEF16 may cooperate to activate Cdc42 and support a potential link between the expression of HPV16 E6 and Cdc42 activation.

Commissioning of electron cyclotron emission imaging instrument on the DIII-D tokamak and first data.

A new electron cyclotron emission imaging diagnostic has been commissioned on the DIII-D tokamak. Dual detector arrays provide simultaneous two-dimensional images of T(e) fluctuations over radially distinct and reconfigurable regions, each with both vertical and radial zoom capability. A total of 320 (20 vertical×16 radial) channels are available. First data from this diagnostic demonstrate the acquisition of coherent electron temperature fluctuations as low as 0.1% with excellent clarity and spatial resolution. Details of the diagnostic features and capabilities are presented.

2D electron cyclotron emission imaging at ASDEX Upgrade (invited).

The newly installed electron cyclotron emission imaging diagnostic on ASDEX Upgrade provides measurements of the 2D electron temperature dynamics with high spatial and temporal resolution. An overview of the technical and experimental properties of the system is presented. These properties are illustrated by the measurements of the edge localized mode and the reversed shear Alfvén eigenmode, showing both the advantage of having a two-dimensional (2D) measurement, as well as some of the limitations of electron cyclotron emission measurements. Furthermore, the application of singular value decomposition as a powerful tool for analyzing and filtering 2D data is presented.

Development of KSTAR ECE imaging system for measurement of temperature fluctuations and edge density fluctuations.

The ECE imaging (ECEI) diagnostic tested on the TEXTOR tokamak revealed the sawtooth reconnection physics in unprecedented detail, including the first observation of high-field-side crash and collective heat transport [H. K. Park, N. C. Luhmann, Jr., A. J. H. Donné et al., Phys. Rev. Lett. 96, 195003 (2006)]. An improved ECEI system capable of visualizing both high- and low-field sides simultaneously with considerably better spatial coverage has been developed for the KSTAR tokamak in order to capture the full picture of core MHD dynamics. Direct 2D imaging of other MHD phenomena such as tearing modes, edge localized modes, and even Alfvén eigenmodes is expected to be feasible. Use of ECE images of the optically thin edge region to recover 2D electron density changes during L/H mode transitions is also envisioned, providing powerful information about the underlying physics. The influence of density fluctuations on optically thin ECE is discussed.

Recurrent respiratory papillomatosis: an uncommon but potentially devastating effect of human papillomavirus in children.

Human papillomavirus (HPV) causes disease not only in the genital tract, but also in the larynx. Within the larynx HPV 6/11 causes recurrent respiratory papillomatosis (RRP). RRP is relatively uncommon, yet it is devastating for the patient who requires many surgical procedures over years to control it. The cost of HPV-related genital tract disease is thought to be around pound31 million per annum, whereas RRP costs in the region of pound4 million annually despite RRP being comparatively rare. The HPV vaccination programme has brought great hope, although it is unfortunate that the current UK programme only targets high-risk HPV. Targeting both low- and high-risk HPV would have had additional benefits for the UK.

The role of HPV type in Recurrent Respiratory Papillomatosis.

OBJECTIVE: Human Papillomavirus (HPV) 6 and 11 are the aetiological agents responsible for Recurrent Respiratory Papillomatosis (RRP). There is general consensus that HPV11 results in more aggressive disease compared to HPV6. METHOD: Pubmed was searched using the terms respiratory papillomatosis, HPV 6 and HPV11. Comparisons were made in the outcomes of HPV6 versus HPV11 positive RRP disease. RESULTS: There are numerous sub-types or variants of both HPV6 and HPV11. These sub-types have different activities at least in-vitro. The numbers of different HPV types within RRP tissue may be more extensive than initially appeared. This depends specifically upon the HPV types tested for. CONCLUSION: The clinical differences between HPV6 and HPV11 disease may not be accurately predictable as these viruses exist in numerous sub-types. Also, RRP tissue may contain more than one subtype or even be co-infected with other viruses that may influence outcome. In-vitro studies upon cell lines are a reasonable starting point for evaluation of these differences.

Advancements in electron cyclotron emission imaging demonstrated by the TEXTOR ECEI diagnostic upgrade.

A new TEXTOR electron cyclotron emission imaging system has been developed and employed, providing a diagnostic with new features and enhanced capabilities when compared to the legacy system it replaces. Optical coupling to the plasma has been completely redesigned, making use of new minilens arrays for reduced optical aberration and providing the new feature of vertical zoom, whereby the vertical coverage is now remotely adjustable on a shot-by-shot basis from 20-35 cm. Other innovations, such as the implementation of stacked quasioptical planar notch filters, allow for the diagnostic to be operated without interruption or degradation in performance during electron cyclotron resonance heating. Successful commissioning of the new diagnostic and a demonstration of the improved capabilities are presented in this paper, along with a discussion of the new technologies employed.