Search

The ampacity of buried cables is significantly influenced by the thermal properties of the burial environment. When these thermal properties are not homogeneous it is usually necessary to utilize simulations with a relatively high computational cost that may also use commercial software. In this paper an alternative approach is proposed using conformal maps. Temperature is calculated in an annular domain which is a conformal mapping of the half plane space. Circumferential dependence is captured by expanding temperature as a Fourier series, a finite difference solver then determines temperature components radially. The model is as flexible as any two-dimensional slice model of heat transfer through thermal conduction. Two case studies are considered: three land-based cables in planar configuration and a submarine export cable. The thermal properties of both burial environments are based on conditions which may be encountered in the field and exhibit a high level of stratification. Using a finite element analysis simulation as a benchmark, typical percentage differences in cable ampacities were 0.5%-1%. In addition to accuracy and flexibility the low computational cost of the proposed approach allows for large parameter sweeps, which may be required in a design phase, without requiring commercial software.

The ampacity of submarine cable circuits is strongly influenced by heat transfer in the marine environment surrounding the cable. It has been demonstrated in previous work that for high permeability sediments convective heat transfer can play a significant roleusing both bespoke two dimensional models and experimental investigations [T. J. Hughes, 2016, C. J. Emeana, 2016]. This paper introduces a one dimensional model which is capable of calculating cable temperatures within both convective and conductive sediments. Agreement between the one dimensional model and a two dimensional simulation was found to be within 1.5 °C. The model is used to demonstrate that the ampacity of power cables may be significantly increased due to convective heat transfer. Further, the one dimensional model offers significant savings in computational time and cost compared to the two dimensional equivalent model. This allows the analysis of large DTS data sets in order to calculate: dynamic ratings; burial depths; and the long-term (annual to decadal) performance of the cable.

Surface charge dynamics can play an important role in electric field distributions in both AC and DC insulation systems. In this paper the theory behind surface charge dynamics is introduced with a particular focus on the calculation of surface divergence; an operator which is used to determine movement of charge constrained to a surface. A detailed discussion of the model implementation is provided and validated against an analytical solution. Surface charge dynamics in AC and DC insulation systems are then investigated. Assuming the measurement data in the literature is representative it is demonstrated that surface currents have the capability to significantly alter electric field distributions in voids, even over the timescales of an AC cycle.

Iron deficiency anaemia (IDA) is a major cause of morbidity and burden of disease worldwide. It can generally be diagnosed by blood testing and remedied by iron replacement therapy (IRT) using the oral or intravenous route. The many causes of iron deficiency include poor dietary intake and malabsorption of dietary iron, as well as a number of significant gastrointestinal (GI) pathologies. Because blood is iron-rich it can result from chronic blood loss, and this is a common mechanism underlying the development of IDA—for example, as a consequence of menstrual or GI blood loss.Approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the GI tract. Therefore optimal management of IDA requires IRT in combination with appropriate investigation to establish the underlying cause. Unexplained IDA in all at-risk individuals is an accepted indication for fast-track secondary care referral in the UK because GI malignancies can present in this way, often in the absence of specific symptoms. Bidirectional GI endoscopy is the standard diagnostic approach to examination of the upper and lower GI tract, though radiological scanning is an alternative in some situations for assessing the large bowel. In recurrent or refractory IDA, wireless capsule endoscopy plays an important role in assessment of the small bowel.IDA may present in primary care or across a range of specialties in secondary care, and because of this and the insidious nature of the condition it has not always been optimally managed despite the considerable burden of disease— with investigation sometimes being inappropriate, incorrectly timed or incomplete, and the role of IRT for symptom relief neglected. It is therefore important that contemporary guidelines for the management of IDA are available to all clinicians. This document is a revision of previous British Society of Gastroenterology guidelines, updated in the light of subsequent evidence and developments.

Introduction Intestinal strictures in Crohn’s disease (CD) produce significant morbidity and are the commonest indication for surgery. Removable stent therapy is emerging as an effective, low complication, stricture resolution technique. (Das et al. 2018, Attar et al 2017) We present the clinical outcomes of the largest, single centre series, of CD patients undergoing removable ‘self-expanding-metal-stent’(SEMS) therapy for stricture resolution. Methods Symptomatic CD patients were assessed with MR enterography. Short (≤ 6cm), fibrotic, ileocolonic and anastomotic strictures were approved for stent therapy from an IBD MDT setting. Strictures were assessed, and only endoscopically impassable strictures treated. Inaccessible or inflammatory strictures were excluded. The Hannaro Diagmed ‘HRC-20–080–230’, partially covered SEMS was deployed under endoscopic and fluoroscopic guidance. Stent retrieval occurred at 6–10 days post insertion. Clinical IBD data was collected. Post-stenting follow-up was conducted, and therapeutic success assessed with validated tools (CDAI/HBI). Results Twenty-six patients were considered for stenting. Six patients were excluded based on endoscopic criteria. Twenty-two stents were placed for 20 patients. Stent deployment and retrieval was successful in 100% of cases when attempted. Ninety percent (18 of 20) of strictures were anastomotic. Patient characteristics are detailed in figure 1. Symptom improvement or resolution was noted in 84.6% of patients at follow up. Re-stenting was needed in two patients, with a single repeat procedure required within 12 months. Across all stenting episodes 5 adverse events were noted (2 episodes of stent related discomfort/3 asymptomatic stent migrations). There were no bleeding events, perforations or any need for emergency surgery. None of the cohort have required stricture related surgery on extended follow up (Range: 2 – 42 months). Conclusions In this series, removable SEMS therapy for ileocolonic CD strictures was found to be technically successful and clinically efficacious. The absence of perforation events and the complete lack of need for any stricture related surgery are both notable. The apparent efficacy, safety, long term benefit and low re-intervention rate with SEMS therapy in CD, merits further large-scale trial investigation in direct comparison with other modalities. References Attar A, et al. New anti-migration extractible metal stents for Crohn’s disease strictures. Journal of Crohn’s & Colitis 2017.11: S389–S390. Das R, et al. Treating ileocolonic Crohn’s strictures with removable. Gut. 2018:67:A55-A56.

BACKGROUND: Oesophageal adenocarcinoma is the sixth most common cause of cancer death worldwide and Barrett's oesophagus is the biggest risk factor. We aimed to evaluate the efficacy of high-dose esomeprazole proton-pump inhibitor (PPI) and aspirin for improving outcomes in patients with Barrett's oesophagus.METHODS: The Aspirin and Esomeprazole Chemoprevention in Barrett's metaplasia Trial had a 2 × 2 factorial design and was done at 84 centres in the UK and one in Canada. Patients with Barrett's oesophagus of 1 cm or more were randomised 1:1:1:1 using a computer-generated schedule held in a central trials unit to receive high-dose (40 mg twice-daily) or low-dose (20 mg once-daily) PPI, with or without aspirin (300 mg per day in the UK, 325 mg per day in Canada) for at least 8 years, in an unblinded manner. Reporting pathologists were masked to treatment allocation. The primary composite endpoint was time to all-cause mortality, oesophageal adenocarcinoma, or high-grade dysplasia, which was analysed with accelerated failure time modelling adjusted for minimisation factors (age, Barrett's oesophagus length, intestinal metaplasia) in all patients in the intention-to-treat population. This trial is registered with EudraCT, number 2004-003836-77.FINDINGS: Between March 10, 2005, and March 1, 2009, 2557 patients were recruited. 705 patients were assigned to low-dose PPI and no aspirin, 704 to high-dose PPI and no aspirin, 571 to low-dose PPI and aspirin, and 577 to high-dose PPI and aspirin. Median follow-up and treatment duration was 8·9 years (IQR 8·2-9·8), and we collected 20 095 follow-up years and 99·9% of planned data. 313 primary events occurred. High-dose PPI (139 events in 1270 patients) was superior to low-dose PPI (174 events in 1265 patients; time ratio [TR] 1·27, 95% CI 1·01-1·58, p=0·038). Aspirin (127 events in 1138 patients) was not significantly better than no aspirin (154 events in 1142 patients; TR 1·24, 0·98-1·57, p=0·068). If patients using non-steroidal anti-inflammatory drugs were censored at the time of first use, aspirin was significantly better than no aspirin (TR 1·29, 1·01-1·66, p=0·043; n=2236). Combining high-dose PPI with aspirin had the strongest effect compared with low-dose PPI without aspirin (TR 1·59, 1·14-2·23, p=0·0068). The numbers needed to treat were 34 for PPI and 43 for aspirin. Only 28 (1%) participants reported study-treatment-related serious adverse events.INTERPRETATION: High-dose PPI and aspirin chemoprevention therapy, especially in combination, significantly and safely improved outcomes in patients with Barrett's oesophagus.FUNDING: Cancer Research UK, AstraZeneca, Wellcome Trust, and Health Technology Assessment.

SummaryBacterial lineages that chronically infect cystic fibrosis (CF) patients genetically diversify during infection. However, the mechanisms driving diversification are unknown. By dissecting ten CF lung pairs and studying ∼12,000 regional isolates, we were able to investigate whether clonally related Pseudomonas aeruginosa inhabiting different lung regions evolve independently and differ functionally. Phylogenetic analysis of genome sequences showed that regional isolation of P. aeruginosa drives divergent evolution. We investigated the consequences of regional evolution by studying isolates from mildly and severely diseased lung regions and found evolved differences in bacterial nutritional requirements, host defense and antibiotic resistance, and virulence due to hyperactivity of the type 3 secretion system. These findings suggest that bacterial intermixing is limited in CF lungs and that regional selective pressures may markedly differ. The findings also may explain how specialized bacterial variants arise during infection and raise the possibility that pathogen diversification occurs in other chronic infections characterized by spatially heterogeneous conditions.

It is considered that the present IEC 60287 standard overestimates the induced losses in SL-type armored cables, which are commonly used to connect offshore windfarms to the onshore grid. This paper addresses the issue through a series of equivalent-circuit models for the estimation of circulating-current, eddy-current, and armor losses in these cables. Finite-element models are used for further validation. Both the finite-element and the equivalent-circuit models use an equivalent-material representation of the armor layer, for which two calculation methods are developed. The results demonstrate clearly that the equation for armor loss in such cables as presently used in IEC standards is overly conservative.

Introduction The ‘Getting it right first time’ (GIRFT) programme will require endoscopy units to demonstrate improvements in efficiency and quality of patient care. Data collection in endoscopy beyond that recorded in the endoscopy report is difficult (e.g. patient flow, coding, use of consumables, externally validated quality markers and complications occurring outside of the room). Barcode technology offers an exciting way to achieve this. Method Between July-October 2016, patients undergoing bowel cancer screening colonoscopy or ERCP at our hospital were ‘tracked’ through their journey in endoscopy using hTrak barcode technology. The following data were collected: patient co-morbidities; patient location; endoscopy equipment used including disposable items; endoscopy personnel; drugs used; reasons for procedure or equipment failure; complications; and route of discharge. Results In the 3 month period 268 bowel cancer screening colonoscopies and 141 ERCPs were tracked Co-morbidity data were successfully gathered on all patients taking Tracking also allowed consumables to be reordered in a timely fashion and reduced loss of out-of-date stock. Equipment failure was recorded 16 cases including both endoscope and stack failures. 32 complications were recorded, 17 in-room and 16 out-of-room. Out-of-room complications included 10 bleeding episodes, 1 use of flumazenil and 2 episodes of patient distress requiring pain relief. In the 3 months prior to tracking only 3 complications had been recorded for 1080 colonoscopies (including screening and symptomatic) and 127 ERCPs. Conclusion Barcode technology has revolutionised data collection in our department allowing us to meet the aims of the GIRFT programme, saving money and (most importantly) improving patient safety. Disclosure of Interest A. Goddard: None Declared, S. Johnstone: None Declared, J. Green: None Declared, J. Mayne: None Declared, K. Downs Conflict with: GS1 Board Member

Increased accountability has been a catalyst for the reformation of curriculum and assessment practices in postsecondary schools throughout North America, including veterinary schools. There is a call for a shift in assessment practices in clinical rotations, from a focus on content to a focus on assessing student performance. Learning is subsequently articulated in terms of observable outcomes and indicators that describe what the learner can do after engaging in a learning experience. The purpose of this study was to examine the ways in which a competency-based program in an early phase of implementation impacted student learning and faculty instructional practices. Findings revealed that negative student perceptions of the assessment instrument's reliability had a detrimental effect on the face validity of the instrument and, subsequently, on students' engagement with competency-based assessment and promotion of student-centered learning. While the examination of faculty practices echoed findings from other studies that cited the need for faculty development to improve rater reliability and for a better data management system, our study found that faculty members' instructional practices improved through the alignment of instruction and curriculum. This snap-shot of the early stages of implementing a competency-based program has been instrumental in refining and advancing the program.

We address the problem of accurately locating buried utility segments by fusing data from multiple sensors using a novel Marching-Cross-Section (MCS) algorithm. Five types of sensors are used in this work: Ground Penetrating Radar (GPR), Passive Magnetic Fields (PMF), Magnetic Gradiometer (MG), Low Frequency Electromagnetic Fields (LFEM) and Vibro-Acoustics (VA). As part of the MCS algorithm, a novel formulation of the extended Kalman Filter (EKF) is proposed for marching existing utility tracks from a scan cross-section (scs) to the next one; novel rules for initializing utilities based on hypothesized detections on the first scs and for associating predicted utility tracks with hypothesized detections in the following scss are introduced. Algorithms are proposed for generating virtual scan lines based on given hypothesized detections when different sensors do not share common scan lines, or when only the coordinates of the hypothesized detections are provided without any information of the actual survey scan lines. The performance of the proposed system is evaluated with both synthetic data and real data. The experimental results in this work demonstrate that the proposed MCS algorithm can locate multiple buried utility segments simultaneously, including both straight and curved utilities, and can separate intersecting segments. By using the probabilities of a hypothesized detection being a pipe or a cable together with its 3D coordinates, the MCS algorithm is able to discriminate a pipe and a cable close to each other. The MCS algorithm can be used for both post-and on-site processing. When it is used on site, the detected tracks on the current scs can help to determine the location and direction of the next scan line. The proposed “multi-utility multi-sensor” system has no limit to the number of buried utilities or the number of sensors, and the more sensor data used, the more buried utility segments can be detected with more accurate location and orientation.

One possible thermal pinch point along the route of a wind farm export circuit is a J tube, commonly used to provide mechanical protection to cable sections between the sea floor and the offshore platform. Current ratings for such cable sections are not covered by the scope of IEC 60287, while the existing publications covering such systems have limitations. This paper presents an updated 2-D analytical method and a 3-D extension for the rating of J tubes with short air section lengths. Continuous rating comparisons have been made against a 3-D finite-element model which shows a 4.5% variation in rating from the 2-D analytical model for air section lengths greater than 10 m, rising to 13% for short air section lengths. With the addition of longitudinal heat transfer within the new 3-D analytical approach, this variation decreases by 2.5%. Both methods proposed can be solved readily using conventional spreadsheet tools and are broadly compliant with the IEC 60287 methodology.

The surface urban transport infrastructures, which are interpreted widely herein to encompass roads, cycle ways, pedestrian areas and railway foundations, are supported by the ground and hence their structural performance is inevitably to some degree controlled by the ground. Since the utility services infrastructure that supports city living is typically buried beneath the surface transport infrastructure, street works activities to install, replace, repair or maintain the utility infrastructure using traditional techniques disrupts, and often significantly damages, the transport infrastructure and the ground on which it bears. As a consequence of this latter argument, the ground and the associated physical infrastructure, whether buried utility service infrastructure or the surface transport infrastructure, exist according to a symbiotic relationship: intervene physically in one and the other is almost inevitably affected in some way, whether immediately or in the future. The physical condition of these assets is therefore of crucial importance in determining what, and how severe, the inevitable impact on each other will be, and the close link between them (i.e. that they are both intimately linked to and to some degree controlled by the ground) must be carefully considered. This paper proposes and discusses the establishment of a universal platform in which the physical infrastructure and the ground, and their conditions, can be mapped.

An extensive array of utility networks are buried underneath the ground surface and provide essential services for society’s daily life in terms of water, natural gas, electricity, telecommunications, sewerage, etc. All utilities have a limited service life and it is crucial to assess their condition throughout their life cycles to avoid potential catastrophic failure due to their deterioration. This paper reviews current state-of-the-art technologies for condition assessment of underground utilities (especially water and sewage pipelines) and their advantages and technical challenges for different application areas. Recommendations on how to address these challenges are made and it is highlighted that the system of combined sensor technologies being developed by the Mapping the Underworld (MTU) project may provide a valuable addition to the street works engineer’s armoury in determining the condition of the buried infrastructure. Moreover the ground in which the utility services infrastructure is buried supports the pipes and cables and prevents their permanent or transient displacement under static and dynamic loads, or lateral stress relief associated with adjacent trenching. The ability of the MTU sensing technologies to determine also the condition of the ground is thus equally relevant and is discussed.

A lightweight `coreless' (100 kW), 2-pole HTS rotor, designed and built at the University of Southampton has been completed and is now in the testing phase of the project. By removing the iron core from the new cold rotor, the weight has been halved in comparison to the previous rotor. The `cold' components of the rotor assembly make up a sixth of the total weight, which has provided significant time and cost savings in the cool down process. A lightweight doughnut shaped cryostat houses the HTS winding. The winding itself is constructed from sixteen double pancake coils, wound from BSCCO HTS tape. Practical testing of the generator began with a series of stationary tests. The critical current (Ic) of the HTS winding is 77 A at liquid nitrogen temperature (77.4 K) and increases to 156 A, when cooled with liquid air (61.6 K). The air-gap flux density is ~ 0.3 T at 156 A. The machines total harmonic distortion (THD) was predicted to be around 5.4% with the measured THD=5% and this despite using an unoptimized stator. Finally, the synchronous reactance, Xs was evaluated to be 0.24 p.u. This is a 1/5 of the value found for conventional synchronous machines and is largely due to its air-core structure.

The systematic performance test program of the 100 kW iron-core HTS synchronous generator has been underway since 2007 at the University of Southampton. The early measurements were conducted at liquid nitrogen temperatures (77 K) and sub-cooled liquid nitrogen close to its triple point (63 K). Further measurements at these operating temperatures for both open circuit and loaded configurations have enabled us to confirm the machine's synchronous reactance. Circulating liquid air through the closed loop cooling system enabled us to lower the rotor temperature down to 61.7 K and boost the critical current Ic of the HTS winding up to 144 A. A number of transient tests were carried out to assess the impact on the machine, in particular the current in the HTS field winding when the stator circuit was suddenly shorted. The results show that the peak current can be almost 3 times the initial operating field current in the first cycle of the response. No `thermal quench' of HTS winding was witnessed, despite the occurrence of large over currents. The recovery of the HTS winding back to the initial operating current occurred in several seconds and depended on the initial operating current and the reaction of the power supply.

Background Gastric polyps are important as some have malignant potential. If such polyps are left untreated, gastric cancer may result. The malignant potential depends on the histological type of the polyp. The literature base is relatively weak and any recommendations made must be viewed in light of this. Definition Gastric polyps are sessile or pedunculated lesions that originate in the gastric epithelium or submucosa and protrude into the stomach lumen. Malignant potential Depending on histological type, some gastric polyps (adenomas and hyperplastic polyps) have malignant potential and are precursors of early gastric cancer. They may also indicate an increased risk of intestinal or extra-intestinal malignancy.

This paper discusses the different possible designs of both cored and coreless superconducting synchronous generators using high-temperature superconducting (HTS) tapes, with particular reference to demonstrators built at the University of Southampton using BiSCCO conductors. An overview of the electromagnetic, thermal, and mechanical issues is provided, the advantages and drawbacks of particular designs are highlighted, the need for compromises is explained, and practical solutions are offered. The scalability of results obtained from small demonstrators is considered.

A final design of a dasiacorelesspsila 100 kW HTS synchronous generator, to be built at the University of Southampton is under way. The new generator will use the same conventional 2-pole, 3 phase stator used by for the dasiairon coredpsila generator. The new HTS rotor has no central core and the rotor winding is built with 15 double pancake coils. Each coil has 38 turns of BiPb2223 superconducting tape, with nominal current of 180 A at 77 K. In this design, only two flux diverters are used at the top and bottom of the winding to help shape the magnetic field. The coils are located on the inner wall of the cryostat. The construction of the cryostat poses our greatest mechanical challenge. Although we have avoided problems with differential thermal contractions by making the cryostat entirely from stainless steel, the cryostat requires considerable reinforcements. Additional supports and stiffening ribs must be welded to the thin-walled structure. Distortion/rippling during welding must be eliminated to ensure the final welds to the ring flanges can be made. The pole-pieces, which help to improve the waveform characteristics of the machine, are located in the warm space between the cold flange of the cryostat and the inner wall of the vacuum vessel. Unfortunately, the overall magnetic performance has been affected by the parallel stacking of the coils. Some suggestions for altering the current stator have been presented which show that improvements to the voltage waveforms can be achieved.

A systematic test program is in progress to fully characterize a 100 kW HTS synchronous generator which was successfully constructed in 2004. The machine was one of the first HTS synchronous generator/motors to operate at liquid nitrogen temperatures while achieving a power rating relevant to practical application. It has a conventional 3-phase stator and a cold rotor with a magnetic core and a superconducting winding consisting of 10 HTS Bi2223 pancake coils separated by magnetic flux diverters. The test program includes a series of tests at various speeds, field currents and temperatures (65 K-77 K) with the machine in open circuit to determine the critical currents of the HTS rotor, the waveform and harmonic characteristics of generated voltage at different levels of iron saturation. Stationary measurements of the rotor critical current are carried out using dc current in the stator windings to quantify the influence of stator field on the performance of the superconducting winding. The voltages and temperatures of the rotor are measured using a radio frequency telemetry system.

An investigation to reduce harmonic content in the air-gap flux density of a high-temperature superconducting synchronous generator with a coreless rotor is reported. Three-dimensional finite-element field simulation has been used to predict the voltage waveform of the machine. A simple technique was applied to guide the design process. This allowed the waveform to be improved using a small number of finite-element models.

Objective One of the 2-week wait (2WW) criteria for suspected lower gastrointestinal cancer states that patients should be referred who have iron deficiency anaemia (IDA) without obvious cause [Haemoglobin (Hb)

In this paper we report on our new design of a liquid nitrogen/air cooled 100 KW synchronous generator with core-less rotor. This follows our successful completion of 100 KW generators with a 9 wt% Ni steel core operating at 77 K. In the new design, we demonstrate that a coreless rotor using commercial BSCCO tape is a realistic choice while maintaining the cooling at 57-77 K rather than 25-30 K and still achieving reasonable air-gap flux density. This is made possible by a combination of improved HTS wire technology and a careful optimization of HTS winding and flux diverters. The maximum flux density normal to the broad face of the tape is kept below 0.13 T, even when the air-gap density is raised to 0.5 T. The superconducting winding consists of 22 pancake coils with a total length of around 1250 meters of HTS tape. The required temperatures down to 57 K are achieved by a purpose-designed refrigeration system where liquid cryogen is circulated via a network of well insulated pipes and a stationery-rotating liquid coupling junction.

Background Self-expanding metallic stent (SEMS) placement is an important method of dysphagia palliation for patients with inoperable esophageal cancer. In most institutions, it is performed with fluoroscopic guidance; however, in 2001, we described a novel, direct-vision approach to SEMS placement, which does not require fluoroscopy. Here we report an audit of our experience over the last 5 years when using this methodology. Objective To describe our 5-year experience of 98 patients in whom esophageal stents were inserted when using the direct-vision technique and compare outcomes with published series of radiography-guided stents. Design Retrospective review of single-center experience. Setting English National Health Service Cancer Centre Hospital. Patients All patients who underwent esophageal stent insertion for a primary esophageal malignancy. Interventions SEMS insertion by direct endoscopic vision. Results Ninety-eight patients underwent SEMS insertion for malignant dysphagia during the study period, 92% of which were inserted without fluoroscopy. The technique had a low complication rate, which was consistent with published fluoroscopic data, and the median survival beyond stent insertion was 100 days (interquartile range, 62, 256; range, 4-921 days). In 59 patients, no further endoscopic palliative procedure was required. Limitations Retrospective data collection. Conclusions This series confirms direct-vision SEMS placement as a safe and efficacious method of malignant dysphagia palliation, providing definitive treatment in almost two thirds of cases.

Iron-deficiency anaemia (IDA) is common and may be caused by blood loss from gastrointestinal tumours. The aim of this study was to define risk factors for gastrointestinal malignancy in patients with IDA.Patients with suspected IDA referred for gastrointestinal investigations were prospectively identified from two neighbouring UK hospitals (serving a population of 550,000 patients) between 1 January 1998 and 31 December 1999. Final diagnoses were determined after 2 years, and those patients with and without gastrointestinal cancer as a cause for their IDA were compared. Data collected included sex, age, haemoglobin, serum ferritin, mean cell volume and drug history.A total of 695 patients (236 men, mean age 68.5 years; 459 women, mean age 66.2 years) with IDA were investigated. Malignancy was diagnosed in 91/695 (13.1%) and gastrointestinal malignancy in 78/91 (11.2%). The most frequently diagnosed cancers were colonic (n = 44, 6.3%), gastric (n = 25, 3.6%) and renal tract (n = 7, 1%). The adjusted odds ratio (+/-95% confidence interval) for gastrointestinal cancer as a cause of IDA was significantly higher for male sex [2.96 (1.80, 4.87)], age over 50 years [7.04 (1.69, 29.32)] and haemoglobin level at presentation (or =9.0 g/dl) [2.25 (1.29, 3.90)]. There was no significant difference in gastrointestinal malignancy in those taking aspirin (12/111, 10.8%), non-aspirin non-steroidal anti-inflammatory drugs (5/84, 6.0%) or warfarin (4/31, 12.9%) compared with those not taking these drugs (57/470, 12.1%). No cause for IDA was found in 53.7%.Cancer was diagnosed in 13.1% and gastrointestinal cancer in 11.2% of patients with IDA. Significant risk factors for gastrointestinal malignancy in IDA patients are male sex, age over 50 years and haemoglobin at presentationor =9.0 g/dl. IDA should not be attributed to aspirin, non-steroidal anti-inflammatory drugs or warfarin use.

In this review paper we present various semi-analytical and numerical calculations, for computing the inductance and resistance of a pair of rectangular conductors. Sections 1-3 deal with the dc inductance of infinitely thin strips and strips of finite thickness. In the former case, the inductance is computed using the T-Ω method, while in the latter case it is computed by direct integration using Maple. In both cases, the results have been checked using finite element analysis. It is also shown how the dc inductance of three strips may be computed using the method of superposition of solutions. Sections 4-6 use conformal mapping theory to obtain the inductance of a pair of infinitely conducting strips. Infinitely thin strips and strips of finite thickness are considered and the inductance is compared against results obtained using finite element analysis. A method of estimating the resistance of the strips is described which is expected to give useful results when the skin depth is small in relation to the thickness of the strips.

In this review paper we present various analytical and numerical calculations for computing the high frequency and low frequency inductance and resistance of isolated conductors. The high frequency estimates are obtained using conformal mapping theory. In both cases, a uniformly distributed return current at an arbitrary radius is assumed. Formulae are presented for the inductance of a strip conductor of zero thickness. The inductance is computed both for dc and for ac infinite conductivity. For regular polygons the conformal mapping is defined by a power series, while finite element analysis is used to compute the dc inductance. Conformal mapping theory is used to obtain estimates of the resistance and inductance of a rectangular conductor when the skin depth is small compared to the thickness of the conductor. A method is then presented for calculating the resistance when the skin depth exceeds the thickness of the conductor but remains small in relation to the width of the conductor. Finite element analysis is used to confirm that one of the two resistance estimates always gives a reasonable estimate of the resistance.

The paper describes an investigation into methods of modelling magnetic fields in electric armour arrays. The investigation focuses on large-scale fields, which are responsible for generating off-axis forces, whereas pinch forces produced by localised high flux densities are not considered here. The limitations of 2D modelling are investigated.

Helicobacter pylori is the principal cause of peptic ulcer disease and an important risk factor for the development of gastric cancer. The efficacy of 1 week triple therapies, which often have eradication rates of > 90%, is undermined by poor patient compliance and bacterial antimicrobial resistance. The development of new anti-H. pylori therapies presents enormous challenges to clinical pharmacologists, not only in the identification of novel targets, but also in ensuring adequate drug delivery to the unique gastric mucus niche of H. pylori. Animal models of H. pylori infection have been developed but their clinical validity has yet to be established. Vaccination, to prevent or treat infection, has been demonstrated in animal models, but human studies have not been so encouraging.

Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association of a low-frequency nonsynonymous SNV in GLP1R (A316T; rs10305492; MAF=1.4%) with lower FG (β=-0.09±0.01mmoll-1, P=3.4 × 10-12), T2D risk (OR[95%CI]=0.86[0.76-0.96], P=0.010), early insulin secretion (β=-0.07±0.035pmolinsulin mmolglucose-1, P=0.048), but higher 2-h glucose (β=0.16±0.05mmoll-1, P=4.3 × 10-4). We identify a gene-based association with FG at G6PC2 (p SKAT =6.8 × 10-6) driven by four rare protein-coding SNVs (H177Y, Y207S, R283X and S324P). We identify rs651007 (MAF=20%) in the first intron of ABO at the putative promoter of an antisense lncRNA, associating with higher FG (β=0.02±0.004mmoll-1, P=1.3 × 10-8). Our approach identifies novel coding variant associations and extends the allelic spectrum of variation underlying diabetes-related quantitative traits and T2D susceptibility. © 2015 Macmillan Publishers Limited. All rights reserved.

The paper presents the main features of a 100 kVA high temperature superconducting (HTS) demonstrator generator, which is designed and being built at the University of Southampton. The generator is a 2-pole synchronous machine with a conventional 3-phase stator and a HTS rotor operating in the temperature range 57–77 K using either liquid nitrogen down to 65 K or liquid air down to 57 K. Liquid air has not been used before in the refrigeration of HTS devices but has recently been commercialised by BOC as a safe alternative to nitrogen for use in freezing of food. The generator will use an existing stator with a bore of 330 mm. The rotor is designed with a magnetic core (invar) to reduce the magnetising current and the field in the coils. For ease of manufacture, a hybrid salient pole construction is used, and the superconducting winding consists of twelve 50-turn identical flat coils. Magnetic invar rings will be used between adjacent HTS coils of the winding to divert the normal component of the magnetic field away from the Bi2223 superconducting tapes. To avoid excessive eddy-current losses in the rotor pole faces, a cold copper screen will be placed around the rotor core to exclude ac magnetic fields.

This paper investigates the preliminary use of radiometric techniques to the detection of PDs in buried cables, and in particular to cable joints. The transfer function from the source to the detector is a function of the propagation characteristics of the media involved. In the case of radiometric detection the inclusion of soil, in general a lossy and dispersive medium with frequency and content dependent characteristics, further contributes to signal attenuation. The work undertaken here examines whether a repetitive pulse of varying amplitude and frequency, injected into an experimental arrangement that simulates buried power cables, is being detected by two simple antennae above ground. Successful detection of the pulses showed the preliminary possibility of the use of such techniques in PD detection, which creates the need for further experiments and antenna designs to be explored.

Design/optimization processes requiring intensive finite-element computation can be made significantly more efficient, while preserving good accuracy, by combining the Response Surface Methodology with on-line learning and dynamic weighting. The paper presents such a new development and uses the multi-parameter design of a brushless pm motor to illustrate the approach.

Aim To find the proportion of patients with a faecal occult blood (FOB) performed as part of the referral for the lower gastrointestinal two week wait (2WW) referral system, and whether this correlates with the cancer status. Method All patients referred to the colorectal cancer service using the 2WW referral criteria, between August 2005 and August 2007, were identified using the hospital’s cancer audit database. Faecal occult bloods and cancer status were recorded for each patient. Results Two thousand one hundred and fifty-nine patients (1177 female: 903 male; median age 58; age range 18–98) were referred by general practitioners. The FOBT was only performed on three samples in all cases. In total, 172 of 2159 patients (7.9%) had an FOB performed prior to their referral, with 55 of 172 patients (31.9%) as part of the referral for 2WW. Sixteen of 172 patients (9.3%) had an FOB performed in the presence of overt rectal bleeding. In only 2 of 172 patients (1.1%) the FOB correlated with a colorectal cancer. Unnecessary testing for FOB costs has cost £4072.96 in total. Discussion A significant number of faecal occult bloods are being performed and the detection rate, even in this symptomatic group of patients, is very low. It is evident that the test is being performed in the community on three samples and not six. This, combined with the high false positive rate, leads to patients not only undergoing unnecessary psycho-social consequences but could potentially lead to significant risks from unnecessary invasive investigation as well as the added financial burden of test itself.

Background : A combination of omeprazole, clarithromycin and either metronidazole or tinidazole is commonly used for Helicobacter pylori eradication. Metronidazole is considerably cheaper than tinidazole but the two have not previously been compared in a randomized trial. Methods : One hundred and twenty dyspeptic H. pylori-positive patients with endoscopically defined peptic ulcer [DU (n = 65), GU (n = 12)] or non-ulcer dyspepsia (NUD, n = 43) were randomized to receive a 1-week course of twice daily omeprazole 20 mg, clarithromycin 250 mg and either metronidazole 400 mg (OCM) or tinidazole 500 mg (OCT) in a double-blind fashion. Eradication of H. pylori, safety and side-effects of treatment, dyspeptic symptom score and consumption of antisecretory drugs were assessed at 6 weeks and 1 year after treatment. Results : H. pylori eradication was successfully achieved in 57/60 (95%, ITT analysis) of patients receiving OCT and 58/60 (97%, ITT analysis) receiving OCM. Both regimens had similar side-effect profiles, which accounted for only one patient withdrawal. All patients remained uninfected (as assessed by 14C-urea breath test) at 1-year follow-up, but major symptom improvements and decreased antisecretory drug use were only seen in patients with DU (P

The paper presents a novel method of calculating AC loss in solenoidal high temperature superconducting windings of the transformer type. Losses caused by the external magnetic field and due to transport current are modelled together and account is taken of highly nonlinear characteristics of the material. In tape conductors the loss due to the parallel field component is usually small whereas the effect of the normal field component is significant. A nonlinear 2D finite difference formulation is derived for the superconductor and linked with a linear finite element model representing the rest of the transformer and the interaction between coils.

Among the many ways investigated for radar estimation of rainfall, polarimetric methods are the most promising. However most polarimetric algorithms are degraded by attenuation by precipitation and clouds and by calibration error. A new method was recently proposed in which the differential polarimetric attenuation is used to perform an accurate rain rate measurement. The method is independent of the radar calibration and of the attenuation by undetected clouds. This algorithm is also usable as a qualitative hail detector, as well as a detector of anomalous propagation. The goal of the paper is to describe the results of the first experimental implementation of this method using the 35 GHz RABELAIS radar, as attenuated radar, and the 3 GHz CAMRa radar as a reference. We show that the proposed algorithm is stable and enables us to retrieve the actual rain rate even from an observed signal attenuated by more than 30 dB. The results are insensitive to the value used for the power coefficient of the Z(R) relation.

To evaluate the effect of omeprazole on the pharmacokinetics of metronidazole and hydroxymetronidazole in plasma, gastric juice and saliva following intravenous infusion or oral dosing of metronidazole.Eight volunteers received single doses of metronidazole (400 mg) intravenously and orally, whilst taking placebo or omeprazole (40 mg, twice daily for 5 days) in a randomized 4-way crossover study. Metronidazole and hydroxymetronidazole concentrations in plasma, saliva and gastric juice samples were determined by h.p.l.c. Pharmacokinetic parameters for metronidazole and hydroxymetronidazole were calculated, and the significance of the mean differences in parameters between omeprazole and placebo co-administration was assessed using a two-tailed, paired t-test.There were no significant differences (P0.05) in any of the plasma or saliva pharmacokinetic parameter values for metronidazole between volunteers receiving omeprazole or placebo when metronidazole was administered either as an intravenous infusion or orally. Following intravenous administration of metronidazole to the placebo group and omeprazole treated group respectively, the gastric transfer of metronidazole was significantly reduced from 15.5 +/- 10.4% to 2.6 +/- 1.0% of the dose (P = 0.007; 95% CI of difference 4.8 to 21.0) with concomitant changes in the metronidazole AUC (from 77.5 +/- 18.0 mumol l-1 h to 352.6 +/- 182.1 mumol l-1 h; P = 0.0003; 95% CI of difference 127.6 to 422.7), Cmax (from 61.4 +/- 26.5 mumol l-1 to 271.8 +/- 104.3 mumol l-1; p = 0.0001; 95% CI of difference 118.6 to 302.1). Similarly, the gastric juice AUC of hydroxymetronidazole was significantly reduced from 3.2 +/- 1.9 mumol l-1 h to 1.5 +/- 0.8 mumol l-1 h of the dose (P = 0.0043; 95% CI of difference 0.4 to 3.0) with a concomitant change in Cmax (from 5.0 +/- 2.5 mumol l-1 to 3.0 +/- 1.2 mumol l-1; P = 0.0007; 95% CI of difference 0.7 to 3.4).Omeprazole had little effect on the plasma and salivary pharmacokinetics of metronidazole (or its hydroxymetabolite) after intravenous or oral administration, but it did have a substantial effect on the pharmacokinetics of metronidazole and hydroxymetronidazole in gastric juice.

The Olympus program was designed to develop new telecommunications technology in space and develop new market applications. This study analyzes attenuation data from two of the Olympus satellite beacons, those operating at 19.77 and 12.502 GHz. It is shown that the difference in the two attenuations provides estimates of rainfall rate that are in close agreement with rain gauge and distrometer measurements at the ground receiver site and along the propagation path. Modeling demonstrates that the attenuation difference using 19.77 and 12.502 GHz is a useful estimator of rainfall because it is largely independent of drop shape and size distribution, making it linearly related to rainfall rate. Attenuation along the propagation path due to the melting layer or ice introduces inaccuracies into estimates of rainfall. However, this difficulty would be eliminated if the method were to be used on terrestrial line-of-site links. Thus attenuation difference provides a means of improving the quality of rainfall estimates when used together with gauges and radar observations.

The urea breath test (UBT) is the most sensitive and specific non-invasive test for the detection of Helicobacter pylori infection both before and after treatment. Labelling of the urea with either 13C or 14C has relative advantages and disadvantages. 13C-UBTs are both safe and well-validated, and have the additional advantage that they can be used in children. However, the initial capital costs of 13CO2 analysis are large compared to those for 14CO2. The protocol details for use of the 13C-UBT are variable: a test meal is important if urea solution is to be used and a single sample time point at 30 min is adequate. The recent development of novel formulations of 13C urea and new analytical techniques for the measurement of 13CO2 should allow reduction in the length of the test and its cost: they may herald a more widespread clinical application of this useful test.

Objective To examine use of CT colonography (CTC) in the English Bowel Cancer Screening Programme (BCSP) and investigate detection rates. Design Retrospective analysis of routinely coded BCSP data. Guaiac faecal occult blood test (gFOBt)-positive screenees undergoing CTC from June 2006 to July 2012 as their first-line colonic investigation were included. Abnormalities found at CTC, subsequent polyp, adenoma and cancer detection and positive predictive value (PPV) were calculated. Detection rates were compared with those observed in gFOBt-positive screenees investigated by colonoscopy. Multilevel logistic regression was used to examine factors associated with variable detection. Results 2731 screenees underwent CTC. Colorectal cancer (CRC) or polyps were suspected in 1027 individuals (37.6%; 95% CI 33.8% to 41.4%); 911 of these underwent confirmatory testing. 124 screenees had CRC (4.5%) and 533 had polyps (19.5%), 468 adenomatous (17.1%). Overall detection was 24.1% (95% CI 21.5% to 26.6%) for CRC or polyps and 21.7% (95% CI 19.2% to 24.1%) for CRC or adenoma. Advanced neoplasia was detected in 504 screenees (18.5%; 95% CI 16.1% to 20.8%). PPV for CRC or polyp was 72.1% (95% CI 66.6% to 77.6%). By comparison, 9.0% of 72 817 screenees undergoing colonoscopy had cancer and 50.6% had polyps; advanced neoplasia was detected in 32.7%. CTC detection rates and PPV were higher at centres with experienced radiologists (>1000 examinations) and at high-volume centres (>175 cases/radiologist/annum). Centres using three-dimensional interpretation detected more neoplasia. Conclusions In the BCSP, detection rates after positive gFOBt are lower for CTC than colonoscopy, although populations undergoing the two tests are different. Centres with more experienced radiologists have higher detection and accuracy. Rigorous quality assurance of BCSP radiology is needed.

BACKGROUND & AIMS: The mechanism by which antimicrobial therapy against Helicobacter pylori is enhanced by acid suppression is unknown. The aim of this study was to investigate the effect of omeprazole on gastric juice, plasma, and saliva concentrations of metronidazole, amoxicillin, and clarithromycin. METHODS: Single doses of antibiotic were administered intravenously to 24 healthy men (each antibiotic to 8 subjects) while taking placebo or omeprazole. Antibiotic concentrations were measured in gastric juice, plasma, and saliva. The pharmacokinetic parameters gastric clearance and gastric transfer fraction were calculated for each antibiotic. RESULTS: In the omeprazole group compared with the placebo group, mean maximum antibiotic gastric juice concentrations (in milligram per liter) of metronidazole decreased from 33.6 to 8.3 (P = 0.0001), whereas those of clarithromycin were unchanged, and those of amoxicillin increased from 0.13 to 0.68 (P = 0.02). Omeprazole increased salivary concentrations of metronidazole (P = 0.02) but had no effect on clarithromycin concentrations (no amoxicillin was detectable in saliva). CONCLUSIONS: Omeprazole decreases the intragastric concentrations of metronidazole by reducing acid secretion and increases intragastric concentrations of amoxicillin partly by reducing gastric juice volume. Novel pharmacokinetic parameters have been described that provide an insight into the mechanisms underlying drug transfer across the blood-stomach barrier. (Gastroenterology 1996 Aug;111(2):358-67)