Formation of large negative deuterium ion beams at ELISE.

Negative ion sources for neutral beam injection (NBI) in fusion experiments are based on the surface production of H- or D- on cesiated low work function surfaces. In the recent years, it was demonstrated at the large RF driven ion source of the ELISE (Extraction from a Large Ion Source Experiment) test facility that the requirements for the ITER NBI systems can be fulfilled by hydrogen. This is a big step toward the first operational period of ITER, planned for up to 2035. However, for the following operational period, neutral beam systems working in deuterium are needed. Operation of negative hydrogen ion sources in deuterium is significantly more demanding than in hydrogen: the amount of coextracted electrons is much higher and their increase during pulses is much more pronounced, limiting the achievable performance. This paper presents the results of investigations aimed to improve the insight into the physics related to this isotope effect. Due to the higher atomic mass of deuterium, cesium is removed much more effectively from reservoirs at the walls, resulting in a depletion of these reservoirs and a strongly increased cesium density in the plasma. Additionally, a correlation between the fluxes of charged particles toward the inner ion source surfaces and the coextracted electrons is identified.

Straight proximal humeral nailing: Risk of iatrogenic tendon injuries with respect to different entry points in anatomical specimens.

BACKGROUND: The purpose of the study was to evaluate the relationship of implant-related injuries to the adjacent anatomical structures in a newer generation straight proximal humeral nail (PHN) regarding different entry points. The proximity of the proximal lateral locking-screws of the MultiLoc proximal humeral nail (ML PHN) may cause iatrogenic tendon injuries to the lateral edge of the bicipital humeral groove (BG) as reference point for the tendon of the long head of biceps brachii (LBT) as well as the lateral insertion of the infraspinatus tendon (IST). MATERIALS AND METHODS: The study comprised n = 40 upper extremities. Nail application was performed through a deltoid approach and supraspinatus tendon (SSP) split with a ML PHN. All tests were performed in three different entry points. First nail (N1) - standard position in line with the humeral shaft axis; second nail (N2) - a more lateral entry point; third alternative (N3) - medial position, centre of the humeral head. After nail placement, each specimen was screened for potential implant-related injuries or worded differently hit rates (HR) to the BG and the IST. The distances to the anatomical structures were measured and statistically interpreted. RESULTS: The observed iatrogenic IST injury rate was 17.5% (n = 7/40) for N1, 5% (n = 2/40) for N2 and 62.5% (n = 25/40) for N3, which was statistically significantly higher (p < 0.001). Regarding the BG, the evaluated HR was 7.5% (n = 3/40) for both N1 and N2. Only the nail placed in the head centre (N3) showed an iatrogenic injury rate of 20% (n = 8/40) (p < 0.062). No statistically significant association between humeral head size and the HR could be observed (head diameter: IST: p = 0.323, BG: p = 0.621; head circumference: IST: p = 0.167; BG: p = 0.940). For the IST and BG, all distances in nail positions N1 and N2 as well as N2 and N3 differ statistically significant (p < 0.001). CONCLUSIONS: An entry point for nail placement in line or slightly laterally to the humeral shaft axis - but still at the cartilage - should be advocated.

Deuterium results at the negative ion source test facility ELISE.

The ITER neutral beam system will be equipped with large radio frequency (RF) driven negative ion sources, with a cross section of 0.9 m × 1.9 m, which have to deliver extracted D- ion beams of 57 A at 1 MeV for 1 h. On the extraction from a large ion source experiment test facility, a source of half of this size is being operational since 2013. The goal of this experiment is to demonstrate a high operational reliability and to achieve the extracted current densities and beam properties required for ITER. Technical improvements of the source design and the RF system were necessary to provide reliable operation in steady state with an RF power of up to 300 kW. While in short pulses the required D- current density has almost been reached, the performance in long pulses is determined in particular in Deuterium by inhomogeneous and unstable currents of co-extracted electrons. By application of refined caesium evaporation and distribution procedures, and reduction and symmetrization of the electron currents, considerable progress has been made and up to 190 A/m2 D-, corresponding to 66% of the value required for ITER, have been extracted for 45 min.

Progress towards non-invasive diagnosis and follow-up of celiac disease in children; a prospective multicentre study to the usefulness of plasma I-FABP.

This prospective study investigates whether measurement of plasma intestinal-fatty acid binding protein (I-FABP), a sensitive marker for small intestinal epithelial damage, improves non-invasive diagnosing of celiac disease (CD), and whether I-FABP levels are useful to evaluate mucosal healing in patients on a gluten-free diet (GFD). Ninety children with elevated tTG-IgA titres and HLA-DQ2/DQ8 positivity were included (study group). Duodenal biopsies were taken, except in those fulfilling the ESPGHAN criteria. Plasma I-FABP levels and tTG-IgA titres were assessed sequentially during six months of follow-up. Eighty children with normal tTG-IgA titres served as control group. In 61/90 (67.8%) of the children in the study group an increased I-FABP level was found; in all these children CD diagnosis was confirmed. Interestingly, in 14/30 (46.7%) children with slightly elevated tTG-IgA titres (<10x upper limit of normal), an increased I-FABP level was found. In all these children the diagnosis of CD was confirmed histologically. After gluten elimination for six weeks I-FABP levels had decreased towards levels in the control group. Measurement of plasma I-FABP, in addition to tTG-IgA, EMA-IgA and HLAtyping, enables non-invasive diagnosing of CD in a substantial number of children, and might therefore be of value in the diagnostic approach of CD.

Towards 20 A negative hydrogen ion beams for up to 1 h: Achievements of the ELISE test facility (invited).

The large-scale RF-driven ion source of the test facility extraction from a large ion source experiment is aimed to deliver an accelerated ion current of 20 A D(-) (23 A H(-)) with an extracted electron-to-ion ratio below one for up to 1 h. Since the first plasma pulses for 20 s in volume operation in early 2013, followed by caesiation of the ion source, substantial progress has been achieved in extending the pulse length and the RF power. The record pulses in hydrogen are stable 400 s pulses with an extracted ion current of 18.3 A at 180 kW total RF power and 9.3 A at 80 kW stable for 1 h. For deuterium pulse, length and RF power are limited by the amount of co-extracted electrons.

Final design of the beam source for the MITICA injector.

The megavolt ITER injector and concept advancement experiment is the prototype and the test bed of the ITER heating and current drive neutral beam injectors, currently in the final design phase, in view of the installation in Padova Research on Injector Megavolt Accelerated facility in Padova, Italy. The beam source is the key component of the system, as its goal is the generation of the 1 MeV accelerated beam of deuterium or hydrogen negative ions. This paper presents the highlights of the latest developments for the finalization of the MITICA beam source design, together with a description of the most recent analyses and R&D activities carried out in support of the design.

On the use and misuse of scalar scores of confounders in design and analysis of observational studies.

We assess the asymptotic bias of estimates of exposure effects conditional on covariates when summary scores of confounders, instead of the confounders themselves, are used to analyze observational data. First, we study regression models for cohort data that are adjusted for summary scores. Second, we derive the asymptotic bias for case-control studies when cases and controls are matched on a summary score, and then analyzed either using conditional logistic regression or by unconditional logistic regression adjusted for the summary score. Two scores, the propensity score (PS) and the disease risk score (DRS) are studied in detail. For cohort analysis, when regression models are adjusted for the PS, the estimated conditional treatment effect is unbiased only for linear models, or at the null for non-linear models. Adjustment of cohort data for DRS yields unbiased estimates only for linear regression; all other estimates of exposure effects are biased. Matching cases and controls on DRS and analyzing them using conditional logistic regression yields unbiased estimates of exposure effect, whereas adjusting for the DRS in unconditional logistic regression yields biased estimates, even under the null hypothesis of no association. Matching cases and controls on the PS yield unbiased estimates only under the null for both conditional and unconditional logistic regression, adjusted for the PS. We study the bias for various confounding scenarios and compare our asymptotic results with those from simulations with limited sample sizes. To create realistic correlations among multiple confounders, we also based simulations on a real dataset.

Optical emission spectroscopy at the large RF driven negative ion test facility ELISE: instrumental setup and first results.

One of the main topics to be investigated at the recently launched large (A(source) = 1.0 × 0.9 m(2)) ITER relevant RF driven negative ion test facility ELISE (Extraction from a Large Ion Source Experiment) is the connection between the homogeneity of the plasma parameters close to the extraction system and the homogeneity of the extracted negative hydrogen ion beam. While several diagnostics techniques are available for measuring the beam homogeneity, the plasma parameters are determined by optical emission spectroscopy (OES) solely. First OES measurements close to the extraction system show that without magnetic filter field the vertical profile of the plasma emission is more or less symmetric, with maxima of the emission representing the projection of the plasma generation volumes, and a distinct minimum in between. The profile changes with the strength of the magnetic filter field but under all circumstances the plasma emission in ELISE is much more homogeneous compared to the smaller IPP prototype sources. Planned after this successful demonstration of the ELISE OES system is to combine OES with tomography in order to determine locally resolved values for the plasma parameters.

Serum I-FABP as marker for enterocyte damage in coeliac disease and its relation to villous atrophy and circulating autoantibodies.

BACKGROUND: Enterocyte damage is the hallmark of coeliac disease (CD) resulting in malabsorption. Little is known about the recovery of enterocyte damage and its clinical consequences. Serum intestinal fatty acid binding protein (I-FABP) is a sensitive marker to study enterocyte damage. AIMS: To evaluate the severity of enterocyte damage in adult-onset CD and its course upon a gluten-free diet (GFD). Furthermore, the correlation among enterocyte damage, CD autoantibodies and histological abnormalities during the course of disease is studied. METHODS: Serum I-FABP levels were determined in 96 biopsy-proven adult CD patients and in 69 patients repeatedly upon a GFD. A total of 141 individuals with normal antitissue transglutaminase antibody (IgA-tTG) levels served as controls. I-FABP levels were related to the degree of villous atrophy (Marsh grade) and IgA-tTG. RESULTS: I-FABP levels were elevated in untreated CD (median 691 pg/mL) compared with controls (median 178 pg/mL, P < 0.001) and correlated with Marsh grade (r = 0.265, P < 0.05) and IgA-tTG (r = 0.403, P < 0.01). Upon a GFD serum levels decreased significantly, however, not within the range observed in controls, despite the common observed normalisation of IgA-tTG levels and Marsh grade. CD patients with elevated I-FABP levels nonresponding to GFD showed persistent histological abnormalities. CONCLUSIONS: Enterocyte damage assessed by serum I-FABP correlates with the severity of villous atrophy in coeliac disease at the time of diagnosis. Although enterocyte damage improves upon treatment, substantial enterocyte damage persists despite absence of villous atrophy and low IgA-tTG levels in the majority of cases. Elevated I-FABP levels nonresponding to gluten-free diet are indicative of histological abnormalities and warrant further evaluation.

The development of the radio frequency driven negative ion source for neutral beam injectors (invited).

Large and powerful negative hydrogen ion sources are required for the neutral beam injection (NBI) systems of future fusion devices. Simplicity and maintenance-free operation favors RF sources, which are developed intensively at the Max-Planck-Institut für Plasmaphysik (IPP) since many years. The negative hydrogen ions are generated by caesium-enhanced surface conversion of atoms and positive ions on the plasma grid surface. With a small scale prototype the required high ion current density and the low fraction of co-extracted electrons at low pressure as well as stable pulses up to 1 h could be demonstrated. The modular design allows extension to large source dimensions. This has led to the decision to choose RF sources for the NBI of the international fusion reactor, ITER. As an intermediate step towards the full size ITER source at IPP, the development will be continued with a half-size source on the new ELISE testbed. This will enable to gain experience for the first time with negative hydrogen ion beams from RF sources of these dimensions.

Endoscopic red flags for the detection of high-risk serrated polyps: an observational study.

BACKGROUND AND STUDY AIMS: In routine practice, colonoscopy may fail to prevent colorectal cancer (CRC), especially in the proximal colon. A better endoscopic recognition of serrated polyps is important, as this pathway may explain some of the post-colonoscopy cancers. In this study, the endoscopic characteristics of serrated polyps were examined. PATIENT AND METHODS: This was a cross-sectional, single-center study of all consecutive patients referred for elective colonoscopy during 1 year. The endoscopists were familiarized with the detection and treatment of nonpolypoid colorectal lesions. Serrated polyps were classified into high risk serrated polyps, defined as dysplastic or large (≥ 6 mm) proximal nondysplastic serrated polyps, and low risk serrated polyps including the remaining nondysplastic serrated polyps. Advanced colorectal neoplasms were defined as multiple (at least three),≥ 10 mm in size, high grade dysplastic adenomas or CRC. RESULTS: A total of 2309 patients were included (46.1 % men, mean age 58.4 years), of whom 2.5 % (57) had at least one high risk serrated polyp and 13.9 % (322) had at least one advanced neoplasm. Overall, serrated polyps were more often nonpolypoid than adenomas (16.2 % vs. 11.1 %; P = 0.002). In total, 65 high risk serrated polyps were found, of which 43.1 % (28) displayed a nonpolypoid endoscopic appearance. Patients with advanced neoplasms were more likely to have synchronous high risk serrated polyps than patients without advanced neoplasms: OR 3.66 (95 % CI 2.03 - 6.61, P < 0.001). CONCLUSIONS: High risk serrated polyps are frequently nonpolypoid and are associated with synchronous advanced colorectal neoplasms. Advanced colorectal neoplasms may therefore be considered red flags for the presence of high risk serrated polyps. Detection, diagnosis, and treatment of high risk serrated lesions may be important targets to improve the quality of colonoscopic cancer prevention.

Low pressure and high power rf sources for negative hydrogen ions for fusion applications (ITER neutral beam injection).

The international fusion experiment ITER requires for the plasma heating and current drive a neutral beam injection system based on negative hydrogen ion sources at 0.3 Pa. The ion source must deliver a current of 40 A D(-) for up to 1 h with an accelerated current density of 200 Am/(2) and a ratio of coextracted electrons to ions below 1. The extraction area is 0.2 m(2) from an aperture array with an envelope of 1.5 x 0.6 m(2). A high power rf-driven negative ion source has been successfully developed at the Max-Planck Institute for Plasma Physics (IPP) at three test facilities in parallel. Current densities of 330 and 230 Am/(2) have been achieved for hydrogen and deuterium, respectively, at a pressure of 0.3 Pa and an electron/ion ratio below 1 for a small extraction area (0.007 m(2)) and short pulses (<4 s). In the long pulse experiment, equipped with an extraction area of 0.02 m(2), the pulse length has been extended to 3600 s. A large rf source, with the width and half the height of the ITER source but without extraction system, is intended to demonstrate the size scaling and plasma homogeneity of rf ion sources. The source operates routinely now. First results on plasma homogeneity obtained from optical emission spectroscopy and Langmuir probes are very promising. Based on the success of the IPP development program, the high power rf-driven negative ion source has been chosen recently for the ITER beam systems in the ITER design review process.

Long pulse large area beam extraction with a rf driven H(-)/D(-) source.

IPP Garching is heavily involved in the development of the rf driven H(-)/D(-) ion source for the ITER NBI. After the successful demonstration of the required physical parameters, the experimental conditions have been extended to long pulses and large area beam extraction. This paper contains descriptions of the source and power supply modifications necessitated for long pulses as well as the latest results including the first 1 h pulse. Suppression of the coextracted electron current is a key issue. Experiments with potential control, different magnetic filter fields, and cesium handling to suppress the electrons and stabilize the currents are also reported.

Presentation of two cases of nasal type NK/T-cell lymphoma.

Nasal type NK/T-cell lymphoma is a rare type of predominantly extranodal non-Hodgkin lymphoma. Early and correct diagnosis with prompt treatment of NK/T-cell lymphoma is important in view of its potentially aggressive behavior and poor response to treatment with additional sites of tumor developing sometimes weeks or months after initial diagnosis. Unfortunately diagnosis of NK/T-cell lymphomas often proves difficult. The diagnosis is essentially based on the clinical presentation of extranodal ulcerative lesions in the upper aero-digestive tract and histopathologic analysis of biopsies using immunohistochemistry. Here we present two cases with nasal-type NK/T-cell lymphoma that illustrate that definitive diagnosis is often delayed due to the atypical initial presentation. We will discuss the pitfalls in diagnosing this rare type of neoplasm and review the treatment options.

[Urinary diversion after cystectomy: aspects of quality of life and options for rehabilitation]. / Harnableitung nach Zystektomie Aspekte zur Lebensqualität und Möglichkeiten der Rehabilitation.

Radical cystectomy in combination with different types of continent and incontinent urinary diversion is an integral part of the treatment concept for bladder tumors. Although in principle this operation does not cause disability in general, it represents a potentially massive encroachment on the physical and psychological integrity of the individual. The term "quality of life" appears with increasing frequency in modern concepts of evidence-based medicine. Also recognition of the subjective assessment of treatment by those affected in comparison to the "objective" view of qualified doctors and functionaries has become more relevant.Nevertheless, few studies have analyzed the "quality of life" after cystectomy. In addition, methodological factors hinder comparability. Only a few authors have used validated measuring instruments that allow comparison of the data. Low case numbers limit the statistical significance. Besides typical postoperative consequences and their effect on quality of life, potential influences on the pre- and postoperative assessment in the intraindividual course are discussed. The authors argue in favor of postoperative urological rehabilitation in qualified urological centers to optimize physical and psychological coping with the new life situation of "cystectomy with urinary diversion."

[Bilateral ureteral obstruction by granuloma formation in chronic granulomatosis]. / Bilaterale Ureterobstruktion durch Granulombildung bei chronischer Granulomatose.

A 24-year-old patient with chronic granulomatous disease had bilateral hydronephrosis resulting from ureteral granuloma formation. He was treated with high-dose steroids, antibiotics and percutaneous nephrostomy. The etiology, incidence, clinical findings and treatment of chronic granulomatous disease are discussed.

[The value of hydrostatic balloon dilatation with adjuvant pentosan polysulfate medication in therapy of chronic interstitial cystitis]. / Stellenwert der hydrostatischen Ballondilatation mit adjuvanter Pentosan-Polysulfat-Medikation in der Therapie der chronischen interstitiellen Zystitis.

Twenty-one female patients suffering from interstitial cystitis were treated by oral medication of pentosane-polysulfates (200 mg/6 months). In cases with a capacity below 150 ml (n = 6) a distension therapy of bladder was performed simultaneously. The combined therapy showed good therapeutic effects for 1-2 years defined by the increase of voiding volumina and decrease of nycturia and pains. Medication of pentosane-polysulfates alone was of lower therapeutic value. Concerning urodynamic investigations we found an increase of capacity while the quality of bladder compliance did not change. We recommend these conservative therapies as an experimental alternative therapy before bladder augmentation.