2018 Status of the Measurement Capabilities for Fusion Gyrotrons at KIT/IHM

This paper gives an overview about three key measurement capabilities at KIT/IHM for fusion gyrotrons. The discussed topics are: RF window test facility, low power launcher test setup and the frequency measurement setup placed at the high power test facility. Further, approaches for upgrading the setups to frequencies above 200 GHz are discussed.

[Periprosthetic fractures following total hip and knee arthroplasty: Risk factors, epidemiological aspects, diagnostics and classification systems]

Periprosthetic fractures following hip and knee arthroplasty are potentially severe complications. As a fundament in diagnostic and therapeutic procedures, specific classification systems are necessary to ensure an optimal individualized treatment of these sometimes complicated fractures. This review article summarizes the epidemiological aspects, risk factors and diagnostics of periprosthetic hip and knee fractures. The most frequently used location related fracture classifications systems are explained. In addition, the recently introduced unified classification system (UCS), which is applicable to any location of periprosthetic fractures, is described in detail. Initial studies have shown a reliable applicability of the UCS to periprosthetic hip and knee fractures.

Cemented Hemiarthroplasties Are Associated with a Higher Mortality Rate after Femoral Neck Fractures in Elderly Patients

PURPOSE OF THE STUDY The postoperative outcomes of total hip replacement and hemiarthroplasty after femoral neck fractures in elderly patients were analysed to determine general and local complications as well as morbidity and mortality rates in order to detect risk profiles and assess the best individual treatment option. MATERIALS AND METHODS One hundred sixty-one femoral neck fractures among patients aged ≥ 65 years treated with cemented hemiarthroplasty (HA) or uncemented total hip arthroplasty (THA) between January 2005 and October 2013 were evaluated. In the presence of articular pathologies as well as a fracture type Garden III or IV, the indication for joint replacement was given. Criteria for performing hemiarthroplasty were previously limited mobility. Freely and fully mobilised patients and patients with manifested osteoarthritis received a cementless THA. A comparison of the observed complications was made, differentiating between general and surgery-specific hip-related complications. Furthermore, the mortality rates were analysed in relation to the respective surgical treatment. RESULTS Seventy cemented HA and ninety-one uncemented THA were performed. There was a high complication rate of approximately 19% in both surgical intervention groups. The patients were more likely to develop general complications (HA 12.8%; THA 10.8%) even though cardiopulmonary complications occurred more frequently in the cemented HA group. Four patients died after cemented hemiarthroplasty due to thromboembolic events (5.7% mortality rate), whereas no deaths occurred after total hip replacement. Surgery-specific complications rates were 7.8% in THA and 5.7% in HA patients. CONCLUSIONS THA in eldery patients with femoral neck fractures is associated with a higher complication rate, mostly of general medical entity. After cemented HA, our study reveals a high mortality rate due to thromboembolic events. For patients with multimorbidity in particular, these findings therefore suggest that uncemented THA should be considered to prevent lethal complications. Key words: femoral neck fracture; total hip arthroplasty; hemiarthroplasty; complications.

Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner

OBJECTIVES

Dual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference.

MATERIALS AND METHODS

Nine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen's kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.

RESULTS

Fourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75-1.0 among all readers) and specificity of 1.0 (0.81-1.0). Interrater agreement was inferior for DECT (κ=0.63-0.89) compared to MRI (κ=0.9-1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r=0.87) and inversely with T1 (-0.89). SNR (0.2+/- 0.2 in VNC and 16.7+/- 7.3 in STIR) and CNR (0.2+/- 0.3 and 7.1+/- 6.3) values were inferior in VNC.

CONCLUSIONS

Detecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity. However, image quality of VNC reconstructions has to be improved to achieve better interrater agreement. Nonetheless, DECT might accelerate the diagnostic work-flow in patients with vertebral compression fractures in the future and reduce the number of additional MRI examinations.

Active microrheology in a colloidal glass

We study the dynamics of a probe particle driven by a constant force through a colloidal glass of hard spheres. This nonequilibrium and anisotropic problem is investigated using a new implementation of the mode-coupling approximation with multiple relaxation channels and Langevin dynamics simulations. A force threshold is found, below which the probe remains localized, while above it the probe acquires a finite velocity. We focus on the localized regime, comparing theory and simulations concerning the dynamics in the length scale of the cage and the properties of the transition to the delocalized regime, such as the critical power-law decay of the probe correlation function. Probe van Hove functions predicted by the theory show exponential tails reminiscent of an intermittent dynamics of the probe. This scenario is microscopically supported by simulations.

New quality assurance program integrating "modern radiotherapy" within the German Hodgkin Study Group

INTRODUCTION

Field design changed substantially from extended-field RT (EF-RT) to involved-field RT (IF-RT) and now to involved-node RT (IN-RT) and involved-site RT (IS-RT) as well as treatment techniques in radiotherapy (RT) of Hodgkin's lymphoma (HL). The purpose of this article is to demonstrate the establishment of a quality assurance program (QAP) including modern RT techniques and field designs within the German Hodgkin Study Group (GHSG).

METHODS

In the era of modern conformal RT, this QAP had to be fundamentally adapted and a new evaluation process has been intensively discussed by the radiotherapeutic expert panel of the GHSG.

RESULTS

The expert panel developed guidelines and criteria to analyse "modern" field designs and treatment techniques. This work is based on a dataset of 11 patients treated within the sixth study generation (HD16-17).

CONCLUSION

To develop a QAP of "modern RT", the expert panel defined criteria for analysing current RT procedures. The consensus of a modified QAP in ongoing and future trials is presented. With this schedule, the QAP of the GHSG could serve as a model for other study groups.

A Renaissance in Nepovirus Research Provides New Insights Into Their Molecular Interface With Hosts and Vectors

Nepoviruses supplied seminal landmarks to the historical trail of plant virology. Among the first agriculturally relevant viruses recognized in the late 1920s and among the first plant viruses officially classified in the early 1970s, nepoviruses also comprise the first species for which a soil-borne ectoparasitic nematode vector was identified. Early research on nepoviruses shed light on the genome structure and expression, biological properties of the two genomic RNAs, and mode of transmission. In recent years, research on nepoviruses enjoyed an extraordinary renaissance. This resurgence provided new insights into the molecular interface between viruses and their plant hosts, and between viruses and dagger nematode vectors to advance our understanding of some of the major steps of the infectious cycle. Here we examine these recent findings, highlight ongoing work, and offer some perspectives for future research.

Quality control of involved field radiotherapy in the HD 13 and HD 14 trials : Report of the radiotherapy panel of the German Hodgkin Study Group (GHSG)

INTRODUCTION

As part of the foundation of the German Hodgkin Study Group (GHSG) in 1978, a central radiotherapy (RT) reference centre was established to evaluate and to improve the quality of treatment. During the study generations, the quality assurance programs (QAP) were continued and adapted to the demands of each study. The purpose of this article is to demonstrate the results of the fifth study generation and to compare them to the previous findings.

METHODS

With the start of the fourth GHSG study generation (HD10-12), a central prospective review of all diagnostic images was established to create an individual treatment plan for each early stage study patient. The quality of involved field RT was retrospectively evaluated by an expert panel of radiation oncologists. In the fifth study generation (HD13-15), the retrospective review of radiotherapy performed was refined and the results were compared with the findings of the fourth generation.

RESULTS

The expert panel analyzed the RT planning and application of 1037 (28 %) patients (HD13 n = 465, HD14 n = 572). Simulation films were available in 85 % of cases and verification films in 87 %. RT was assessed as major violation in 46 % (HD13 = 38 %, HD14 = 52 %), minor violation in 9 % (HD13 = 9 %, HD14 = 9 %) and according to the protocol in 45 % (HD13 = 52 %, HD14 = 38 %).

CONCLUSION

The value for QAP of RT within the GHSG trials is well known. Still there were several protocol violations. In the future, the QAP program has to be adapted to the requirements of "modern RT" in malignant lymphoma.

HCV eradication does not impact gut dysbiosis or systemic inflammation in cirrhotic patients

BACKGROUND

Eradication of hepatitis C virus (HCV) is increasing but its residual impact on the pro-inflammatory milieu in cirrhosis, which is associated with gut dysbiosis, is unclear.

AIM

To define the impact of sustained virological response (SVR) on gut dysbiosis and systemic inflammation in HCV cirrhosis patients.

METHODS

Cirrhotic out-patients with HCV with/without SVR (achieved >1 year prior) and age-matched healthy controls underwent serum and stool collection. Serum was analysed for IL-6, TNF-α and endotoxin while stool microbiota analysis was performed using multitagged pyrosequencing. Microbial comparisons were made using UNIFRAC and cirrhosis dysbiosis ratio (lower score indicates dysbiosis). Comparisons were performed between cirrhotics with/without SVR and controls vs. cirrhotic patients.

RESULTS

A total of 105 HCV cirrhotics and 45 age-matched healthy controls were enrolled. Twenty-one patients had achieved SVR using pegylated interferon + ribavrin a median of 15 months prior. No significant differences on demographics, cirrhosis severity, concomitant medications or diabetes were seen between cirrhotics with/without SVR. There was no significant difference in overall microbiota composition (UNIFRAC P = 0.3) overall or within specific microbial families (cirrhosis dysbiosis ratio median 1.3 vs. 1.0, P = 0.45) between groups with/without SVR. This also extended towards IL-6, TNF-α and endotoxin levels. Both cirrhosis groups, however, had significant dysbiosis compared to healthy controls [UNIFRAC P = 0.01, cirrhosis dysbiosis ratio (1.1 vs. 2.9, P < 0.001)] along with higher levels of endotoxin, IL-6 and TNF-α.

CONCLUSIONS

Gut dysbiosis and a pro-inflammatory systemic milieu, are found in HCV cirrhosis regardless of SVR. This persistent dysbiosis could contribute towards varying rates of improvement after HCV eradication in cirrhosis.

A new fully integrated X-ray irradiator system for dosimetric research

A fully housed X-ray irradiator was developed for use within lexsyg or Magnettech desktop equipment. The importance of hardening of the low energy photon radiation is discussed, its performance and feasibility is empirically shown and sustained by basic numerical simulations. Results of the latter for various materials are given for different X-ray source settings in order to provide estimates on the required setup for the irradiation of different geometries and materials. A Si-photodiode provides real-time monitoring of the X-ray-irradiator designed for use in dosimetric dating and other dosimetric application where irradiation of small samples or dosemeters is required.

Limited Genetic Variability Among American Isolates of Grapevine virus E from Vitis spp

A survey for the presence of Grapevine virus E (GVE, genus Vitivirus, family Betaflexiviridae) in vineyards in New York and California was conducted using macroarray hybridization or reverse-transcription polymerase chain reaction (RT-PCR) assays. In New York, GVE was detected in 10 of 46 vines of Vitis labrusca, one V. riparia, and one Vitis hybrid. All GVE-infected New York vines were coinfected with Grapevine leafroll-associated virus-3. In California, GVE was detected in 8 of 417 vines of V. vinifera. All GVE-infected California vines were also coinfected by one of the leafroll-associated viruses and other vitiviruses. In order to assess the genetic diversity among GVE isolates, a viral cDNA was amplified by RT-PCR, and a 675-nucleotide region that included the 3' terminus of the coat protein gene, a short intergenic region, and the 5' terminus of the putative nucleic acid binding protein gene was sequenced. All 20 GVE isolates sequenced in this study were very closely related, with >98% nucleotide identity to the SA94 isolate from South Africa. These findings confirm the presence of GVE in major grape-growing regions of the United States and indicate a very low level of genetic diversity.

Concordance in the interpretation of PET after chemotherapy in advanced stage Hodgkin lymphoma

The aim was to analyze the degree of agreement between the central review panel and the local PET interpretation within the HD15 trial and its impact on subsequent treatment and progression free survival.

PATIENTS, METHODS

The analysis set consisted of 739 patients with residues ≥ 2.5 cm after 6 or 8 cycles of BEACOPPesc from the HD15 trial performed by the German Hodgkin Study Group. The recommendation for or against further radiotherapy was based on the central [(18)F]FDG-PET interpretation. Central PET interpretation was compared to the local PET interpretation and concordance was measured using Cohen's Kappa coefficient. Prognostic impact of the analysis of concordance between local and central PET interpretations was evaluated using progression free survival (PFS); groups were compared with the log rank test.

RESULTS

The central panel rated 548 of 739 patients (74%) as PET negative. Of these, 513 were also rated as PET negative in the local PET interpretation. PET positivity was seen by central reviewers in the remaining 191 patients (26%), in concordance with local reviewers in 155 cases. Even though substantial agreement was found (Cohen's Kappa 0.81), the interpretation of the central PET review panel led to a different therapeutic recommendation in 71/739 (10%) patients. PFS was equally high in groups in which the therapeutic regime had been changed on the basis of the central panel decision.

CONCLUSION

High concordance is found between local and central reviewers with regard to PET interpretation in residual tissue after intense chemotherapy. The existence of the central PET review panel allows the identification of additional patients as PET negative so that radiotherapy can be safely omitted (35 of 548 patients = 4.7%).

Long-Distance Dispersal Potential for Onion Thrips (Thysanoptera: Thripidae) and Iris yellow spot virus (Bunyaviridae: Tospovirus) in an Onion Ecosystem

Onion thrips, Thrips tabaci Lindeman, is a worldwide pest of onion whose feeding damage and transmission of Iris yellow spot virus (IYSV) may reduce onion yields. Little is known about the seasonal dynamics of T. tabaci dispersal, the distance of dispersal, or the movement of thrips infected with IYSV during the onion-growing season. To address these questions, T. tabaci adults were collected using transparent sticky card traps in commercial onion fields three times during the onion-growing season (June, July, and late August) at varying heights above the canopy (0.5-6 m above soil surface) and with trap-equipped unmanned aircraft (UAVs) flying 50-60 m above onion fields during August sampling periods in 2012 and 2013. Randomly selected subsamples of captured T. tabaci were tested for IYSV using RT-PCR. Most T. tabaci adults were captured in late August and near the onion canopy (<2 m) throughout the season. However, 4% of T. tabaci adults captured on sticky cards were at altitudes ≥2 m, and T. tabaci were also captured on UAV-mounted traps. These data strongly suggest that long-distance dispersal occurs. More T. tabaci captured on sticky cards tested positive for IYSV in August (53.6%) than earlier in the season (2.3 to 21.5% in June and July, respectively), and 20 and 15% of T. tabaci captured on UAV-mounted traps tested positive for IYSV in 2012 and 2013, respectively. Our results indicate that T. tabaci adults, including viruliferous individuals, engage in long-distance dispersal late in the season and likely contribute to the spread of IYSV.

[Intraoperative Evaluation of Total Knee Arthroplasty: Anatomic and Kinematic Assessment with Trial Components]

The intraoperative use of trial components in total knee arthroplasty (TKA) is of paramount importance to prevent inadequate ligament balance and to achieve optimal position of the definitive components. This review demonstrates an 8-step algorithm to assess the anatomy of the femoral, tibial and patellar component as well as the kinematics of the tibiofemoral and patellofemoral joints. Trial components allow an easy assessment of the anatomic fit of the final implants. Upon the trials insertion, bone coverage and the component overhang should be evaluated. The femoral rotation should be assessed using the transepicondylar axis and for the tibial component rotation assessment, the tibial tuberosity would be the most reliable bony landmark. Addressing the patella, sizing and bone coverage should be thoroughly evaluated. In order to restore physiological kinematics the remnants of the meniscus rim can be used to determine the correct reconstruction of the joint line. A tight extension gap results in limited extension, whereas a tight or unbalanced flexion gap leads to "booking" or "spin-out" of the inlay. The POLO test (pull-out, lift- off) allows an easy assessment of the posterior cruciate ligament tension and the size of the flexion gap as well. To prevent postoperative dislocation and overstuffing, specific tests for correct patellar positioning and tracking support should be performed. The anatomy and kinematics of total knee arthroplasty have to be evaluated by trial components on a routine basis before inserting the final implants in order to identify implant positioning errors and inadequate ligament balance.

Nonlinear rheology of glass-forming colloidal dispersions: transient stress-strain relations from anisotropic mode coupling theory and thermosensitive microgels

Transient stress-strain relations close to the colloidal glass transition are obtained within the integration through transients framework generalizing mode coupling theory to flow driven systems. Results from large-scale numerical calculations are quantitatively compared to experiments on thermosensitive microgels, which reveals that theory captures the magnitudes of stresses semi-quantitatively even in the nonlinear regime, but overestimates the characteristic strain where plastic events set in. The former conclusion can also be drawn from flow curves, while the latter conclusion is supported by a comparison to single particle motion measured by confocal microscopy. The qualitative picture, as previously obtained from simplifications of the theory in schematic models, is recovered by the quantitative solutions of the theory for Brownian hard spheres.

[Rehabilitation of patients with acid-base and fluid balance disorders with short bowel syndrome after ileostomies]

BACKGROUND

Patients with ileostomies regularly suffer from short bowel syndrome or high volume output associated with loss of absorptive surface and subsequent impairment of absorption for drugs and different nutrients resulting in electrolyte and fluid balance disorders as well as renal insufficiency. Adaptation of these fundamental functions of the gut with adequate fluid uptake, absorption of sufficient different nutrients and vitamins represents a major challenge to rehabilitate these patients shortly after surgery. Patients with ileostomy often develop metabolic acidosis with normal anion gap. In our retrospective study we would like to draw attention to these metabolic disorders in patients with ileostomy in comparison to patients with colostomy and patients undergoing gastrectomy for gastric cancer.

METHODS

In the period from 2005 to 2012 we examined 164 patients with ileostomy in our rehabilitation clinic, 109 patients with colostomy and 193 patients after surgery for gastric cancer of the possible presence of metabolic acidosis by using capillary blood gas analysis (metabolic acidosis was anticipated, if base excess was ≤- 3,0 mmol/l). Patients are treated as inpatients both in early stage and for follow-up rehabilitation. The length of time in our rehabilitation clinic lies in between 24-28 days. On the basis of random samples we tested blood samples in 19 patients with ileostomy in succession for ferritin, folic acid, zinc, selenium and vitamin B12. Statistical analysis comprised the classical intervals (mean and standard deviation, range and T-test for dependent and independent samples).

RESULTS

In total we tested 164 inpatients with ileostomy in our rehabilitation clinic (median age 67.4 years, range 19-79 years). Surgery for ileostomy took place about 1.4 months on average ago (range ¼-56 months). 60 (36.5%) inpatients suffered from metabolic acidosis often combined with renal insufficiency. Supportive therapy intravenously administered in 10 patients and sodium bicarbonate given by mouth in 40 patients significantly improved metabolic acid (base excess improved on average from -7.2 to -3.2 mmol/l, p<0.00138) and renal function calculated on the basis of serum creatinine (serum creatinine decreased from 1.49 on average to 1.34 mg/dl, p<0.04039). Body weight remained constant over the whole period on average with 74 kg. Diuretics did not show any influence on the base excess. In 19 patients with ileostomy who did not take any kind of supplements, among the parameters tested were a high percentage of zinc (9 of 19 patients, 47%) and selenium deficiency (13 of 19 patients, 68%). 50 patients with ileostomy were younger than 65 years of age and thus in the working age population. In the group of patients after gastrectomy because of gastric cancer (n=193, median age 69.1 years, range 36-82 years), surgery for gastrectomy took place about 1.8 months on average ago and in this group only 14 patients (7%) showed metabolic acidosis. In the group of patients with colostomy (n=109, median age 69.5 years, range 39-82 years), surgery for colostomy took place about 2.1 months on average ago and in this group only 6 patients (5.5%) suffered from metabolic acidosis.

CONCLUSION

Medical rehabilitation is indicated for patients with enterostoma. Acceptance of the enterostoma by the patient himself, psychological stabilization, achievement of self-sufficiency in stoma care, improvement of physical abilities and finally being fit for full or limited employment are the most important objectives in rehabilitation medicine. Metabolic acidosis was often found in patients with ileostomy and was an important clinical appearance. Blood gas analysis is recommended to verify metabolic acidosis and if confirmed sodium bicarbonate and in cases of high volume output salt-depleting ileostomy additionally intravenous fluid support should be offered controlling body weight in the follow-up. As could be shown by our analysis patients with ileostomy should also be tested for zinc and selenium deficiency.

Three-body nature of N(*) and Δ(*) resonances from sequential decay chains

The Nπ^{0}π^{0} decays of positive-parity N^{*} and Δ^{*} resonances at about 2 GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances: Δ(1232), N(1520)3/2^{-}, and N(1680)5/2^{+}, with spin parities J^{P}=3/2^{+}, 3/2^{-}, and 5/2^{+}. The partial wave analysis (within the Bonn-Gatchina approach) identifies N(1440)1/2^{+} and the N(ππ)_{S wave} (abbreviated as Nσ here) as further isobars and assigns the final states to the formation of nucleon and Δ resonances and to nonresonant contributions. We observe the known Δ(1232)π decays of Δ(1910)1/2^{+}, Δ(1920)3/2^{+}, Δ(1905)5/2^{+}, Δ(1950)7/2^{+}, and of the corresponding spin-parity series in the nucleon sector, N(1880)1/2^{+}, N(1900)3/2^{+}, N(2000)5/2^{+}, and N(1990)7/2^{+}. For the nucleon resonances, these decay modes are reported here for the first time. Further new decay modes proceed via N(1440)1/2^{+}π, N(1520)3/2^{-}π, N(1680)5/2^{+}π, and Nσ. The latter decay modes are observed in the decay of N^{*} resonances and at most weakly in Δ^{*} decays. It is argued that these decay modes provide evidence for a 3-quark nature of N^{*} resonances rather than a quark-diquark structure.