A new shielding effectiveness measurement method based on a skin-effect transmission line coupler

We propose a new convenient material shielding effectiveness measurement method based on a skin-effect transmission line coupler. The method is somewhat similar to the arrangement with two coupled TEM cells known from literature. The transmission line coupler consists of a pair of identical transmission line 2-port devices. Each device contains a coaxial waveguide, with a circular inner conductor and an outer conductor having a square cross section. One side of the outer conductor is left completely open as a slot. The slot is surrounded by a large metal housing to contact the two halves. As a measure for the shielding effectiveness the coupling between the two devices is measured in terms of scattering parameters after the test material is brought between the two halves. The devices can be used in a range from low frequencies to a few GHz

Measured Response of Local, Mid-range and Far-range Discontinuities of Large Metal Groundplanes using Time Domain Techniques

This work describes a method to detect and to quantify any local or mid-range discontinuity on extended flat metal planes. Often these planes are used for antenna calibration (open area test site-OATS) or the plane could be the ground of a semi-anechoic chamber used in Electromagnetic Compatibility (EMC) testing. The measurement uncertainty of antenna calibration or EMC testing depends on the groundplane's quality, which can be accessed using this method. A vector network analyzer with time-domain option is used to determine the complex-valued input scattering parameter S̄11,F of an aperture antenna in a monostatic setup. S̄11,F contains the information desired about the discontinuities and is measured in the frequency domain with high dynamic range. But only after a linear filtering utilizing the Chirp-Z-Transform the obtained time-domain signal S̄11,T give clear evidence of local and mid-range discontinuities

Synergistic and Additive Effects of Epigallocatechin Gallate and Digitonin on Plasmodium Sporozoite Survival and Motility

BACKGROUND: Most medicinal plants contain a mixture of bioactive compounds, including chemicals that interact with intracellular targets and others that can act as adjuvants to facilitate absorption of polar agents across cellular membranes. However, little is known about synergistic effects between such potential drug candidates and adjuvants. To probe for such effects, we tested the green tea compound epigallocatechin gallate (EGCG) and the membrane permeabilising digitonin on Plasmodium sporozoite motility and viability. METHODOLOGY/PRINCIPAL FINDINGS: Green fluorescent P. berghei sporozoites were imaged using a recently developed visual screening methodology. Motility and viability parameters were automatically analyzed and IC50 values were calculated, and the synergism of drug and adjuvant was assessed by the fractional inhibitory concentration index. Validating our visual screening procedure, we showed that sporozoite motility and liver cell infection is inhibited by EGCG at nontoxic concentrations. Digitonin synergistically increases the cytotoxicity of EGCG on sporozoite survival, but shows an additive effect on sporozoite motility. CONCLUSIONS/SIGNIFICANCE: We proved the feasibility of performing highly reliable visual screens for compounds against Plasmodium sporozoites. We thereby could show an advantage of administering mixtures of plant metabolites on inhibition of cell motility and survival. Although the effective concentration of both drugs is too high for use in malaria prophylaxis, the demonstration of a synergistic effect between two plant compounds could lead to new avenues in drug discovery

Airborne field strength monitoring

In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper

Evaluation of Measurement Uncertainty of Radiated EMC Tests in Arbitrary Field Generators using Surface Currents on DUT

We present a method for the evaluation of measurement uncertainty in radiated EMC tests. It is based on the measurement of surface current densities on a sphere, the results are compared to the surface current distribution on a sphere in a free-space environment obtained by numerical calculations. The free-space is considered to be a reference field generator. By this method we avoid burdening any systematic deviations of one particular (historic) method to any of the others. We evaluate the ratio J/E of the measured surface current density J and the measured empty electrical field strength E for both the reverberation chamber and the semi-anechoic chamber

Raster-scanned carbon ion therapy for malignant salivary gland tumors: acute toxicity and initial treatment response

<p>Abstract</p> <p>Background and purpose</p> <p>To investigate toxicity and efficacy in high-risk malignant salivary gland tumors (MSGT) of the head and neck. Local control in R2-resected adenoid cystic carcinoma was already improved with a combination of IMRT and carbon ion boost at only mild side-effects, hence this treatment was also offered to patients with MSGT and microscopic residual disease (R1) or perineural spread (Pn+).</p> <p>Methods</p> <p>From November 2009, all patients with MSGT treated with carbon ion therapy were evaluated. Acute side effects were scored according to CTCAE v.4.03. Tumor response was assessed according to RECIST where applicable.</p> <p>Results</p> <p>103 patients were treated from 11/2009 to 03/2011, median follow-up is 6 months. 60 pts received treatment following R2 resections or as definitive radiation, 43 patients received adjuvant radiation for R1 and/or Pn+. 16 patients received carbon ion treatment for re-irradiation. Median total dose was 73.2 GyE (23.9 GyE carbon ions + 49,9 Gy IMRT) for primary treatment and 44.9 GyE carbon ions for re-irradiation. All treatments were completed as planned and generally well tolerated with no > CTC°III toxicity. Rates of CTC°III toxicity (mucositis and dysphagia) were 8.7% with side-effects almost completely resolved at first follow-up.</p> <p>47 patients showed good treatment responses (CR/PR) according to RECIST.</p> <p>Conclusion</p> <p>Acute toxicity remains low in IMRT with carbon ion boost also in R1-resected patients and patients undergoing re-irradiation. R2-resected patients showed high rates of treatment response, though follow-up is too short to assess long-term disease control.</p

Randomised trial of proton vs. carbon ion radiation therapy in patients with chordoma of the skull base, clinical phase III study HIT-1-Study

<p>Abstract</p> <p>Background</p> <p>Chordomas of the skull base are relative rare lesions of the bones. Surgical resection is the primary treatment standard, though complete resection is nearly impossible due to close proximity to critical and hence also dose limiting organs for radiation therapy. Level of recurrence after surgery alone is comparatively high, so adjuvant radiation therapy is very important for the improvement of local control rates. Proton therapy is the gold standard in the treatment of skull base chordomas. However, high-LET beams such as carbon ions theoretically offer biologic advantages by enhanced biologic effectiveness in slow-growing tumors.</p> <p>Methods/design</p> <p>This clinical study is a prospective randomised phase III trial. The trial will be carried out at Heidelberger Ionenstrahl-Therapie centre (HIT) and is a monocentric study.</p> <p>Patients with skull base chordoma will be randomised to either proton or carbon ion radiation therapy. As a standard, patients will undergo non-invasive, rigid immobilization and target volume delineation will be carried out based on CT and MRI data. The biologically isoeffective target dose to the PTV in carbon ion treatment (accelerated dose) will be 63 Gy E ± 5% and 72 Gy E ± 5% (standard dose) in proton therapy respectively. Local-progression free survival (LPFS) will be analysed as primary end point. Toxicity and overall survival are the secondary end points. Additional examined parameters are patterns of recurrence, prognostic factors and plan quality analysis.</p> <p>Discussion</p> <p>Up until now it was impossible to compare two different particle therapies, i.e. protons and carbon ions directly at the same facility.</p> <p>The aim of this study is to find out, whether the biological advantages of carbon ion therapy can also be clinically confirmed and translated into the better local control rates in the treatment of skull base chordomas.</p> <p>Trial registration</p> <p>ClinicalTrials.gov identifier: NCT01182779</p

Sequential FDG-PET and induction chemotherapy in locally advanced adenocarcinoma of the Oesophago-gastric junction (AEG): The Heidelberg Imaging program in Cancer of the oesophago-gastric junction during Neoadjuvant treatment: HICON trial

<p>Abstract</p> <p>Background</p> <p>18-Fluorodeoxyglucose-PET (¹⁸F-FDG-PET) can be used for early response assessment in patients with locally advanced adenocarcinomas of the oesophagogastric junction (AEG) undergoing neoadjuvant chemotherapy. It has been recently shown in the MUNICON trials that response-guided treatment algorithms based on early changes of the FDG tumor uptake detected by PET are feasible and that they can be implemented into clinical practice.</p> <p>Only 40%-50% of the patients respond metabolically to therapy. As metabolic non-response is known to be associated with a dismal prognosis, metabolic non-responders are increasingly treated with alternative neoadjuvant chemotherapies or chemoradiation in order to improve their clinical outcome. We plan to investigate whether PET can be used as response assessment during radiochemotherapy given as salvage treatment in early metabolic non-responders to standard chemotherapy.</p> <p>Methods/Design</p> <p>The HICON trial is a prospective, non-randomized, explorative imaging study evaluating the value of PET as a predictor of histopathological response in metabolic non-responders. Patients with resectable AEG type I and II according to Siewerts classification, staged cT3/4 and/or cN+ and cM0 by endoscopic ultrasound, spiral CT or MRI and FDG-PET are eligible. Tumors must be potentially R0 resectable and must have a sufficient FDG-baseline uptake. Only metabolic non-responders, showing a < 35% decrease of SUV two weeks after the start of neoadjuvant chemotherapy are eligible for the study and are taken to intensified taxane-based RCT (chemoradiotherapy (45 Gy) before surgery. ¹⁸FDG-PET scans will be performed before ( = Baseline) and after 14 days of standard neoadjuvant therapy as well as after the first cycle of salvage docetaxel/cisplatin chemotherapy (PET 1) and at the end of radiochemotherapy (PET2). Tracer uptake will be assessed semiquantitatively using standardized uptake values (SUV). The percentage difference ΔSUV = 100 (SUV_Baseline- SUV _PET1)/SUV_Baselinewill be calculated and assessed as an early predictor of histopathological response. In a secondary analysis, the association between the difference SUV_PET1- SUV_PET2and histopathological response will be evaluated.</p> <p>Discussion</p> <p>The aim of this study is to investigate the potential of sequential ¹⁸FDG-PET in predicting histopathological response in AEG tumors to salvage neoadjuvant radiochemotherapy in patients who do not show metabolic response to standard neoadjuvant chemotherapy.</p> <p>Trial Registration</p> <p>Clinical trial identifier <a href="http://www.clinicaltrials.gov/ct2/show/NCT01271322">NCT01271322</a></p

Carbon ion therapy for ameloblastic carcinoma

Ameloblastic carcinomas are rare odontogenic tumors. Treatment usually consists of surgical resection and sometimes adjuvant radiation. We report the case of a 71 year-old male patient undergoing carbon ion therapy for extensive local relapse of ameloblastic carcinoma. Treatment outcome was favourable with a complete remission at 6 weeks post completion of radiotherapy while RT-treatment itself was tolerated well with only mild side effects. High dose radiation hence is a potential alternative for patients unfit or unwilling to undergo extensive surgery or in cases when only a subtotal resection is planned or the resection is mutilating

Treatment of non-small cell lung cancer with intensity-modulated radiation therapy in combination with cetuximab: the NEAR protocol (NCT00115518)

BACKGROUND: Even today, treatment of Stage III NSCLC still poses a serious challenge. So far, surgical resection is the treatment of choice. Patients whose tumour is not resectable or who are unfit to undergo surgery are usually referred to a combined radio-chemotherapy. However, combined radio-chemotherapeutic treatment is also associated with sometimes marked side effects but has been shown to be more efficient than radiation therapy alone. Nevertheless, there is a significant subset of patients whose overall condition does not permit administration of chemotherapy in a combined-modality treatment. It could be demonstrated though, that NSCLCs often exhibit over-expression of EGF-receptors hence providing an excellent target for the monoclonal EGFR-antagonist cetuximab (Erbitux(®)) which has already been shown to be effective in colorectal as well as head-and-neck tumours with comparatively mild side-effects. METHODS/DESIGN: The NEAR trial is a prospective phase II feasibility study combining a monoclonal EGF-receptor antibody with loco-regional irradiation in patients with stage III NSCLC. This trial aims at testing the combination's efficacy and rate of development of distant metastases with an accrual of 30 patients. Patients receive weekly infusions of cetuximab (Erbitux(®)) plus loco-regional radiation therapy as intensity-modulated radiation therapy. After conclusion of radiation treatment patients continue to receive weekly cetuximab for 13 more cycles. DISCUSSION: The primary objective of the NEAR trial is to evaluate toxicities and feasibility of the combined treatment with cetuximab (Erbitux(®)) and IMRT loco-regional irradiation. Secondary objectives are remission rates, 3-year-survival and local/systemic progression-free survival