Letter to the editor: Pending challenges in passenger contact tracing in air transport – a German perspective

Peer Reviewe

Approaches for the treatment of perforated peptic ulcers : a network meta-analysis of randomised controlled trials - study protocol

Introduction: Perforated peptic ulcers are a life-threatening complication associated with high morbidity and mortality. Several treatment approaches are available. The aim of this network meta-analysis (NMA) is to compare surgical and alternative approaches for the treatment of perforated peptic ulcers regarding mortality and other patient-relevant outcomes. Methods and analysis: A systematic literature search of PubMed/MEDLINE, Cochrane Library, Embase, CINAHL, ClinicalTrials.gov trial registry and ICTRP will be conducted with predefined search terms. To address the question of the most effective treatment approach, an NMA will be performed for each of the outcomes mentioned above. A closed network of interventions is expected. The standardised mean difference with its 95% CI will be used as the effect measure for the continuous outcomes, and the ORs with 95% CI will be calculated for the binary outcomes. Ethics and dissemination: In accordance with the nature of the data used in this meta-analysis, which involves aggregate information from previously published studies ethical approval is deemed unnecessary. Results will be disseminated directly to decision-makers (eg, surgeons, gastroenterologists) through publication in peer-reviewed journals and presentation at conferences

Whole brain radiation therapy alone versus radiosurgery for patients with 1–10 brain metastases from small cell lung cancer (ENCEPHALON Trial): study protocol for a randomized controlled trial

Background: Conventional whole brain radiotherapy (WBRT) has been established as the treatment standard in patients with cerebral metastases from small-cell lung cancer (SCLC), however, it has only modest efficacy and limited prospective data is available for WBRT as well as local treatments such as stereotactic radiosurgery (SRS). Methods/design: The present single-center prospective randomized study, conducted at Heidelberg University Hospital, compares neurocognitive function, as objectively measured by significant deterioration in Hopkins Verbal Learning Test – Revised total recall at 3 months. Fifty-six patients will be randomized to receive either SRS of all brain metastases (up to ten lesions) or WBRT. Secondary endpoints include intracranial progression (local tumor progression and number of new cerebral metastases), extracranial progression, overall survival, death due to brain metastases, local (neurological) progression-free survival, progression-free survival, changes in other cognitive performance measures, quality of life and toxicity. Discussion: Recent evidence suggests that SRS might be a promising treatment option for SCLC patients with brain metastases. The present trial is the first to prospectively investigate the treatment response, toxicity and neurocognition of WBRT and SRS in SCLC patients. Trial registration: Clinicaltrials.gov NCT03297788 . Registered September 29, 2017

Simultaneous Operation of Three Laser Systems at the FLASH Photoinjector

The free-electron laser facility FLASH at DESY (Hamburg,Germany) operates two undulator beamlines simultaneously. Both undulator beamlines are driven by a common linear superconducting accelerator with a beam energy of up to 1.25 GeV. The superconducting technology allows the acceleration of trains of several hundred micro second spaced bunches with a repetition rate of 10 Hz. A fastkickers-septum system is installed to distribute one part ofthe electron bunch train to FLASH1 and the other part to FLASH2 keeping the full 10 Hz repetition rate for both beamlines. In order to deliver different beam properties to each beamline, the FLASH photoinjector uses two independent laser systems to generate different bunch pattern and bunch charges. One laser serves the FLASH1 beamline, the other the FLASH2 beamline. A third laser with adjustable laser pulse duration is used to generate ultra-short bunches for single spike lasing

FLASH Photoinjector Laser Systems

The free-electron laser facility FLASH at DESY (Hamburg, Germany) operates two undulator beamlines simultaneously for FEL operation and a third for plasma acceleration experiments (FLASHForward). The L-band superconducting technology allows accelerating fields of up to 0.8 ms in length at a repetition rate of 10 Hz (burst mode). A fast kicker-septum system picks one part of the 1 MHz electron bunch train and kicks it to the second beamline such that two beamlines are operated simultaneously with the full repetition rate of 10 Hz. The photoinjector operates three laser systems. They have different pulse durations and transverse shapes and are chosen to serve best for the given user experiment in terms of electron bunch charge, bunch compression, and bunch pattern. It is also possible to operate the laser systems on the same beamline to provide specific double pulses for certain type of experiments