Transverse emittance growth of proton sources from laser-irradiated sub-μm-thin planar targets

Proton bunches with maximum energies between 12 and 22 MeV were emitted from submicrometer-thin plastic foils upon irradiation by laser pulses with peak intensity of 4×10^{20}W/cm^{2}. The images of the protons by a magnetic quadrupole doublet on a screen remained consistently larger by a factor of 10 compared to expectations drawn from the ultralow transverse emittance values reported for thick foil targets. Analytic estimates and particle-in-cell simulations attribute this drastically increased emittance to formerly excluded Coulomb collisions between charged particles. The presence of carbon ions and significant transparency likely play a decisive role. This observation is highly relevant because such thin, partially transparent foils are considered ideal for optimizing maximum proton energies.

Breast cancer therapy in women under 35 years and between 50 and 69 years: influence of the observation period

PURPOSE

In recent years, therapeutic strategies based on tumour biology have increased significantly. We aimed to provide an overview of the recent changes in patient characteristics, treatment procedures and survival factors for two groups of patients: women younger than 35 years and women between 50 and 69 years.

METHODS

We used data from the population-based Cancer Registry Magdeburg. Subjects included women with non-metastatic breast cancer treated between 2000 and 2015. We compared between two observation periods: 2000-2007 and 2008-2015.

RESULTS

There was an increase in patient survival from the first to the second observation period. Tumour characteristics and treatment modalities changed, especially in the group of older patients. The proportion of prognostically more favourable tumour subtypes, such as Luminal A, increased significantly. Between 2008 and 2015, there were more hormone receptor-positive, lymph-node-negative, human epidermal growth factor receptor-2 (HER2)-negative and well-differentiated tumours. Surgical methods were associated with significantly reduced radicality, while the rate of neoadjuvant therapy increased in both groups. There was a decrease in cyclophosphamide, methotrexate and 5-fluoruracil (CMF) and anthracycline therapies, but taxane-containing chemotherapy increased. While tamoxifen was used more frequently in younger patients in the later observation period, its use was reduced in older patients, superseded by aromatase inhibitors. Furthermore, the use of immune therapy increased.

CONCLUSION

In both age groups, but primarily in older patients, there were significant changes in tumour biology and treatment options between the two observation periods. These changes have led to a continuous improvement in patient outcomes.

Water in the terrestrial planet-forming zone of the PDS 70 disk

Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 AU) regions of protoplanetary disks1. Water plays a key role in their formation2-4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk5,6. So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks7, similar to PDS 70, the first system with direct confirmation of protoplanet presence8,9. Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large (approximately 54 AU) planet-carved gap separating an inner and outer disk10,11. Our findings show water in the inner disk of PDS 70. This implies that potential terrestrial planets forming therein have access to a water reservoir. The column densities of water vapour suggest in-situ formation via a reaction sequence involving O, H2 and/or OH, and survival through water self-shielding5. This is also supported by the presence of CO2 emission, another molecule sensitive to ultraviolet photodissociation. Dust shielding, and replenishment of both gas and small dust from the outer disk, may also play a role in sustaining the water reservoir12. Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.

Occupational Therapy Practitioners' Implementation of Home Programs for Individuals Post Burn: An Initial Cross-Sectional Survey

Occupational therapy practitioners who care for individuals post burn often prescribe home programs to facilitate continued progress toward occupational therapy goals. This study identified the components included in home programs, how practitioners create and prescribe home programs, and perceived supports and barriers to adherence in this population. Thirty-nine practitioners employed at American Burn Association-verified centers completed an online survey. Results suggest that home programs are primarily designed to address range of motion with less emphasis on function. The highest-ranked barriers to adherence were pain and lack of motivation while the highest-ranked supports were client motivation and family/caregiver support. Practitioners reported using handouts and demonstration frequently for delivery, with infrequent use of technology. Recommendations for incorporating evidence-based strategies into home program creation and administration are included.

Measuring spatio-temporal couplings using modal spatio-spectral wavefront retrieval

Knowledge of spatio-temporal couplings such as pulse-front tilt or curvature is important to determine the focused intensity of high-power lasers. Common techniques to diagnose these couplings are either qualitative or require hundreds of measurements. Here we present both a new algorithm for retrieving spatio-temporal couplings, as well as novel experimental implementations. Our method is based on the expression of the spatio-spectral phase in terms of a Zernike-Taylor basis, allowing us to directly quantify the coefficients for common spatio-temporal couplings. We take advantage of this method to perform quantitative measurements using a simple experimental setup, consisting of different bandpass filters in front of a Shack-Hartmann wavefront sensor. This fast acquisition of laser couplings using narrowband filters, abbreviated FALCON, is easy and cheap to implement in existing facilities. To this end, we present a measurement of spatio-temporal couplings at the ATLAS-3000 petawatt laser using our technique.

The role of collisional ionization in heavy ion acceleration by high intensity laser pulses

We present here simulation results of the laser-driven acceleration of gold ions using the EPOCH code. Recently, an experiment reported the acceleration of gold ions up to 7 MeV/nucleon with a strong dependency of the charge-state distribution on target thickness and the detection of the highest charge states [Formula: see text]. Our simulations using a developmental branch of EPOCH (4.18-Ionization) show that collisional ionization is the most important cause of charge states beyond Z = 51 up to He-like Au.

Healthcare utilisation and unmet health needs in children with intellectual disability: a propensity score matching approach using longitudinal cohort data

BACKGROUND

Health disparities for children with intellectual disabilities can be challenging to measure due to many other factors that can impact health and healthcare use. The aim of the current study was to use longitudinal cohort data to compare children with intellectual disability (ID) in Ireland between 2006 and 2014 on healthcare utilisation and unmet need, at ages 9 and 13, using a propensity score matching (PSM) approach.

METHODS

Using data from the Growing up in Ireland study, PSM was used to identify an appropriate control sample to compare with a sample of children with ID (n = 124). Participants were matched on variables that are known to influence healthcare utilisation to reduce the impact of confounding variables between groups so that differences between the groups can be estimated. Logistic regression was used to estimate effects at ages 9 and 13.

RESULTS

Children with ID were no more likely to have visited a general practitioner or emergency department in the past 12 months than children without ID. They did have a greater likelihood of visiting a doctor in a hospital in the past 12 months and of having an overnight stay in hospital by age 9. Primary caregivers of children with ID were more likely to report unmet health needs at ages 9 and 13.

CONCLUSIONS

This approach is a novel means of comparing healthcare use in this population by balancing the impact of other factors that may result in inequities, to which children with ID may be more vulnerable.

Charge-state resolved laser acceleration of gold ions to beyond 7 MeV/u

In the past years, the interest in the laser-driven acceleration of heavy ions in the mass range of $$\text {A}\approx 200$$ A ≈ 200 has been increasing due to promising application ideas like the fission-fusion nuclear reaction mechanism, aiming at the production of neutron-rich isotopes relevant for the astrophysical r-process nucleosynthesis. In this paper, we report on the laser acceleration of gold ions to beyond 7 MeV/u, exceeding for the first time an important prerequisite for this nuclear reaction scheme. Moreover, the gold ion charge states have been detected with an unprecedented resolution, which enables the separation of individual charge states up to 4 MeV/u. The recorded charge-state distributions show a remarkable dependency on the target foil thickness and differ from simulations, lacking a straight-forward explanation by the established ionization models.

Geant4 Monte Carlo simulation study of the secondary radiation fields at the laser-driven ion source LION

At the Center for Advanced Laser Applications (CALA), Garching, Germany, the LION (Laser-driven ION Acceleration) experiment is being commissioned, aiming at the production of laser-driven bunches of protons and light ions with multi-MeV energies and repetition frequency up to 1 Hz. A Geant4 Monte Carlo-based study of the secondary neutron and photon fields expected during LION's different commissioning phases is presented. Goal of this study is the characterization of the secondary radiation environment present inside and outside the LION cave. Three different primary proton spectra, taken from experimental results reported in the literature and representative of three different future stages of the LION's commissioning path are used. Together with protons, also electrons are emitted through laser-target interaction and are also responsible for the production of secondary radiation. For the electron component of the three source terms, a simplified exponential model is used. Moreover, in order to reduce the simulation complexity, a two-components simplified geometrical model of proton and electron sources is proposed. It has been found that the radiation environment inside the experimental cave is either dominated by photons or neutrons depending on the position in the room and the source term used. The higher the intensity of the source, the higher the neutron contribution to the total dose for all scored positions. Maximum neutron and photon ambient dose equivalent values normalized to 109 simulated incident primaries were calculated at the exit of the vacuum chamber, where values of about 85 nSv (109 primaries)-1 and 1.0 μSv (109 primaries)-1 were found.

Real-Time Electron Solvation Induced by Bursts of Laser-Accelerated Protons in Liquid Water

Understanding the mechanisms of proton energy deposition in matter and subsequent damage formation is fundamental to radiation science. Here we exploit the picosecond (10^{-12}  s) resolution of laser-driven accelerators to track ultrafast solvation dynamics for electrons due to proton radiolysis in liquid water (H_{2}O). Comparing these results with modeling that assumes initial conditions similar to those found in photolysis reveals that solvation time due to protons is extended by >20  ps. Supported by magnetohydrodynamic theory this indicates a highly dynamic phase in the immediate aftermath of the proton interaction that is not accounted for in current models.

Laser-driven x-ray and proton micro-source and application to simultaneous single-shot bi-modal radiographic imaging

Radiographic imaging with x-rays and protons is an omnipresent tool in basic research and applications in industry, material science and medical diagnostics. The information contained in both modalities can often be valuable in principle, but difficult to access simultaneously. Laser-driven solid-density plasma-sources deliver both kinds of radiation, but mostly single modalities have been explored for applications. Their potential for bi-modal radiographic imaging has never been fully realized, due to problems in generating appropriate sources and separating image modalities. Here, we report on the generation of proton and x-ray micro-sources in laser-plasma interactions of the focused Texas Petawatt laser with solid-density, micrometer-sized tungsten needles. We apply them for bi-modal radiographic imaging of biological and technological objects in a single laser shot. Thereby, advantages of laser-driven sources could be enriched beyond their small footprint by embracing their additional unique properties, including the spectral bandwidth, small source size and multi-mode emission.

Here the authors show a synchronized single-shot bi-modal x-ray and proton source based on laser-generated plasma. This source can be useful for radiographic and tomographic imaging.

Radiation protection modelling for 2.5 Petawatt-laser production of ultrashort x-ray, proton and ion bunches: Monte Carlo model of the Munich CALA facility

The 'Centre for Advanced Laser Applications' (CALA) is a new research institute for laser-based acceleration of electron beams for brilliant x-ray generation, laser-driven sub-nanosecond bunches of protons and heavy ions for biomedical applications like imaging and tumour therapy as well as for nuclear and high-field physics.The radiation sources emerging from experiments using the up to 2.5 petawatt laser pulses with 25 femtosecond duration will be mixed particle-species of high intensity, high energy and pulsed, thus posing new challenges compared to conventional radiation protection. Such worldwide pioneering laser experiments result in source characteristics that require careful a-priori radiation safety simulations.The FLUKA Monte-Carlo code was used to model the five CALA experimental caves, including the corridors, halls and air spaces surrounding the caves. Beams of electrons (<5 GeV), protons (<200 MeV),¹²C (<400MeV/u) and¹⁹⁷Au (<10MeV/u) ions were simulated using spectra, divergences and bunch-charges based on expectations from recent scientific progress.Simulated dose rates locally can exceed 1.5 kSv h^-1inside beam dumps. Vacuum pipes in the cave walls for laser transport and extraction channels for the generated x-rays result in small dose leakage to neighboring areas. Secondary neutrons contribute to most of the prompt dose rate outside caves into which the beam is delivered. This secondary radiation component causes non-negligible dose rates to occur behind walls to which large fluences of secondary particles are directed.By employing adequate beam dumps matched to beam-divergence, magnets, passive shielding and laser pulse repetition limits, average dose rates in- and outside the experimental building stay below design specifications (<0.5μSv h-1) for unclassified areas,<2.5μSv h-1for supervised areas,<7.5μSv h-1maximum local dose rate) and regulatory limits (<1mSv a-1for unclassified areas).

[Studies on Factors Influencing Influenza Vaccination Rates in Patients with Chronic Obstructive Pulmonary Disease]

BACKGROUND : With low influenza vaccination rates among the chronically ill, approaches to increase these rates among risk patients with chronic obstructive pulmonary disease (COPD) are to be uncovered. METHODS : 120 COPD patients from Magdeburg filled out a questionnaire and were analyzed regarding the influenza vaccination status 2015/2016 or 2016/2017. Vaccinated and unvaccinated were compared in socio-epidemiological factors, the health belief model (HBM), self-efficacy (GESIS-ASKU), anxiety/depression (HADS-D) and disease processing (FKV-LIS). RESULTS : 62.5 % (n = 75) were vaccinated, 31.7 % (n = 38) unvaccinated, 5.8 % (n = 7) made no statement. In over or equal to 60-year-olds 76 % were vaccinated, in under 60-year-olds 42 % were vaccinated. 60 % (n = 72) knew to belong to a risk group. Unvaccinated indicated greater concern about side effects of the vaccination (p = .004) and drew a worse benefit-expense balance (p = .001). Unvaccinated were more often uncertain about the vaccination protection and the severity of influenza (p ≤ .001). Vaccinated were highly motivated to think about vaccination themselves and more often had a positive vaccination history (p = .001). COPD patients showed a lower self-efficacy than the reference group of the German general population (p = .000), vaccinated and unvaccinated did not differ (p = .418). No difference between vaccinated and unvaccinated was found in the processing of the disease and in depression and anxiety, but unvaccinated tended to give higher anxiety values. CONCLUSION : Measures should particularly target COPD patients under 60 years of age with a negative vaccination history and sensitize them as risk patients. Widespread uncertainties about the severity of influenza and vaccination protection should be addressed. It should be communicated that influenza vaccination does not lead to exacerbation. The vaccination recommendation should increasingly be made by pulmonologists.

[Operability and Pathological Response of Non-Small Cell Lung Cancer (NSCLC) after Neoadjuvant Therapy with Immune Checkpoint Inhibition]

BACKGROUND

 The blockade of immune escape mechanisms (e. g. PD1 /PD-L1) using immune checkpoint inhibition (ICI) can significantly prolong survival and induce remission in patients with advanced non-small cell lung cancer (NSCLC). Less is known about neoadjuvant ICI in patients with resectable (UICC stage III) or oligometastatic (UICC stage IVa) NSCLC.

METHODS

 Tissue biopsies from patients with advanced or oligometastatic NSCLC were screened for PD-L1 expression. In case of PD-L1-expression > 50 %, ECOG status of 0 or 1 and expected operability, patients received ICI. After about four weeks, patients underwent thoracic surgical resection. In all patients, a complete staging, including PET-CT, cMRI, and endobronchial ultrasound, was performed. The tolerability, the radiological and the histopathological tumor response as well as the surgical and oncological outcomes were analyzed.

FINDINGS

 Four patients (2 male, 2 female, age 56 - 78 years, n = 3 adenocarcinoma, n = 1 squamous cell carcinoma) with local advanced tumors received ICI before surgical resection. In three cases the mediastinal lymph nodes were positive. One patient had a single cerebral metastasis which was treated with radiotherapy. All four patients underwent therapy with two to six cycles of ICI (3 × pembrolizumab, 1 × atezolizumab) without any complication, and ICI did not delay the time of surgical resection. According to iRECIST, three patients showed partial response (PR), one patient had stable disease (SD). All tumors were completely resected. The thoracic surgical procedures proved to be technically unproblematic despite inflammatory changes. There were neither treatment-related deaths nor perioperative complications. In the resectates, complete pathological response (CPR, regression grade III ) and regression grade IIb were detected twice. The average time of follow-up was 12 (1 - 24) months. Patients with PPR developed distant metastasis after six months or a local recurrence after four months. The CPR patient is relapse free to date.

CONCLUSION

 In selected patients, neoadjuvant therapy with ICI is well tolerated and can induce a complete remission of the tumor. Treatment with ICI has no negative impact on the surgical procedure. Prognosis seems to be promising in CPR and limited in PPR.

A Monte Carlo feasibility study on quantitative laser-driven proton radiography

Laser-accelerated proton bunches with kinetic energies up to several tens of MeV and at repetition rates in the order of Hz are nowadays achievable at several research centres housing high-power laser system. The unique features of such ultra-short bunches are also arousing interest in the field of radiological and biomedical applications. For many of these applications, accurate positioning of the biological target is crucial, raising the need for on-site imaging. One convenient option is proton radiography, which can exploit the polyenergetic spectrum of laser-accelerated proton bunches. We present a Monte Carlo (MC) feasibility study to assess the applicability and potential of laser-driven proton radiography of millimetre to centimetre sized objects. Our radiography setup consists of a thin time-of-flight spectrometer operated in transmission prior to the object and a pixelated silicon detector for imaging. Proton bunches with kinetic energies up to 20MeV and up to 100MeV were investigated. The water equivalent thickness (WET) of the traversed material is calculated from the energy deposition inside an imaging detector, using an online generated calibration curve that is based on a MC generated look-up table and the reconstructed proton energy distribution. With a dose of 43mGy for a 1mm thin object imaged with protons up to 20MeV, the reconstructed WET of defined regions-of-interest was within 1.5% of the ground truth values. The spatial resolution, which strongly depends on the gap between object and imaging detector, was 2.5lpmm^-1 for a realistic distance of 5mm. Due to this relatively high imaging dose, our proposed setup for laser-driven proton radiography is currently limited to objects with low radio-sensitivity, but possibilities for further dose reduction are presented and discussed.

A feasibility study of zebrafish embryo irradiation with laser-accelerated protons

The development from single shot basic laser plasma interaction research toward experiments in which repetition rated laser-driven ion sources can be applied requires technological improvements. For example, in the case of radio-biological experiments, irradiation duration and reproducible controlled conditions are important for performing studies with a large number of samples. We present important technological advancements of recent years at the ATLAS 300 laser in Garching near Munich since our last radiation biology experiment. Improvements range from target positioning over proton transport and diagnostics to specimen handling. Exemplarily, we show the current capabilities by performing an application oriented experiment employing the zebrafish embryo model as a living vertebrate organism for laser-driven proton irradiation. The size, intensity, and energy of the laser-driven proton bunches resulted in evaluable partial body changes in the small (<1 mm) embryos, confirming the feasibility of the experimental system. The outcomes of this first study show both the appropriateness of the current capabilities and the required improvements of our laser-driven proton source for in vivo biological experiments, in particular the need for accurate, spatially resolved single bunch dosimetry and image guidance.

Towards a novel small animal proton irradiation platform: the SIRMIO project

Background: Precision small animal radiotherapy research is a young emerging field aiming to provide new experimental insights into tumor and normal tissue models in different microenvironments, to unravel complex mechanisms of radiation damage in target and non-target tissues and assess efficacy of novel therapeutic strategies. For photon therapy, modern small animal radiotherapy research platforms have been developed over the last years and are meanwhile commercially available. Conversely, for proton therapy, which holds potential for an even superior outcome than photon therapy, no commercial system exists yet. Material and methods: The project SIRMIO (Small Animal Proton Irradiator for Research in Molecular Image-guided Radiation-Oncology) aims at realizing and demonstrating an innovative portable prototype system for precision image-guided small animal proton irradiation, suitable for installation at existing clinical treatment facilities. The proposed design combines precise dose application with in situ multi-modal anatomical image guidance and in vivo verification of the actual treatment delivery. Results and conclusions: This manuscript describes the status of the different components under development, featuring a dedicated beamline for degradation and focusing of clinical proton beams, along with novel detector systems for in situimaging and range verification. The foreseen workflow includes pre-treatment proton transmission imaging, complemented by ultrasonic tumor localization, for treatment planning and position verification, followed by image-guided delivery with on site range verification by means of ionoacoustics (for pulsed beams) and positron-emission-tomography (PET, for continuous beams). The proposed compact and cost-effective system promises to open a new era in small animal proton therapy research, contributing to the basic understanding of in vivo radiation action to identify areas of potential breakthroughs for future translation into innovative clinical strategies.

[Lung involvement in hematologic systemic diseases]

Pulmonary diseases can occur across the entire disease spectrum of malignant hematologic systemic diseases. Although infectious processes of the lungs are common in these immunosuppressed patient collectives, noninfectious causes account for up to half of the pulmonary manifestations found in hematologic malignancies. Besides the frequent infections including opportunistic pathogens, a broad differential diagnosis including drug-induced lung injury by cytostatic substances, cytokines, and innovative immunotherapeutic agents, rarer transfusion of blood products and intrathoracic manifestations of the hematologic malignancy itself, have to be kept in mind. Finally, vascular complications can also lead to pulmonary reactions. Early and consistent diagnostics and treatment of the bronchopulmonary, intrathoracic and vascular complications within the framwework of hematologic systemic diseases can be essential for the patient's prognosis.

Temporally Resolved Intensity Contouring (TRIC) for characterization of the absolute spatio-temporal intensity distribution of a relativistic, femtosecond laser pulse

Today’s high-power laser systems are capable of reaching photon intensities up to 10²² W cm⁻², generating plasmas when interacting with material. The high intensity and ultrashort laser pulse duration (fs) make direct observation of plasma dynamics a challenging task. In the field of laser-plasma physics and especially for the acceleration of ions, the spatio-temporal intensity distribution is one of the most critical aspects. We describe a novel method based on a single-shot (i.e. single laser pulse) chirped probing scheme, taking nine sequential frames at frame rates up to THz. This technique, to which we refer as temporally resolved intensity contouring (TRIC) enables single-shot measurement of laser-plasma dynamics. Using TRIC, we demonstrate the reconstruction of the complete spatio-temporal intensity distribution of a high-power laser pulse in the focal plane at full pulse energy with sub-picosecond resolution.

Sub-cycle dynamics in relativistic nanoplasma acceleration

The interaction of light with nanometer-sized solids provides the means of focusing optical radiation to sub-wavelength spatial scales with associated electric field enhancements offering new opportunities for multifaceted applications. We utilize collective effects in nanoplasmas with sub-two-cycle light pulses of extreme intensity to extend the waveform-dependent electron acceleration regime into the relativistic realm, by using 106 times higher intensity than previous works to date. Through irradiation of nanometric tungsten needles, we obtain multi-MeV energy electron bunches, whose energy and direction can be steered by the combined effect of the induced near-field and the laser field. We identified a two-step mechanism for the electron acceleration: (i) ejection within a sub-half-optical-cycle into the near-field from the target at >TVm-1 acceleration fields, and (ii) subsequent acceleration in vacuum by the intense laser field. Our observations raise the prospect of isolating and controlling relativistic attosecond electron bunches, and pave the way for next generation electron and photon sources.

Laser Acceleration of Highly Energetic Carbon Ions Using a Double-Layer Target Composed of Slightly Underdense Plasma and Ultrathin Foil

We report the experimental generation of highly energetic carbon ions up to 48 MeV per nucleon by shooting double-layer targets composed of well-controlled slightly underdense plasma and ultrathin foils with ultraintense femtosecond laser pulses. Particle-in-cell simulations reveal that carbon ions are ejected from the ultrathin foils due to radiation pressure and then accelerated in an enhanced sheath field established by the superponderomotive electron flow. Such a cascaded acceleration is especially suited for heavy ion acceleration with femtosecond laser pulses. The breakthrough of heavy ion energy up to many tens of MeV/u at a high repetition rate would be able to trigger significant advances in nuclear physics, high energy density physics, and medical physics.

Time-of-flight spectrometry of ultra-short, polyenergetic proton bunches

A common approach for spectrum determination of polyenergetic proton bunches from laser-ion acceleration experiments is based on the time-of-flight (TOF) method. However, spectra obtained using this method are typically given in relative units or are estimated based on some prior assumptions on the energy distribution of the accelerated ions. In this work, we present a new approach using the TOF method that allows for an absolute energy spectrum reconstruction from a current signal acquired with a sub-nanosecond fast and 10 µm thin silicon detector. The reconstruction is based on solving a linear least-squares problem, taking into account the response function of the detection system. The general principle of signal generation and spectrum reconstruction by setting up an appropriate system response matrix is presented. Proof-of-principle experiments at a 12 MV Tandem accelerator using different nanosecond-short (quasi-)monoenergetic and polyenergetic proton bunches at energies up to 20 MeV were successfully performed. Within the experimental uncertainties of 2.4% and 12.1% for energy and particle number, respectively, reconstructed energy distributions were found in excellent agreement with the spectra calculated using Monte Carlo simulations and measured by a magnetic spectrometer. This TOF method can hence be used for absolute online spectrometry of laser-accelerated particle bunches.

[Treatment of rheumatic diseases and pulmonary toxicity]

Rheumatic diseases are treated with manifold different drugs that can potentially be pneumotoxic. Adverse effects of drug therapy may induce a wide variety of bronchopulmonary and pleural disorders, which can have a life-threatening course. These side effects rarely have pathognomonic features; therefore, drug-induced diseases are relevant differential diagnoses of pulmonary manifestations of rheumatic diseases, infections, and other independent genuine pulmonary diseases. Diagnosis is based mainly on verification of a compatible disease pattern and exclusion of differential diagnoses, as well as on assessment of the temporal relationship and the consequences of drug abstention.

AN ONLINE, RADIATION HARD PROTON ENERGY-RESOLVING SCINTILLATOR STACK FOR LASER-DRIVEN PROTON BUNCHES

We report on a scintillator-based online detection system for the spectral characterization of polychromatic proton bunches. Using up to nine stacked layers of radiation hard polysiloxane scintillators, coupled to and readout edge-on by a large area pixelated CMOS detector, impinging polychromatic proton bunches were characterized. The energy spectra were reconstructed using calibration data and simulated using Monte-Carlo simulations. Despite the scintillator stack showed some problems like thickness inhomogeneities and unequal layer coupling, the prototype allows to obtain a first estimate of the energy spectrum of proton beams.

Observation of Laser Power Amplification in a Self-Injecting Laser Wakefield Accelerator

We report on the depletion and power amplification of the driving laser pulse in a strongly driven laser wakefield accelerator. Simultaneous measurement of the transmitted pulse energy and temporal shape indicate an increase in peak power from 187±11  TW to a maximum of 318±12  TW after 13 mm of propagation in a plasma density of 0.9×10^{18}  cm^{-3}. The power amplification is correlated with the injection and acceleration of electrons in the nonlinear wakefield. This process is modeled by including a localized redshift and subsequent group delay dispersion at the laser pulse front.

Patientenfragebogen zur Erfassung der Ursachen interstitieller und seltener Lungenerkrankungen – klinische Sektion der DGP

Hintergrund Interstitielle Lungenerkrankungen (ILD) umfassen verschiedenste heterogene, zumeist chronische Erkrankungen des Interstitiums und/oder der Alveolen mit bekannten und unbekannten Ursachen. Die Diagnostik der ILD ist sehr komplex und sollte interdisziplinär erfolgen. Eine der wesentlichen Basisuntersuchungen ist eine umfangreiche Anamnese. Hierzu kam im deutschsprachigen Raum bisher der Frankfurter Bogen von 1985 zur Anwendung, der mittlerweile jedoch sprachlich und inhaltlich einer Überarbeitung bedurfte.

Methode Unter Schirmherrschaft der klinischen Sektion der DGP erfolgte die Erstellung eines neuen Patientenfragebogens zur Diagnostik interstitieller und seltener Lungenerkrankungen. Der Fragebogen entstand unter Mitarbeit von Pneumologen mit ILD-Expertise, Arbeitsmedizinern und Psychologen sowie der Unterstützung von Selbsthilfegruppen. Abschließend wurde der Fragebogen mithilfe von Patienten sprachlich optimiert.

Ergebnisse Der neu erstellte Patientenfragebogen zur Diagnostik interstitieller und seltener Lungenerkrankungen umfasst mehrere Bereiche: Initiale und aktuelle Symptome, Fragen zur Vorgeschichte inklusive Medikation, pulmonale und extrapulmonale Vorerkrankungen, mögliche Expositionen im häuslichen, privatem und beruflichem Umfeld sowie Familienanamnese und Reisetätigkeiten.

Schlussfolgerung Der neu erstellte Fragebogen kann in der klinischen Routine die Diagnostik bei Patienten mit Verdacht auf eine interstitielle Lungenerkrankung wesentlich erleichtern.

Self-assembled Pt2L2 boxes strongly bind G-quadruplex DNA and influence gene expression in cancer cells

Supramolecular Pt(ii) quadrangular boxes bind native and G-quadruplex DNA motifs in a size-dependent fashion. Three Pt molecular squares of distinct size show biological activity against cancer cells and heavily influence the expression of genes known to form G-quadruplexes in their promoter regions. The smallest Pt-box displays less activity but more selectivity for a quadruplex formed in the c-Kit gene.

A novel approach to electron data background treatment in an online wide-angle spectrometer for laser-accelerated ion and electron bunches

Laser-based ion acceleration is driven by electrical fields emerging when target electrons absorb laser energy and consecutively leave the target material. A direct correlation between these electrons and the accelerated ions is thus to be expected and predicted by theoretical models. We report on a modified wide-angle spectrometer, allowing the simultaneous characterization of angularly resolved energy distributions of both ions and electrons. Equipped with online pixel detectors, the RadEye1 detectors, the investigation of this correlation gets attainable on a single shot basis. In addition to first insights, we present a novel approach for reliably extracting the primary electron energy distribution from the interfering secondary radiation background. This proves vitally important for quantitative extraction of average electron energies (temperatures) and emitted total charge.

A transportable Paul-trap for levitation and accurate positioning of micron-scale particles in vacuum for laser-plasma experiments

We report on a Paul-trap system with large access angles that allows positioning of fully isolated micrometer-scale particles with micrometer precision as targets in high-intensity laser-plasma interactions. This paper summarizes theoretical and experimental concepts of the apparatus as well as supporting measurements that were performed for the trapping process of single particles.

Characterization of online high dynamic range imaging for laser-driven ion beam diagnostics using visible light

Laser-driven acceleration of particle beams is an emerging modality under research for biomedical applications. The spatially resolved diagnostics of laser-accelerated proton bunches is crucial for their application. The RadEye detector, featuring up to 10 cm x 5 cm area of online complementary metal-oxide-semiconductor (CMOS) detector made of 48 μm pixels, is established for x-ray, proton and ion beam diagnostics. We exploit the usually undesired ‘Image lag’ phenomenon of incomplete pixel reset to generate 2D-images with a larger dynamic range than the single frame range of 12-bit. Using 532 nm laser pulses and computer simulations for single-slit diffraction, calibration factors to stack multiple readouts were successfully derived to quantitatively reconstruct spatial information about an optical beam and hence extend the dynamic range of the detector compared to a single frame. The final goal is focus quantification for a permanent magnet quadrupole system for protons and terawatt (TW-class) laser focus diagnostics.

Considerations on employing a PMQ-doublet for narrow and broad proton energy distributions

We simulated a doublet of permanent magnet quadrupoles (PMQs) to estimate the sensitivity on positioning precision and its impact on the spectral properties of transported protons. The study guided the construction and testing of a focusing setup for laser-accelerated proton bunches with energies between 6 and 10 MeV. Our results shed light on possible applications that may arise from broad input particle spectra.

Studying the Dynamics of Relativistic Laser-Plasma Interaction on Thin Foils by Means of Fourier-Transform Spectral Interferometry

We apply Fourier-transform spectral interferometry (FTSI) to study the interaction of intense laser pulses with ultrathin targets. Ultrathin submicrometer-thick solid CH targets were shot at the PHELIX laser facility with an intensity in the mid to upper 10^{19}  W/cm^{2} range using an innovative double-pulse structure. The transmitted pulse structure was analyzed by FTSI and shows a transition from a relativistic transparency-dominated regime for targets thinner than 500 nm to a hole-boring-dominated laser-plasma interaction for thicker targets. The results also confirm that the inevitable preplasma expansion happening during the rising slope of the pulse, a few picoseconds before the maximum of the pulse is reached, cannot be neglected and plays a dominant role in laser-plasma interaction with ultrathin solid targets.

Dynamics of laser-driven proton acceleration exhibited by measured laser absorptivity and reflectivity

Proton acceleration from nanometer thin foils with intense laser pulses is investigated experimentally. We analyzed the laser absorptivity by parallel monitoring of laser transmissivity and reflectivity with different laser intensities when moving the targets along the laser axis. A direct correlation between laser absorptivity and maximum proton energy is observed. Experimental results are interpreted in analytical estimation, exhibiting a coexistence of plasma expansion and light-sail form of radiation pressure acceleration (RPA-LS) mechanisms during the entire proton acceleration process based on the measured laser absorptivity and reflectivity.