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Abstract Background Coronary computed tomography angiography (CCTA) offers non-invasive diagnostics of the coronary arteries. Vessel evaluation requires the administration of intravenous contrast. The purpose of this study was to evaluate the utility of gadolinium-based contrast agent (GBCA) as an alternative to iodinated contrast for CCTA on a first-generation clinical dual-source photon-counting-detector (PCD)-CT system. Methods A dynamic circulating phantom containing a three-dimensional-printed model of the thoracic aorta and the coronary arteries were used to evaluate injection protocols using gadopentetate dimeglumine at 50%, 100%, 150%, and 200% of the maximum approved clinical dose (0.3 mmol/kg). Virtual monoenergetic image (VMI) reconstructions ranging from 40 keV to 100 keV with 5 keV increments were generated on a PCD-CT. Contrast-to-noise ratio (CNR) was calculated from attenuations measured in the aorta and coronary arteries and noise measured in the background tissue. Attenuation of at least 350 HU was deemed as diagnostic. Results The highest coronary attenuation (441 ± 23 HU, mean ± standard deviation) and CNR (29.5 ± 1.5) was achieved at 40 keV and at the highest GBCA dose (200%). There was a systematic decline of attenuation and CNR with higher keV reconstructions and lower GBCA doses. Only reconstructions at 40 and 45 keV at 200% and 40 keV at 150% GBCA dose demonstrated sufficient attenuation above 350 HU. Conclusion Current PCD-CT protocols and settings are unsuitable for the use of GBCA for CCTA at clinically approved doses. Future advances to the PCD-CT system including a 4-threshold mode, as well as multi-material decomposition may add new opportunities for k-edge imaging of GBCA. Relevance statement Patients allergic to iodine-based contrast media and the future of multicontrast CT examinations would benefit greatly from alternative contrast media, but the utility of GBCA for coronary photon-counting-dector-CT angiography remains limited without further optimization of protocols and scanner settings. Key Points GBCA-enhanced coronary PCD-CT angiography is not feasible at clinically approved doses. GBCAs have potential applications for the visualization of larger vessels, such as the aorta, on PCD-CT angiography. Higher GBCA doses and lower keV reconstructions achieved higher attenuation values and CNR. Graphical Abstract

Purpose: To evaluate the performance of calcium quantification on photon-counting detector CT (PCD-CT) with high-pitch at low radiation doses compared to third-generation dual-source energy-integrating detector CT (EID-CT). Materials and methods: The phantom with three calcium inserts (50, 100, and 300 mg of calcium per milliliter), with and without the elliptical outer layer, was evaluated using high-pitch (3.2) and standard pitch (0.8) on PCD-CT, and standard pitch on EID-CT. Scans were performed with different tube voltages (PCD-CT: 120 and 140 kilo-voltage peak [kVp]; EID-CT: 70/Sn150 and 100/Sn150 kVp) and four radiation doses (1, 3, 5, and, 10 milli-Gray [mGy]). Utilizing the true calcium concentrations (CCtrue) of the phantom as the gold standard references, regression equations for each kVp setting were formulated to convert CT attenuations (CaCT) into measured calcium concentrations (CCm). The correlation analysis between CaCT and CCtrue was performed. The percentage absolute bias (PAB) was calculated from the differences between CCm and CCtrue and used to analyze the effects of scanning parameters on calcium quantification accuracy. Results: A strong correlation was found between CaCT and CCtrue on PCD-CT (r > 0.99) and EID-CT (r > 0.98). For high- and standard-pitch scans on PCD-CT, the accuracy of calcium quantification is comparable (p = 0.615): the median (interquartile range [IQR]) of PAB was 5.59% (2.79%–8.31%) and 4.87 % (2.62%–8.01%), respectively. The PAB median (IQR) was 7.43% (3.77%–11.75%) for EID-CT. The calcium quantification accuracy of PCD-CT is superior to EID-CT at the large phantom (5.46% [2.68%–9.55%] versus 9.01% [6.22%–12.74%]), and at the radiation dose of 1 mGy (4.43% [2.08%–8.59%] versus 13.89% [8.93%–23.09%]) and 3 mGy (4.61% [2.75%–6.51%] versus 9.97% [5.17%–14.41%]), all p < 0.001. Conclusions: Calcium quantification using low-dose PCD-CT with high-pitch scanning is feasible and accurate, and superior to EID-CT.

1 Abstract: Rationale and objectives: Coronary computed tomography angiography (CCTA) is becoming increasingly important for the diagnostic workup of coronary artery disease, nevertheless, imaging of in-stent stenosis remains challenging. For the first time, spectral imaging in Ultra High Resolution (UHR) is now possible in clinically available photon counting CT. The aim of this work is to determine the optimal virtual monoenergetic image (VMI) for imaging in-stent stenoses in cardiac stents. Materials and methods: 6 stents with inserted hypodense stenoses were scanned in an established phantom in UHR mode. Images were reconstructed with 3 different kernels for spectral data (Qr56, Qr64, Qr72) with varying levels of sharpness. Based on region of interest (ROI) measurements image quality parameters including contrast-to-noise ratio (CNR) were analyzed for all available VMI (40 keV–190 keV). Finally, based on quantitative results and VMI used in clinical routine, a set of VMI was included in a qualitative reading. Results: CNR showed significant variations across different keV levels (p

Beyond the transition to retirement, research rarely focuses on transitions in later life. This may be due to the absence of appropriate theoretical models. In order to remedy this, the article contains a theory-based reflection with the aim to work out aspects of educational offers for older people. It links the knowledge about ‘transitions in later life’, ‘skills and competencies’ to concepts of learning in later life. The systematic approach is based on a detailed review of the state of the art of the different concepts in the field of educational science and related academic disciplines. The analysis identifies the crucial aspects of different learning situations which help develop relevant competencies and skills useful for coping with transitions. Based on these reflections we derive some relevant features for programs to help develop older adults’ abilities to cope with transitions.

Photon-counting CT systems generally allow for acquiring multiple spectral datasets and thus for decomposing CT images into multiple materials. We introduce a prior knowledge-free deterministic material decomposition approach for quantifying three material concentrations on a commercial photon-counting CT system based on a single CT scan. We acquired two phantom measurement series: one to calibrate and one to test the algorithm. For evaluation, we used an anthropomorphic abdominal phantom with inserts of either aqueous iodine solution, aqueous tungsten solution, or water. Material CT numbers were predicted based on a polynomial in the following parameters: Water-equivalent object diameter, object center-to-isocenter distance, voxel-to-isocenter distance, voxel-to-object center distance, and X-ray tube current. The material decomposition was performed as a generalized least-squares estimation. The algorithm provided material maps of iodine, tungsten, and water with average estimation errors of 4% in the contrast agent maps and 1% in the water map with respect to the material concentrations in the inserts. The contrast-to-noise ratio in the iodine and tungsten map was 36% and 16% compared to the noise-minimal threshold image. We were able to decompose four spectral images into iodine, tungsten, and water.

Peripheral arterial disease (PAD) is common in elderly patients. Lower-extremity CT angiography (LE-CTA) can be useful for detecting PAD and planning its treatment. PAD can also be accurately evaluated on reconstructed monoenergetic images (MEIs) from low kiloelectron volt (keV) to high keV images using dualenergy CT. Low keV images generally provide higher contrast than high keV images but also feature more severe image noise. The noise-reduced virtual MEI reconstruction algorithm, called the Mono+ technique, was recently introduced to overcome such image noise. Therefore, this pictorial review aimed to present the imaging findings of PAD on LE-CTA and compare low and high keV images with those subjected to the Mono+ technique. We found that, in many cases, the overall and segmental image qualities were better and metal artifacts and venous contamination were decreased in the high keV images.

Our aim was to compare the image quality and patient dose of contrast-enhanced oncologic chest-CT of a first-generation photon-counting detector (PCD-CT) and a second-generation dual-source dual-energy CT (DSCT). For this reason, one hundred consecutive oncologic patients (63 male, 65 ± 11 years, BMI: 16–42 kg/m2) were prospectively enrolled and evaluated. Clinically indicated contrast-enhanced chest-CT were obtained with PCD-CT and compared to previously obtained chest-DSCT in the same individuals. The median time interval between the scans was three months. The same contrast media protocol was used for both scans. PCD-CT was performed in QuantumPlus mode (obtaining full spectral information) at 120 kVp. DSCT was performed using 100 kV for Tube A and 140 kV for Tube B. “T3D” PCD-CT images were evaluated, which emulate conventional 120 keV polychromatic images. For DSCT, the convolution algorithm was set at I31f with class 1 iterative reconstruction, whereas comparable Br40 kernel and iterative reconstruction strengths (Q1 and Q3) were applied for PCD-CT. Two radiologists assessed image quality using a five-point Likert scale and performed measurements of vessels and lung parenchyma for signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and in the case of pulmonary metastases tumor-to-lung parenchyma contrast ratio. PCD-CT CNRvessel was significantly higher than DSCT CNRvessel (all, p < 0.05). Readers rated image contrast of mediastinum, vessels, and lung parenchyma significantly higher in PCD-CT than DSCT images (p < 0.001). Q3 PCD-CT CNRlung_parenchyma was significantly higher than DSCT CNRlung_parenchyma and Q1 PCD-CT CNRlung_parenchyma (p < 0.01). The tumor-to-lung parenchyma contrast ratio was significantly higher on PCD-CT than DSCT images (0.08 ± 0.04 vs. 0.03 ± 0.02, p < 0.001). CTDI, DLP, SSDE mean values for PCD-CT and DSCT were 4.17 ± 1.29 mGy vs. 7.21 ± 0.49 mGy, 151.01 ± 48.56 mGy * cm vs. 288.64 ± 31.17 mGy * cm and 4.23 ± 0.97 vs. 7.48 ± 1.09, respectively. PCD-CT enables oncologic chest-CT with a significantly reduced dose while maintaining image quality similar to a second-generation DSCT for comparable protocol settings.

(1) To explore the potential impact of an AI dual-energy CT (DECT) prototype on decision making and workflows by investigating its capabilities to differentiate COVID-19 from immunotherapy-related pneumonitis. (2) Methods: From 3 April 2020 to 12 February 2021, DECT from biometrically matching patients with COVID-19, pneumonitis, and inconspicuous findings were selected from our clinical routine. Three blinded readers independently scored each pulmonary lobe analogous to CO-RADS. Inter-rater agreement was determined with an intraclass correlation coefficient (ICC). Averaged perfusion metrics per lobe (iodine uptake in mg, volume without vessels in ml, iodine concentration in mg/mL) were extracted using manual segmentation and an AI DECT prototype. A generalized linear mixed model was used to investigate metric validity and potential distinctions at equal CO-RADS scores. Multinomial regression measured the contribution “Reader”, “CO-RADS score”, and “perfusion metrics” to diagnosis. The time to diagnosis was measured for manual vs. AI segmentation. (3) Results: We included 105 patients (62 ± 13 years, mean BMI 27 ± 2). There were no significant differences between manually and AI-extracted perfusion metrics (p = 0.999). Regardless of the CO-RADS score, iodine uptake and concentration per lobe were significantly higher in COVID-19 than in pneumonitis (p < 0.001). In regression, iodine uptake had a greater contribution to diagnosis than CO-RADS scoring (Odds Ratio (OR) = 1.82 [95%CI 1.10–2.99] vs. OR = 0.20 [95%CI 0.14–0.29]). The AI prototype extracted the relevant perfusion metrics significantly faster than radiologists (10 ± 1 vs. 15 ± 2 min, p < 0.001). (4) Conclusions: The investigated AI prototype positively impacts decision making and workflows by extracting perfusion metrics that differentiate COVID-19 from visually similar pneumonitis significantly faster than radiologists.

Aufgrund des technologischen Fortschritts stellt die Entwicklung von medienbezogenen Kompetenzen eine sich stetig wandelnde Aufgabe dar, die durch Angebote der Erwachsenenbildung und Weiterbildung unterstützt werden kann. Um Kompetenzausprägungen sowie Entwicklungsbedarfe bei Lehrenden und (potentiellen) Zielgruppen von Bildungsangeboten zu identifizieren, wird bereits über verschiedene Wege und mit unterschiedlichen Methoden versucht, medienbezogene Kompetenzen zu erfassen. Im Rahmen dieses Beitrags werden zunächst verschiedene Arten der Kompetenzmessung aufgezeigt und anschliessend drei Ansätze der medienbezogenen Kompetenzerfassung bei Erwachsenen exemplarisch betrachtet (Rammstedt 2013; Rott 2020; Treumann et al. 2002). Vergleiche von Selbsteinschätzungsskalen mit einem Testinstrument im Rahmen des Bildungsmonitorings sowie einem Kompetenztest zeigen jeweils spezifische Potentiale, Grenzen und Optimierungsmöglichkeiten der einzelnen Instrumente und Erhebungsarten auf, mit der Schlussfolgerung, dass eine Kombination aus Selbsteinschätzung und Kompetenztests weitere Möglichkeiten für Forschung und Praxis im Feld der Erwachsenenbildung eröffnet, auch wenn kritisch hinterfragt werden muss, welche Art medienbezogener Kompetenzen für welche erwachsene Zielgruppe überhaupt relevant ist.

In adult training practice, dropout marks the transition from participation to non-participation. There are only a few theoretical models, especially from the second half of the 20th century, that address this phenomenon. With special consideration to the congruence model of Boshier (1973) and the integration model of Tinto (1975, 1993) the study focuses first on the theoretical discussion of empirically grounded models for the explanation of dropout in the field of adult education. Against the background of analyses of 40 problem-centered interviews with dropouts from adult education, the two models are examined as to their explanatory contributions. Based on these empirical and theoretical explorations, a newly developed typology of as well as a model for dropout are proposed which topicalize dropout in adult education as a phenomenon of fit.

With the COVID-19 pandemic the education sector is facing major new challenges and opportunities, e.g., changes in the pedagogical relationships between teachers and learners. Various publications have already inquired into the importance of pedagogical relationships in primary and secondary education, but not in adult education. Therefore, a closer look should now be taken at pedagogical relationships in adult education and their impact on successful teaching – both in the analogue and the digital realm. The person-centred approach as well as the approach of professional proximity and distance are relevant concepts in this field. From the perspective of person-centred pedagogy, respectful interaction with one another and the facilitation of an equal dialogue between teachers and learners are of great importance. The relevance of relationships between teachers and learners in adult education should not be underestimated – also with regard to enabling successful relationship building in distance learning.

Abstract Background To investigate the potential value of volumetric iodine quantification using preoperative dual-energy computed tomography (DECT) for predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC). Methods This retrospective study included patients with single HCC treated through surgical resection who underwent preoperative DECT. Quantitative DECT features, including normalized iodine concentration (NIC) to the aorta and mixed-energy CT attenuation value in the arterial phase, were three-dimensionally measured for peritumoral and intratumoral regions: (i) layer-by-layer analysis for peritumoral layers (outer layers 1 and 2; numbered in close order from the tumor boundary) and intratumoral layers (inner layers 1 and 2) with 2-mm layer thickness and (ii) volume of interest (VOI)-based analysis with different volume coverage (tumor itself; VOIO1, tumor plus outer layer 1; VOIO2, tumor plus outer layers 1 and 2; VOII1, tumor minus inner layer 1; VOII2, tumor minus inner layers 1 and 2). In addition, qualitative CT features, including peritumoral enhancement and tumor margin, were assessed. Qualitative and quantitative CT features were compared between HCC patients with and without MVI. Diagnostic performance of DECT parameters of layers and VOIs was assessed using receiver operating characteristic curve analysis. Results A total of 36 patients (24 men, mean age 59.9 ± 8.5 years) with MVI (n = 14) and without MVI (n = 22) were included. HCCs with MVI showed significantly higher NICs of outer layer 1, outer layer 2, VOIO1, and VOIO2 than those without MVI (P = 0.01, 0.04, 0.02, 0.02, respectively). Among the NICs of layers and VOIs, the highest area under the curve was obtained in outer layer 1 (0.747). Qualitative features, including peritumoral enhancement and tumor margin, and the mean CT attenuation of each layer and each VOI were not significantly different between HCCs with and without MVI (both P > 0.05). Conclusions Volumetric iodine quantification of peritumoral and intratumoral regions in arterial phase using DECT may help predict the MVI of HCC.

Abstract Against the backdrop of an increasing digitalisation in the field of adult education, the paper presents a model for media pedagogical competence of professionals in this area. This model is built on preliminary works in adult education research and existing models from schools. Corresponding with this model a competence test has been developed and proved with a sample of 622 adult education teachers. Results substantially confirm the structure of the model, which subdivide media pedagogical competence into four facets. Further, data enable for the first-time statements related to the media pedagogical competence of different subgroups of adult education teachers and point to differences between these groups according to sociodemographic and employment-biographical variables.

The integration of artificial intelligence (AI) in application-based contexts has created the need for skilled workers with AI knowledge and competencies. In order to meet this demand, it is necessary to integrate AI into vocational education and training (VET) in Germany, for example in the form of an additional AI qualification. Such an additional qualification in the field of AI in the VET system is innovative and comparatively new. Therefore, this article explores the views of both teachers and apprentices regarding the requirements for an additional AI qualification, - perspectives which have not been sufficiently researched, yet. Results from a mixed-methods needs analysis based on interviews with 12 vocational school teachers and a survey of 746 apprentices reveals the following key results. Both groups – teachers and apprentices – agree that the learning content of the qualification must primarily cover the basic theoretical concepts of AI. Teachers consider blended learning formats combining online learning with face-to-face instruction to be the most appropriate form for such a qualification. Ultimately, they consider an action-oriented and student-centered didactic design to be useful, whereas apprentices seem to prefer a teacher-centered additional AI qualification. Both the study's contributions and its limitations provide useful insights regarding the implementation of AI contents in VET. It is still a matter for further research to determine the necessary prerequisites for an AI qualification as well as its relevance and practical aspects; in this respect, the employers’ perspective could prove to be insightful.

Background: This study evaluated the feasibility of reducing the radiation dose in abdominal imaging of urolithiasis with a clinical photon-counting CT (PCCT) by gradually lowering the image quality level (IQL) without compromising the image quality and diagnostic value. Methods: Ninety-eight PCCT examinations using either IQL70 (n = 31), IQL60 (n = 31) or IQL50 (n = 36) were retrospectively included. Parameters for the radiation dose and the quantitative image quality were analyzed. Qualitative image quality, presence of urolithiasis and diagnostic confidence were rated. Results: Lowering the IQL from 70 to 50 led to a significant decrease (22.8%) in the size-specific dose estimate (SSDE, IQL70 4.57 ± 0.84 mGy, IQL50 3.53 ± 0.70 mGy, p < 0.001). Simultaneously, lowering the IQL led to a minimal deterioration of the quantitative quality, e.g., image noise increased from 9.13 ± 1.99 (IQL70) to 9.91 ± 1.77 (IQL50, p = 0.248). Radiologists did not notice major changes in the image quality throughout the IQLs. Detection rates of urolithiasis (91.3–100%) did not differ markedly. Diagnostic confidence was high and not influenced by the IQL. Conclusions: Adjusting the PCCT scan protocol by lowering the IQL can significantly reduce the radiation dose without significant impairment of the image quality. The detection rate and diagnostic confidence are not impaired by using an ultra-low-dose PCCT scan protocol.

Abstract Background We investigated the influence of dose, spectral separation, pitch, rotation time, and reconstruction kernel on accuracy and image noise of virtual non-calcium images using a bone marrow phantom. Methods The phantom was developed at our institution and scanned using a third-generation dual-source dual-energy CT scanner at five different spectral separations by varying the tube-voltage combinations (70 kV/Sn150 kV, 80 kV/Sn150 kV, 90 kV/Sn150 kV, and 100 kV/Sn150 kV, all with 0.6-mm tin filter [Sn]; 80 kV/140 kV without tin filter) at six different doses (volume computed tomography dose index from 1 to 80 mGy). In separate experiments, rotation times, pitch, and reconstruction kernels were varied at a constant dose and tube voltage. Accuracy was determined by measuring the mean error between virtual non-calcium values in the fluid within and outside of the bone. Image noise was defined as the standard deviation of virtual non-calcium values. Results Spectral separation, dose, rotation time, or pitch did not significantly correlate (p > 0.083) with mean error. Increased spectral separation (r s-0.96, p

Abstract The early termination of educational measures is usually critically discussed as “drop-out”. The discontinuation of further education activities is considered a problem above all when existing interest in further education cannot be realized and/or when this initiates a categorical withdrawal from the system of further education. In educational research carried out in German-speaking countries (especially in research on university-, school-, and vocational education), the already wide-spread term “drop-out” is increasingly used as a synonym for the discontinuation of educational participation. In research on further education, however, this term is less common and, so far, no relevant studies have been conducted regarding the reasons for dropping out, the methods of dealing with this issue, or the importance of the drop-out phenomenon in continuing education. Against this background, the authors focus on the actual need for basic research and carry out a systematic categorization of the drop-out phenomenon in the context of further education. To this end, they first investigate which drop-out concept is most common in the field of adult education. They then link the present state of the art in research to perspectives formulated by eleven experts (representatives of education providers and continuing education associations) interviewed with regard to this topic. Findings are further substantiated through a reflection on the operationalization of early termination of further education in the National Educational Panel Study (NEPS). In a discussion summarizing the major lines of reasoning, the results thus gained are condensed against the theoretical and empirical background and guiding implications for future (empirical) research activities are outlined.

Vor dem Hintergrund der Qualitätsoffensive Lehrerbildung wurden an der Tübingen School of Education (TüSE) im Teilprojekt „Lehrerfort- und -weiterbildung“ bedarfsgerechte und wissenschaftlich fundierte Fort- und Weiterbildungsangebote für Lehrkräfte in Baden-Württemberg pilotiert. Auf dieser Basis und orientiert an erwachsenenpädagogischen Prinzipien wurden Leitlinien für die dritte Phase der Lehrerbildung an Universitäten entwickelt.

Abstract Background This cross-sectional study investigates the potential association between active periodontal disease and high HbA1c levels in type-2-diabetes mellitus subjects under physical training. Methods Women and men with a diagnosis of non-insulin-dependent diabetes mellitus and ongoing physical and an ongoing exercise program were included. Periodontal conditions were assessed according to the CDC-AAP case definitions. Venous blood samples were collected for the quantitative analysis of HbA1c. Associations between the variables were examined with univariate and multivariate regression models. Results Forty-four subjects with a mean age of 63.4 ± 7.0 years were examined. Twenty-nine subjects had no periodontitis, 11 had a moderate and 4 had a severe form of periodontal disease. High fasting serum glucose (p

We evaluated the accuracy of coronary artery calcium (CAC) scoring on a dual-source photon-counting detector CT (PCD-CT). An anthropomorphic chest phantom underwent ECG-gated sequential scanning on a PCD-CT at 120 kV with four radiation dose levels (CTDIvol, 2.0–8.6 mGy). Polychromatic images at 120 kV (T3D) and virtual monoenergetic images (VMI), from 60 to 75 keV without quantum iterative reconstruction (no QIR) and QIR strength levels 1–4, were reconstructed. For reference, the same phantom was scanned on a conventional energy-integrating detector CT (120 kV; filtered back projection) at identical radiation doses. CAC scoring in 20 patients with PCD-CT (120 kV; no QIR and QIR 1–4) were included. In the phantom, there were no differences between CAC scores of different radiation doses (all, p > 0.05). Images with 70 keV, no QIR (CAC score, 649); 65 keV, QIR 3 (656); 65 keV; QIR4 (648) and T3D, QIR4 (656) showed a p < 0.001) and for each 5 keV-increase (all, p < 0.001). Patient data (median CAC score: 86 [inter-quartile range: 38–978] at 70 keV) confirmed relationships and differences between reconstructions from the phantom. First phantom and in-vivo experience with a clinical dual-source PCD-CT system shows accurate CAC scoring with VMI reconstructions at different radiation dose levels.

Media pedagogical competence is critical for the modern-day adult educator. In the process of adult learning, both the use of digital media in the classroom and the transfer of knowledge in dealing with media are the basis for social participation and individual development that must be provided by teachers. However, at present little or no research has been conducted that assess media pedagogical competence of adult educators. Moreover, an instrument to measure media pedagogical competence was lacking. In order to redress these concerns, in the present paper an instrument for objectively measuring media pedagogical competence is designed and piloted with adult educators (n=622). The study provides the first results concerning objective measurement of adult educator media pedagogical competence.

X-ray free-electron lasers based on superconducting accelerator technology deliver ultrashort photon pulses with unprecedented peak brilliance at high repetition rates. Continuous and noninvasive monitoring of the current profile of the electron bunches is essential for the operation and control of the accelerator. Longitudinal diagnostics based on coherent radiation have already shown their potential at various free-electron laser facilities, and the multi-GeV electron beams of x-ray free-electron lasers are powerful sources for the generation of broadband coherent diffraction radiation. We present noninvasive current profile measurements with a few femtoseconds resolution based on spectroscopy of coherent diffraction radiation in the frequency range 0.7–58 THz. The current profiles, reconstructed from the spectroscopic data with an advanced phase retrieval method, are compared with measurement results obtained with a transverse deflecting structure. For the first time, bunch-resolved current profiles have been recorded simultaneously to user operation at European XFEL for all bunches in the bunch train at MHz repetition rates.

We present a systematic comparison of two complementary methods for determining the longitudinal charge density profile of the compressed electron bunches in the soft x-ray free-electron laser FLASH: a frequency-domain technique—coherent transition radiation (CTR) spectroscopy—and a time-domain technique—streaking of the electron beam with a transversely deflecting microwave structure (TDS). While the direct time-profile measurement with a TDS is a well-established method invented at SLAC, our group has pioneered high-resolution bunch shape analysis based on coherent radiation spectroscopy. We have developed a broadband spectrometer covering the wavelength range from 5 μm to 433 μm with two sets of remotely interchangeable staged reflection gratings. The measured spectral intensity allows to compute the absolute magnitude of the bunch form factor but not its phase which, however, is needed to retrieve the bunch profile. Two phase retrieval methods are investigated in detail: analytic phase computation by means of the Kramers-Kronig dispersion relation, and iterative phase retrieval. Several computational techniques are compared and evaluated in view of their applicability and efficiency. For a large variety of bunch shapes, the time profiles derived from the spectroscopic data are compared with the TDS profiles, and generally excellent agreement is observed down to the 10 fs level. For part of the measurements, two independent CTR spectrometer systems have been available, yielding almost identical bunch shapes. In summary, we demonstrate that using well calibrated and broadband spectroscopy data, a fast and reliable phase reconstruction algorithm leads to bunch profiles competitive to high resolution TDS measurements.

Summary: Multiple sulfatase deficiency (MSD) is a fatal, inherited lysosomal storage disorder characterized by reduced activities of all sulfatases in patients. Sulfatases require a unique post-translational modification of an active-site cysteine to formylglycine that is catalyzed by the formylglycine-generating enzyme (FGE). FGE mutations that affect intracellular protein stability determine residual enzyme activity and disease severity in MSD patients. Here, we show that protein disulfide isomerase (PDI) plays a pivotal role in the recognition and quality control of MSD-causing FGE variants. Overexpression of PDI reduces the residual activity of unstable FGE variants, whereas inhibition of PDI function rescues the residual activity of sulfatases in MSD fibroblasts. Mass spectrometric analysis of a PDI+FGE variant covalent complex allowed determination of the molecular signature for FGE recognition by PDI. Our findings highlight the role of PDI as a disease modifier in MSD, which may also be relevant for other ER-associated protein folding pathologies. : Impaired activity of misfolded formylglycine-generating enzyme (FGE) results in multiple sulfatase deficiency (MSD) in humans. Schlotawa et al. show that recognition and quality control of misfolded FGE by protein disulfide isomerase (PDI) play a crucial role in the manifestation of MSD as a severe disease. Keywords: endoplasmic reticulum, protein disulfide isomerase, protein folding, quality control, formylglycine, sulfatases, multiple sulfatase deficiency, lysosomal storage disorders, formylglycine generating enzyme, SUMF1

Anliegen des vorliegenden Themenheftes ist es, das Verhältnis von Medienpädagogik und Erwachsenenbildung zu diskutieren, als auch die Aufmerksamkeit beider Bereiche im Sinne möglicher gegenseitiger Impulse aufeinander zu lenken. Medienpädagogik kann «als übergeordnete Bezeichnung für alle pädagogisch orientierten Beschäftigungen mit Medien in Theorie und Praxis» (Baacke 2007, 7) verstanden werden, die als Querschnittsdisziplin in Beziehung zu allen erziehungswissenschaftlichen Teildisziplinen und Fachrichtungen steht. Da die Medialität aber andersherum auch «jede Bildungssituation und jeden pädagogischen Handlungszusammenhang betrifft (...) muss sich auch jede Subdisziplin – ob es die Schulpädagogik, die Didaktik, die Sozialpädagogik, die Behindertenpädagogik oder die Erwachsenenbildung ist – sich [sic!] mit den Medien der Darstellung, der Verständigung und der Interaktion in ihrem Bereich beschäftigen.» (Meder 2017, 15, Hervorhebung durch Autoren).

With the ongoing political debate in many western countries on retirement age and ways of designing the transition into the post-professional phase of life, the transition from work to retirement seems to be on the agenda again. The research questions guiding this study are: how do older workers plan their retirement and how do they prepare themselves for it? Which facets of their current conditions of living and working and which biographical aspects have an impact on the way they learn and prepare for this new phase of life? How do retired adults sum up the transition and the significance of learning related to this process? To better understand the ways older workers prepare themselves for this next phase of life, on the one hand, and to contrast their expectations and plans with the actual experiences of those who already went through this transitional process, we collected data from 24 qualitative interviews and from a questionnaire answered by a representative quantitative sample of German adults aged 50 to 69. Some of the initial results derived from this data are presented here. We provide some empirical insight into the transition to retirement and, based on this, point to possible ways of supporting older workers faced with this transition through educational programs.

Mass spectrometry-based proteomics methods are finding increasing use in structural biology research. Beyond simple interaction networks, information about stable protein-protein complexes or spatially proximal proteins helps to elucidate the biological functions of proteins in a wider cellular context. To shed light on new developments in this field, the Göttingen Proteomics Forum organized a one-day symposium focused on complexome profiling and proximity labeling, two emerging technologies that are gaining significant attention in biomolecular research. The symposium was held in Göttingen, Germany on 23 May, 2019, as part of a series of regular symposia organized by the Göttingen Proteomics Forum.

Gliosis is a hallmark of prion disease. A neurotoxic prion peptide (PrP106-126) induces astrocyte proliferation in the presence of microglia. This peptide also directly enhances microglial proliferation in culture. We have investigated this further to understand the method by which factors released by microglia and PrP106-126 work together to enhance astrocyte proliferation. PrP106-126 in the presence of microglia specifically enhanced type 1 astrocyte proliferation but not Type 2. Astrocytes that do not express the prion protein were more sensitive to oxidative stress and the toxicity of cytosine arabinoside. In the presence of cytosine arabinoside, PrP106-126 was toxic to pure astrocyte cultures. Using conditioned medium from microglia we have shown that PrPc-expressing astrocytes proliferate in response to factors released by microglia stimulated by granulocyte/macrophage colony-stimulating factor. This response is enhanced in the presence of PrP106-126. PrPc-deficient astrocytes do not show this response. These results suggest that astrocytes are primed by PrP106-126 to respond more to factors released by proliferating microglia. Astrocytes may proliferate in this system to escape entering the cell suicide pathway.

Purpose. To estimate effective dose and organ equivalent doses of prospective ECG-triggered high-pitch CTCA. Materials and Methods. For dose measurements, an Alderson-Rando phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to ICRP 103. Exposure was performed on a second-generation dual-source scanner (SOMATOM Definition Flash, Siemens Medical Solutions, Germany). The following scan parameters were used: 320 mAs per rotation, 100 and 120 kV, pitch 3.4 for prospectively ECG-triggered high-pitch CTCA, scan range of 13.5 cm, collimation 64×2×0.6 mm with z-flying focal spot, gantry rotation time 280 ms, and simulated heart rate of 60 beats per minute. Results. Depending on the applied tube potential, the effective whole-body dose of the cardiac scan ranged from 1.1 mSv to 1.6 mSv and from 1.2 to 1.8 mSv for males and females, respectively. The radiosensitive breast tissue in the range of the primary beam caused an increased female-specific effective dose of 8.6%±0.3% compared to males. Decreasing the tube potential, a significant reduction of the effective dose of 35.8% and 36.0% can be achieved for males and females, respectively (𝑃

Der Artikel greift die Frage nach den Zielen und der Gestaltung von Prüfungen vor dem Hintergrund der veränderten Anforderungen in modularisierten Studiengängen auf. Dabei wird für die Herstellung einer Passung zwischen Lernzielen, Lehrmethoden und Prüfungsformen plädiert und auf die Gestaltung von Prüfungen in lehrer- wie in lernerzentrierten Lernarrangements eingegangen. Aus hochschuldidaktischer Perspektive wird verdeutlicht, welche - bisher noch wenig oder nur rudimentär genutzten - Chancen von Konzepten des peer- und self-assessment in lernerzentrierten Settings ausgehen. Daran anschließend werden die unterschiedlichen Funktionen und Ziele von Prüfungen vertieft analysiert und diskutiert, um schließlich an exemplarisch ausgewählten Lehr-Lern-Situationen die Möglichkeiten einer Stärkung der Lernmöglichkeiten durch Prüfungen über Feedback-Verfahren aufzuzeigen. 07.06.2009 | Andreas Müller & Bernhard Schmidt (München)

We present two cases in which displaced proximal humeral fractures are accompanied by vascular injury. These Injuries are very rare but severe and the accompanying vascular impairment can have great clinical consequences. Therefore, we try to emphasize on the importance of thorough and accurate diagnostics, because it is obligatory for early diagnosis and improving the eventual outcome of these injuries. The specific order in treatment (internal fixation first or vascular repair first) depends on the severity of the accompanying vascular injury. The increasing use of endovascular procedures to treat vascular lesions is a very interesting development with several advantages, especially in elderly and multimorbid patients.

BackgroundCasein kinase 1 delta (CK1delta) phosphorylates many key proteins playing important roles in such biological processes as cell growth, differentiation, apoptosis, circadian rhythm and vesicle transport. Furthermore, deregulation of CK1delta has been linked to neurodegenerative diseases and cancer. In this study, the cell specific distribution of CK1delta in various tissues and organs of young adult BALB/c mice was analysed by immunohistochemistry.Methodology/principal findingsImmunohistochemical staining of CK1delta was performed using three different antibodies against CK1delta. A high expression of CK1delta was found in a variety of tissues and organ systems and in several cell types of endodermal, mesodermal and ectodermal origin.ConclusionsThese results give an overview of the cell-type specific expression of CK1delta in different organs under normal conditions. Thus, they provide evidence for possible cell-type specific functions of CK1delta, where CK1delta can interact with and modulate the activity of key regulator proteins by site directed phosphorylation. Furthermore, they provide the basis for future analyses of CK1delta in these tissues.

High-brightness electron beams with low energy spread at existing and future x-ray free-electron lasers are affected by various collective beam self-interactions and microbunching instabilities. The corresponding coherent optical radiation effects, e.g., coherent optical transition radiation, impede electron beam profile imaging and become a serious issue for all kinds of electron beam diagnostics using imaging screens. Furthermore, coherent optical radiation effects can also be related to intrinsically ultrashort electron bunches or the existence of ultrashort spikes inside the electron bunches. In this paper, we discuss methods to suppress coherent optical radiation effects both by electron beam profile imaging in dispersive beam lines and by using scintillation imaging screens in combination with separation techniques. The suppression of coherent optical emission in dispersive beam lines is shown by analytical calculations, numerical simulations, and measurements. Transverse and longitudinal electron beam profile measurements in the presence of coherent optical radiation effects in nondispersive beam lines are demonstrated by applying a temporal separation technique.

High-gain free-electron lasers (FELs) in the ultraviolet and x-ray regime put stringent demands on the peak current, transverse emittance, and energy spread of the driving electron beam. At the soft x-ray FEL FLASH, a transverse deflecting microwave structure (TDS) has been installed to determine these parameters for the longitudinally compressed bunches, which are characterized by a narrow leading peak of high charge density and a long tail. The rapidly varying electromagnetic field in the TDS deflects the electrons vertically and transforms the time profile into a streak on an observation screen. The bunch current profile was measured single shot with an unprecedented resolution of 27 fs under FEL operating conditions. A precise single-shot measurement of the energy distribution along a bunch was accomplished by using the TDS in combination with an energy spectrometer. Variation of quadrupole strengths allowed for a determination of the horizontal emittance as a function of the longitudinal position within a bunch, the so-called slice emittance. In the bunch tail, a normalized slice emittance of about 2 μm was found, in agreement with expectations. In the leading spike, however, surprisingly large emittance values were observed, in apparent contradiction with the low emittance deduced from the measured FEL gain. By applying three-dimensional phase space tomography, we were able to show that the bunch head contains a central core of low emittance and high local current density, which is presumably the lasing part of the bunch.