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Objectives 4D flow MRI enables quantitative assessment of helical flow. We sought to generate normal values and elucidate changes of helical flow (duration, volume, length, velocities and rotational direction) and flow jet (displacement, flow angle) as well as wall shear stress (WSS). Methods We assessed the temporal helical existence (THEX), maximum helical volume (HVmax), accumulated helical volume (HVacc), accumulated helical volume length (HVLacc), maximum forward velocity (maxVfor), maximum circumferential velocity (maxVcirc), rotational direction (RD) and maximum wall shear stress (WSS) as reported elsewhere using the software tool Bloodline in 86 healthy volunteers (46 females, mean age 41 ± 13 years). Results WSS decreased by 42.1% and maxVfor by 55.7% across age. There was no link between age and gender regarding the other parameters. Conclusion This study provides age-dependent normal values regarding WSS and maxVfor and age- and gender-independent normal values regarding THEX, HVmax, HVacc, HVLacc, RD and maxVcirc. Key Points • 4D flow provides numerous new parameters; therefore, normal values are mandatory. • Wall shear stress decreases over age. • Maximum helical forward velocity decreases over age.

This paper presents an overview of policy frameworks for district heating (DH) in Europe. We develop a classification for policy aspects addressing DH, comprising regulation of ownership, prices, metering, consumer grid connection, third party access as well as support schemes and carbon taxes. This classification builds on existing literature and expert assessments collected in an online survey and interviews. The relevance of the paper lies in giving a comprehensive picture of the existing policy frameworks for DH in 23 European countries. For the overview, the countries are clustered along assigned categories. It is shown that the policy frameworks for DH can be clustered into five distinguishable groups. While some countries apply very strict regulations in special DH laws, others rely on less regulatory intervention, both with varying degrees of support for DH in place. The different policy frameworks are discussed in the context of the diffusion of DH and the integration of renewable and waste heat in DH. This analysis shows that high shares of DH and high shares of renewable and waste heat in DH can be observed in countries with a high degree of regulation as well as in countries with less regulatory intervention in DH markets.

4D flow MRI enables quantitative assessment of helical flow. Current methods are susceptible to noise. To evaluate helical flow patterns in healthy volunteers and patients with bicuspid aortic valves (BAV) at 1.5 T and 3 T using pressure-based helix-extraction in 4D flow MRI. Two intraindividual 4D flow MRI examinations were performed at 1.5 T and 3 T in ten healthy volunteers (5 females, 32 ± 3 years) and 2 patients with BAV using different acceleration techniques (kt-GRAPPA and centra). Several new quantitative parameters for the evaluation of volumes [ml], lengths [mm] as well as temporal parameters [ms] of helical flow were introduced and analyzed using the software tool Bloodline. We found good correlations between measurements in volunteers at 1.5 T and 3 T regarding helical flow volumes (R = 0.98) and temporal existence (R = 0.99) of helices in the ascending aorta. Furthermore, we found significantly larger (11.7 vs. 77.6 ml) and longer lasting (317 vs. 769 ms) helices in patients with BAV than in volunteers. The assessed parameters do not depend on the magnetic field strength used for the acquisition. The technique of pressure-based extraction of 4D flow MRI pattern is suitable for differentiation of normal and pathological flow.

4D PC-MRI enables the assessment of blood flow velocity vectors of one heart beat. These time-dependent, three-dimensional data allow for a comprehensive analysis and contain plenty of information. So far, 4D PC-MRI is used for research purposes. One reason is a lack of standardized, easy-to-use evaluation software, which is crucial for potential application in clinical routine. In this system’s paper, we present our software Bloodline, a tool combining advanced visual exploration and analysis of 4D PC-MRI data. We will put emphasis on design decisions and requirements that arose from the close collaboration with cardiologists and radiologists. The tool provides a guided data processing and evaluation workflow. The pre-processing pipeline comprises generic data import, artifact correction, vessel segmentation, surface as well as centerline extraction, cardiac cycle definition, and landmark specification. Bloodline integrates advanced visualization techniques and facilitates a dataset evaluation within ten minutes. Qualitative and quantitative flow analysis methods are provided. The focus lies on the detection and characterization of vortices, which are correlated to cardiovascular diseases.

To compare two broadly used 4D-flow- with a 2D-flow-sequence in healthy volunteers, regarding absolute flow parameters, image quality (IQ), and eddy current correction (ECC). Forty volunteers (42 ± 11.8 years, 22 females) were examined with a 3T scanner. Thoracic aortic flow was assessed using a 3D-T2w-SPACE-STIR-sequence for morphology and two accelerated 4D-flow sequences for comparison, one with k-t undersampling and one with standard GRAPPA parallel-imaging. 2D-flow was used as reference standard. The custom-made software tool Bloodline enabled flow measurements for all analyses at the same location. Quantitative flow analyses were performed with and without ECC. One reader assessed pathline IQ (IQ-PATH) and occurrence of motion artefacts (IQ-ART) on a 3-point grading scale, the higher the better. k-t GRAPPA allowed a significant mean scan time reduction of 46% (17:56 ± 5:26 min vs. 10:40 ± 3:15 min) and provided significantly fewer motion artefacts than standard GRAPPA (IQ-ART 1.57 ± 0.55 vs. 0.84 ± 0.48; p k-t GRAPPA sequence performed best (R = 0.96 vs. 0.90). k-t GRAPPA 4D-flow was not inferior to a standard GRAPPA-sequence, showed fewer artefacts, comparable IQ and was almost two-fold faster.

Summary Background Women with complete androgen insensitivity syndrome (CAIS) after gonadectomy have complained about reduced psychological wellbeing and sexual satisfaction. The aim of this study was to compare the effectiveness of hormone-replacement therapy with either androgen or oestrogen in women with 46,XY karyotype and CAIS after gonadectomy. Methods This national, multicentre, double-blind, randomised crossover trial was performed at three university medical centres and three specialised treatment institutions in Germany. Eligible participants were women aged 18–54 years with 46,XY karyotype, genetically diagnosed CAIS, and removed gonads. Participants were randomly assigned (14:12) by a central computer-based minimisation method to either oestradiol 1·5 mg/day for 6 months followed by crossover to testosterone 50 mg/day for 6 months (sequence A) or to testosterone 50 mg/day for 6 months followed by crossover to oestradiol 1·5 mg/day for 6 months (sequence B). Participants also received oestradiol or testosterone dummy to avoid identification of the active substance. All participants received oestradiol 1·5 mg/day during a 2 months' run-in phase. The primary outcome was mental health-related quality of life, as measured with the standardised German version of the SF-36 questionnaire. Secondary outcomes were psychological wellbeing, as measured with the Brief Symptom Inventory (BSI), sexual function, as measured with the Female Sexual Function Index (FSFI), and somatic effects, such as signs of virilisation and effects on metabolic blood values. The primary analysis included all patients who were available at least until visit 5, even if protocol violations occurred. The safety analysis included all patients who received at least oestradiol during the run-in phase. This trial is registered with the German Clinical Trials Register, number DRKS00003136, and with the European Clinical Trials Database, number 2010-021790-37. Findings We enrolled 26 patients into the study, with the first patient enrolled on Nov 7, 2011, and the last patient leaving the study on Jan 23, 2016. 14 patients were assigned to sequence A and 12 were assigned to sequence B. Ten participants were withdrawn from the study, two of whom attended at least five visits and so could be included in the primary analysis. Mental health-related quality of life did not differ between treatment groups (linear mixed model, p=0·794), nor did BSI scores for psychological wellbeing (global severity index, p=0·638; positive symptom distress index, p=0·378; positive symptom total, p=0·570). For the FSFI, testosterone was superior to oestradiol only in improving sexual desire (linear mixed model, p=0·018). No virilisation was observed, and gonadotrophin concentrations remained stable in both treatment groups. Oestradiol and testosterone concentrations changed substantially during the study in both treatment groups. 28 adverse events were reported for patients receiving oestradiol (23 grade 1 and five grade 2), and 38 adverse events were reported for patients receiving testosterone (34 grade 1, three grade 2, and one grade 3). One serious adverse event (fibrous mastopathy) and 20 adverse events (16 grade 1 and four grade 2) were reported during the run-in phase, and 12 adverse events during follow-up (nine grade 1 and three grade 2). Interpretation Testosterone was well tolerated and as safe as oestrogen for hormone-replacement therapy. Testosterone can be an alternative hormone substitution in CAIS, especially for woment with reduced sexual functioning. Funding German Federal Ministry of Education and Research.

In order to contribute to the German Energiewende (energy transition) adequately, the building sector has to be almost completely decarbonised in the long term. Our analysis investigates how the German building stock can be transformed into a nearly climate-neutral state by 2050. Using a stock modelling approach based on a typology of the German residential and non-residential building sector, we develop different visions (target states) of what a nearly climate-neutral building stock could look like. All developed target states achieve the overall goal of reducing the non-renewable primary energy demand in 2050 by at least 80%. In order to span a broad target corridor, the target states differ in the two central target dimensions: efficiency (reduction in final energy demand) and energy/technology supply mix (especially the herein contained share of renewable energies). Additionally, using the energy system model REMod-D, the interactions of the building stock with the energy system as a whole are investigated. We explore the differences between a target state focussing on efficiency measures and a target state where efficiency is partly compensated for by an increased use of renewable energies. We learn that from a private cost perspective no clear recommendation can be derived as to which target state should be given priority. This means that other criteria become more relevant, such as social acceptance regarding the different measures, or the challenges that arise from rolling out additional renewable energy capacity on top of what is necessary to achieve the climate goals in other sectors.

Radiant systems are established today and have a high ecological potential in buildings while ensuring thermal comfort. Free-hanging sound absorbers are commonly used for room acoustic control, but can reduce the heat exchange when suspended under an active slab. The aim of this study is to evaluate the impact on thermal comfort of horizontal and vertical free-hanging porous sound absorbers placed in rooms of a building cooled by Thermo-Active Building System (TABS), under real operation conditions. A design comparing five different ceiling coverage ratios and two room types has been implemented during three measurement periods. A clear correlation between increase of ceiling coverage ratio and reduction of thermal comfort could not be derived systematically for each measurement period and room type, contrarily to what was expected from literature. In the first two monitoring periods in the larger office rooms, rooms with higher coverage ratios reported higher operative temperatures. This correlation was however not clear from the monitoring in the smaller offices and other measurement periods. In all monitored rooms, a strong influence of the user behaviour on thermal comfort has been observed. A higher temporal offset between ceiling and operative temperature was also observed in rooms equipped with absorbers.

Aims We examined prevalence and progression of retinopathy in dependence on diabetes duration in order to estimate the probability of progression. Patients/Methods In a retrospective cohort-analysis from an academic outpatient department of endocrinology and metabolic diseases we analyzed 17461 consultations of 4513 patients with DM2 from 1987 to 2014. 50.3% of the patients (n=2272) had at least one documented result of funduscopy. Results 25.8% of the patients had retinopathy (20.2% non-proliferative, 4.7% proliferative, 0.7% were not classified, 0.1% blindness). The prevalence of retinopathy in dependence on diabetes duration was 1.1% at diagnosis, 6.6% after 0 Conclusions/Interpretations Within the first 10 years of diabetes duration, the prevalence of retinopathy is low and the progression infrequent. Most patients have a non-proliferative form which can be reversible and rarely requires interventions. Patients with DM2 without retinopathy and good glycaemic control do not run into additional risk from expanding funduscopy intervals to biennial.

Background Four-dimensional (4D) flow magnetic resonance imaging (MRI) sequences with advanced parallel imaging have the potential to reduce scan time with equivalent image quality and accuracy compared with standard two-dimensional (2D) flow MRI. We compared 4D flow to standard 2D flow sequences using a constant and pulsatile flow phantom at 3 T. Methods Two accelerated 4D flow sequences (GRAPPA2 and k-t-GRAPPA5) were evaluated regarding the concordance of flow volumes, flow velocities, and reproducibility as well as dependency on measuring plane and velocity encoding (V enc). The calculated flow volumes and peak velocities of the phantom were used as reference standard. Flow analysis was performed using the custom-made software “Bloodline”. Results No significant differences in flow volume were found between the 2D, both 4D flow MRI sequences, and the pump reference (p = 0.994) or flow velocities (p = 0.998) in continuous and pulsatile flow. An excellent correlation (R = 0.99–1.0) with a reference standard and excellent reproducibility of measurements (R = 0.99) was achieved for all sequences. A V enc overestimated by up to two times had no impact on flow measurements. However, misaligned measuring planes led to an increasing underestimation of flow volume and mean velocity in 2D flow accuracy, while both 4D flow measurements were not affected. Scan time was significantly shorter for k-t-GRAPPA5 (1:54 ± 0:01 min, mean ± standard deviation) compared to GRAPPA2 (3:56 ± 0:02 min) (p = 0.002). Conclusions Both 4D flow sequences demonstrated equal agreement with 2D flow measurements, without impact of V enc overestimation and plane misalignment. The highly accelerated k-t-GRAPPA5 sequence yielded results similar to those of GRAPPA2.

We present an Aortic Vortex Classification (AVOCLA) that allows to classify vortices in the human aorta semi-automatically. Current medical studies assume a strong relation between cardiovascular diseases and blood flow patterns such as vortices. Such vortices are extracted and manually classified according to specific, unstandardized properties. We employ an agglomerative hierarchical clustering to group vortex-representing path lines as basis for the subsequent classification. Classes are based on the vortex' size, orientation and shape, its temporal occurrence relative to the cardiac cycle as well as its spatial position relative to the vessel course. The classification results are presented by a 2D and 3D visualization technique. To confirm the usefulness of both approaches, we report on the results of a user study. Moreover, AVOCLA was applied to 15 datasets of healthy volunteers and patients with different cardiovascular diseases. The results of the semi-automatic classification were qualitatively compared to a manually generated ground truth of two domain experts considering the vortex number and five specific properties.

4D PC-MRI enables the measurement of time-resolved blood flow directions within a 3D volume. These data facilitate a comprehensive qualitative and quantitative analysis. However, noise is introduced, e.g., due to inhomogeneous magnetic field gradients. Blood is commonly assumed as a non-Newtonian fluid, thus, incompressible, and divergence should be zero. Divergence-free filters enforce this model assumption and have been shown to improve data quality. In this paper, we compare binomial smoothing and three of these techniques: The finite difference method (FDM), divergence-free radial basis functions (DFRBF) and divergence-free wavelets (DFW). The results show that average and maximum velocities tend to decrease, while average line lengths tend to increase slightly. We recommend FDM or DFW divergence-free filtering as an optional pre-processing step in 4D PC-MRI processing pipelines, as they have feasible computation times of few seconds.

In this work the standard wet chemical and plasma texturing processes for multi wire slurry abrasive sawn multi-crystalline silicon were applied to fixed diamond wire sawn (DW) multi-crystalline silicon. The plasma etch produced an effective anti-reflective layer without any changes to the process parameters. The achieved texture features a reflectance well below 5% in the visible range. Furthermore the mechanical strength of the wafers was investigated. 4-point bending tests revealed that anisotropic strength behavior is still present for the plasma textured wafer. In addition to their excellent optical properties, the plasma textured wafers show increase of 123% in characteristic fracture stress related to the as-cut batch for the critical loading with the saw marks parallel to the rollers. This can lead to a significantly reduced breakage rates during solar cell production. It is shown, that the characteristic fracture stress of the multi-crystalline plasma textured batch is equal to the strength of mono-crystalline industrial wet etched fixed diamond wire sawn wafer.

Four-dimensional phase-contrast magnetic resonance imaging 4D PC-MRI allows the non-invasive acquisition of time-resolved, 3D blood flow information. Stroke volumes SVs and regurgitation fractions RFs are two of the main measures to assess the cardiac function and severity of valvular pathologies. The flow rates in forward and backward direction through a plane above the aortic or pulmonary valve are required for their quantification. Unfortunately, the calculations are highly sensitive towards the plane's angulation since orthogonally passing flow is considered. This often leads to physiologically implausible results. In this work, a robust quantification method is introduced to overcome this problem. Collaborating radiologists and cardiologists were carefully observed while estimating SVs and RFs in various healthy volunteer and patient 4D PC-MRI data sets with conventional quantification methods, that is, using a single plane above the valve that is freely movable along the centerline. By default it is aligned perpendicular to the vessel's centerline, but free angulation rotation is possible. This facilitated the automation of their approach which, in turn, allows to derive statistical information about the plane angulation sensitivity. Moreover, the experts expect a continuous decrease of the blood flow volume along the vessel course. Conventional methods are often unable to produce this behaviour. Thus, we present a procedure to fit a monotonous function that ensures such physiologically plausible results. In addition, this technique was adapted for the usage in branching vessels such as the pulmonary artery. The performed informal evaluation shows the capability of our method to support diagnosis; a parameter evaluation confirms the robustness. Vortex flow was identified as one of the main causes for quantification uncertainties.

Der soziologiemagazin e.V. ist ein Akteur Offentlicher Soziologie, welcher vor allem im Social Web aktiv ist und damit in einem Verhaltnis mit Teiloffentlichkeiten steht. Anhand eines erweiterten Offentlichkeitsbegriffs zeigen die Autoren praxisbezogen auf, dass u.a. durch redaktionelle Arbeit Diskurse angeregt werden und es unter bestimmten Umstanden zu einem dialogischen Austausch kommt. Dabei fallt auf, dass kreative Selbstinszenierungen eine wichtige Rolle spielen und das Verhaltnis von Privatem, Offentlichem und Wissenschaftlichem verandern. Der Text soll auserdem zeigen, dass eine Offentliche Soziologie zwar subversive Potentiale fordert, aber ebenso Raum fur Polemiken liefert. Aus der Perspektive einer online-Redaktion lasst sich feststellen, dass Offentliche Soziologie einerseits (nachwuchs)wissenschaftliche Singularitaten hervorbringt und gleichzeitig von Anerkennungsstrukturen gepragt ist.

Bibliographie : Pollmanns, Claas/Kohler, Benjamin: Experteninterview zum Thema mit Prof. Dr. Stephan Lessenich, Soziologiemagazin, 1-2014, S. 6-17. https://doi.org/10.3224/soz.v7i1.16047

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Their initiation and evolution depends strongly on the blood flow characteristics. In recent years, advances in 4D PC-MRI acquisition enable reliable and time-resolved 3D flow measuring, which allows a qualitative and quantitative analysis of the patient-specific hemodynamics. Currently, medical researchers investigate the relation between characteristic flow patterns like vortices and different pathologies. The manual extraction and evaluation is tedious and requires expert knowledge. Standardized, (semi-)automatic and reliable techniques are necessary to make the analysis of 4D PC-MRI applicable for the clinical routine. In this work, we present an approach for the extraction of vortex flow in the aorta and pulmonary artery incorporating line predicates. We provide an extensive comparison of existent vortex extraction methods to determine the most suitable vortex criterion for cardiac blood flow and apply our approach to ten datasets with different pathologies like coarctations, Tetralogy of Fallot and aneurysms. For two cases we provide a detailed discussion how our results are capable to complement existent diagnosis information. To ensure real-time feedback for the domain experts we implement our method completely on the GPU.

6 páginas, 4 figuras., The complex process of supercontinuum generation (SG) is known to be exploitable for designing spatially coherent white light sources emitting light simultaneously in the ultraviolet, visible, and infrared ranges. Herein the first natural material able to generate in laboratory conditions a supercontinuum similar to those known from man-made photonic crystal fibers is described. The ability resides in siliceous 20–50 cm long spicules of the glass sponge Sericolophus hawaiicus. By shedding into the spicules optical peak intensities ranging from 1 to 100 TW cm−2 the generation of a SG is revealed. The SG involves wavelengths between 650 and 900 nm and shows a maximum spectral spread for excitation at a wavelength of 750 nm. It is hypothesized that the SG is favored by spicules being a biocomposite that incorporates together isotopically pure biogenic silica (δ30Si = −3.28) and 15.2 ± 1.3 μg N-acetyl-glucosamine (chitin) per mg of silica. The internal organization of these spicules is distinguished by a solid silica core with a 1 μm wide axial channel as well as a highly ordered silica–chitin composite. Such a composition and organization pattern may be of potential interest for the design of low temperature synthesis of future materials for light guidance., This work was partially supported by the following research grants DFG Grant EH 394/3-1, Krüger Research School, Biohydrometallurgical Center for Strategic Elements (BHMZ) at TU Bergakademie Freiberg, BMBF within the project CryPhys Concept (03EK3029A), Germany, and a grant of the Spanish Government (CTM2015-67221-R) to M.M.