TY - JOUR A1 - Schneider, Norbert A1 - Huestegge, Lynn T1 - Interaction of oculomotor and manual behavior: evidence from simulated driving in an approach–avoidance steering task JF - Cognitive Research: Principles and Implications N2 - Background While the coordination of oculomotor and manual behavior is essential for driving a car, surprisingly little is known about this interaction, especially in situations requiring a quick steering reaction. In the present study, we analyzed oculomotor gaze and manual steering behavior in approach and avoidance tasks. Three task blocks were implemented within a dynamic simulated driving environment requiring the driver either to steer away from/toward a visual stimulus or to switch between both tasks. Results Task blocks requiring task switches were associated with higher manual response times and increased error rates. Manual response times did not significantly differ depending on whether drivers had to steer away from vs toward a stimulus, whereas oculomotor response times and gaze pattern variability were increased when drivers had to steer away from a stimulus compared to steering toward a stimulus. Conclusion The increased manual response times and error rates in mixed tasks indicate performance costs associated with cognitive flexibility, while the increased oculomotor response times and gaze pattern variability indicate a parsimonious cross-modal action control strategy (avoiding stimulus fixation prior to steering away from it) for the avoidance scenario. Several discrepancies between these results and typical eye–hand interaction patterns in basic laboratory research suggest that the specific goals and complex perceptual affordances associated with driving a vehicle strongly shape cross-modal control of behavior. KW - steering KW - driving simulation KW - gaze control KW - visual orientation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200419 VL - 4 ER - TY - JOUR A1 - Ruf, Katharina A1 - Thomas, Wolfgang A1 - Brunner, Maximilian A1 - Speer, Christian P. A1 - Hebestreit, Helge T1 - Diverging effects of premature birth and bronchopulmonary dysplasia on exercise capacity and physical activity – a case control study JF - Respiratory Research N2 - Background Extreme prematurity has been associated with exercise intolerance and reduced physical activity. We hypothesized that children with bronchopulmonary dysplasia (BPD) would be especially affected based on long-term lung function impairments. Therefore, the objective of this study was to compare exercise capacity and habitual physical activity between children born very and extremely preterm with and without BPD and term-born children. Methods Twenty-two school-aged children (aged 8 to 12 years) born with a gestational age < 32 weeks and a birthweight < 1500 g (9 with moderate or severe BPD (=BPD), 13 without BPD (=No-BPD)) and 15 healthy term-born children (=CONTROL) were included in the study. Physical activity was measured by accelerometry, lung function by spirometry and exercise capacity by an incremental cardiopulmonary exercise test. Results Peak oxygen uptake was reduced in the BPD-group (83 ± 11%predicted) compared to the No-BPD group (91 ± 8%predicted) and the CONTROL group (94 ± 9%predicted). In a general linear model, variance of peak oxygen uptake was significantly explained by BPD status and height but not by prematurity (p < 0.001). Compared to CONTROL, all children born preterm spent significantly more time in sedentary behaviour (BPD 478 ± 50 min, No-BPD 450 ± 52 min, CONTROL 398 ± 56 min, p < 0.05) and less time in moderate-to-vigorous-physical activity (BPD 13 ± 8 min, No-BPD 16 ± 8 min, CONTROL 33 ± 16 min, p < 0.001). Prematurity but not BPD contributed significantly to explained variance in a general linear model of sedentary behaviour and likewise moderate-to-vigorous-physical activity (p < 0.05 and p < 0.001 respectively). Conclusion In our cohort, BPD but not prematurity was associated with a reduced exercise capacity at school-age. However, prematurity regardless of BPD was related to less engagement in physical activity and more time spent in sedentary behaviour. Thus, our findings suggest diverging effects of prematurity and BPD on exercise capacity and physical activity." KW - Bronchopulmonary dysplasia KW - Physical activity KW - Exercise testing KW - Preterm birth KW - Exercise capacity Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202449 VL - 20 ER - TY - JOUR A1 - Richter, Anne A1 - Exner, Florian A1 - Bratengeier, Klaus A1 - Polat, Bülent A1 - Flentje, Michael A1 - Weick, Stefan T1 - Impact of beam configuration on VMAT plan quality for Pinnacle\(^3\)Auto-Planning for head and neck cases JF - Radiation Oncology N2 - Background The purpose of this study was to compare automatically generated VMAT plans to find the superior beam configurations for Pinnacle3 Auto-Planning and share “best practices”. Methods VMAT plans for 20 patients with head and neck cancer were generated using Pinnacle3 Auto-Planning Module (Pinnacle3 Version 9.10) with different beam setup parameters. VMAT plans for single (V1) or double arc (V2) and partial or full gantry rotation were optimized. Beam configurations with different collimator positions were defined. Target coverage and sparing of organs at risk were evaluated based on scoring of an evaluation parameter set. Furthermore, dosimetric evaluation was performed based on the composite objective value (COV) and a new cross comparison method was applied using the COVs. Results The evaluation showed a superior plan quality for double arcs compared to one single arc or two single arcs for all cases. Plan quality was superior if a full gantry rotation was allowed during optimization for unilateral target volumes. A double arc technique with collimator setting of 15° was superior to a double arc with collimator 60° and a two single arcs with collimator setting of 15° and 345°. Conclusion The evaluation showed that double and full arcs are superior to single and partial arcs in terms of organs at risk sparing even for unilateral target volumes. The collimator position was found as an additional setup parameter, which can further improve the target coverage and sparing of organs at risk. KW - auto-planning KW - VMAT KW - single arc KW - double arc KW - full arc KW - partial arc KW - plan comparison Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200301 VL - 14 ER - TY - JOUR A1 - Rullmann, Michael A1 - Preusser, Sven A1 - Poppitz, Sindy A1 - Heba, Stefanie A1 - Gousias, Konstantinos A1 - Hoyer, Jana A1 - Schütz, Tatjana A1 - Dietrich, Arne A1 - Müller, Karsten A1 - Hankir, Mohammed K. A1 - Pleger, Burkhard T1 - Adiposity Related Brain Plasticity Induced by Bariatric Surgery JF - Froniers in Human Neuroscience N2 - Previous magnetic resonance imaging (MRI) studies revealed structural-functional brain reorganization 12 months after gastric-bypass surgery, encompassing cortical and subcortical regions of all brain lobes as well as the cerebellum. Changes in the mean of cluster-wise gray/white matter density (GMD/WMD) were correlated with the individual loss of body mass index (BMI), rendering the BMI a potential marker of widespread surgery-induced brain plasticity. Here, we investigated voxel-by-voxel associations between surgery-induced changes in adiposity, metabolism and inflammation and markers of functional and structural neural plasticity. We re-visited the data of patients who underwent functional and structural MRI, 6 months (n = 27) and 12 months after surgery (n = 22), and computed voxel-wise regression analyses. Only the surgery-induced weight loss was significantly associated with brain plasticity, and this only for GMD changes. After 6 months, weight loss overlapped with altered GMD in the hypothalamus, the brain's homeostatic control site, the lateral orbitofrontal cortex, assumed to host reward and gustatory processes, as well as abdominal representations in somatosensory cortex. After 12 months, weight loss scaled with GMD changes in right cerebellar lobule VII, involved in language-related/cognitive processes, and, by trend, with the striatum, assumed to underpin (food) reward. These findings suggest time-dependent and weight-loss related gray matter plasticity in brain regions involved in the control of eating, sensory processing and cognitive functioning. KW - adiposity KW - magnetic resonance imaging KW - brain plasticity KW - bariatric surgery KW - gastric-bypass surgery Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227168 VL - 13 ER - TY - JOUR A1 - Bratengeier, Klaus A1 - Holubyev, Kostyantyn A1 - Wegener, Sonja T1 - Steeper dose gradients resulting from reduced source to target distance—a planning system independent study JF - Journal of Applied Clinical Medical Physics N2 - Purpose: To quantify the contribution of penumbra in the improvement of healthy tissue sparing at reduced source‐to‐axis distance (SAD) for simple spherical target and different prescription isodoses (PI). Method: A TPS‐independent method was used to estimate three‐dimensional (3D) dose distribution for stereotactic treatment of spherical targets of 0.5 cm radius based on single beam two‐dimensional (2D) film dosimetry measurements. 1 cm target constitutes the worst case for the conformation with standard Multi‐Leaf Collimator (MLC) with 0.5 cm leaf width. The measured 2D transverse dose cross‐sections and the profiles in leaf and jaw directions were used to calculate radial dose distribution from isotropic beam arrangement, for both quadratic and circular beam openings, respectively. The results were compared for standard (100 cm) and reduced SAD 70 and 55 cm for different PI. Results: For practical reduction of SAD using quadratic openings, the improvement of healthy tissue sparing (HTS) at distances up to 3 times the PTV radius was at least 6%–12%; gradient indices (GI) were reduced by 3–39% for PI between 40% and 90%. Except for PI of 80% and 90%, quadratic apertures at SAD 70 cm improved the HTS by up to 20% compared to circular openings at 100 cm or were at least equivalent; GI were 3%–33% lower for reduced SAD in the PI range 40%–70%. For PI = 80% and 90% the results depend on the circular collimator model. Conclusion: Stereotactic treatments of spherical targets delivered at reduced SAD of 70 or 55 cm using MLC spare healthy tissue around the target at least as good as treatments at SAD 100 cm using circular collimators. The steeper beam penumbra at reduced SAD seems to be as important as perfect target conformity. The authors argue therefore that the beam penumbra width should be addressed in the stereotactic studies. KW - radiotherapy KW - stereotactic irradiation KW - penumbra KW - leaf width KW - virtual isocenter Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177424 VL - 20 IS - 1 ER - TY - JOUR A1 - Mansour, Ahmed M. A1 - Steiger, Christoph A1 - Nagel, Christoph A1 - Schatzschneider, Ulrich T1 - Wavelength‐dependent control of the CO release kinetics of manganese(I) tricarbonyl PhotoCORMs with benzimidazole coligands JF - European Journal of Inorganic Chemistry N2 - A series of photoactivatable CO‐releasing molecules (PhotoCORMs) was prepared from manganese pentacarbonyl bromide and 1H‐benzimidazol‐2‐ylmethyl‐(N‐phenyl)amine ligands (L) bearing different electron‐donating and electron‐withdrawing groups R = H, 4‐CH\(_3\), 4‐OCH\(_3\), 4‐Cl, 4‐NO\(_2\), 2‐, 3‐, and 4‐COOCH\(_3\) on the phenyl substituent to give octahedral manganese(I) complexes of the general formula [MnBr(CO)\(_3\)(L)]. Aerated DMSO solutions of the compounds are stable in the dark for 16 h with no CO release. However, the compounds rapidly release CO upon illumination at 412–525 nm, depending on the substitution pattern. Its influence on the photophysical and photochemical properties was systematically explored using UV/Vis spectroscopy and CO release measurements with a commercial gas sensor system. In the nitro‐substituted compound, the electronically excited state switched from benzimidazole‐ to phenyl‐centered, leading to a markedly different photochemical behavior of this visible‐light activated PhotoCORM. KW - CO‐releasing molecules (CORMs) KW - Manganese Carbonyl ligands KW - Benzimidazole KW - TDDFT Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218362 VL - 2019 IS - 42 ER - TY - JOUR A1 - Lenczyk, Carsten A1 - Roy, Dipak Kumar A1 - Nitsch, Jörn A1 - Radacki, Krzysztof A1 - Rauch, Florian A1 - Dewhurst, Rian D. A1 - Bickelhaupt, F. Matthias A1 - Marder, Todd B. A1 - Braunschweig, Holger T1 - Steric Effects Dictate the Formation of Terminal Arylborylene Complexes of Ruthenium from Dihydroboranes JF - Chemistry - A European Journal N2 - The steric and electronic properties of aryl substituents in monoaryl borohydrides (Li[ArBH\(_3\)]) and dihydroboranes were systematically varied and their reactions with [Ru(PCy\(_3\))\(_2\)HCl(H\(_2\))] (Cy: cyclohexyl) were studied, resulting in bis(σ)‐borane or terminal borylene complexes of ruthenium. These variations allowed for the investigation of the factors involved in the activation of dihydroboranes in the synthesis of terminal borylene complexes. The complexes were studied by multinuclear NMR spectroscopy, mass spectrometry, X‐ray diffraction analysis, and density functional theory (DFT) calculations. The experimental and computational results suggest that the ortho‐substitution of the aryl groups is necessary for the formation of terminal borylene complexes. KW - Arylborylene Complexes KW - Ruthenium KW - Dihydroboranes KW - boranes KW - borohydrides KW - borylenes KW - steric effects KW - sigma boranes Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219537 SN - 1521-3765 VL - 25 IS - 59 ER - TY - JOUR A1 - Bélanger‐Chabot, Guillaume A1 - Braunschweig, Holger T1 - Hexahalodiborate Dianions: A New Family of Binary Boron Halides JF - Angewandte Chemie International Edition N2 - The electron‐precise binary boron subhalide species [B\(_2\)X\(_6\)]\(^{2−}\) X=F, Br, I) were synthesized and their structures confirmed by X‐ray crystallography. The existence of the previously claimed [B\(_2\)Cl\(_6\)]\(^{2−}\), which had been questioned, was also confirmed by X‐ray crystallography. The dianions are isoelectronic to hexahaloethanes, are subhalide analogues of the well‐known tetrahaloborate anions (BX\(_4\)\(^−\)), and are rare examples of molecular electron‐precise binary boron species beyond B\(_2\)X\(_4\), BX\(_3\), and [BX\(_4\)]\(^−\). KW - binary species KW - boron KW - electron-precise diborates KW - halogens Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219688 VL - 58 IS - 40 ER - TY - JOUR A1 - Steinmetzger, Christian A1 - Bessi, Irene A1 - Lenz, Ann-Kathrin A1 - Höbartner, Claudia T1 - Structure-fluorescence activation relationships of a large Stokes shift fluorogenic RNA aptamer JF - Nucleic Acids Research N2 - The Chili RNA aptamer is a 52 nt long fluorogen-activating RNA aptamer (FLAP) that confers fluorescence to structurally diverse derivatives of fluorescent protein chromophores. A key feature of Chili is the formation of highly stable complexes with different ligands, which exhibit bright, highly Stokes-shifted fluorescence emission. In this work, we have analyzed the interactions between the Chili RNA and a family of conditionally fluorescent ligands using a variety of spectroscopic, calorimetric and biochemical techniques to reveal key structure - fluorescence activation relationships (SFARs). The ligands under investigation form two categories with emission maxima of ~540 nm or ~590 nm, respectively, and bind with affinities in the nanomolar to low-micromolar range. Isothermal titration calorimetry was used to elucidate the enthalpic and entropic contributions to binding affinity for a cationic ligand that is unique to the Chili aptamer. In addition to fluorescence activation, ligand binding was also observed by NMR spectroscopy, revealing characteristic signals for the formation of a G-quadruplex only upon ligand binding. These data shed light on the molecular features required and responsible for the large Stokes shift and the strong fluorescence enhancement of red and green emitting RNA-chromophore complexes. KW - Chili RNA Aptamer KW - fluorogen-activating RNA aptamer (FLAP) KW - Stokes-shifted fluorescence emission KW - key structure - fluorescence activation relationships (SFARs) KW - ligand binding Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-192340 ER - TY - JOUR A1 - Pöppler, Ann-Christin A1 - Lübtow, Michael M. A1 - Schlauersbach, Jonas A1 - Wiest, Johannes A1 - Meinel, Lorenz A1 - Luxenhofer, Robert T1 - Loading dependent Structural Model of Polymeric Micelles Encapsulating Curcumin by Solid-State NMR Spectroscopy JF - Angewandte Chemie International Edition N2 - Detailed insight into the internal structure of drug‐loaded polymeric micelles is scarce, but important for developing optimized delivery systems. We observed that an increase in the curcumin loading of triblock copolymers based on poly(2‐oxazolines) and poly(2‐oxazines) results in poorer dissolution properties. Using solid‐state NMR spectroscopy and complementary tools we propose a loading‐dependent structural model on the molecular level that provides an explanation for these pronounced differences. Changes in the chemical shifts and cross‐peaks in 2D NMR experiments give evidence for the involvement of the hydrophobic polymer block in the curcumin coordination at low loadings, while at higher loadings an increase in the interaction with the hydrophilic polymer blocks is observed. The involvement of the hydrophilic compartment may be critical for ultrahigh‐loaded polymer micelles and can help to rationalize specific polymer modifications to improve the performance of similar drug delivery systems. KW - dissolution rates KW - micelles KW - polymers KW - short-range order KW - solid-state NMR spectroscopy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-206705 VL - 58 IS - 51 ER -