Isotope shifts of 223–226,228Ra19F were measured for different vibrational levels in the electronic transition A2II1/2 ← X2Σ+. The observed isotope shifts demonstrate the particularly high ...sensitivity of radium monofluoride to nuclear size effects, offering a stringent test of models describing the electronic density within the radium nucleus. Ab initio quantum chemical calculations are in excellent agreement with experimental observations. These results highlight some of the unique opportunities that short-lived molecules could offer in nuclear structure and in fundamental symmetry studies.
We report the first high resolution spectroscopic study of the NH3-H2 van der Waals molecular complex. Three different experimental techniques, a molecular beam Fourier transform microwave ...spectrometer, a millimeter-wave intracavity jet OROTRON spectrometer, and a submillimeter-wave jet spectrometer with multipass cell, were used to detect pure rotational transitions of NH3-H2 in the wide frequency range from 39 to 230 GHz. Two nuclear spin species, (o)-NH3-(o)-H2 and (p)-NH3-(o)-H2, have been assigned as carriers of the observed lines on the basis of accompanying rovibrational calculations performed using the ab initio intermolecular potential energy surface (PES) of Maret et al. The experimental spectra were compared with the theoretical bound state results, thus providing a critical test of the quality of the NH3-H2 PES, which is a key issue for reliable computations of the collisional excitation and de-excitation of ammonia in the dense interstellar medium.
Nanotherapy has recently emerged as an experimental treatment option for atherosclerosis. To fulfill its promise, robust noninvasive imaging approaches for subject selection and treatment evaluation ...are warranted. To that end, we present here a positron emission tomography (PET)-based method for quantification of liposomal nanoparticle uptake in the atherosclerotic vessel wall. We evaluated a modular procedure to label liposomal nanoparticles with the radioisotope zirconium-89 (89Zr). Their biodistribution and vessel wall targeting in a rabbit atherosclerosis model was evaluated up to 15 days after intravenous injection by PET/computed tomography (CT) and PET/magnetic resonance imaging (PET/MRI). Vascular permeability was assessed in vivo using three-dimensional dynamic contrast-enhanced MRI (3D DCE-MRI) and ex vivo using near-infrared fluorescence (NIRF) imaging. The 89Zr-radiolabeled liposomes displayed a biodistribution pattern typical of long-circulating nanoparticles. Importantly, they markedly accumulated in atherosclerotic lesions in the abdominal aorta, as evident on PET/MRI and confirmed by autoradiography, and this uptake moderately correlated with vascular permeability. The method presented herein facilitates the development of nanotherapy for atherosclerotic disease as it provides a tool to screen for nanoparticle targeting in individual subjects’ plaques.
We have studied the spin excitations of ferromagnetic rings and observed a distinct series of quantized modes in the vortex state. We attribute them to spin waves that circulate around the ring and ...interfere constructively. They form azimuthal eigenmodes of a magnetic ring resonator which we resolve up to the fourth order. The eigenfrequencies are calculated semianalytically and classified as a function of magnetic field by a quantization rule which takes into account a periodic boundary condition. Strikingly each mode exists only below a characteristic field.
The content of supervised group exercise (SGE) for axial spondyloarthritis (axSpA) has hardly changed in recent decades, despite new evidence-based insights to improve SGE quality. This pilot ...implementation study evaluated the effects and feasibility of enhancements in axSpA-specific SGE in four regions in the Netherlands.
The implemented enhancements included: more high-intensity aerobic exercise; exercise personalization with periodic assessments; and patient education on home exercise. The implementation strategy included a one-day supervisor training course and telephone support. To evaluate effects, aerobic capacity Six-Minute Walk Test (6MWT), physical functioning Ankylosing Spondylitis Performance-based Improvement (ASPI); improved/not improved, health status Assessment of SpondyloArthritis international Society Health Index (ASAS HI) questionnaire, and home exercise engagement Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH) were assessed at baseline and after one year in 60 participants. Changes were analysed with the Wilcoxon signed-rank test. To evaluate feasibility, a survey of participants and semi-structured interviews with four SGE supervisors assessed uptake and satisfaction with the enhancements.
Aerobic capacity increased significantly and 35% of participants improved functioning, whereas health status and home exercise engagement did not change. The participants' survey and supervisors' interviews showed that high-intensity aerobic exercise was implemented successfully, exercise personalization and periodic assessments were implemented partially, and patient education was not implemented at all. Most participants were satisfied with the changes.
After this pilot implementation, SGE enhancements were only partially implemented. Nevertheless, aerobic capacity improved significantly and satisfaction with accomplished changes was high. Nationwide implementation would require adaptations to improve feasibility.
Modern electron microscopy (EM) such as fine-scale transmission EM, focused ion beam scanning EM, and EM tomography have enormously improved our knowledge about the synaptic organization of the ...normal, developmental, and pathologically altered brain. In contrast to various animal species, comparably little is known about these structures in the human brain. Non-epileptic neocortical access tissue from epilepsy surgery was used to generate quantitative 3D models of synapses. Beside the overall geometry, the number, size, and shape of active zones and of the three functionally defined pools of synaptic vesicles representing morphological correlates for synaptic transmission and plasticity were quantified. EM tomography further allowed new insights in the morphological organization and size of the functionally defined readily releasable pool. Beside similarities, human synaptic boutons, although comparably small (approximately 5 µm), differed substantially in several structural parameters, such as the shape and size of active zones, which were on average 2 to 3-fold larger than in experimental animals. The total pool of synaptic vesicles exceeded that in experimental animals by approximately 2 to 3-fold, in particular the readily releasable and recycling pool by approximately 2 to 5-fold, although these pools seemed to be layer-specifically organized. Taken together, synaptic boutons in the human temporal lobe neocortex represent unique entities perfectly adapted to the "job" they have to fulfill in the circuitry in which they are embedded. Furthermore, the quantitative 3D models of synaptic boutons are useful to explain and even predict the functional properties of synaptic connections in the human neocortex.
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