Topographic hub maps of the human structural neocortical network

Hubs within the neocortical structural network determined by graph theoretical analysis play a crucial role in brain function. We mapped neocortical hubs topographically, using a sample population of 63 young adults. Subjects were imaged with high resolution structural and diffusion weighted magnetic resonance imaging techniques. Multiple network configurations were then constructed per subject, using random parcellations to define the nodes and using fibre tractography to determine the connectivity between the nodes. The networks were analysed with graph theoretical measures. Our results give reference maps of hub distribution measured with betweenness centrality and node degree. The loci of the hubs correspond with key areas from known overlapping cognitive networks. Several hubs were asymmetrically organized across hemispheres. Furthermore, females have hubs with higher betweenness centrality and males have hubs with higher node degree. Female networks have higher small-world indices

Serious adverse events and deaths in PCSK9 inhibitor trials reported on ClinicalTrials.gov:a systematic review

Background: Previous reviews of PCSK9 inhibitor trials are limited by a focus on composite cardiovascular outcomes. ClinicalTrials.gov provides trial results for individual clinical outcomes. Aim of this systematic review was to assess the effect of PCSK9 inhibitors on the risk of myocardial infarction, stroke/TIA, heart failure, diabetes mellitus, neurocognitive events, all-cause serious adverse events (SAE), and all-cause deaths as registered on ClinicalTrials.gov. Methods: PubMed, regulatory reports, ClinicalTrials.gov, and company websites were used to search studies. Randomized trials comparing PCSK9 inhibitor with placebo in participants with hypercholesterolemia were eligible. Study characteristics, risk of bias, and numbers of participants with the outcomes of interest were collected. Results: We identified 33 lipid-lowering and 4 clinical outcomes trials with results on ClinicalTrials.gov (n = 16,958 and n = 73,836, respectively). Risk of bias was generally high. PCSK9 inhibitors did not affect the risk of any of the investigated outcomes in either type of trial. However, in clinical outcomes studies, alirocumab decreased the risk of all-cause SAE (OR 0.92; 95% CI 0.86–0.98), and evolocumab probably increased the risk of mortality (OR 1.12; 95% CI 1.00–1.25). Conclusions: Our meta-analysis of clinical events registered on ClinicalTrials.gov did not show that PCSK9 inhibitors improve cardiovascular health. Evolocumab increased the risk of all-cause mortality

Optimisation of ITER Nb3Sn CICCs for coupling loss, transverse electromagnetic load and axial thermal contraction

The ITER cable-in-conduit conductors (CICCs) are built up from sub-cable bundles, wound in different stages, which are twisted to counter coupling loss caused by time-changing external magnet fields. The selection of the twist pitch lengths has major implications for the performance of the cable in the case of strain sensitive superconductors, i.e. Nb3Sn, as the electromagnetic and thermal contraction loads are large but also for the heat load from the AC coupling loss. Reduction of the transverse load and warm-up cool-down degradation can be reached by applying longer twist pitches in a particular sequence for the sub-stages, offering a large cable transverse stiffness, adequate axial flexibility and maximum allowed lateral strand support. Analysis of short sample (TF conductor) data reveals that increasing the twist pitch can lead to a gain of the effective axial compressive strain of more than 0.3 % with practically no degradation from bending. For reduction of the coupling loss, specific choices of the cabling twist sequence are needed with the aim to minimize the area of linked strands and bundles that are coupled and form loops with the applied changing magnetic field, instead of simply avoiding longer pitches. In addition we recommend increasing the wrap coverage of the CS conductor from 50 % to at least 70 %. The models predict significant improvement against strain sensitivity and substantial decrease of the AC coupling loss in Nb3Sn CICCs, but also for NbTi CICCs minimization of the coupling loss can be achieved. Although the success of long pitches to transverse load degradation was already demonstrated, the prediction of the combination with low coupling loss needs to be validated by a short sample test.Comment: to be published in Supercond Sci Techno

Elliptic surface grid generation on minimal and parmetrized surfaces

An elliptic grid generation method is presented which generates excellent boundary conforming grids in domains in 2D physical space. The method is based on the composition of an algebraic and elliptic transformation. The composite mapping obeys the familiar Poisson grid generation system with control functions specified by the algebraic transformation. New expressions are given for the control functions. Grid orthogonality at the boundary is achieved by modification of the algebraic transformation. It is shown that grid generation on a minimal surface in 3D physical space is in fact equivalent to grid generation in a domain in 2D physical space. A second elliptic grid generation method is presented which generates excellent boundary conforming grids on smooth surfaces. It is assumed that the surfaces are parametrized and that the grid only depends on the shape of the surface and is independent of the parametrization. Concerning surface modeling, it is shown that bicubic Hermite interpolation is an excellent method to generate a smooth surface which is passing through a given discrete set of control points. In contrast to bicubic spline interpolation, there is extra freedom to model the tangent and twist vectors such that spurious oscillations are prevented

Colorless nonlinear optical D-p-A polymers with sulfones as electron acceptors

Colorless side-chain methacrylate copolymers exhibiting relatively narrow charge-transfer bands at 335 nm and second-order optical nonlinearities up to d33 = 4.3 pmV-1 (at 1064 nm) were synthesized and characterized. [on SciFinder (R)