No evidence for retinal damage evolving from reduced retinal blood flow in carotid artery disease

Introduction. Carotid artery disease (CAD) comprising high-grade internal carotid artery stenosis (CAS) or carotid artery occlusion (CAO) may lead to ipsilateral impaired cerebral blood flow and reduced retinal blood supply. Objective. To examine the influence of chronic CAD on retinal blood flow, retinal morphology, and visual function. Methods. Patients with unilateral CAS ≥ 50% (ECST criteria) or CAO were grouped according to the grade of the stenosis and to the flow direction of the ophthalmic artery (OA). Retinal perfusion was measured by transorbital duplex ultrasound, assessing central retinal artery (CRA) blood flow velocities. In addition, optic nerve and optic nerve sheath diameter were measured. Optical coherence tomography (OCT) was performed to study retinal morphology. Visual function was assessed using high- and low-contrast visual paradigms. Results. Twenty-seven patients were enrolled. Eyes with CAS ≥ 80%/CAO and retrograde OA blood flow showed a significant reduction in CRA peak systolic velocity (no-CAD side: 0.130 ± 0.035 m/s, CAS/CAO side: 0.098 ± 0.028; p = 0.005; n = 12). OCT, optic nerve thicknesses, and visual functional parameters did not show a significant difference. Conclusion. Despite assessable hemodynamic effects, chronic high-grade CAD does not lead to gaugeable morphological or functional changes of the retina

Tolerance and cross-tolerance to neurocognitive effects of THC and alcohol in heavy cannabis users

and cross-tolerance to neurocognitive effects of THC and alcohol in heavy cannabis user

Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Einrichtung zum Transport von Stueckguetern, insbesondere Bauteilen

Es wird eine Einrichtung zum Transport von Stueckguetern, insbesondere Bauteilen (5, 6), von einem ersten Aufnahme- oder Abgabeplatz zu einem zweiten, einem Bearbeitungsplatz zugeordneten Aufnahme- oder Abgabeplatz mit einer Hubeinrichtung (4) und zwei parallel angeordneten, axial beabstandeten Transporteinheiten (7), welche je aus einem unteren und oberen, das Stueckgut zum unteren entgegensetzt bewegenden Transportmittel (7a) bestehen, beschrieben. Die oberen und unteren Transportmittel (7a, 7b) werden gemeinsam von den Hubeinrichtungen (4) auf die jeweilige Aufnahme- oder Abgabehoehe eingestellt. Dabei werden die Stueckgueter (5, 6) von in der Hoehe fest angeordneten Transporteinrichtungen (7) beim Anheben der Hubeinrichtungen (4) auf die oberen und unteren Transportmittel (7a, 7b) abgelegt und gegensinnig gleichzeitig auf den oberen und auf den unteren Transportmitteln (7a, 7b) bewegt (Fig. 3)

DNA Origami Nanoneedles on Freestanding Lipid Membranes as a Tool To Observe Isotropic-Nematic Transition in Two Dimensions

We introduce a simple experimental system to study dynamics of needle-like nanoobjects in two dimensions (2D) as a function of their surface density close to the isotropicnematic transition. Using fluorescence correlation spectroscopy, we find that translational and rotational diffusion of rigid DNA origami nanoneedles bound to freestanding lipid membranes is strongly suppressed upon an increase in the surface particle density. Our experimental observations show a good agreement with results of Monte Carlo simulations of Brownian hard needles in 2D

Amphipathic DNA Origami Nanoparticles to Scaffold and Deform Lipid Membrane Vesicles

We report a synthetic biology-inspired approach for the engineering of amphipathic DNA origami structures as membrane-scaffolding tools. The structures have a flat membrane-binding interface decorated with cholesterol-derived anchors. Sticky oligonucleotide overhangs on their side facets enable lateral interactions leading to the formation of ordered arrays on the membrane. Such a tight and regular arrangement makes our DNA origami capable of deforming free-standing lipid membranes, mimicking the biological activity of coat-forming proteins, for example, from the I-/F-BAR family

Switchable domain partitioning and diffusion of DNA origami rods on membranes

Recently, DNA origami became a powerful tool for custom-shaped functional biomolecules. In this paper, we present the first approach towards assembling amphipathic three-dimensional DNA origami nanostructures and assessing their dynamics on the surface of freestanding phospholipid membranes. Our nanostructures were stiff DNA origami rods comprising six DNA helices. They were functionalized with hydrophobic cholesteryl-ethylene glycol anchors and fluorescently labeled at defined positions. Having these tools in hand, we could demonstrate not only the capability of the amphipathic nanorods to coat membranes of various phospholipid compositions, but also their switchable liquid-ordered/liquid-disordered partitioning on phase separated membranes. The observed translocation of our nanostructures between different domains was controlled by divalent ions. Moreover, selective fluorescent labeling enabled us to distinguish between the translational and rotational diffusion of our six helix bundles on the membranes by fluorescence correlation spectroscopy. The obtained data reveal how DNA origami can be employed as a valuable tool in membrane biophysics