BACKGROUND AND PURPOSE Experimental studies have shown that solutes diffuse more slowly into degenerated intervertebral disks than into normal disks. A noninvasive clinical study of diffusion in intervertebral disks is not generally available. Our purpose was to evaluate contrast-enhanced MR images to study diffusion in normal and degenerated lumbar intervertebral disks. METHODS The change in...

We describe new, deep MIPS photometry and new high signal-to-noise optical spectroscopy of the 2.5 Myr-old IC 348 Nebula. To probe the properties of the IC 348 disk population, we combine these data with previous optical/infrared photometry and spectroscopy to identify stars with gas accretion, to examine their mid-IR colors, and to model their spectral energy distributions. IC 348 contains man...

A high speed high performance liquid chromatography (HPLC) method for the quantification of putrescine, spermidine, and spermine in biological samples is described. The dansylation is followed by a sample cleanup. The isocratic HPLC-analysis with acetonitrile:H(2)O (72:28 volume/volume) on 10 centimeter long, 3 micrometer octadecyl silica columns (3 millimeter inner diameter) takes only 4.5 min...

Organic-sulfur-zinc hybrid materials were prepared via polycondensation of Zn(OAc)2 and trithiols bearing various alkyl groups. A soluble nanoparticle could be obtained by the polycondensation using a trithiol bearing octadecyl moieties. The good dispersing ability as nano-scaled particles was confirmed by dynamic light scattering and atomic force microscopy analyses. This hybrid nanoparticle w...

We use electrostatic interactions to direct the patterning of gold disks having ∼10-μm diameters on functionalized surfaces. Planar and curved substrates with patterned surface charge were generated either by microcontact printing or by photolithography. Small charged gold disks were generated by electroplating gold into photoresist molds and derivatizing these disks with charged self-assembled...

Given a convex polygon of n sides, one can draw n disks (called side disks) where each disk has a different side of the polygon as diameter and the midpoint of the side as its center. The intersection graph of such disks is the undirected graph with vertices the n disks and two disks are adjacent if and only if they have a point in common. We prove that for every convex polygon this graph is pl...

We report the formation of self-assembled monolayers (SAMs) onto gold substrates by exposure to lithium dialkyldithiocarbamate salts [(Li+(R2DTC-), where R = n-propyl, n-butyl, n-octyl, n-decyl, n-dodecyl, or n-octadecyl] in ethanol or methylene chloride. The crystallinity and composition of the monolayers were assessed by polarized modulation infrared reflection absorption spectroscopy (PM-IRR...

we study local stability of self-gravitating fluid and stellar disk in the context of modified gravity theories which predict a yukawa-like term in the gravitational potential of a point mass. we investigate the effect of such a yukawa-like term on the dynamics of self-gravitating disks. more specifically, we investigate the consequences of the presence of this term for the local stability of t...

The chromatographic selectivities of polystyrene-coated zirconia (PS-ZrO2) have been investigated in detail by means of homologue series retention studies and studies of a variety of nonpolar aromatic positional isomers. This material has been compared to polybutadiene-coated zirconia, octadecyl- and phenyl-bonded silica, and polymer-based reversed phases. In addition, the separations of a wide...