Accumulation of hypointense lesions ("black holes") on T1 spin-echo MRI correlates with disease progression in multiple sclerosis

MRI findings are increasingly used as outcome measures in therapeutic trials in MS. The discrepancy between the extent of the lesions on conventional T2 images and the clinical condition of the patient is one of the problems encountered in such studies. This clinical-radiological paradox prevents the use of MRI data as surrogate markers of disability in MS. A recent pilot study suggested a relationship between hypointense lesions on T1 MRI and disability. To assess in more detail the correlation of changes in hypointense lesion load on T1-weighted spin-echo MR images ("black holes") with changes in disability in MS, we studied 46 patients with clinically definite MS at baseline and after a median follow-up of 40 months. There was a significant correlation between baseline disability and hypointense lesion load (Spearman rank correlation coefficient [SRCC] = 0.46, p = 0.001). In secondary progressive patients, the rate of accumulation of these "black holes" was significantly related to progression rate (SRCC = 0.81, p < 0.0001). We speculate that the appearance of hypointense lesions is the MRI equivalent of a failure of remission. Overall, T1 lesion load measurements correlated better with clinical assessments than T2 lesion load measurements. Quantification of hypointense lesion load on T1-weighted spin-echo MRI helps to resolve the clinical-radiological paradox between disability and MRI and has the potential to be a surrogate marker of disability in MS.     

Novel cellulose derivatives. I. Liquid crystal phase formation in tri-O-α-naphthylmethyl cellulose solutions

Tri-O-α-naphthylmethyl cellulose was prepared by homogeneous phase reaction using SO₂–diethylamine (DEA)–dimethyl sulfoxide (DMSO) as the solvent system. Observations made by dynamic mechanical spectrometry and by cross-polarized optical microscopy revealed liquid crystalline behavior for the concentrated solutions of tri-O-α-naphthylmethyl cellulose in dimethylacetamide (DMAc). Experimental and calculated (predicted) critical volume fraction of the derivative, V^c_p, did not show agreement. It is determined that V^c_p is affected by bulky substituents on the cellulose backbone to some extent. © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of triglyceride‐based polyols and tack‐free coatings via the air oxidation of soy oil

The effect of time and temperature on the air oxidation of soybean oil in the absence of catalysts or added initiators was investigated. It was possible to divide the air oxidation of soybean oil into three regimes. The first regime of air oxidation resulted in insignificant change in the hydroxyl number. During this regime, it was proposed that natural antioxidants, which are present in raw soybean oil, were consumed and peroxide formation occurred. A drastic increase in hydroxyl number due to the formation and subsequent decomposition of peroxides marked the second regime of air oxidation. In the third regime of air oxidation, free radical crosslinking of the soybean oil occurred, and an insoluble gel was formed. The three regimes of air oxidation were used as a guide for the preparation of soy‐based polyols and crosslinked polymers. Crosslinked, tack‐free coatings were prepared from a metal catalyzed oxidation of soybean oil, where soybean oil and ambient oxygen were the only reactants. Higher temperatures (125°C) were more efficient than lower (50°C) for obtaining high gel fractions and tack‐free coatings. Cure of the coatings was expedited with exposure of the coating to UV irradiation after initial heating. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 690–697, 2006     

On the positivity of cotes numbers for interpolatory quadratures with Jacobi abscissas

For interpolatory quadrature rules having abscissas at the zeros of then-th Jacobi polynomialP _n ^(α,β) (x), we show by counterexample that positive Cotes numbers do not exist for all ?1<α,β≤3/2.     

13C CP/MAS NMR study of a wood/phenol–formaldehyde resin bondline

The dynamics and interactions of a wood powder/phenol–formaldehyde (PF) resin composite are evaluated by solid-state ¹³C NMR. A ¹³C labeled and perdeuterated PF resin, with low molecular weight distribution, is synthesized and cured in the neat state and also in combination with yellow-poplar wood powder. The ¹³C NMR spectral features and cross-polarization dynamics of the PF hydroxymethyl and methylene nuclei are compared in the neat resin and in the wood powder composite. In the composite, a downfield shift of the PF hydroxyl bearing carbons suggests secondary interactions between the PF resin and wood. In addition, the PF resin methylene and hydroxymethyl carbons exhibit slower CP dynamics compared to the neat resin. Lower resin CP rates in the composite indicate lower molecular rigidity of the resin in presence of wood compared to the neat cured PF resin.     

Couple-Focused Group Intervention for Women With Early Stage Breast Cancer.

This study examined the efficacy of a couple-focused group intervention on psychological adaptation of women with early stage breast cancer and evaluated whether perceived partner unsupportive behavior or patient functional impairment moderated intervention effects. Two hundred thirty-eight women were randomly assigned to receive either 6 sessions of a couple-focused group intervention or usual care. Intent-to-treat growth curve analyses indicated that participants assigned to the couples' group reported lower depressive symptoms. Women rating their partners as more unsupportive benefited more from the intervention than did women with less unsupportive partners, and women with more physical impairment benefited more from the intervention group than did women with less impairment. Subgroup analyses comparing women attending the couple-focused group intervention with women not attending groups and with usual care participants indicated that women attending sessions reported significantly less distress than did women receiving usual care and women who dropped out of the intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Meta-Analysis of Intellectual and Neuropsychological Test Performance in Attention-Deficit/Hyperactivity Disorder.

Cognitive measures are used frequently in the assessment and diagnosis of attention-deficit/hyperactivity disorder (ADHD). In this meta-analytic review, the authors sought to examine the magnitude of differences between ADHD and healthy participants on several commonly used intellectual and neuropsychological measures. Effect sizes for overall intellectual ability (Full Scale IQ; FSIQ) were significantly different between ADHD and healthy participants (weighted d = .61). Effect sizes for FSIQ were significantly smaller than those for spelling and arithmetic achievement tests and marginally significantly smaller than those for continuous performance tests but were comparable to effect sizes for all other measures. These findings indicate that overall cognitive ability is significantly lower among persons with ADHD and that FSIQ may show as large a difference between ADHD and control participants as most other measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microstenciling: a generic technology for microscale patterning of vapor deposited materials

The fabrication of microstencils for patterning on unconventional substrates was demonstrated. Stencil feature sizes ranging from 6 to 370 /spl mu/m with aspect ratios (stencil feature height :width) in the range of 0.5 : 1 to 15 : 1 were fabricated using ICP etching of silicon. The stenciling process was demonstrated for the deposition of metals (Ti/Au) and dielectrics (silicon dioxide) onto silicon, glass, and polymer based substrates for microfluidic system development. The results demonstrated some dependency of the deposition rate on the stencil feature size and aspect ratio. Results from adhesion studies showed excellent adhesion on all substrates with the exception of PMMA.