Human magnetic resonance imaging at 8 T

BACKGROUND: Antibodies to Epstein Barr Virus (EBV) antigens have been used for the diagnosis of nasopharyngeal carcinoma (NPC). While immunofluorescence assays (IFA) of IgA antiviral capsid and early antigens have been the mainstay of this diagnosis, enzyme immunoassays (ELISA) of various EBV antigens are now available. However in almost all of these assays, the sensitivities and specificities have been calculated using blood donors and normal hospital staff as controls, who may not be the most appropriate controls. We wanted to evaluate the usefulness of IFA and ELISA of various EBV antigens in a clinical setting to distinguish between patients with NPC and those suspected of NPC but being biopsy negative. METHODS: Between January 1987 and June 1988, 322 consecutive patients suspected of NPC and who had a post-nasal biopsy were studied. Blood was taken for EBV tests before diagnosis. Tests included IFA and ELISA IgA anti-VCA and anti-EA and ELISA IgA and IgG anti-ribonucleotide reductase, a cloned EA antigen. RESULTS: IFA IgA anti-VCA together with IFA IgA anti-EA both at a cut-off of 1:10 gave the best discrimination between patients with NPC and those suspected of NPC but were biopsy negative. CONCLUSION: The ELISA IgG anti-ribonucleotide reductase test is convenient to perform and looks very promising. An ELISA using a cocktail of cloned EA peptides may be even better.     

Grid with a view: optimal texturing for perception of layered surface shape

We present the results of two controlled studies comparing layered surface visualizations under various texture conditions. The task was to estimate surface normals, measured by accuracy of a hand-set surface normal probe. A single surface visualization was compared with the two-surfaces case under conditions of no texture and with projected grid textures. Variations in relative texture spacing on top and bottom surfaces were compared, as well as opacity of the top surface. Significant improvements are found for the textured cases over non-textured surfaces. Either larger or thinner top-surface textures, and lower top surface opacities are shown to give less bottom surface error. Top surface error appears to be highly resilient to changes in texture. Given the results we also present an example of how appropriate textures might be useful in volume visualization.     

The temperature and pressure dependence of viscosity and volume for two reference liquids

The new quantitative elastohydrodynamics has resulted in rapid advances in understanding concentrated contact lubrication behaviour by employing real transport properties. A key component of this revolution has been the use of reference liquids. In this paper, two liquids, a triester and a perfluoropolyether, which are under consideration as possible viscosity standards are characterised to 1 GPa for conditions relevant to tribology. Two correlations are provided for interpolation and data smoothing, and an explanation for difficulties encountered with free volume theory is offered. The perfluoropolyether is only appropriate as a reference liquid when an identical lot is available. Copyright © 2015 John Wiley & Sons, Ltd.     

Preparation of nano-sized particles from collagen II by a high-voltage electrostatic field system

The pilot study describes a novel method for preparing nano-sized particles from collagen II using a high-voltage electrostatic field system. Observations from transmission electron microscopy showed that, in one of the cases, the nano-sized collagen II particles exhibited good sphericity, and the particles were in the range of 23.3+/-1.7 nm in diameter at the experimental setting of 3 kV cm(-1), for a 3 h treatment period and at 25 degrees C (with a collagen concentration of 0.2 mg ml(-1)). When the treatment temperature increased to 30 degrees C, the collagen II began to lose the tendency to form individually separated spherically shaped nano-particles. Moreover, a fibrous structure of collagen II was formed instead of a nano-particle shape at the temperature of 37 degrees C. This result is probably contributed to by an entropy-driven process that is termed fibrillogenesis, a larger force causing the collagen molecules to self-assemble and then form collagen fibrils. It is interesting to note that this is practically the first attempt to produce nano-particles directly from collagen II solution under the treatment of a high-voltage electrostatic field, together with a set of working parameters for the collagen concentration and low-temperature setting.     

An approach to the perceptual optimization of complex visualizations

This paper proposes a new experimental framework within which evidence regarding the perceptual characteristics of a visualization method can be collected, and describes how this evidence can be explored to discover principles and insights to guide the design of perceptually near-optimal visualizations. We make the case that each of the current approaches for evaluating visualizations is limited in what it can tell us about optimal tuning and visual design. We go on to argue that our new approach is better suited to optimizing the kinds of complex visual displays that are commonly created in visualization. Our method uses human-in-the-loop experiments to selectively search through the parameter space of a visualization method, generating large databases of rated visualization solutions. Data mining is then used to extract results from the database, ranging from highly specific exemplar visualizations for a particular data set, to more broadly applicable guidelines for visualization design. We illustrate our approach using a recent study of optimal texturing for layered surfaces viewed in stereo and in motion. We show that a genetic algorithm is a valuable way of guiding the human-in-the-loop search through visualization parameter space. We also demonstrate several useful data mining methods including clustering, principal component analysis, neural networks, and statistical comparisons of functions of parameters.     

DSC and 13C-NMR studies of the imidazole-accelerated reaction between epoxides and phenols

The imidazole-accelerated reaction between epoxides and phenols has been studied through DSC and ¹³C-NMR of model compounds. The selectivity of the accelerator has been found to be strongly dependent on its concentration. If a low amount of accelerator is used, the reaction takes place almost exclusively through the addition of phenols to epoxides even if the latter are used in excess. However, a larger amount of accelerator will cause the secondary hydroxyls (produced by the main reaction) to react with the epoxides. In any case, the lower reactivity of the secondary hydroxyls prevents them from reacting to any significant extent as long as there are any phenols present. When polyfunctional resins are used, the effect of the selectivity of the reaction on the properties of the crosslinked network is very clear. If a low amount of accelerator is used (to promote only the epoxy–phenol reaction), the maximum glass transition temperature (T_g) occurs when the epoxides and phenols are stoichiometrically balanced, reaching 178°C. However, when an excess of epoxides over phenols is used, along with a larger amount of accelarator, the maximum T_g increases its value to 199°C.     

Multi-modal behavioral approach to the treatment and management of essential hypertension.

Explored the efficacy of a multimodal behavioral approach for the treatment and long-term management of essential hypertension in a 24-yr-old male. Generalization techniques and community measurements were integral components of treatment as well as data collection procedures. Blood pressure was brought within the normotensive range and stabilized without the use of anti-hypertensive medications. Normal readings were maintained throughout a 6-mo follow-up period. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity and factor analyses of naval air training predictor and criterion measurers.

"The most substantial relationships existed between tests of academic aptitude and grades in the pre-flight phase of training. Tests of spatial and perceptual abilities correlated highest with final basic and advanced flight grades. Four significant factors derived by factor analysis were: perceptual, academic potential, comprehension of relationships, and applied spatial relations [these factors, however, accounted for only 51 percent of the total variance]. Although the inclusion of criterion variables did not reveal any new factors, it did aid considerably in defining those factors found." 15 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A critical evaluation of film thickness‐derived pressure–viscosity coefficients

A single parameter, the pressure–viscosity coefficient, α, quantifies the pressure dependence of the viscosity of the liquid in elastohydrodynamic lubrication (EHL). Most published values of α have not been obtained from measurements of viscosity as a function of pressure. Rather, these effective pressure–viscosity coefficients have been derived from the measurement of the EHL film thickness, a more difficult procedure. In this article, five well‐characterized liquids that should be Newtonian in the EHL inlet are identified for which film‐derived coefficients have been reported. These coefficients are compared with coefficients derived from published viscosity correlations and new viscosity measurements. The film‐derived coefficients are found to not be an accurate representation of the piezoviscous response. The procedure of deriving a pressure–viscosity coefficient from a film thickness measurement does not offer an alternative to the simpler and easier viscometer measurement. Copyright © 2014 John Wiley & Sons, Ltd.