Calcium ion‐mediated grafting of a phosphate‐containing monomer

Grafting of monoacryloxyethyl phosphate onto expanded polytetrafluoroethylene was achieved using simultaneous grafting with the aim of improving the membrane wettability and mineralization capacity. This study explored the effect of adding calcium ions to the grafting solution and observed increased graft yield and wettability when compared with samples grafted in the absence of calcium ions. Fourier transform infrared spectroscopy mapping found the graft copolymer to be distributed in a patchy manner across the surface as well as throughout the membrane. Through X‐ray photoelectron spectroscopy analysis, it was found that calcium ions were incorporated into the graft copolymer and could be extracted using a basic ethylenediaminetetraacetic acid solution without reduction in graft yield. This implies that the presence of calcium ions is affecting the graft yield by increasing the local concentration of monomer near the surface during the grafting process. Investigation of the mineralization capacity of the grafted membranes in simulated body fluid revealed that the increased wettability of the membranes rather than the presence of the calcium ions affected the mineralization outcome. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42808.     

A comparison of optional shift performance and language skills in middle-class and Canadian Indian children.

Compared performances of middle-class and canadian indian children on the optional reversal shift (ors) task to examine deficits hypothesized as being associated with disadvantaged experiential background and slow english-language development. Ss were (a) 60 indian children from a population of 8 yr. Olds attending 2 indian reservation schools, randomly assigned to control and experimental groups; and (b) 30 8-yr-old children from an educationally-advantaged urban area. Ss were selected by their scores on the visual motor gestalt test and later given the peabody picture vocabulary test and the wisc. Results show that middle-class ss surpassed indian control ss on selected language measures and in the number of ors reversers. Relationships between ors choice and language scores were found for some of the urban middle-class scores but not for indian scores. Under an experimental treatment condition of eliciting verbalization prior to choice response, indian experimental ss exceeded indian control ss on initial discrimination learning and in number of reversers on the ors task. Results support hypothesized cultural differences and hypothesized facilitation from requiring indian ss to employ overt verbal mediators. (french summary) (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory of double magnetic induction (DMI) for measuring eyemovements: correction for nonlinearity and simple calibration in twodimensions

An analytical theory approach, based on the concept of mutual induction, to describe the double magnetic induction method for measuring eye movements is presented. A polynomial approach to quantify the method's inherent nonlinearity is evaluated. The solutions to the one-dimensional problem are further elaborated, giving a simple approximation of the two-dimensional problem. The tow-dimensional approximation provides an easily applicable tool for double magnetic induction calibration. According to this theory, calibrations need only be performed parallel to the two main magnetic fields. As a final results, eye rotations are given in any direction as a function of the two measured induction voltages     

Retardation of ossification of the lumbar vertebral column in ankylosing spondylitis by means of phenylbutazone

Does phenylbutazone exert an inhibitory influence on the progression of ossification of the lumbar vertebral column? In a retrospective study of 40 definite cases of ankylosing spondylitis the case histories were divided into periods demarcated by the radiological examinations. An adequately exact method was used for quantitative assessment of ossification. The periods were divided into three groups: (A) continuous phenylbutazone medication; (B) phenylbutazone medication, but not throughout the period; (C) no phenylbutazone medication. Rapid progression of ossification had occurred in group C. In group A, ossification had either remained absent or, if already in progress, had been arrested or substantially delayed. In early or relatively early stages of ankylosing spondylitis, continuous phenylbutazone medication can completely or largely control ossification of the vertebral column. Possibilities of further improvement of this therapy are discussed.     

CATALYTIC PROPERTIES OF ALKALI METAL-GRAPHITE INTERCALATION COMPOUNDS

Graphite reacts with a large number of substances to give lamellar compounds in which the reactant is present in the form of monolayers separated by one or more carbon layers. The compositions of some of the compounds can differ in the repeat frequency of the reactant layer, and occasionally also in the arrangement of atoms within the reactant layer. The “concentration stage” of a compound is defined as the ratio of the number of carbon layers to that of reactant layers. Thus a compound of Stage 1 is always the most concentrated one in a range of intercalation compounds of the same reactant. A survey of some graphite inclusion compounds is given in Table 1.     

Lipid and fatty acid composition of diatoms revisited: rapid wound-activated change of food quality parameters influences herbivorous copepod reproductive success

Lipid and fatty acid composition are considered to be key parameters that determine the nutritive quality of phytoplankton diets for zooplanktonic herbivores. The fitness, reproduction and physiology of the grazers are influenced by these factors. The trophic transfer of lipids and fatty acids from algal cells has been typically studied by using simple extraction and quantification approaches, which, as we argue here, do not reflect the actual situation in the plankton. We show that cell disruption, as it occurs during a predator's grazing on diatoms can drastically change the lipid and fatty acid content of the food. In some algae, a rapid depletion of polyunsaturated fatty acids (PUFAs) is observed within the first minutes after cell disruption. This fatty acid depletion is directly linked to the production of PUFA-derived polyunsaturated aldehydes (PUA); these are molecules that are thought to be involved in the chemical defence of the algae. PUA-releasing diatoms are even capable of transforming lipids from other sources if these are available in the vicinity of the wounded cells. Fluorescent staining reveals that the enzymes involved in lipid transformation are active in the foregut of copepods, and therefore link the depletion processes directly to food uptake. Incubation experiments with the calanoid copepod Temora longicornis showed that PUFA depletion in PUA-producing diatoms is correlated to reduced hatching success, and can be compensated for by externally added single fatty acids.