Effect of the hydroxyl content and molecular weight of polyvinyl butyral on tape properties

Despite the desire to replace organics with water in tape casting systems, thick films often use solvent in order to speed up drying rates. Polyvinyl butyral having hydroxyl contents ranging between 11 and 20% and molecular weights between 40,000 and 120,000 g/mol was plasticized with butyl benzyl phthalate at solids contents between 62 and 75 vol.% La_0.5Sr_0.5CoO₃ once the toluene/ethanol solvent was evaporated. High-hydroxyl content was more important than high molecular weight in increasing the Young's modulus, yield strength, and tensile strength of the tapes at room temperature. Annealing tapes at low temperatures (65 °C) for short times (10 min) relaxed stresses and tended to equalize modulus, strength, and ductility. Low hydroxyl content and low molecular weight enhanced particle packing, which resulted in cracking as tape thickness increased from 0.2 mm to 0.7 mm at higher solids contents. Crack-free tapes were made at all solids contents when the hydroxyl content was greater than 18%. Lower molecular weight at high-hydroxyl content, along with high solids content, was important for minimizing the amount of solvent used.     

Gamma interferon is not essential in host defense against disseminated candidiasis in mice

Apoptosis is well known to be mediated by oxidative stress. To evaluate the functional role of reactive oxygen intermediates (ROI) produced by neutrophils, we compared the rates of apoptosis in neutrophils isolated from normal donors and from patients with chronic granulomatous disease (CGD), a hereditary defect in ROI production. Spontaneous cell death in CGD neutrophils in vitro was significantly inhibited relative to normal neutrophils. The acceleration of apoptosis induced by anti-Fas monoclonal antibody (MoAb) in CGD neutrophils was much slower than that seen in normal neutrophils. These findings suggest that the apoptosis of neutrophils may be mediated by endogenous oxidative products. This suggestion was confirmed by observation that apoptosis of normal neutrophils was markedly inhibited by reduction of intracellular levels of hydrogen peroxide (H2O2). The inhibition of apoptosis in normal neutrophils by adding catalase occurred regardless of the presence of anti-Fas MoAb. H2O2 increased both spontaneous apoptosis and Fas-mediated apoptosis of the CGD neutrophils in proportion to that seen in normal neutrophils. Although several factors that mediate the apoptosis of neutrophils remain to be determined, these results suggest that ROI are major mediators of the apoptosis in neutrophils and may be involved in Fas-mediated signal transduction pathway.     

Getting along and getting ahead: Empirical support for a theory of protective and acquisitive self-presentation.

Study 1, with 386 undergraduates, demonstrated that the Concern for Appropriateness Scale and the Revised Self-Monitoring Scale (SMS—R) developed by the 1st 2 authors (see record 1984-27678-001) were orthogonal and that they were predictably related to measures of self-esteem, social anxiety, shyness, and sociability. Study 2, with an additional 249 Ss, showed that Ss high in concern for appropriateness tended to describe their own drug use as due to inducement by others, whereas Ss who scored high on the SMS—R tended to describe their drug use as self-initiated. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cloning in silico

Cellulose is a major component of plant cell walls, but identification of the enzymes that synthesize it has proven difficult. Now, however, several candidate proteins with sequence homology to bacterial cellulose synthases have been identified by partial sequencing of anonymous cDNA clones from cotton fibers.     

Lysosomal targeting of P-selectin is mediated by a novel sequence within its cytoplasmic tail

Signals controlling the intracellular targeting of many membrane proteins are present as short sequences within their cytoplasmic domains. P-selectin is a type I membrane protein receptor for leukocytes, acting during the inflammation response. Heterologous expression experiments have demonstrated that its 35-residue cytoplasmic tail contains signals for targeting to synaptic-like microvesicles, dense-cored granules, and lysosomes. We have examined the lysosomal targeting information present within the cytoplasmic tail by site-directed mutagenesis of horseradish peroxidase-P-selectin chimeras followed by transient transfection in H.Ep.2 cells. Assaying lysosomal targeting by subcellular fractionation as well as intracellular proteolysis, we have discovered a novel lysosomal targeting signal, KCPL, located within the C1 domain of the cytoplasmic tail. Alanine substitution of this tetrapeptide reduced lysosomal targeting to the level of a tailless horseradish peroxidase-P-selectin chimera, which was previously found to be deficient in both internalization and delivery to lysosomes. A proline residue within this lysosomal targeting signal makes a major contribution to the efficiency of lysosomal targeting. A diaminobenzidine density shift procedure established that chimeras with an inactivated KCPL sequence are present within transferrin-positive compartments. Such a mutant also displays an increased level of expression at the plasma membrane. Our results indicate that the sequence KCPL within the cytoplasmic tail of P-selectin is a structural element that mediates sorting from endosomes to lysosomes.     

A comparison of Japanese and US high-technology transfer practices

Some empirical results and observations are presented which describe the principal ways in which a sample of industrial researchers in Japan and in the US utilize certain technologies resulting from university research. The findings are from a survey conducted in Japan and the US between October 1986 and December 1987. These results indicate that personal communications and technical collaboration are the key factors in the rapid diffusion of research results in both countries, and that in Japan, government agencies and professional societies take a much more active role in organizing and energizing the civilian technology-transfer process than do counterpart organizations in the US     

Urban and regional distinctions for aggregating time series data

Abstract.  This article argues that using either the SIC or NAICS one-digit classifications as a method of aggregating two- and three-digit time series data can ignore important regional characteristics. We present a pairwise cointegration approach of aggregation where the aggregated sectors can vary widely across regions. By systematically constructing region-specific sectors from more detailed industries, we find that the level of agglomeration across rural and urban areas can affect the composition and number of local sectors in a region. We use the results pointing to rural/urban geographic distinctiveness to further consider the Carlino and Defina (1998, 1999 ) finding that monetary policy has disparate effects across regions in the U.S.     

Impact of chronic pain patients'' job perception variables on actual return to work

A structural model is constructed for the integral membrane protein, sensory rhodopsin I (SRI), the phototaxis receptor of the archaeon Halobacterium salinarium. The model is built on the template of the homologous bacteriorhodopsin (BR). The modeling procedure includes sequence alignment, a side chain rotamer search and simulated annealing by restricted molecular dynamics. The structure is in general agreement with previous results from mutagenesis experiments, chromophore substitution and room and cryogenic temperature spectroscopy. In particular, a residue near the beta-ionone ring of the retinylidene chromophore is found to be critical in maintaining the proper isomeric conformation of the chromophore; a layer of residues lying on the cytoplasmic side of the chromophore pocket is found to modulate the restraints around the C13 region of the chromophore, affecting the isomerizations around its 13 = 14 bond that are important to the protein's activity. The restraints in these regions are more stringent in SRI than in BR. The tightened restraints are chiefly due to van der Waals interactions, where the attractive and repulsive components play separable roles. Aromatic residues account for a majority of the restrictive interactions. It is hypothesized that the enhanced barriers due to these restrictions regulate the progress of SRI's photocycle, so that it can couple with the phototaxis reaction chain in the bacterium. A possibility is also suggested that conformational changes of the protein provide the signal recognized by the transducer.