Solid-state spun fibers and yarns from 1-mm long carbon nanotube forests synthesized by water-assisted chemical vapor deposition

We report continuous carbon nanotube (CNT) fibers and yarns dry-drawn directly from water-assisted chemical vapor deposition (CVD) grown forests with about 1-mm height. As-drawn CNT fibers exist as aerogel and can be transformed into more compact fibers through twisting or densification with a volatile organic liquid. CNT fibers are characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Raman microscopy, and wide-angle X-ray diffraction. Mechanical properties and electrical conductivity of the post-treated CNT fibers are investigated. The resulting fibers show the work of rupture of 30 J/g and DC electrical conductivity of 5.0 × 10⁴ S/m.     

Temperament stability between the neonatal period and 24 months.

The predictive relation between neonatal behavior and temperament at 24 months was examined for 67 infants. Behaviors rated by trained examiners at both ages were aggregated into composite scores to provide a more reliable indicator of individual differences than single-item scores. Longitudinal analyses revealed several significant relations between the two ages, most notably that irritable neonates were rated as more upset, less attentive to stimuli, and less responsive to the staff at 24 months. The common variable describing behavior at both ages was related to emotionality. Examination of extreme groups on ratings of emotional tone indicated that the distressed toddler had high irritability ratings as a neonate, but the more pleasant toddler was not different from the average group in neonatal irritability scores. It was concluded that a modest predictive relation between temperament variables was demonstrated from the neonatal period to 24 months. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing,Structure, and Properties of PAN/MWNT Composite Fibers

Conventional dry‐jet wet fiber spinning techniques were used to fabricate continuous PAN/MWNT composite fibers with up to 20 wt.‐% nanotube loading. PAN at the MWNT interface exhibited lower solubility under thermodynamically favorable conditions than in bulk PAN, indicating good interfacial interaction. Due to the PAN/MWNT interaction at the interface, thermal shrinkage decreases with increasing MWNT loading (5 to 20 wt.‐%). For high MWNT loadings, PAN/MWNT composite fiber at 15 wt.‐% MWNT loading showed an axial electrical conductivity of 1.24 S · m^?1. For all loadings, PAN/MWNT composite fibers exhibited higher tensile moduli than theoretically predicted by rule‐of‐mixture calculations, suggesting good reinforcement of the PAN by MWNT.

     

Effect of orally administered phenethyl isothiocyanate on hepatic gene expression in rats

Scope: Phenethyl isothiocyanate (PEITC) is a constituent of cruciferous vegetables that has demonstrated cancer preventive activity in a number of cancer models including lung, prostate, and breast cancer. Our objective was to examine the effects of the oral administration of PEITC for 7 days on the hepatic expression of genes important in drug metabolism and toxicity in Sprague Dawley rats. The liver is the major site for the metabolism of various xenobiotics and carcinogens, and determining the effects of PEITC on the gene expression of hepatic enzymes may provide insight into mechanisms underlying the cancer preventive activity of PEITC. Methods and results: Using a microarray containing 282 genes, we observed that PEITC significantly up‐regulated UDP‐glucuronosyltransferase UGT1A6 and strongly down‐regulated nicotinamide N‐methyltransferase (NNMT). We also confirmed the down‐regulation of NNMT by real‐time quantitative RT‐PCR. Other genes that were significantly up‐regulated were the drug metabolizing enzyme cyp2b15, the anti‐apoptotic gene bcl2l2, and the stress regulators Gadd45b, Dnajb9, Dnajb5 and Hspb1. Conclusion: Our results indicate new targets that may be important in the mechanisms of the anticancer effects of PEITC. Of particular significance was the down‐regulation of NNMT which may represent a new target for the treatment of a variety of cancers.     

Training the word recognition skills of reading disabled children: Treatment and transfer effects.

54 disabled readers were randomly assigned to 1 of 2 word recognition and spelling training programs or to a problem solving and study skills training program. One word-training program taught orthographically regular words by whole word methods alone; the other trained constituent grapheme–phoneme correspondences. The word-training groups made significant gains in word recognition accuracy and speed and in spelling. Significant transfer was observed on uninstructed spelling content but not on uninstructed reading vocabulary. In general, the word-training programs were equally effective for instructed content, but the whole-word group was superior on some transfer measures at posttest. Although the results demonstrate that dyslexic readers can be instructed successfully, the children did not profit differentially from letter-sound over whole-word training in the present context. We speculate that severely disabled readers may require either a more extended period of letter–sound instruction to reliably adopt an alphabetic decoding strategy or additional specific training in phonological awareness and subsyllabic segmentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Buoyancy-driven heat transfer enhancement in a two-dimensional enclosure utilizing nanofluids

Heat transfer enhancement in a two-dimensional enclosure utilizing nanofluids is investigated for various pertinent parameters. A model is developed to analyze heat transfer performance of nanofluids inside an enclosure taking into account the solid particle dispersion. The transport equations are solved numerically using the finite-volume approach along with the alternating direct implicit procedure. Comparisons with previously published work on the basis of special cases are performed and found to be in excellent agreement. The effect of suspended ultrafine metallic nanoparticles on the fluid flow and heat transfer processes within the enclosure is analyzed and effective thermal conductivity enhancement maps are developed for various controlling parameters. In addition, an analysis of variants based on the thermophysical properties of nanofluid is developed and presented. It is shown that the variances within different models have substantial effects on the results. Finally, a heat transfer correlation of the average Nusselt number for various Grashof numbers and volume fractions is presented.     

Models of visual word recognition: When obscuring the stimulus yields a clearer view.

It is well known that visual word recognition is influenced by context, word frequency, and stimulus quality. A processing account is outlined in which stimulus quality affects the orthographic input lexicon, whereas context influences both the orthographic input lexicon and the semantic system. Word frequency exerts its primary effects on the pathways that link lexical systems with each other and with the semantic system. Previous findings that are problematic for alternative models along with the results of 2 new experiments are consistent with this account. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examining the locus of age effects on complex span tasks.

To investigate the locus of age effects on complex span tasks, the authors evaluated the contributions of working memory functions and processing speed. Age differences were found in measures of storage capacity, language processing speed, and lower level speed. Statistically controlling for each of these in hierarchical regressions substantially reduced, but did not eliminate, the complex span age effect. Accounting for lower level speed and storage, however, removed essentially the entire age effect, suggesting that both functions play important and independent roles. Additional evidence for the role of storage capacity was the absence of complex span age differences with span size calibrated to individual word span performance. Explanations for age differences based on inhibition and concurrent task performance were not supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wundt's American doctoral students.

Using the student records in the archives at Karl Marx University in Leipzig, Germany, 33 American students have been identified who took their doctoral degrees with Wilhelm Wundt. Wundt served as major reader (Erstgutachter) for 16 students and as secondary reader (Zweitgutachter) for another 17. Many of these students are unknown to psychologists, even among historians of psychology. This article provides the 1st comprehensive catalog of these students and includes information on their dissertation work and subsequent careers. Wundt's effect on his American students is also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)