1,751 research outputs found
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The structure of junctions between carbon nanotubes and graphene shells
Junctions between carbon nanotubes and flat or curved graphene structures are fascinating for a number of reasons. It has been suggested that such junctions could be used in nanoelectronic devices, or as the basis of three-dimensional carbon materials, with many potential applications. However, there have been few detailed experimental analyses of nanotube-graphene connections. Here we describe junctions between nanotubes and graphene shells in a material produced by passing a current through graphite. Transmission electron micrographs show that the junction angles are not random but fall close to multiples of 30°. We show that connections with these angles are the only ones which are consistent with the symmetry of the hexagonal lattice, and molecular models show that a continuous lattice requires the presence of large carbon rings at the junction. Some of the configurations we propose have not been previously considered, and could be used to construct new kinds of three-dimensional carbon architecture. We also discuss the possible formation mechanism of the junctions
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Catalysis-free transformation of non-graphitising carbons into highly crystalline graphite
High-purity graphite is a sought-after material for lithium-ion batteries and graphene production. Most organic materials do not graphitise upon heating unless a metal catalyst is present. The catalyst becomes embedded in the graphite and is difficult to remove. Here, we present a catalysis-free technique capable of producing highly crystalline graphite from materials generally considered incapable of this transformation. Using the furnace inside an Atomic Absorption Spectrometer, we perform repeated high-temperature pulsing of polyvinylidene chloride followed by analysis with Raman, X-ray diffraction and transmission electron microscopy. Unexpectedly, ~90% of the sample transforms into highly ordered graphite with very few defects. A combustion route is proposed in which oxygen attacks the structural units that inhibit graphitisation. We apply the same approach to cellulose and obtain ten times more ordered material than conventional furnaces, confirming that polyvinylidene chloride is not an isolated case. Potentially, this method could be used to synthesise graphite from any organic material, including waste sources such as biomass
Challenges to conducting research with older people living in nursing homes
<p>Abstract</p> <p>Background</p> <p>Although older people are increasingly cared for in nursing homes towards the end of life, there is a dearth of research exploring the views of residents. There are however, a number of challenges and methodological issues involved in doing this. The aim of this paper is to discuss some of these, along with residents' views on taking part in a study of the perceptions of dignity of older people in care homes and make recommendations for future research in these settings.</p> <p>Methods</p> <p>Qualitative interviews were used to obtain the views on maintaining dignity of 18 people aged 75 years and over, living in two private nursing homes in South East London. Detailed field notes on experiences of recruiting and interviewing participants were kept.</p> <p>Results</p> <p>Challenges included taking informed consent (completing reply slips and having a 'reasonable' understanding of their participation); finding opportunities to conduct interviews; involvement of care home staff and residents' families and trying to maintain privacy during the interviews. Most residents were positive about their participation in the study, however, five had concerns either before or during their interviews. Although 15 residents seemed to feel free to air their views, three seemed reluctant to express their opinions on their care in the home.</p> <p>Conclusion</p> <p>Although we experienced many challenges to conducting this study, they were not insurmountable, and once overcome, allowed this often unheard vulnerable group to express their views, with potential long-term benefits for future delivery of care.</p
The Iowa Homemaker vol.26, no.2
Alma Mater, J. C. Harris, page 2
Travel With Poise, Mary Ann Hakes, page 3
Report From Athens, Joan Kelleher, page 4
Blanche Pederson Interviews an Aussie Bride, Blanche Pederson, page 5
Coeds are Veterans, Too, Mary Margaret Ryan, page 6
Future Home Economics Classroom, Helen Hochriem, page 7
Vicky Grins at the Sun, Breta Soldat, page 9
Whatâs New in Home Economics, Marjorie Clampitt, page 10
Wardrobe Worries? Hereâs What We Wear, Textiles and Clothing Club, page 12
âI Have a Dozen Bossesâ, Genevieve Callahan, page 14
Albino Rats Get in on the Ground Floor, Margaret Waterland, page 17
Alums Prove Chemistry can Pay, June Welch, page 18
Education Begins Egyptian Modernizing, Lois Bronson, page 19
Across Alumnae Desks, Mary Neff, page 21
Keeping Up With Today, Joyce Edgar, page 22
How Does Your Garden Grow?, Irene Meyer, page 23
Alums in the News, Goldie Rouse, page 2
The potential and value of objective eye tracking in the ophthalmology clinic
Numerous research studies have demonstrated the scope and value of eye movement recording (EMR). There is now potential for EMR to be helpful in a range of clinical contexts and it could be developed as a routine part of the repertoire of clinical investigations offered by the NHS, at least in tertiary centres. We highlight potential uses and challenges below, as a prelude to further development and debat
Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (Pâ<â5âĂâ10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and Îł-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition
Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.
The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain âŒ8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD
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