36,304 research outputs found
Highlights of the Science and Life of Peter Varga (1946—2018)
Peter Varga has passed on October 27, 2018. His pioneering discoveries of chemical resolution at the atomic scale on surface alloys, atomic resolution of ultrathin alkali halides, nucleation of bcc iron in ultrathin films, and the microscopic structure of ultrathin alumina films stimulated worldwide research. In recognition of his outstanding scientific contributions, in December 2017 the Japanese Society for the Promotion of Science (JSPS) awarded him a prize for his distinguished contribution on the clarification of surface phenomena by atomic level investigations and the development of novel functional materials. This contribution highlights the life of Peter Varga as a scientist and as a person. With his elegance, his energy, his wit, and his generosity he was a close friend and role model to many of us, and showed us how to combine scientific curiosity and creativity with the lightness of being
Effect of aggregation on chromophore structure in allophycocyanin studied by resonance CARS-spectroscopy
Chicken BAFF
Members of the tumor necrosis factor (TNF) family play key roles in the regulation of inflammation, immune responses and tissue homeostasis. Here we describe the identification of the chicken homologue of mammalian B cell activating factor of the TNF family (BAFF/BLyS). By searching a chicken EST database we identified two overlapping cDNA clones that code for the entire open reading frame of chicken BAFF (chBAFF), which contains a predicted transmembrane domain and a putative furin protease cleavage site like its mammalian counterparts. The amino acid identity between soluble chicken and human BAFF is 76%, considerably higher than for most other known cytokines. The chBAFF gene is most strongly expressed in the bursa of Fabricius. Soluble recombinant chBAFF produced by human 293T cells interacted with the mammalian cell-surface receptors TACI, BCMA and BAFF-R. It bound to chicken B cells, but not to other lymphocytes, and it promoted the survival of splenic chicken B cells in culture. Furthermore, bacterially expressed chBAFF induced the selective expansion of B cells in the spleen and cecal tonsils when administered to young chicks. Our results suggest that like its mammalian counterpart, chBAFF plays an important role in survival and/or proliferation of chicken B cells
Cytokines of Birds: Conserved Functions
Targeted disruptions of the mouse genes for cytokines, cytokine receptors, or components of cytokine signaling cascades convincingly revealed the important roles of these molecules in immunologic processes. Cytokines are used at present as drugs to fight chronic microbial infections and cancer in humans, and they are being evaluated as immune response modifiers to improve vaccines. Until recently, only a few avian cytokines have been characterized, and potential applications thus have remained limited to mammals. Classic approaches to identify cytokine genes in birds proved difficult because sequence conservation is generally low. As new technology and high throughput sequencing became available, this situation changed quickly. We review here recent work that led to the identification of genes for the avian homologs of interferon-a/b (IFNa/b) and IFN-g, various interleukins (IL), and several chemokines. From the initial data on the biochemical properties of these molecules, a picture is emerging that shows that avian and mammalian cytokines may perform similar tasks, although their primary structures in most cases are remarkably different
STUDIES ON PLANT BILE PIGMENTS.
The (4 Z, 10 2, 15Ej-2,3-dihydrobilindione 4, along with the fully unsaturated (E, 2, Z)-analogue
8, has been prepared from the corresponding (Z, Z, Z)-isomer by a variation of Falk's method
(Falk et ul., 1980). The photochemical and acid-catalyzed back-reactions have been studied by UV-vis
and 'H-NMR spectroscopy
Identification of the relationship between Chinese Adiantum reniforme var. sinense and Canary Adiantum reniforme
© 2014 Wang et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
DNA Translocation through Graphene Nanopores
Nanopores -- nanosized holes that can transport ions and molecules -- are
very promising devices for genomic screening, in particular DNA sequencing.
Both solid-state and biological pores suffer from the drawback, however, that
the channel constituting the pore is long, viz. 10-100 times the distance
between two bases in a DNA molecule (0.5 nm for single-stranded DNA). Here, we
demonstrate that it is possible to realize and use ultrathin nanopores
fabricated in graphene monolayers for single-molecule DNA translocation. The
pores are obtained by placing a graphene flake over a microsize hole in a
silicon nitride membrane and drilling a nanosize hole in the graphene using an
electron beam. As individual DNA molecules translocate through the pore,
characteristic temporary conductance changes are observed in the ionic current
through the nanopore, setting the stage for future genomic screening
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