Colony stimulating factor-1 (Csf-1) receptor and its ligand Csf-1 control macrophage development, maintenance, and function. The development of both Langerhans cells (LCs) and microglia is highly ...dependent on Csf-1 receptor signaling but independent of Csf-1. Here we show that in both mice and humans, interleukin-34 (IL-34), an alternative ligand for Csf-1 receptor, is produced by keratinocytes in the epidermis and by neurons in the brain. Mice lacking IL-34 displayed a marked reduction of LCs and a decrease of microglia, whereas monocytes, dermal, and lymphoid tissue macrophages and DCs were unaffected. We identified IL-34 as a nonredundant cytokine for the development of LCs during embryogenesis as well as for their homeostasis in the adult skin. Whereas inflammation-induced repopulation of LCs appears to be dependent on Csf-1, once inflammation is resolved, LC survival is again IL-34-dependent. In contrast, microglia and their yolk sac precursors develop independently of IL-34 but rely on it for their maintenance in the adult brain.
► IL-34 is critical for the development and maintenance of LCs ► IL-34 is required for LC maintenance but not monocyte-derived repopulation in inflammation ► IL-34 is critical for the homeostasis of adult microglia ► IL-34 protein is produced in the epidermis and brain of mice and humans
A Companion to Border Studies Wilson, Thomas M; Donnan, Hastings
2012, 2012., 2012-03-28, 20120101, Letnik:
46
eBook
A Companion to Border Studiesintroduces an exciting and expanding field of interdisciplinary research, through the writing of an international array of scholars, from diverse perspectives that ...include anthropology, development studies, geography, history, political science and sociology.Explores how nations and cultural identities are being transformed by their dynamic, shifting borders where mobility is sometimes facilitated, other times impeded or preventedOffers an array of international views which together form an authoritative guide for students, instructors and researchersReflects recent significant growth in the importance of understanding the distinctive characteristics of borders and frontiers, including cross-border cooperation, security and controls, migration and population displacements, hybridity, and transnationalism
2,2'-Azobis(5-azidotetrazole) (C
N
,
), a highly energetic nitrogen-rich binary CN compound was obtained in a three-step synthesis through the formation of 5-azidotetrazole (
), subsequent amination ...using
-tosylhydroxylamine to give 2-amino-5-azidotetrazole (
), and oxidative azo coupling of
using
BuOCl as an oxidant in MeCN. A nitrogen:carbon ratio of 8:1, eight nitrogen atoms in a row, and a nitrogen content of over 90% was unknown for a binary heterocyclic compound until now. The successful isolation was confirmed through X-ray diffraction as well as by vibrational and
C NMR spectroscopy. C
N
can explode instantly and shows mechanical sensitivities far higher than quantitatively measurable. Nevertheless, it features interesting energetic performances, which were calculated using different quantum-chemical methods.
Driving range and fast charge capability of electric vehicles are heavily dependent on the 3D microstructure of lithium-ion batteries (LiBs) and substantial fundamental research is required to ...optimise electrode design for specific operating conditions. Here we have developed a full microstructure-resolved 3D model using a novel X-ray nano-computed tomography (CT) dual-scan superimposition technique that captures features of the carbon-binder domain. This elucidates how LiB performance is markedly affected by microstructural heterogeneities, particularly under high rate conditions. The elongated shape and wide size distribution of the active particles not only affect the lithium-ion transport but also lead to a heterogeneous current distribution and non-uniform lithiation between particles and along the through-thickness direction. Building on these insights, we propose and compare potential graded-microstructure designs for next-generation battery electrodes. To guide manufacturing of electrode architectures, in-situ X-ray CT is shown to reliably reveal the porosity and tortuosity changes with incremental calendering steps.
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