University of Stuttgart

About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.

Intracellular action of the cytokine MIF to modulate AP-1 activity and the cell cycle through Jab1

Abstract: Cytokines are multifunctional mediators that classically modulate immune activity by receptor-mediated pathways Macrophage migration inhibitory factor (MIF) is a cytokine that has a critical role in several inflammatory conditions but that also has endocrine and enzymatic functions The molecular targets of MIF action have so far remained unclear Here we show that MIF specifically interacts with an intracellular protein, Jab1, which is a coactivator of AP-1 transcription that also promotes degradation of the cyclin-dependent kinase inhibitor p27Kip1 (ref 10) MIF colocalizes with Jab1 in the cytosol, and both endogenous and exogenously added MIF following endocytosis bind Jab1 MIF inhibits Jab1- and stimulus-enhanced AP-1 activity, but does not interfere with the induction of the transcription factor NFkappaB Jab1 activates c-Jun amino-terminal kinase (JNK) activity and enhances endogenous phospho-c-Jun levels, and MIF inhibits these effects MIF also antagonizes Jab1-dependent cell-cycle regulation by increasing p27Kip1 expression through stabilization of p27Kip1 protein Consequently, Jab1-mediated rescue of fibroblasts from growth arrest is blocked by MIF Amino acids 50-65 and Cys 60 of MIF are important for Jab1 binding and modulation We conclude that MIF may act broadly to negatively regulate Jab1-controlled pathways and that the MIF-Jab1 interaction may provide a molecular basis for key activities of MIF

Enantioselective Construction of Quaternary Stereocenters

Abstract: The stereoselective formation of C-C bonds is of great importance for the synthesis of enantiomerically pure natural products and pharmaceuticals. A broad repertoire of chiral auxiliaries, reagents, and catalysts can be utilized for the reliable generation of tertiary stereocenters. In contrast, the synthesis of organic compounds with quaternary stereocenters is a much more demanding and challenging task. Every enantioselective synthetic method can demonstrate its value through the generation of a fully substituted carbon center. In this Minireview examples of newer stoichiometric and catalytic methods are summarized which have proved their suitability for the enantioselective construction of quaternary stereocenters.

Coherent control of single spins in silicon carbide at room temperature

Abstract: Defects in silicon carbide have recently been proposed as bright single-photon sources. It is now shown that they can be used as sources of single electron spins having long coherence times at room temperature. Spins in solids are cornerstone elements of quantum spintronics1. Leading contenders such as defects in diamond2,3,4,5 or individual phosphorus dopants in silicon6 have shown spectacular progress, but either lack established nanotechnology or an efficient spin/photon interface. Silicon carbide (SiC) combines the strength of both systems5: it has a large bandgap with deep defects7,8,9 and benefits from mature fabrication techniques10,11,12. Here, we report the characterization of photoluminescence and optical spin polarization from single silicon vacancies in SiC, and demonstrate that single spins can be addressed at room temperature. We show coherent control of a single defect spin and find long spin coherence times under ambient conditions. Our study provides evidence that SiC is a promising system for atomic-scale spintronics and quantum technology.

Impact of long-term conventional and organic farming on the diversity of arbuscular mycorrhizal fungi

Abstract: Previous work has shown considerably en- hanced soil fertility in agroecosystems managed by organic farming as compared to conventional farming. Arbuscular mycorrhizal fungi (AMF) play a crucial role in nutrient acquisition and soil fertility. The objective of this study was to investigate the diversity of AMF in the context of a long-term study in which replicated field plots, at a single site in Central Europe, had been cultivated for 22 years according to two "organic" and two "conventional" farming systems. In the 23rd year, the field plots, carrying an 18-month-old grass-clover stand, were examined in two ways with respect to AMF diversity. Firstly, AMF spores were isolated and morphologically identified from soil samples. The study revealed that the AMF spore abundance and species diversity was sig- nificantly higher in the organic than in the conventional systems. Furthermore, the AMF community differed in the conventional and organic systems: Glomus species were similarly abundant in all systems but spores of Acaulos- pora and Scutellospora species were more abundant in the organic systems. Secondly, the soils were used to establish AMF-trap cultures using a consortium of Plantago lanceolata, Trifolium pratense and Lolium perenne as host plants. The AMF spore community developing in the trap cultures differed: after 12 months, two species of the Acaulosporaceae (A. paulinae and A. longula) were consistently found to account for a large part of the spore community in the trap cultures from the organic systems but were found rarely in the ones from the conventional systems. The findings show that some AMF species present in natural ecosystems are maintained under organic farming but severely depressed under conven- tional farming, indicating a potentially severe loss of ecosystem function under conventional farming.