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981.
James TY Kauff F Schoch CL Matheny PB Hofstetter V Cox CJ Celio G Gueidan C Fraker E Miadlikowska J Lumbsch HT Rauhut A Reeb V Arnold AE Amtoft A Stajich JE Hosaka K Sung GH Johnson D O'Rourke B Crockett M Binder M Curtis JM Slot JC Wang Z Wilson AW Schüssler A Longcore JE O'Donnell K Mozley-Standridge S Porter D Letcher PM Powell MJ Taylor JW White MM Griffith GW Davies DR Humber RA Morton JB Sugiyama J Rossman AY Rogers JD Pfister DH Hewitt D Hansen K Hambleton S Shoemaker RA Kohlmeyer J 《Nature》2006,443(7113):818-822
The ancestors of fungi are believed to be simple aquatic forms with flagellated spores, similar to members of the extant phylum Chytridiomycota (chytrids). Current classifications assume that chytrids form an early-diverging clade within the kingdom Fungi and imply a single loss of the spore flagellum, leading to the diversification of terrestrial fungi. Here we develop phylogenetic hypotheses for Fungi using data from six gene regions and nearly 200 species. Our results indicate that there may have been at least four independent losses of the flagellum in the kingdom Fungi. These losses of swimming spores coincided with the evolution of new mechanisms of spore dispersal, such as aerial dispersal in mycelial groups and polar tube eversion in the microsporidia (unicellular forms that lack mitochondria). The enigmatic microsporidia seem to be derived from an endoparasitic chytrid ancestor similar to Rozella allomycis, on the earliest diverging branch of the fungal phylogenetic tree. 相似文献
982.
983.
Gross O Gewies A Finger K Schäfer M Sparwasser T Peschel C Förster I Ruland J 《Nature》2006,442(7103):651-656
Fungal infections are increasing worldwide due to the marked rise in immunodeficiencies including AIDS; however, immune responses to fungi are poorly understood. Dectin-1 is the major mammalian pattern recognition receptor for the fungal component zymosan. Dectin-1 represents the prototype of innate non-Toll-like receptors (TLRs) containing immunoreceptor tyrosine-based activation motifs (ITAMs) related to those of adaptive antigen receptors. Here we identify Card9 as a key transducer of Dectin-1 signalling. Although being dispensable for TLR/MyD88-induced responses, Card9 controls Dectin-1-mediated myeloid cell activation, cytokine production and innate anti-fungal immunity. Card9 couples to Bcl10 and regulates Bcl10-Malt1-mediated NF-kappaB activation induced by zymosan. Yet, Card9 is dispensable for antigen receptor signalling that uses Carma1 as a link to Bcl10-Malt1. Thus, our results define a novel innate immune pathway and indicate that evolutionarily distinct ITAM receptors in innate and adaptive immune cells use diverse adaptor proteins to engage selectively the conserved Bcl10-Malt1 module. 相似文献
984.
Single-electron transistor of a single organic molecule with access to several redox states 总被引:1,自引:0,他引:1
Kubatkin S Danilov A Hjort M Cornil J Brédas JL Stuhr-Hansen N Hedegård P Bjørnholm T 《Nature》2003,425(6959):698-701
A combination of classical Coulomb charging, electronic level spacings, spin, and vibrational modes determines the single-electron transfer reactions through nanoscale systems connected to external electrodes by tunnelling barriers. Coulomb charging effects have been shown to dominate such transport in semiconductor quantum dots, metallic and semiconducting nanoparticles, carbon nanotubes, and single molecules. Recently, transport has been shown to be also influenced by spin--through the Kondo effect--for both nanotubes and single molecules, as well as by vibrational fine structure. Here we describe a single-electron transistor where the electronic levels of a single pi-conjugated molecule in several distinct charged states control the transport properties. The molecular electronic levels extracted from the single-electron-transistor measurements are strongly perturbed compared to those of the molecule in solution, leading to a very significant reduction of the gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. We suggest, and verify by simple model calculations, that this surprising effect could be caused by image charges generated in the source and drain electrodes resulting in a strong localization of the charges on the molecule. 相似文献
985.
Riebe M Häffner H Roos CF Hänsel W Benhelm J Lancaster GP Körber TW Becher C Schmidt-Kaler F James DF Blatt R 《Nature》2004,429(6993):734-737
Teleportation of a quantum state encompasses the complete transfer of information from one particle to another. The complete specification of the quantum state of a system generally requires an infinite amount of information, even for simple two-level systems (qubits). Moreover, the principles of quantum mechanics dictate that any measurement on a system immediately alters its state, while yielding at most one bit of information. The transfer of a state from one system to another (by performing measurements on the first and operations on the second) might therefore appear impossible. However, it has been shown that the entangling properties of quantum mechanics, in combination with classical communication, allow quantum-state teleportation to be performed. Teleportation using pairs of entangled photons has been demonstrated, but such techniques are probabilistic, requiring post-selection of measured photons. Here, we report deterministic quantum-state teleportation between a pair of trapped calcium ions. Following closely the original proposal, we create a highly entangled pair of ions and perform a complete Bell-state measurement involving one ion from this pair and a third source ion. State reconstruction conditioned on this measurement is then performed on the other half of the entangled pair. The measured fidelity is 75%, demonstrating unequivocally the quantum nature of the process. 相似文献
986.
Loss-of-function mutations in TYROBP (DAP12) result in a presenile dementia with bone cysts 总被引:20,自引:0,他引:20
Paloneva J Kestilä M Wu J Salminen A Böhling T Ruotsalainen V Hakola P Bakker AB Phillips JH Pekkarinen P Lanier LL Timonen T Peltonen L 《Nature genetics》2000,25(3):357-361
Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL; MIM 221770), also known as Nasu-Hakola disease, is a recessively inherited disease characterized by a combination of psychotic symptoms rapidly progressing to presenile dementia and bone cysts restricted to wrists and ankles. PLOSL has a global distribution, although most of the patients have been diagnosed in Finland and Japan, with an estimated population prevalence of 2x10-6 (ref. 2) in the Finns. We have previously identified a shared 153-kb ancestor haplotype in all Finnish disease alleles between markers D19S1175 and D19S608 on chromosome 19q13.1 (refs 5,6). Here we characterize the molecular defect in PLOSL by identifying one large deletion in all Finnish PLOSL alleles and another mutation in a Japanese patient, both representing loss-of-function mutations, in the gene encoding TYRO protein tyrosine kinase binding protein (TYROBP; formerly DAP12). TYROBP is a transmembrane protein that has been recognized as a key activating signal transduction element in natural killer (NK) cells. On the plasma membrane of NK cells, TYROBP associates with activating receptors recognizing major histocompatibility complex (MHC) class I molecules. No abnormalities in NK cell function were detected in PLOSL patients homozygous for a null allele of TYROBP. 相似文献
987.
A. M. Ganzoni B. Späti H. Bühler H. Bühlmann 《Cellular and molecular life sciences : CMLS》1973,29(3):345-346
Zusammenfassung In Actinomycin-behandelten Mäusen nahm die Zahl der zirkulierenden Erythrozyten linear ab. Zellulärer Hämoglobinverlust erklärt die scheinbar altersunabhängige Komponente der Erythrozytendestruktion welche Isotopenstudien vermuten lassen. 相似文献
988.
989.
990.
Wu T Mayaffre H Krämer S Horvatić M Berthier C Hardy WN Liang R Bonn DA Julien MH 《Nature》2011,477(7363):191-194
Electronic charges introduced in copper-oxide (CuO(2)) planes generate high-transition-temperature (T(c)) superconductivity but, under special circumstances, they can also order into filaments called stripes. Whether an underlying tendency towards charge order is present in all copper oxides and whether this has any relationship with superconductivity are, however, two highly controversial issues. To uncover underlying electronic order, magnetic fields strong enough to destabilize superconductivity can be used. Such experiments, including quantum oscillations in YBa(2)Cu(3)O(y) (an extremely clean copper oxide in which charge order has not until now been observed) have suggested that superconductivity competes with spin, rather than charge, order. Here we report nuclear magnetic resonance measurements showing that high magnetic fields actually induce charge order, without spin order, in the CuO(2) planes of YBa(2)Cu(3)O(y). The observed static, unidirectional, modulation of the charge density breaks translational symmetry, thus explaining quantum oscillation results, and we argue that it is most probably the same 4a-periodic modulation as in stripe-ordered copper oxides. That it develops only when superconductivity fades away and near the same 1/8 hole doping as in La(2-x)Ba(x)CuO(4) (ref.?1) suggests that charge order, although visibly pinned by CuO chains in YBa(2)Cu(3)O(y), is an intrinsic propensity of the superconducting planes of high-T(c) copper oxides. 相似文献