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21.
Based on the biological model of cell-to-cell communication proposed by A. Rustom et al. (Science, 2004, 303: 1007—1010), we investigate the possibilities to apply P systems with dynamic channels transporting membrane vesicles for describing processes in distributed systems. 相似文献
22.
P Binder L Perrot Y Beaudry C Bottex R Fontanges 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1975,281(20):1545-1547
We studied the effect of neuraminidase injection in rat's tumor at different doses: 5,10,50,100, 500 U and we concluded that: There was no difference between the rats treated with 5,10,50 U and the controls. The y died 3 weeks after the injection. But the rats treated by 100 at 500 U of NA died quickley, in the week, of long metastases. 相似文献
23.
Summary For the first time we have isolated a major psychoactive cannabinoid, (3R, 4R)-
1(6)-tetrahydrocannabinol3 from callus cultures ofCannabis sativa L.3 was obtained as an artefact of the actually formed (3R, 4R)-
1-tetrahydrocannabinol-3- and/or 5-carboxylic acids1 and2 by subjecting the culture material to a decarboxylation step prior to extraction. No attempt was made to isolated acids1 and2. The identity of3 was confirmed by comparison with an authentic sample of (3R, 4R)-
1-tetrahydrocannabinol. Culture conditions, isolation procedure and identification of the cannabinoid are described.Acknowledgment. The authors are greatly indebted to Dr W. Heller and Dr G. Schroeder-Frey for deriving the callus cultures from seedlings ofC. sativa and to Prof. N. Amrhein for valuable gifts of culture media and growth regulators. 相似文献
24.
Interleukin-4-dependent production of PPAR-gamma ligands in macrophages by 12/15-lipoxygenase. 总被引:21,自引:0,他引:21
J T Huang J S Welch M Ricote C J Binder T M Willson C Kelly J L Witztum C D Funk D Conrad C K Glass 《Nature》1999,400(6742):378-382
25.
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