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51.
Takuya Kajimoto Yojiro Matsuura Akira Osawa Anatoly S. Prokushkin Mark A. Sofronov Anatoly P. Abaimov 《Plant and Soil》2003,255(1):281-292
Spatial distributions of root systems of Larix gmelinii (Rupr.) Rupr. trees were examined in two stands in central Siberia: an even-aged stand (ca. 100 yrs-old) and a mature, uneven-aged (240–280 yrs-old) stand. Five larch trees of different sizes were sampled by excavating coarse roots (diameter > 5 mm) in each stand. Dimensions and ages of all first-order lateral roots were measured. Micro-scale conditions of soil temperature and soil water suction (each 10 cm deep) were also examined in relation to earth hummock topography (mound vs. trough) and/or ground floor vegetation types (moss vs. lichens). All larch trees developed superficial root systems, consisting of the aborted short tap root (10–40 cm in soil depth) and some well-spread lateral roots (n= 4-13). The root network of each tree was asymmetric, and its rooting area reached about four times the crown projection area. Lateral roots generally expanded into the upper soil layers of the mounds where summer soil temperature was 1–6°C higher than inside nearby troughs. Chronological analysis indicated that lateral root expansion started successively from lower to upper parts of each aborted tap root, and some lateral roots occurred simultaneously at several decades after tree establishment. The process of root system development was likely to be primarily linked with post-fire dynamics of rhizosphere environment of the permafrost soils. 相似文献
52.
The systems biology markup language (SBML): a medium for representation and exchange of biochemical network models 总被引:22,自引:0,他引:22
Hucka M Finney A Sauro HM Bolouri H Doyle JC Kitano H Arkin AP Bornstein BJ Bray D Cornish-Bowden A Cuellar AA Dronov S Gilles ED Ginkel M Gor V Goryanin II Hedley WJ Hodgman TC Hofmeyr JH Hunter PJ Juty NS Kasberger JL Kremling A Kummer U Le Novère N Loew LM Lucio D Mendes P Minch E Mjolsness ED Nakayama Y Nelson MR Nielsen PF Sakurada T Schaff JC Shapiro BE Shimizu TS Spence HD Stelling J Takahashi K Tomita M Wagner J Wang J;SBML Forum 《Bioinformatics (Oxford, England)》2003,19(4):524-531
MOTIVATION: Molecular biotechnology now makes it possible to build elaborate systems models, but the systems biology community needs information standards if models are to be shared, evaluated and developed cooperatively. RESULTS: We summarize the Systems Biology Markup Language (SBML) Level 1, a free, open, XML-based format for representing biochemical reaction networks. SBML is a software-independent language for describing models common to research in many areas of computational biology, including cell signaling pathways, metabolic pathways, gene regulation, and others. AVAILABILITY: The specification of SBML Level 1 is freely available from http://www.sbml.org/ 相似文献
53.
Seishirō Aoki Akiyoshi Kawaoka Masami Sekine Takanari Ichikawa Tomomichi Fujita Atsuhiko Shinmyō Kunihiko Syōno 《Molecular genetics and genomics : MGG》1994,243(6):706-710
A region homologous to the TL-DNA of Agrobacterium rhizogenes was previously detected in the genome of untransformed Nicotiana glauca and designated cellular T-DNA (cT-DNA). Subsequently, part of this region was sequenced and two genes, which corresponded to rolB and rolC and were named NgrolB and NgrolC, were found. We have now sequenced a region of the cT-DNA other than the region that includes NgrolB and C and we have found two other open reading frames (ORFs), NgORF13 and NgORF14. These ORFs correspond to ORFs 13 and 14 of the TL-DNA of A. rhizogenes and exhibit a high degree of homology to these ORFs, without having a nonsense codon. We have not found any sequence homologous to rolD (ORF15). The two genes, NgORF13 and 14, as well as the NgrolB and C genes, are expressed in genetic tumors of hybrids between N. glauca and N. langsdorffii but not in leaf tissues of the hybrid. 相似文献
54.
Hasegawa JY Hamada M Miyamoto T Nishide K Kajimoto T Uenishi J Node M 《Carbohydrate research》2005,340(15):2360-2368
p-octyloxyphenylmethanethiol and p-dodecylbenzenethiol were prepared as new odorless organosulfur reagents. Thiosugars and thioglycosides were synthesized using these reagents without encountering any malodorous procedures. 相似文献
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56.
Biotin uptake by isolated rat intestinal cells 总被引:1,自引:0,他引:1
Isolated intestinal mucosa cells of rats were used to investigate the intestinal transport of biotin. This method utilizing a double-label isotope technique showed that uptake could not be saturated, even in a wide range of biotin concentrations (0.01-2 microM). A metabolic inhibitor (antimycin A) did not prevent cell uptake of biotin. The transport mechanism was independent of temperature (Q10 = 1.04). When excess biotin was added to the incubation medium, there was no efflux of the vitamin from intestinal cells. The results also showed that the cells did not concentrate the vitamin, regardless of its concentration in the incubation medium. The mechanism of biotin uptake by rat cells at physiological concentrations is thus a passive diffusion phenomenon. 相似文献
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60.
Gorączko AJ 《Journal of molecular modeling》2011,17(9):2203-2208
The present work attempts to predict the mass spectra of structures containing many clusters of doubly charged ions as well
as singly charged ions. The method is applied to dodecacarbonylo-triangulo-triosmium, Os3(CO)12, a particularly difficult example for modeling. The starting spectrum (25 points) can be reconstructed satisfactorily with
2% precision into a full form containing more than 400 peaks, which is consistent with the experimental form. 相似文献