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41.
Danielle-Julie Carrier Nathalie Chauret Michael Mancini Pierre Coulombe Ronald Neufeld Martin Weber Jean Archambault 《Plant cell reports》1991,10(5):256-259
Ginkgo biloba cells were cultured in two 500 mL shake flasks and in 2 L and 6 L immobilization bioreactors using MS medium supplemented with 1 mg.L–1 NAA, 0.1 mg.L–1 K and 30 g.L–1 sucrose. Specific growth rates were 0.06 d–1, 0.11 d–1 and 0.07 d–1 for the 2 L and 6 L bioreactors and shake flask cultures, respectively. Extracellular phosphate, nitrate, ammonium and carbohydrate uptake rates of the bio reactor cultures were approximately 17 to 39% slower than those of shake flask cultures. The specific oxygen uptake and carbon dioxide transfer rates of immobilized Ginkgo biloba cells ranged from 0.027 to 0.041 mmol O2.g–1.d.w.hr–1 (maximum uptake at 14 days) and 0.020 to 0.057 mmol CO2g. –1.d.w.hr–1 (maximum production at 14 days). Extracts from the biomass of the two immobilized and shake flask suspension cultures were analysed for ginkgolide A by GC-MS. Yields of 7, 17, 19 and 7 ng.g. –1d.w. of ginkgolide A were determined for shake flask 1, shake flask 2 and the 2 L and 6 L immobilized cultures, respectively. Traces of ginkgolide B were detected with the signal to noise ratio, however, being too low for positive confirmation of this last product.Abbreviations CTR
Carbon dioxide transfer rate
- DO
Dissolved oxygen
- g.d.w.
Gram dry weight
- GA
Ginkgolide A
- GB
Ginkgolide B
- GC
Gas chromatography
- GC-MS
Gas chromatography-mass spectrometry
- HPLC
High performance liquid chromatography
- K
Kinetin
- MS
Murashige and Skoog salt medium
- N1K1MS
Complete Murashige and Skoog medium supplemented with 1 mg.L–1 NAA, 0.1 mg.L–1 K and 30g.L–1 sucrose
- NAA
Naphthaleneacetic acid
- OTR
Oxygen transfer rate
- PAF
Platelet Aggregating Factor
- qCO2
Specific carbon dioxide production rate
- qO2
Specific oxygen uptake rate
- u
Specific growth rate 相似文献
42.
McQueen Donald J. Johannes Mark R. S. Lafontaine Nathalie R. Young Andrew S. Longbotham Eric Lean David R. S. 《Hydrobiologia》1990,(1):337-341
We used two analyses to test the hypothesis that planktivore abundances contribute to the residual variations of Secchi depth
or chlorophyll-a plotted with respect to mean summer epilimnetic total phosphorus. The first analysis involved 15 lake years of data from
six lakes. The data set comprised mark-recapture assessments of piscivore and planktivore numbers and estimates of mean summer
chlorophyll-a, total phosphorus and Secchi depth. We found that residual chlorophyll-a variation was not significantly (p>0.05) correlated with planktivore densities, but that planktivore densities did contribute (p<0.02) to the residual variation of Secchi depth on mean total phosphorus. The second analysis included all of the data used
in the first plus an additional 13 lake years of data from the literature. These data showed that the percentage of the total
fish community comprising planktivores did not significantly (p>0.05) contribute to the residual variation in chlorophyll-a with respect to mean summer total phosphorus. Together, our results suggest that planktivore abundance has a significant
cascading impact on water clarity, but no long term statistically significant impact on mean summer chlorophyll-a concentration. 相似文献
43.
Ellen Cocquyt Gillian H Gile Frederik Leliaert Heroen Verbruggen Patrick J Keeling Olivier De Clerck 《BMC evolutionary biology》2010,10(1):327
Background
A non-canonical nuclear genetic code, in which TAG and TAA have been reassigned from stop codons to glutamine, has evolved independently in several eukaryotic lineages, including the ulvophycean green algal orders Dasycladales and Cladophorales. To study the phylogenetic distribution of the standard and non-canonical genetic codes, we generated sequence data of a representative set of ulvophycean green algae and used a robust green algal phylogeny to evaluate different evolutionary scenarios that may account for the origin of the non-canonical code. 相似文献44.
Persistence of conidia of the entomopathogenic fungus Paecilomyces fumosoroseus exposed to artificial and solar radiation at a constant temperature was studied by monitoring the ability to germinate and to form colonies (colony - forming units , CFUs) . The photic effect of radiation on each of these variables was modelled by a decreasing function of UVB irradiation ( in J m 2) . Germination ability was represented by a logistic function and viability (log CFU) by an infinitely decreasing function . Experiments carried out under artificial conditions , at three different UVB irradiances ( from 0 . 3 to 1 . 6 W m 2) , similar to those observed in nature , confirmed the adequacy of the predictor variable and of the functions chosen for describing these data . The proposed models appeared to be irradiance independent . Under solar radiation , the models were able to describe data collected on three different summer days in France (48 o 51 N , 2 o 06 E) . However , it took a greater amount of solar UVB radiation to produce the same effect as that achieved indoors . This could be explained by differences in radiation spectra . For each model , one set of parameters was sufficient for representing all three sets of data: this constitutes an initial validation of the models proposed . 相似文献
45.
A checklist of identified oribatid mite taxa from riverine freshwater environments from six islands in Polynesia (New Caledonia, Tahiti, Moorea, Rurutu, Tubuai, Raiatea) is presented; 18 species, 16 genera and eight families were recorded. Trhypochthoniellus longisetus (Berlese, 1904) and Trimalaconothrus albulus Hammer, 1972 prevailed on distribution. Fortuynia smiti
sp. n. (Fortuyniidae) is described from New Caledonia. The new speciesis morphologically most similar to Fortuynia marina Hammen, 1960 from New Guinea, but it differs from the latter by the longer notogastral setae dm, lm, c2, p1, epimeral setae 3b and adanal setae ad1 and the presence of prodorsal lateral ridges. 相似文献
46.
47.
48.
Martin Lange Laure Guillou Daniel Vaulot Nathalie Simon Rudolf I. Amann Wolfgang Ludwig Linda K. Medlin 《Journal of phycology》1996,32(5):858-868
Target regions specific for the class Prymnesiophyceae and the genus Phaeocystis (Har.) Lag. were identified from 18S ribosomal RNA coding regions, and two complementary probes were designed (PRYMN01 and PHAEO01). Detection of whole cells hybridized with these probes labeled with fluorescein isothiocyanate was difficult using epifluorescence microscopy because autofluorescence of the chlorophylls seriously interfered with the fluorescence of the probes. In contrast, flow cytometry proved very useful to detect and quantify the fluorescence of the hybridized cells. Hybridization conditions were optimized, especially with respect to formamide concentration. Both probes were tested on a large array of both target and nontarget strains. Positive and negative controls were also analyzed. Specificity was tested by adding a competing nonlabeled probe. Whereas probe PHAEO01 seems to have good specificity, probe PRYMN01 appeared less specific and must be used with stringent positive and negative controls. 相似文献
49.
Kai Bao Xiaofei Li Tetsuhiro Kajikawa Abe Toshiharu Nathalie Selevsek Jonas Grossmann George Hajishengallis Nagihan Bostanci 《Proteomics》2020,20(3-4)
Understanding the progression of periodontal tissue destruction is at the forefront of periodontal research. The authors aimed to capture the dynamics of gingival tissue proteome during the initiation and progression of experimental (ligature‐induced) periodontitis in mice. Pressure cycling technology (PCT), a recently developed platform that uses ultra‐high pressure to disrupt tissues, is utilized to achieve efficient and reproducible protein extraction from ultra‐small amounts of gingival tissues in combination with liquid chromatography‐tandem mass spectrometry (MS). The MS data are processed using Progenesis QI and the regulated proteins are subjected to METACORE, STRING, and WebGestalt for functional enrichment analysis. A total of 1614 proteins with ≥2 peptides are quantified with an estimated protein false discovery rate of 0.06%. Unsupervised clustering analysis shows that the gingival tissue protein abundance is mainly dependent on the periodontitis progression stage. Gene ontology enrichment analysis reveals an overrepresentation in innate immune regulation (e.g., neutrophil‐mediated immunity and antimicrobial peptides), signal transduction (e.g., integrin signaling), and homeostasis processes (e.g., platelet activation and aggregation). In conclusion, a PCT‐assisted label‐free quantitative proteomics workflow that allowed cataloging the deepest gingival tissue proteome on a rapid timescale and provided novel mechanistic insights into host perturbation during periodontitis progression is applied. 相似文献
50.
Nirvana Sadaghianloo Julie Contenti Maeva Dufies Julien Parola Matthieu Rouleau Shinrong Lee Jean-François Peyron Lucilla Fabbri Réda Hassen-Khodja Jacques Pouysségur Frédéric Bost Elixène Jean-Baptiste Alan Dardik Nathalie M. Mazure 《Journal of cellular and molecular medicine》2020,24(5):2931-2941
Arteriovenous fistulas (AVFs) are the preferred vascular access for haemodialysis of patients suffering from end-stage renal disease, a worldwide public health problem. However, they are prone to a high rate of failure due to neointimal hyperplasia and stenosis. This study aimed to determine if osteopontin (OPN) was induced in hypoxia and if OPN could be responsible for driving AVF failure. Identification of new factors that participate in remodelling of AVFs is a challenge. Three cell lines representing the cells of the three layers of the walls of arteries and veins, fibroblasts, smooth muscle cells and endothelial cells, were tested in mono- and co-culture in vitro for OPN expression and secretion in normoxia compared to hypoxia after silencing the hypoxia-inducible factors (HIF-1α, HIF-2α and HIF-1/2α) with siRNA or after treatment with an inhibitor of NF-kB. None of the cells in mono-culture showed OPN induction in hypoxia, whereas cells in co-culture secreted OPN in hypoxia. The changes in oxygenation that occur during AVF maturation up-regulate secretion of OPN through cell-cell interactions between the different cell layers that form AVF, and in turn, these promote endothelial cell proliferation and could participate in neointimal hyperplasia. 相似文献