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1.
2.
Lone Bruun 《Nordic Journal of Botany》1987,7(5):543-551
The mature embryo sac of Beta vulgaris consists of one egg cell, one persistent and one degenerated synergid, one cental cell with two fused polar nuclei, and five to six antipodals. The degeneration of one of the synergids appears before pollination in the maturing process. The two fused polar nuclei are located in the chalazal part of the central cell. The antipodals may have secretory activities. It is suggested that the embryo sac of the sugar beet completes the maturing process independently of pollination. 相似文献
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Tina Pallesen Annette Vangsted Lars Drivsholm Henrik Clausen Jesper Zeuthen Håkan Wallin 《Glycoconjugate journal》1992,9(6):331-335
We here report an enzyme linked immunosorbent assay (ELISA) and a scintillation proximity assay (SPA) for detection of the ganglioside FucGM1 in sera from small cell lung cancer (SCLC) patients. The SPA was more sensitive and reproducible than the ELISA. In this assay, monoclonal antibodies specific for FucGM1 were bound to SPA particles and incubated with labelled FucGM1 and 100 µl test-serum overnight, and counted in a -counter. The sensitivity was 0.2 ng. Seven out of twenty sera from SCLC patients were positive, whereas none of twenty sera from healthy individuals were positive for FucGM1. The SPA was more sensitive than the previously reported HPTLC as well as a direct ELISA.Abbreviations MAb
monoclonal antibody
- SPA
scintillation proximity assay
- HPTLC
high performance thin layer chromatography
- SCLC
small cell lung cancer
- FucGM1
Fuc1-2Gal1-3GalNAc1-4(NeuAc2-3)-Gal1-4Glc1-1Cer
- ELISA
enzyme linked immunosorbent assay
- FCS
foetal calf serum
- PBS
phosphate buffered saline 相似文献
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The growth retardants paclobutrazol (β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) and RSW
0411 (β-(cyclohexyl methylene)-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) were tested on two-year-old trees of Granny
Smith and Fuji apple. RSW 0411 at 100 mg/L did not cause any growth reduction in Granny Smith, while 500 and 1000 mg/L significantly
reduced growth below that of the control between 27 and 40 days after application. Paclobutrazol at 100 mg/L had significantly
reduced shoot growth between 27 and 55 days after application, and 1000 mg/L reduced shoot growth between 27 and 82 days after
application. By 100 days after application, there were no longer differences between treatments. Shoot growth on Fuji trees
was reduced below that of the control as follows: between 14 and 27 days following a single application of 500 mg/L RSW 0411;
between 27 and 55 days following two applications; between 14 and 72 days following three applications; and between 14 and
82 days following four applications. Treatments were applied 14 days apart. Paclobutrazol was a more active growth retardant
than RSW 0411 at the same rate, and the growth-retarding effects of RSW 0411 were short-lived. 相似文献
7.
Kirsten Christoffersen Bo Riemann Lone R. Hansen Annette Klysner Helle B. Sørensen 《Microbial ecology》1990,20(1):253-272
Plankton community structure and major pools and fluxes of carbon were observed before and after culmination of a bloom of cyanobacteria in eutrophic Frederiksborg Slotssø, Denmark. Biomass changes of heterotrophic nanoflagellates, ciliates, microzooplankton (50 to 140 μm), and macrozooplankton (larger than 140 μm) were compared to phytoplankton and bacterial production as well as micro- and macrozooplankton ingestion rates of phytoplankton and bacteria. The carbon budget was used as a means to examine causal relationships in the plankton community. Phytoplankton biomass decreased and algae smaller than 20 μm replacedAphanizomenon after the culmination of cyanobacteria. Bacterial net production peaked shortly after the culmination of the bloom (510 μg C liter?1 d?1 and decreased thereafter to a level of approximately 124 μg C liter?1 d?1. Phytoplankton extracellular release of organic carbon accounted for only 4–9% of bacterial carbon demand. Cyclopoid copepods and small-sized cladocerans started to grow after the culmination, but food limitation probably controlled the biomass after the collapse of the bloom. Grazing of micro- and macrozooplankton were estimated from in situ experiments using labeled bacteria and algae. Macrozooplankton grazed 22% of bacterial net production during the bloom and 86% after the bloom, while microzooplankton (nauplii, rotifers and ciliates larger than 50 μm) ingested low amounts of bacteria and removed 10–16% of bacterial carbon. Both macro-and microzooplankton grazed algae smaller than 20 μm, although they did not control algal biomass. From calculated clearance rates it was found that heterotrophic nanoflagellates (40–440 ml?1) grazed 3–4% of the bacterial production, while ciliates smaller than 50 μm removed 19–39% of bacterial production, supporting the idea that ciliates are an important link between bacteria and higher trophic levels. During and after the bloom ofAphanizomenon, major fluxes of carbon between bacteria, ciliates and crustaceans were observed, and heterotrophic nanoflagellates played a minor role in the pelagic food web. 相似文献
8.
Linker insertion analysis of the FimH adhesin of type 1 fimbriae in an Escherichia coli fimH-null background 总被引:2,自引:0,他引:2
Mark A. Schembri Lars Pallesen Hugh Connell David L. Hasty Per Klemm 《FEMS microbiology letters》1996,137(2-3):257-263
Abstract The gene encoding the Escherichia coli FimH adhesin of type 1 fimbriae has been subjected to linker insertion mutagenesis. Amino acid changes were introduced at a number of positions spanning the entire sequence in order to probe the structure-function relationship of the FimH protein. The effect of these mutations on the ability of bacteria to express a D-mannose binding phenotype was assessed in a fimH null mutant (MS4) constructed by allelic exchange in the E. coli K-12 strain PC31. Mutations mapping at amino acid residues 36, 58 and 279 of the mature FimH protein were shown to completely abolish binding to D-mannose receptors. Differences in the level of fimbriation were also observed as a result of some of the mutations in the fimH gene. These mutants may prove useful in dissecting receptor-ligand interactions by defining regions of the FimH protein that are important in erythrocyte binding. 相似文献
9.
Mammalian Genome - Type 2 diabetes (T2D) is a metabolic disease with an imbalance in blood glucose concentration. There are significant studies currently showing association between T2D and... 相似文献
10.
The micropyle and the integuments of sugar beet (Beta vulgaris) ovules have been investigated by light and electron microscopy during differentiation and maturation of the ovule. The micropyle itself is formed by the inner integument which is surrounded by the outer integument at its base. The micropyle containts a fibrillar PAS+ substance and is often covered by a thin sheet or hymen. Both integuments are cuticle-covered thin sheets, each 2-few cell layers in thickness. In the outer integument an increase in starch accumulation occurs during ovule maturation and probably functions as nutrient storage for embryo development. The inner epidermis of the inner integument differentiates as the most conspicuous cell layer of the beet ovule. During growth and maturation of the ovule a system of small perinuclear vacuoles containing dense material increases steadily in these cells. At maturity this system fills up more than half of each cell and very dense material has accumulated in each vacuole. This vacuole content is highly refractive and contains tannins and/or polyphenols. 相似文献