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1.
Summary Infrared and proton resonance spectra have been used to characterize fraction extracted sequentially from humic and fulvic
acids by diethylether, acetone, dioxane, tetrahydrofuran, pyridine and dimethylformamide. The results showed that the same
solvents extracted structurally similar components from both humic and fulvic acids. On the other hand, the spectra showed
solvent-dependent differences, some being characteristic for a preponderance of aliphatic structures, others for aromatic
structures. 相似文献
2.
Tiziana Bellini Diana Degani Maurizio Matteuzzi Franco Dallocchio 《Bioscience reports》1990,10(1):73-78
Pre-treatment of human lymphocytes with 17-estradiol diminishes the increase in concentration of cytosolic free calcium after stimulation with phytohaemagglutinin. The effect is dependent on 17-estradiol concentration and on the preincubation time. The effect is not due to an interaction between 17-estradiol and phytohaemagglutinin, but appears to be a consequence of the binding of the hormone to the cell surface. The effect is specific for 17-estradiol, since the isomer and other steroid hormones (progesterone, testosterone, diethylstilbestrol and 5-androstan), have no effect. Since the effect of the 17-estradiol can be suppressed by treatment of lymphocytes with ouabain, it appears that the effect of estradiol on the rise of cytosolic calcium induced by phytohaemagglutinin is mediated by the (Na, K)-ATPase. 相似文献
3.
Silvia Sartoris Andrea De Lerma Barbaro Tiziana Cestari Giuseppe Tridente Roberto S. Accolla 《Immunogenetics》1994,39(1):8-14
RJ 2.2.5 is a human B cell mutant, derived from Raji cells, which has lost expression of major histocompatibility complex (MHC) class II genes because of a defect in the AIR1 locus function. The MHC class II-positive phenotype can be restored by introducing an active AIR1 locus or its mouse equivalent, Air-1. An example of the latter is the H4 cell hybrid, derived by somatic cell fusion between RJ 2.2.5 and mouse class II-positive spleen cells. H4 contains a single mouse chromosome, autosome 16, in which the Air-1 locus maps, and an entire RJ 2.2.5-derived genome. In the present study we show that the physiologic target of the Air-1 locus product is contained within a limited HLA-DRA promoter sequence of 300 base pairs, encompassing the crucial Y, X, and W cis-acting elements. A plasmid construct, pDRA300neo, containing the HLA-DRA promoter sequence which drives the expression of the neomycin resistance gene, has been stably integrated in the genome of the H4 hybrid. Transfectants selected in the presence of G418 retain mouse chromosome 16 and express the DR genes. On the other hand, transfectants grown in a non-selective medium segregate mouse chromosome 16; this is accompanied by a loss of DRA gene expression and G418 resistance, although pDRA300neo is still integrated in the genome. These results offer scope for using this experimental model to clone the Air-1 gene in a straightforward way.
Correspondence to: R. S. Accolla. 相似文献
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Daniele De Simone Lorella D’Amico Daniela Bressanin Emma Motta Tiziana Annesi 《Mycological Progress》2011,10(3):301-306
Thirteen isolates of Inonotus rickii/Ptychogaster cubensis, from different geographic provenances, were analyzed by sequencing ITS1, ITS 2 and 5,8S ribosomal RNA region. A phylogenetic
tree, also including sequences available in Genbank database, showed that the strains enclosed in this study fall into two
well-separated groups, one formed by isolates from Florida (USA) and the other one by isolates from Europe, Argentina and
China. Differences were also highlighted on the growth rate of mycelial cultures at different temperatures. In fact, although
the tested isolates generally attained the best growth at 30°C, isolates from Europe seem well adapted to higher temperatures
and went on growing at 40°C whilst the growth of isolates from Florida significantly decreased at 35°C. Since the teleomorph
I. rickii was never detected in Florida, and in this study noticeable differences were detected by analysis of ITS region, the existence
of two possible distinct species, not discriminated solely on the basis of morphological characters, could be suggested. 相似文献
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Amino Acids - Unfortunately in the online published article, the name of compound “L-salicylidenealanine” was published with incorrect spelling in the section “Synthesis of... 相似文献