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排序方式: 共有143条查询结果,搜索用时 93 毫秒
101.
Onion (Allium cepa) is an important horticulture crop because of its value as a food with a long shelf life being a relatively non-perishable product. It is very helpful to understand the growth response of the seeded onion crop to conduct appropriate field practices in attaining the highest or optimum yields. A three year field experiment was conducted using a variety of onion Valcatorce INTA, in a randomized block design with five replicates. Treatments were two plant densities and three rates of N application. The bulb growth followed a classical sigmoid curve. During the rapid growing period, the crop had the greatest leaf area (LA) with at least six leaves per plant. Increasing plant density increased yield in kg/ha, but decreased bulb size. Defoliating 40 to 60% of the LA had a significant impact on bulb production only at early growth stages. Late in the growing period, the remaining LA was apparently large enough for producing sufficient amounts of metabolites to feed new leaves, increasing their photosynthesis efficiency for the benefit of bulb production. 相似文献
102.
Purification of galectin-3 from ovine placenta: developmentally regulated expression and immunological relevance 总被引:1,自引:1,他引:1
Iglesias MM; Rabinovich GA; Ambrosio AL; Castagna LF; Sotomayor CE; Wolfenstein-Todel C 《Glycobiology》1998,8(1):59-65
Galectins, beta-galactoside-binding lectins, are extensively distributed in
the animal kingdom and share some basic molecular properties. Galectin-3, a
member of this family, is generally associated with differentiation,
morphogenesis, and metastasis. In this study, galectin-3 was isolated from
ovine placental cotyledons round the middle of the gestation period by
lactose extraction followed by affinity chromatography on lactosyl-agarose,
and separated from galectin-1 by size exclusion chromatography on a
Superose 12 column. Under native conditions this lectin behaved as a
monomer with an apparent molecular weight of approximately 29,000 and an
isoelectric point of 9.0. The partial amino acid sequence of the peptides
obtained by tryptic digestion of this protein followed by HPLC separation
showed striking homology with other members of the galectin-3 subfamily.
Furthermore, ovine placental galectin-3 exhibited specific mitogenic
activity toward rat spleen mononuclear cells. Besides, this protein
strongly reacted with a rabbit antiserum raised against a chicken galectin.
Results obtained by Western blot analysis showed that its expression was
greatly decreased in term placenta with respect to the middle of the
gestation period, suggesting a regulated expression throughout development.
相似文献
103.
高浓度的硫酸铵阻碍了紫云英根瘤菌诱导紫云英根毛发生典型的根毛变形并明显抑制了紫云英结瘤能力。通过对融合子的β-半乳精苷酶活性的测定进一步表明高浓度的硫酸铵对紫云英的结瘤调节基因nodDZ、共同结瘤基因nodA及nodBC的表达有抑制作用而对结瘤调节基因nodD1的表达无抑制作用。 相似文献
104.
Taxol from fungal endophytes and the issue of biodiversity 总被引:7,自引:0,他引:7
GA Strobel WM Hess E. Ford RS Sidhu X Yang 《Journal of industrial microbiology & biotechnology》1996,17(5-6):417-423
Fungi represent one of the most understudied and diverse group of organisms. Commonly, these organisms make associations with higher life forms and may proceed to biochemically mimic the host organism. An excellent example of this is the anticancer drug, taxol, which had been previously supposed to occur only in the plant genusTaxus (yew). However, taxol has been reported in a novel endophytic fungus—Taxomyces andreanae, but also has been demonstrated to occur in a number of unrelated fungal endophytes includingPestalotia, Pestalotiopsis, Fusarium, Alternaria, Pithomyces, Monochaetia and others. Thus, this report presents information on the presence of taxol among disparate fungal genera, and uses these observations as an additional argument to support efforts to study fungal endophytes and preserve their associated host plants. 相似文献
105.
Keith R. Shelton Carrington S. Cobbs John T. Povlishock Rosalind K. Burkat 《Archives of biochemistry and biophysics》1976,174(1):177-186
A nuclear envelope fraction is obtained from circulating erythrocytes of mature chickens. This fraction was characterized by chemical analysis, ultramicroscopic examination and electrophoretic analysis of the polypeptides. It is free of plasma membrane polypeptides, of hemoglobin and of deoxyribonucleohistone. Comparisons of the sodium dodecyl sulfate-polyacrylamide-gel electropherograms of the nuclear envelope fraction polypeptides with either chromosomal fraction or the total nonhistone fraction polypeptides from Triton X-100-washed nuclei indicate that certain major polypeptides are common to all fractions. This indicates that many chicken erythrocyte nonhistone “chromosomal” polypeptides may be primarily associated with nuclear structural elements which are not, in fact, deoxyribonucleohistone. Although this finding cannot be extended per se to other cells, it does suggest that caution should be exercised in describing nuclear components as “chromosomal” when this designation is intended to imply primary association with the deoxyribonucleohistone. This analysis of the polypeptides in the nuclear envelope fraction of the erythrocyte indicates that further study of the envelope fraction will provide new insights into nuclear structure and function. 相似文献
106.
Sandra J Tanahatoe Joseph McDonnell Angelique J Goverde Peter GA Hompes Cornelis B Lambalk 《Reproductive biology and endocrinology : RB&E》2009,7(1):3
Background
To gain more insight in whether failure of intrauterine insemination (IUI) treatment in patients with idiopathic subfertility could be related to diminished fertilization, the aim of this study is to compare the fertilization of an initial IVF procedure after six cycles of IUI and the fertilization of an initial IVF procedure without preceding IUI cycles in couples with idiopathic subfertility. 相似文献107.
108.
109.
110.
目的:研究对比三种抗癫痫药(苯妥因钠、丙戊酸钠、卡马西平)对癫痫患者脑电图的背景影响。方法:选取我院于2009年3月至2011年2月收治的60例癫痫患者,随机分为苯妥因钠(PHT)、卡马西平(CBZ)和丙戊酸钠(SVP)组各20例,动态观察各组患者于治疗期间痫样波放电的频度和EEG背景的变化。结果:EEG痫样波放电的抑制率以SVP最为明显,而CBZ在EEG背景活动影响方面均比其他两组显著。结论:三种药物对癫痫波放电的抑制顺序是SVP〉PHT〉CBZ,SVP组明显优于其他两组。 相似文献