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排序方式: 共有254条查询结果,搜索用时 15 毫秒
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棉苗黑斑病的致病菌在关中棉区初步认为是 Alternaria tenuis Nees 与棉成株期叶片上的致病菌不同。病菌孢子借气流传布。种子带菌率虽然很高,但诱发苗病率却很低,因此,种子消毒或采用轮栽来控制这个病害,是不能达到预期效果的。病害发生与棉苗受冻、强风对棉苗的伤害以及棉苗阶段发育有密切的关系。各年发病期有早有晚,但以真叶出现时为易感阶段。本文阐述了棉苗生育阶段、气候条件与发病的关系,为预测病害发生的物候与气象参考条件提供了资料。棉株伤害与发病有关系,建议在生产上适当降低播种量,提高播种质量,适期早疏苗、早间苗;以减轻由于伤损而导致病害侵染。品种与病害发生的关系不显著。试验证明,使用波尔多液加1059于降温前喷射效果较好。 相似文献
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Human endothelial cell growth factor: cloning, nucleotide sequence, and chromosome localization 总被引:78,自引:0,他引:78
M Jaye R Howk W Burgess G A Ricca I M Chiu M W Ravera S J O'Brien W S Modi T Maciag W N Drohan 《Science (New York, N.Y.)》1986,233(4763):541-545
Several of the endothelial cell polypeptide mitogens that have been described probably play a role in blood vessel homeostasis. Two overlapping complementary DNA clones encoding human endothelial cell growth factor (ECGF) were isolated from a human brain stem complementary DNA library. Southern blot analysis suggested that there is a single copy of the ECGF gene and that it maps to human chromosome 5 at bands 5q31.3 to 33.2 A 4.8-kilobase messenger RNA was present in human brain stem messenger RNA. The complete amino acid sequence of human ECGF was deduced from the nucleic acid sequence of these clones; it encompasses all the well-characterized acidic endothelial cell polypeptide mitogens described by several laboratories. The ECGF-encoding open reading frame is flanked by translation stop codons and provides no signal peptide or internal hydrophobic domain for the secretion of ECGF. This property is shared by human interleukin-1, which is approximately 30 percent homologous to ECGF. 相似文献
77.
Pang PC Chiu PC Lee CL Chang LY Panico M Morris HR Haslam SM Khoo KH Clark GF Yeung WS Dell A 《Science (New York, N.Y.)》2011,333(6050):1761-1764
Human fertilization begins when spermatozoa bind to the extracellular matrix coating of the oocyte, known as the zona pellucida (ZP). One spermatozoan then penetrates this matrix and fuses with the egg cell, generating a zygote. Although carbohydrate sequences on the ZP have been implicated in sperm binding, the nature of the ligand was unknown. Here, ultrasensitive mass spectrometric analyses revealed that the sialyl-Lewis(x) sequence [NeuAcα2-3Galβ1-4(Fucα1-3)GlcNAc], a well-known selectin ligand, is the most abundant terminal sequence on the N- and O-glycans of human ZP. Sperm-ZP binding was largely inhibited by glycoconjugates terminated with sialyl-Lewis(x) sequences or by antibodies directed against this sequence. Thus, the sialyl-Lewis(x) sequence represents the major carbohydrate ligand for human sperm-egg binding. 相似文献
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K Muegge T M Williams J Kant M Karin R Chiu A Schmidt U Siebenlist H A Young S K Durum 《Science (New York, N.Y.)》1989,246(4927):249-251
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Neuroleptic drug-induced dopamine receptor supersensitivity: antagonism by L-prolyl-L-leucyl-glycinamide 总被引:1,自引:0,他引:1
An animal model of tardive dyskinesia was used to evaluate the potential antidyskinetic properties of the neuropeptide L-prolyl-L-leucyl-glycinamide (PLG). In rats, PLG administered concurrently with the neuroleptic drug haloperidol or chlorpromazine antagonized the enhancement of specific [3H]spiroperidol binding in the striatum that is associated with long-term neuroleptic treatment. The results are discussed in relation to a possible functional coupling of the putative PLG receptor with neuroleptic-dopamine receptor complex and clinical implications for tardive dyskinesia. 相似文献
80.
Loftus BJ Fung E Roncaglia P Rowley D Amedeo P Bruno D Vamathevan J Miranda M Anderson IJ Fraser JA Allen JE Bosdet IE Brent MR Chiu R Doering TL Donlin MJ D'Souza CA Fox DS Grinberg V Fu J Fukushima M Haas BJ Huang JC Janbon G Jones SJ Koo HL Krzywinski MI Kwon-Chung JK Lengeler KB Maiti R Marra MA Marra RE Mathewson CA Mitchell TG Pertea M Riggs FR Salzberg SL Schein JE Shvartsbeyn A Shin H Shumway M Specht CA Suh BB Tenney A Utterback TR Wickes BL Wortman JR Wye NH Kronstad JW Lodge JK 《Science (New York, N.Y.)》2005,307(5713):1321-1324