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221.
选用微米级碳酸钙、碳酸镁作为无机填料,研究了二元复配填料填充对聚乙烯复合材料性能的影响。通过对无机粉体活化实验,复合材料熔体指数、力学性能以及结晶性能的比较,讨论了无机组合粒子级复配共混的协同效应。结果表明,复配填料能够产生一定的协同效应,提高聚乙烯复合材料的综合性能。 相似文献
222.
利用作者克隆的酿酒酵母基因启动子片段Y8为探针和菌落原位杂交方法,从构建的S.cerevisiae YNN27基因组文库中共筛选8个阳性克隆。根据这些克隆中插入片段大小和限制酶切结果,可将其划分为6种,分别命名为YN1-YN6.Southern杂交结果表明,这6种DNA片段不仅能与6.5kb的全长Y8探针我,而且均能与PstI酶切Y8所得的3段DNA探针杂交。 相似文献
223.
To determine whether gonadotropin-like substance in the brain and Hatschek' s pit of amphioxus issynthesized by the tissue in situ or transported from other tissue, a histochemical study was carried out by in situ hy- bridization using digoxigenin (DIG)-labelled LHβRNAprobes. The results showed that LHβmRNA expressed in the nerve cells of brain and the epithelial cells of Hatschek' s pit, thus providing new evidence for the homology of pituitary of ver- tebrates with Hatschek' s pit and the functional evolution of gonadotropin. 相似文献
224.
A male-sterileT. aestivum-Ag. intermedium partial amphiploid with cytoplasm ofT. timopheevii as a female parent was crossed to common wheat. The hybrid was backcrossed to the male parent several times continually and
setf-crossed at last. Two stable lines with common wheat phenotype, H96269-2 and H96278, have been obtained. The chromosome
numbers of the two lines are all2n = 42 in somatic cetls. By inoculation test, the two lines show a high levet of resistance to yetlow rust. Through genomicin situ hybridization (GISH) withAg. intermedium total genomic DNA as a probe, it is demonstrated that the two stable lines are all small segmental translocation lines, and
the translocated chromosome segments fromAg. intermedium are located on the short arm terminals of wheat chromosomes. Genetics analysis suggests that the yetlow rust resistance gene(s)
are probably located on the translocated chromosome segments ofAg. intermedium. 相似文献
225.
QIU Jiwen OUYANG Ping LI Dawei JIN Demin LI Chuanyou JIA Jianhang WANG Bin William TAI 《科学通报(英文版)》2000,45(6)
RAPD and RFLP analyses of double haploid lines which derived from hybridization between hexaploid wheat (Triticum aestivum L.2n=42) and eastern gamagrass (Tripsacum dactyloides L.2n=4x=72) are reported.Two of the 340 Operon primers have been screened,which stably amplified Tripsacum dactyloides (male parent) specific bands in the double haploid lines.These results confirm the fact that Tripsacum dactyloides DNA has been integrated into wheat genome by sexual hybridization at molecular level.This idea has been further testified by RFLP analysis.Application and potentials of transferring Tripsacum dactyloides DNA into wheat genome by sexual hybridization in wheat breeding are discussed. 相似文献
226.
《科学通报(英文版)》2007,52(14)
A novel salicylaldehyde dehydrogenase involved in catabolism of naphthalene from Pseudomonas putida ND6, NahV, has been identified. NahV exhibited lower identity in amino acid sequence with the classic salicylaldehyde dehydrogenase, NahF, from P. putida ND6. This is the first report of an isofunctional enzyme of bacterial salicylaldehyde dehydrogenase. Comparison of Km and Vmax values of NahV and NahF demonstrated that NahF has a more efficient catalytic reaction than NahV, while NahV has much higher affinity for salicylaldehyde and NAD . Both enzymes exhibited broad substrate speci- ficities and catalyzed the oxidation of salicylaldehyde, 5-chlorosalicylaldehyde, formaldehyde, m-nitrobenzaldehyde, o-nitrobenzaldehyde, o-methoxybenxaldehyde, glutaraldehyde, caprylic aldehyde, and glyoxal. However, the relative rates at which the substituted analogs are transformed differ considerably. NahV activity could be enhanced by Fe2 , Cu2 and Zn2 ; whereas NahF activity could only be stimulated by Fe2 . NahF is more stable than NahV at elevated temperatures. Dot-blot hybridization analyses showed that nahF-like genes occurred in all naphthalene-degradation bacteria isolated in this study, whereas nahV-like genes were present in only some naphthalene-degrading bacteria. 相似文献
227.
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229.
Antral follicles are present in the ovaries throughout gestation. These follicles are “physically immature” and cannot ovulate
under the induction of LH/hCG. The purpose of the present study is to examine whether follicles in pregnant rat ovaries are
capable of steroidogenesis. StAR is believed to be the key regulator of steroid hormone biosynthesis. Antisense StAR probe
and anti-StAR rabbit serum have been used to detect the StAR expression in ovarian follicles at various stages of pregnant
rats. The results indicate that theca-interstitial cells and the membrane granulosa cells at the stages from the estrous or
pre-estrous in the normal cycling rat ovary express StAR mRNA and its protein, whereas neither granulosa cells nor the theca
cells in pregnant ovary throughout gestation express StAR. These results indicate that the pregnant follicles throughout gestation
are incapable of steroidogenesis. 相似文献
230.
胎儿左右大脑差异表达基因片段的克隆 总被引:1,自引:0,他引:1
应用抑制性消减杂交(SSH)技术从一24 周流产男性胎儿的左右大脑m RNA 中克隆到了42 个左脑特异表达基因的cDNA 片段,并随机挑选15 个克隆的测序结果与美国NIH 基因库EST进行了同源性分析,同源性范围是64% ~100% ,其中有5 个克隆的基因库同源序列与脑有关,其余10 个克隆同源于脑以外的其它组织. 相似文献