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981.
采用荧光分光光度法测定喹喏酮类抗生素氧氟沙星,有较高的灵敏度,在氧氟沙星浓度为1.38×10-6.92×10-5mol/L间,荧光强度与浓度有良好的线性关系,线性相关系数为0.9999,该测定方法的回收率为99.0%,对氧氟沙星胶囊含量测定的结果与用紫外分光光度法测量结果间无显著性差异.该方法操作简单,所用试剂少,结果可信,完全可在临床医学和医药工业领域作为对该药物的常规测定方法使用. 相似文献
982.
983.
In order to identify the genes associated with glioblastoma differentiation, some ESTs, expressed differentially in the control cell and the differentiated human glioblastoma cell line BT-325 induced by the all-trans retinoid acid, have been isolated by the method of DDRT-PCR. Of the 46 ESTs sequenced, 19 are from new genes. A full-length 1 535-bp cDNA, termed gene GDR1, has been isolated from the human cDNA library using the probe designed according to one of the novel ESTs, HGBB098. The open reading frame of GDR1 gene encodes a putative protein containing 334 amino acid residues. Blast against the current GenBank DNA and protein sequence database did not reveal significant homology with any known proteins. RT-PCR shows that GDR1 mRNA level increased in the differentiated BT-325 cells after being treated with RA. The different expression patterns of GDR1 mRNA in human tissues have been detected through the multiple tissue Northern blot hybridization. 相似文献
984.
985.
Spatiotemporal asymmetric auxin distribution: a means to coordinate plant development 总被引:1,自引:0,他引:1
Tanaka H Dhonukshe P Brewer PB Friml J 《Cellular and molecular life sciences : CMLS》2006,63(23):2738-2754
The plant hormone auxin plays crucial roles in regulating plant growth development, including embryo and root patterning,
organ formation, vascular tissue differentiation and growth responses to environmental stimuli. Asymmetric auxin distribution
patterns have been observed within tissues, and these so-called auxin gradients change dynamically during different developmental
processes. Most auxin is synthesized in the shoot and distributed directionally throughout the plant. This polar auxin transport
is mediated by auxin influx and efflux facilitators, whose subcellular polar localizations guide the direction of auxin flow.
The polar localization of PIN auxin efflux carriers changes in response to developmental and external cues in order to channel
auxin flow in a regulated manner for organized growth. Auxin itself modulates the expression and subcellular localization
of PIN proteins, contributing to a complex pattern of feedback regulation. Here we review the available information mainly
from studies of a model plant, Arabidopsis thaliana, on the generation of auxin gradients, the regulation of polar auxin transport and further downstream cellular events.
Received 10 March 2006; received after revision 26 June 2006; accepted 9 August 2006 相似文献
986.
白花前胡提取液抗慢性压力超负荷大鼠心肌细胞凋亡研究 总被引:4,自引:0,他引:4
目的:探讨白花前胡抗心力衰竭疗效及可能机制.方法:用腹主动脉缩窄法建立慢性超负荷大鼠心衰模型,比较白花前胡提取液对心衰大鼠心脏系数、血压、心肌细胞凋亡率及凋亡相关基因的影响,并与依拉普利比较.结果:Pd-E能剂量相关性降低心衰大鼠的心脏系数、血压及凋亡率,显著改善肥大心肌细胞凋亡相关基因的表达,疗效与依拉普利基本相当.结论:白花前胡提取液可抑制心肌重塑,对心衰发挥生物学治疗作用. 相似文献
987.
988.
Okada Y Kubo M Ohmiya H Takahashi A Kumasaka N Hosono N Maeda S Wen W Dorajoo R Go MJ Zheng W Kato N Wu JY Lu Q;GIANT consortium Tsunoda T Yamamoto K Nakamura Y Kamatani N Tanaka T 《Nature genetics》2012,44(3):302-306
Obesity is a disorder with a complex genetic etiology, and its epidemic is a worldwide problem. Although multiple genetic loci associated with body mass index, the most common measure of obesity, have been identified in European populations, few studies have focused on Asian populations. Here we report a genome-wide association study and replication studies with 62,245 east Asian subjects, which identified two new body mass index-associated loci in the CDKAL1 locus at 6p22 (rs2206734, P = 1.4 × 10(-11)) and the KLF9 locus at 9q21 (rs11142387, P = 1.3 × 10(-9)), as well as several previously reported loci (the SEC16B, BDNF, FTO, MC4R and GIPR loci, P < 5.0 × 10(-8)). We subsequently performed gene-gene interaction analyses and identified an interaction (P = 2.0 × 10(-8)) between a SNP in the KLF9 locus (rs11142387) and one in the MSTN (also known as GDF8) locus at 2q32 (rs13034723). These findings should provide useful insights into the etiology of obesity. 相似文献
989.
本文研究了单向和宽角度的宽带MIMO雷达发射方向图合成.首先构造了单一范数优化准则下单向发射方向图合成的统一框架,使得已有的一些方法可视为其特例.在此基础上,提出了一种基于单向发射方向图合成的波形设计方法,并考虑了设计的波形具有单模或低的峰均比(PAPR)特性;进而提出了一种混合范数的宽角度的发射方向图合成方法.本文将上述的方向图合成和波形设计问题转化成凸优化问题,然后利用公开的模型系统CVX求解.仿真结果表明,本文方法设计的单向方向图能有效地逼近了期望的方向图,也验证了合成波形满足期望的单模或PAPR约束;另外,仿真显示设计的宽角度的方向图在主瓣区域内逼近了期望主瓣响应,而将旁瓣峰值比控制在-40 dB以下. 相似文献
990.