NaCl胁迫下枸杞愈伤组织可溶性蛋白含量的变化

以枸杞愈伤组织为材料,分别接种于对照及含100,200,400mmol／L NaCl的培养基上,培养1,3,5,7,11d．实验结果表明,随着盐浓度的升高．枸杞愈伤组织可溶性蛋白含量降低,且随着时间的延长呈先上升后下降的趋势,即随着盐浓度的升高,培养1,3,5d时可溶性蛋白含量上升,5d后开始下降;培养11d时在不同含盐培养基上加入外源ABA,愈伤组织可溶性蛋白含量升高,通过SDS-PAGE电泳实验发现,当NaCl浓度为400mmol／L时,在愈伤组织中诱导出一条40．5kD的新蛋白．     

雪鸡与环境的相互关系

在驯养雪鸡中，从最小空间需要量，饲科与食性、光照与繁殖、气温与调控等六个方面，阐述了环境对雪鸡的行为反应，提出了人工养殖雪鸡的综合性措施，并为开发雪鸡自然资源提出了理论和技术依据。     

杂质粒子对二维尘埃等离子体系统相变的影响

利用分子动力学模拟研究了杂质粒子对二维尘埃等离子体系统的影响.分别计算了平均平方位移,两体相关函数来分析系统的机构特性.结果表明,在参数范围内,杂质的含量以及杂质的质量和电荷的大小都会减慢系统的相变.杂质粒子在质量和电荷上都小于背景的尘埃粒子.     

CUSI神经元模型的一般形式及其应用

提出了ＣＵＳＩ神经元模型的一般形式，给出其学习算法。通过实例将ＣＵＳＩ神经元模型应用到地质数据的分析上，取得了比线性回归更好的效果。     

高分子稳定的水溶性铂氧化物纳米颗粒的制备

利用铂氯化物的水解反应,制备出聚乙烯吡咯烷酮(PVP)稳定的水溶性二氧化铂纳米颗粒.此法所得的产物颗粒小,粒径分布窄,稳定,室温下放置几个月无沉淀.用紫外-可见光谱检测纳米颗粒的形成过程,用X-射线光电子能谱(XPS)和透射电子显微镜(TEM)对样品的成分、形貌、尺寸进行了表征,并考察了PVP的浓度以及体系的酸碱度对形成二氧化铂颗粒粒径的影响.     

Avian flu: isolation of drug-resistant H5N1 virus

The persistence of H5N1 avian influenza viruses in many Asian countries and their ability to cause fatal infections in humans have raised serious concerns about a global flu pandemic. Here we report the isolation of an H5N1 virus from a Vietnamese girl that is resistant to the drug oseltamivir, which is an inhibitor of the viral enzyme neuraminidase and is currently used for protection against and treatment of influenza. Further investigation is necessary to determine the prevalence of oseltamivir-resistant H5N1 viruses among patients treated with this drug.     

Transcriptional regulation of a metastasis suppressor gene by Tip60 and beta-catenin complexes

Defining the molecular strategies that integrate diverse signalling pathways in the expression of specific gene programmes that are critical in homeostasis and disease remains a central issue in biology. This is particularly pertinent in cancer biology because downregulation of tumour metastasis suppressor genes is a common occurrence, and the underlying molecular mechanisms are not well established. Here we report that the downregulation of a metastasis suppressor gene, KAI1, in prostate cancer cells involves the inhibitory actions of beta-catenin, along with a reptin chromatin remodelling complex. This inhibitory function of beta-catenin-reptin requires both increased beta-catenin expression and recruitment of histone deacetylase activity. The coordinated actions of beta-catenin-reptin components that mediate the repressive state serve to antagonize a Tip60 coactivator complex that is required for activation; the balance of these opposing complexes controls the expression of KAI1 and metastatic potential. The molecular mechanisms underlying the antagonistic regulation of beta-catenin-reptin and the Tip60 coactivator complexes for the metastasis suppressor gene, KAI1, are likely to be prototypic of a selective downregulation strategy for many genes, including a subset of NF-kappaB target genes.     

Polyalanine expansion and frameshift mutations of the paired-like homeobox gene PHOX2B in congenital central hypoventilation syndrome

Congenital central hypoventilation syndrome (CCHS or Ondine's curse; OMIM 209880) is a life-threatening disorder involving an impaired ventilatory response to hypercarbia and hypoxemia. This core phenotype is associated with lower-penetrance anomalies of the autonomic nervous system (ANS) including Hirschsprung disease and tumors of neural-crest derivatives such as ganglioneuromas and neuroblastomas. In mice, the development of ANS reflex circuits is dependent on the paired-like homeobox gene Phox2b. Thus, we regarded its human ortholog, PHOX2B, as a candidate gene in CCHS. We found heterozygous de novo mutations in PHOX2B in 18 of 29 individuals with CCHS. Most mutations consisted of 5-9 alanine expansions within a 20-residue polyalanine tract probably resulting from non-homologous recombination. We show that PHOX2B is expressed in both the central and the peripheral ANS during human embryonic development. Our data support an essential role of PHOX2B in the normal patterning of the autonomous ventilation system and, more generally, of the ANS in humans.     

塔里木盆地12000年来的环境变迁

本文综合分析了地层、考古、树轮等方面的考察资料，认为新疆塔里木盆地在最近１２０００年中，一直是在干旱的荒漠环境控制之下，与现代自然环境的特征基本相似。尽管塔里木盆地干旱多风、水源短缺、植被稀少等环境条件是生存环境恶化的潜在因素，但历史时期发生的河水断流、湖泊变干、沙漠扩张等环境劣变主要是人类活动改变了地表水的地域分配造成的。因此，合理用水、平衡水土是我们今后开发塔里木盆地自然资源应当吸取的历史教训。