Multifractal analysis of resting state fMRI series in default mode network: age and gender effects

Age-related changes of resting state in default mode network （DMN） may provide new clues to the developing mechanism of normal brain as well as early diagnosis and therapy of some neuropsychiatric disorders. The application of multifractal theory to functional magnetic resonance imaging （fMRI） signals has recently raised increasing attention. We aim to explore the multifractal characteristics underlying the resting state functional magnetic resonance imaging （rs-fMRI） series extracted from DMN, and two issues are mainly discussed： （1） whether there exist multifractals in rs-fMRI series; （2） whether it is possible to distinguish between the different ages or genders by means of multifractal characteristics. Results demon- strated the existence of multifractals in rs-fMRI series in DMN. In addition, slight differences between young subjects and middle-aged or elderly subjects can be successfully detected by △asα, a modified measure we proposed. Furthermore, it is revealed that the rs-fMRI series from young subjects possess smaller averaged scale index and weaker long range correlation, while those from middle-aged or elderly people present increasing averaged scale index andstronger long range correlation. Whereas no significant statistical differences has been found between male and female group. Our results, therefore, highlight the potential useful- ness of multifractal analysis in fMRI series of a certain brain region, and provide important insights into healthy aging in DMN.     

稻米重金属污染风险及控制

稻米是我国的主粮,随着工农业和城市化的快速发展,稻米重金属污染胁迫问题日益突出。针对我国稻米重金属污染的种类、形成原因进行了分析,并对稻米重金属的控制技术及对策提出了建议,以期待为稻米重金属污染的解决、保障食品安全提供指导。     

齐齐哈尔市2002年的生态足迹分析

生态足迹分析法是近年来国际国内度量可持续发展的一种新方法．本文简要介绍了生态足迹分析法的相关概念和计算方法,利用此方法计算了齐齐哈尔市2002年的生态足迹和生态承载力,并对计算结果进行分析讨论,认为该地区的生态足迹需求对本地生态系统可持续发展构成威胁。     

李超代数的Jacobson幂零性定理

本文将李代数的Jacobson定理推广到李超代数中,得到李超代数的Jacobson幂零性定理,证明了如下结论,如果一般线性李超代数中的诣零的李超闭子集张成的李超代数是有限维的,那么此李超代数在其底空间上必是严格上三角的。     

提高服务质量 造就现代化读者

图书馆由传统走向现代化,服务质量更应进一步提高.本文从馆藏、馆员的自身建设、图书馆与大众生活的关系到现代化读者的塑造方面作了简要阐述.     

苯氧乙酰脲类嘧啶衍生物的合成及生物活性测定

从氯乙酰胺出发,经三步反应合成了１０种含不同取代嘧啶环的苯氧乙酰脲类新化合物,用ＩＲ,＾１Ｈ ＮＭＲ,元素分析等对它们的结构进行了确证,初步的生物活性测定结果表明,部分目标化合物有良好的除草活性。     

非天然D（L）—4—吡啶丙氨酸盐酸盐的合成

合成了２－乙酰氨基－３－（４‘－吡啶基）丙酸乙酯,经过酶的动力学拆分得到Ｄ（Ｌ）－４－吡啶丙氨酸盐酸盐,其结构核磁共振氢谱,光学测定和元素分析得到确证。     

基于局部模式的话音编码算法

提出了一种新的基于非线性局部模式的信号处理方法,并将其应用于话音编码中,在相同的编码条件下,基于ＮＬＬＰ的编码方案性能好于标准的线性预测编码算法和由线性局部预测模式构成的方案。     

Characteristics and geological significance of the eclogites from the Tongbai Mountains, Henan Province

Some eclogites and the related high-P metamorphic belt have been found for the first time from the Tongbai Mountains, Henan Province, where the eclogites and their probable retrogressive products ——garnet amphibolites——occur as lenses in mica-schists. The fresh eclogites comprise garnet, omphacite, quartz, rutile, phengite, barroisite, etc. The compositional features of garnet and available geothermobarometers indicated that the eclogites belong to the low-T type. The mica-schists contain phengite, quartz, garnet and rutile that are also attributed to high-P assemblage. The eclogites and related high-P belt probably belong to the Early Paleozoic in age, which is distinct from the Indosinian Dabie high- and ultrahigh-P metamorphic belt.     

米非司酮对JAR细胞凋亡的诱导作用

米非司酮是一类抗孕激素和抗糖皮质激素药物,在临床被广泛用于早孕的终止．发现米非司酮能抑制人滋养层瘤细胞（ＪＡＲ）的生长．药物处理使细胞形态出现典型的凋亡特征．被处理细胞的ＤＮＡ经琼脂糖电泳呈凋亡细胞特有的云梯状条带．原位凋亡检测也证实了凋亡细胞的存在．临床样品分析证明,米非司酮药物流产的人绒毛组织也发生了明显的细胞凋亡．说明米非司酮诱导流产的机制除了对子宫蜕膜的作用外,还可能与诱导滋养层细胞凋亡有关