The neuronal sortilin-related receptor SORL1 is genetically associated with Alzheimer disease

The recycling of the amyloid precursor protein (APP) from the cell surface via the endocytic pathways plays a key role in the generation of amyloid beta peptide (Abeta) in Alzheimer disease. We report here that inherited variants in the SORL1 neuronal sorting receptor are associated with late-onset Alzheimer disease. These variants, which occur in at least two different clusters of intronic sequences within the SORL1 gene (also known as LR11 or SORLA) may regulate tissue-specific expression of SORL1. We also show that SORL1 directs trafficking of APP into recycling pathways and that when SORL1 is underexpressed, APP is sorted into Abeta-generating compartments. These data suggest that inherited or acquired changes in SORL1 expression or function are mechanistically involved in causing Alzheimer disease.     

纳米管TiO2的形貌结构和物理化学特性

对新型纳米管状ＴｉＯ２的形貌结构和物理化学特性进行了考察,发现此种ＴｉＯ２纳米管由２～５个单层ＴｉＯ２分子组成,管内径在４．２～５．９ｎｍ之间,有很高的比表面积和孔体积（分别这３７９ｍ＾２ｇ和１．４３１ｃｍ＾３／ｇ）,对染料活性艳红Ｘ－３Ｂ的脱色活性可比ＤｅｇｕｓｓａＰ－２５ＴｉＯ２提高约２倍,是一种很有希望在光催化和复合纳米材料等方面应用的新型ＴｉＯ２材料。     

Optimization of the cellular import of functionally active SH2-domain-interacting phosphopeptides

Phosphopeptides interacting with src homology 2 (SH2) domains can activate essential signaling enzymes in vitro. When delivered to cells, they may disrupt protein-protein interactions, thereby influencing intracellular signaling. We showed earlier that phosphopeptides corresponding to the inhibitory motif of Fcγ receptor IIb and a motif of the Grb2-associated binder 1 adaptor protein activate SH2-containing tyrosine phosphatase 2 in vitro. To study the ex vivo effects of these peptides, we have now compared different methods for peptide delivery: (i) permeabilization of the target cells and (ii) the use of cell-permeable vectors, which are potentially able to transport biologically active compounds into B cells. We found octanoyl-Arg₈ to be an optimal carrier for the delivery of phosphopeptides to the cells. With this strategy, the function of cell-permeable SHP-2-binding phosphopeptides was analyzed. These peptides modulated the protein phosphorylation in B cells in a dose- and time-dependent manner. Received 27 July 2006; received after revision 4 September 2006; accepted 18 September 2006     

The ubiquitin-specific protease USP25 interacts with three sarcomeric proteins

The biological functions of the more than one hundred genes coding for deubiquitinating enzymes in the human genome remain mostly unknown. The USP25 gene, located at 21q11.2, encodes three protein isoforms produced by alternative splicing. While two of the isoforms are expressed nearly ubiquituously, the expression of the longer USP25 isoform (USP25m) is restricted to muscular tissues and is upregulated during myogenesis. USP25m interacts with three sarcomeric proteins: actin alpha-1 (ACTA1), filamin C (FLNC), and myosin binding protein C1 (MyBPC1), which are critically involved in muscle differentiation and maintenance, and have been implicated in the pathogenesis of severe myopathies. Biochemical analyses demonstrated that MyBPC1 is a short-lived proteasomal substrate, and its degradation is prevented by over-expression of USP25m but not by other USP25 isoforms. In contrast, ACTA1 and FLNC appear to be stable proteins, indicating that their interaction with USP25m is not related to their turnover rate. Received 7 November 2005; received after revision 7 January 2006; accepted 13 January 2006     

喜马拉雅山中段达索普粒雪芯中夏季风和尘埃信号记录研究

通过粒雪芯δ＾１８Ｏ和主要离子（Ｃａ＾２＋,Ｍｇ＾２＋,ＮＨ＾＋４,ＳＯ＾２－４和ＮＯ＾－３）的分析表明,该粒雪芯年平均积累量为０．７５ｍ水当量。粒雪芯中δ＾１８Ｏ和主要离子浓度的季节变化表明,达索普冰川中高精度的记录了现代夏季风和尘埃信号。夏季风期间降水中δ＾１８Ｏ值由“降水量效应”所控制,雪层中较低δ＾１８Ｏ值则代表了夏季风信号。亚洲中部干旱半干旱区的春季尘暴输入是造成粒雪芯中Ｃａ＾２＋,Ｍｇ     

技术转移:企业资助的学术发明对创新的促进

<正>一般认为企业资助的学术研究对其他人来说是不太容易获取且用处不大的,布莱恩D.怀特及其同事提出的数据对这个看法提出了挑战。政府长期以来一直鼓励大学—企业之间的合作,以期对可以带来工作机会、强化投资并生产出改善生活质量产品的创新进行激励。同时,政府在科学上预算的收缩迫使大学通过其他途径寻求经费支持。根据美国国家科学基金会的统计,2012年由企业提供的科研经费只占到美国研究型大学年度科研经费的5%(大约32亿美元)。     

Enhanced performance of nano-sized SiC reinforced Al metal matrix nanocomposites synthesized through microwave sintering and hot extrusion techniques

In the present study, nano-sized SiC (0, 0.3, 0.5, 1.0 and 1.5 vol%) reinforced aluminum (Al) metal matrix composites were fabricated by microwave sintering and hot extrusion techniques. The structural (XRD, SEM), mechanical (nanoindentation, compression, tensile) and thermal properties (co-efficient of thermal expansion- CTE) of the developed Al-SiC nanocomposites were studied. The SEM/EDS mapping images show a homogeneous distribution of SiC nanoparticles into the Al matrix. A significant increase in the strength (compressive and tensile) of the Al-SiC nanocomposites with the addition of SiC content is observed. However, it is noticed that the ductility of Al-SiC nanocomposites decreases with increasing volume fraction of SiC. The thermal analysis indicates that CTE of Al-SiC nanocomposites decreases with the progressive addition of hard SiC nanoparticles. Overall, hot extruded Al 1.5 vol% SiC nanocomposites exhibited the best mechanical and thermal performance as compared to the other developed Al-SiC nanocomposites.     

泛代数上的Groebner-Shirshov基理论

综述了域上或交换代数上的线性（-）代数的相应的簇（范畴）的 Groebner-Shirshov 基理论的新成果，如:结合代数（包括群（半群）代数），自由代数的张量积，李代数，Di-代数，pre-李代数，Rota-Baxter代数，metabelian李代数，L-代数，半环代数，范畴代数，等．以上结果包含了许多应用，尤其是给出了一些著名结论的新的证明．