神经酰胺类物质的分离纯化及应用

神经酰胺是一类重要的生物活性物质,也是细胞内重要的脂质第二信使.系统分析了神经酰胺类物质的结构、分离纯化和测定的方法等,介绍了其在食品、医药、化妆品等方面的应用,针对化学合成的神经酰胺的局限性,提出了从植物中提取天然的神经酰胺及其发展前景.     

抗癌神经酰胺类似物的最新研究进展

本文论述一种新的抗癌靶点神经酰胺信号通路的性质及特点,并结合近年来神经酰胺类似物的最新研究进展,提出了影响神经酰胺促凋亡活性的几个重要的结构因素。     

神经酰胺的研究进展及在护肤品中的应用

在人类皮肤中,神经酰胺作为皮肤角质层的重要组分之一,具有维持皮肤屏障、保湿、抗衰老、抗过敏等生理功能,在医学和化妆品领域中,吸引了大量的研究和关注.文章综述了神经酰胺这一成分的发展史、研究现状、在皮肤中的功能、影响皮肤中神经酰胺含量的因素,以及对应的神经酰胺缺失所需要的解决方案等.同时,对未来的发展提出一些展望.     

Eu^2＋激活的（CaMgBa）5（PO4）3（ClF）荧光体发光性能的研究

Ca_5(PO_4)_3Cl:Eu~(2+)和Ba_5(PO_4)_3Cl:Eu~(2+)都具有较强的蓝色荧光,它们的发射峰峰值波长分别为460nm和443nm,半高宽均为40nm。(Ca_(1-x)Ba_x)_5(PO_4)_3Cl:Eu~(2+)二元体系的固溶体范围为x=0.0～0.4和0.6～1.0,其中(Ba_(0.8)Ca_(0.2))_5(PO_4)_3Cl:Eu~(2+)发光亮度最高,发射峰峰值波长为508nm,半高宽为95nm,发光颜色为蓝绿色。Mg部分取代(Ba_(0.8)Ca_(0.2))_5(PO_4)_3Cl:Eu~(2+)中阳离子后,其发光强度可提高约25％。     

温和化学渗透剂对解脂假丝酵母神经酰胺含量的影响

为了分析温和化学渗透剂木瓜蛋白酶、甘氨酸对解脂假丝酵母33M Candida lipolytica中神经酰胺含量的影响，分别采用氯仿甲醇抽提法和乙醇抽提法提取神经酰胺，用固相萃取法（SPE）分离神经酰胺与其它膜中脂类，并用薄层色谱（TLC）方法和高效液相色谱-蒸发光散射器（HPLC-ELSD）对其进行定性和定量分析，结果表明：加温和化学渗透剂木瓜蛋白酶、甘氨酸能增加解脂假丝酵母中的神经酰胺含量，并以木瓜蛋白酶效果最好。     

硝酸钍与缩二脲固体配合物的合成及性质

本文报道了硝酸钍与缩二脲(BuH_2)的固体配合物 Th(BuH_2)_4(NO_3)_4的合成及化学组成的测定,并研究了该配合物的红外光谱、差热、热重、X—射线粉末衍射和摩尔电导等性质.结果表明,缩二脲通过羰基氧原子与 Th(Ⅳ)配位,同时部分 NO_3-也参与配位,并推测出该配合物可能的结构式为[Th(BuH_2)_4 (NO_3)_2](NO_3)_2.     

神经酰胺的代谢及其在细胞凋亡中的作用

神经酰胺是鞘脂类,作为第二信使普遍存在于细胞膜和细胞质之间并传递信号,是进化上保守的信号系统。现在已有的研究数据表明,电离辐射、紫外线、氧化应激等细胞外应激因子均能迅速激活细胞膜上的酸性鞘磷脂酶,水解鞘磷脂产生神经酰胺,从而诱导细胞凋亡,而且神经酰胺代谢中的很多产物,如鞘氨醇-1-磷酸具有抗凋亡活性,能控制凋亡反应强度,有助于阐明细胞抗辐射的机制。     

碱金属掺杂橄榄石型NaFePO_4的第一性原理研究

采用基于密度泛函理论(DFT)的第一性原理方法研究了钠离子电池正极材料橄榄石型NaFePO_4及其碱金属(Li、Na)掺杂体系的结构稳定性、电子结构、充放电过程结构演化及相关电化学性质.计算结果显示,NaFePO_4可掺杂适量Li、Na,且掺杂后结构稳定.脱钠相结构形成能的计算模拟了NaFePO_4及其掺杂体系充电过程中的相变,NaFePO_4在充电过程中存在Na_5/_6FePO_4与Na_2/_3FePO_42个中间相,铁位锂掺杂体系存在Na_3/_4(Li_1/_(12)Fe_(11)/_(12))PO_4、Na_1/_2(Li_1/_(12)Fe_(11)/_(12))PO_4、Na_1/_6(Li_1/_(12)Fe_(11)/_(12))PO_43个稳定中间相,铁位钠掺杂体系存在Na_5/_(12)(Na_1/_(12)Fe_(11)/_(12))PO_4、Na_1/_6(Na_1/_(12)Fe_(11)/_(12))PO_4、Na_(1/12)(Na_(1/12)Fe_(11/12))PO_43个稳定中间相.此外,通过分析电子结构,还发现Li、Na掺杂体系中有部分O~(2-)发生氧化参与电荷补偿,这使得掺杂体系的充电电压略高于未掺杂的NaFePO_4.     

3-酮基嘌呤还原酶(TSC10)基因表达载体的构建及其在毕赤酵母中的表达

TSC10基因所编码的3-酮基嘌呤还原酶是酵母中神经酰胺合成的重要因子。设计了一种从酵母中提取神经酰胺经济、便捷、高效的方法:(1)利用构建含有TSC10基因的毕赤酵母GS115表达载体p PIC3.5K-TSC10;(2)电转化法将该表达质粒转化到GS115感受态细胞中;(3)用G418筛选以及PCR鉴定;(4)使用qRT-PCR和SDS-PAGE进行检测。结果经过G418筛选以及PCR鉴定后确定获得了包含TSC10基因的毕赤酵母转化子,经过qRT-PCR和SDS-PAGE进行检测后发现TSC10基因在20个阳性菌株中均可以稳定、高效表达。成功构建了3-酮基嘌呤还原酶高表达的毕赤酵母菌株,并为后续获得高收率神经酰胺奠定了基础。     

均匀沉淀BaSO_4的过程中(NH_4)_2S_2O_8与EDTA反应机理的探讨

本文通过实验证明,在均相沉淀 BaSO_4的过程中,BaY~(2-)被(NH_4)_2S_2O_(?)破坏的反应机理是:一部分 EDTA 被氧化,一部分则是因为(NH_4)_2S_2O_3水解产生 H~ 和 SO_4~(2-),BaY~(2-)与 H~ 作用将 Ba~(2 )释放出来。Ba~(2 )与 SO_4~(2-)结合成BaSO_4沉淀。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

正~~     

An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.