磁性纳米标记检测技术在生物医学即时检测领域的研究进展

基于磁性纳米材料的磁标记检测技术具有灵敏度高、线性范围广、信号检测便捷等优点。由于生物样品自身磁背景信号极低,相比于光学标记检测技术,磁标记检测技术在蛋白质、核酸、细胞、病原体及生物组织检测中均表现出更高的灵敏度,在生物医学即时检测领域展现了良好的应用前景。该文围绕磁性纳米粒在即时检测领域的最新研究进展,重点介绍了其在蛋白质、核酸以及几类病原体检测方面的应用,并对基于磁性纳米粒的即时检测技术发展方向及应用前景进行了展望。     

Hydrolysis of DNA by cerium(IV)/EDTA complex

Homogeneous solutions are formed from equimolar amounts of Ce(NH₄)₂(NO₃)₆ and EDTA. These solutions hydrolyze single-stranded DNA far more efficiently than double-stranded DNA. In contrast, Ce(IV) hydroxide gel, obtained in the absence of EDTA, hydrolyzes both single-stranded and double-stranded DNAs at almost the same rates. In order to achieve this substrate-specificity sufficiently, the mole ratio of EDTA to Ce(NH₄)₂(NO₃)₆ must be 1.0 or greater. By using this remarkable specificity of Ce(IV)/EDTA complex, gap-site in substrate DNA is selectively hydrolyzed. The scission-site is modulated by use of appropriate combination of oligonucleotide additives. The reactions have been kinetically analyzed.     

Solving the 3-SAT problem based on DNA computing

The 3-SAT problem is an NP-complete problem, and many algorithms based on DNA computing have been proposed for solving it since Adleman's pioneering work. This paper presents a new algorithm based on the literal string strategy proposed by Sakamoto et al. Simulation results show that the maximal number of literal strings produced during the computing process is greatly reduced. Moreover, the length of the literal strings is also reduced from m to n at most.     

微波合成铝掺杂钻酸锂材料及性能研究

以LiOH·H2O，Al2O3和Co3O4为原料，微波加热合成Li离子电池正极材料LiAlxCo（1-x）O2．通过XRD测试表征了不同Al加入量时合成产物的晶体结构，确定当x≤0．4时，产物为单一相层状结构．计算了不同x时LiAlxCo（1-x）O2的晶胞参数，随着x的增大，a值减小，c值增大．对合成LiAlxCo（1-x）O2样品进行DSC—TGA测试，结果表明，当x不同时，合成样品的热稳定性不同．SEM测试表明，合成晶体粒度较均匀，粒径在5μm左右．电化学测试表明，LiAl0.2Co0.8O2的电化学性能最好，首次循环放电容量为127mAh／g，多次循环容量损失率小于LiCoO2．     

Pr0.6-xNdxSr0.4FeO3-δ电极材料的光谱及性能研究

以柠檬酸-硝酸盐自蔓延燃烧法合成了ABO₃型钙钛矿结构的Pr_0.6-xNd_xSr_0.4FeO_3-δ(x=0.0～0.6)系列稀土复合氧化物粉体。利用傅立叶变换红外光谱(FTIR)和激光共焦拉曼光谱(LRS)对产物的晶体结构进行了表征。分别采用热膨胀仪测定烧结陶瓷体的热膨胀系数(TEC)；TG-DTA记录材料的热稳定性；XRD研究阴极材料与中温电解质Sm_0.2Ce_0.8O_1.9(SDC)及La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ(LSGM)的化学相容性；SEM观察阴极/电解质复合材料的断口形貌。结果表明，该系列样品在高、低温热循环过程中化学稳定、晶型稳定；在室温至1 100 ℃范围内的平均热膨胀系数为1.16 × 10^-5 K^-1，与SDC及LSGM的热膨胀系数十分接近。阴极/电解质混合粉体1 200 ℃煅烧10 h，XRD未检测到新物质；SEM显示复合层断面界面清晰，没有相互扩散现象。该体系有望成为以SDC或LSGM为电解质的中温固体氧化物燃料电池合适的阴极材料。     

Synthesis and Characterization of a Novel Biomaterial： Maleic Anhydride-modified Poly（dl-lactic acid）

A novel modified poly(dl-lactic acid) (PDLLA) was obtained by covalently grafting of maleic anhydride onto the backbone of PDLLA, attempting to improve PDLLA‘s hydrophilicity and cell affinity and to provide reactive groups for further chemical modification. FTIR, ^13 C NMR and DSC were used to characterize the maleic anhydride-modified PDLLA.     

纳米Re2O7的萃取法制备及光催化特性研究

本工作从N235-正庚烷萃取体系中，以饱和萃取法制得前体物和纳米粉体Re₂O₇，平均粒径30 nm。以此纳米粉为光催化剂，研究了光降解甲基橙染料的最佳条件，并在相同条件下，与非纳米Re₂O₇及工业常用的纳米TiO₂进行比较，光降解甲基橙能力大小为：纳米Re₂O₇ > 锐钛矿型纳米TiO₂ > 非纳米Re₂O₇。     

Synthesis of the Biomimetic Polymer： Aliphatic Diamine and RGDS Modified Poly（d,l-lactic acid）

A novel poly（d, /-lactic acid） （PDLLA） based biomimetic polymer was synthesized by grafting maleic anhydride, butanediamine and arg-gly-asp-ser （RGDS） peptides onto the backbone of PDLLA, aiming to overcome the acidity and auto-accelerating degradation of PDLLA during degradation and to improve its biospecificity and biocompatibility. The synthetic copolymer was characterized by FTIR, ^13C NMR and amino acid analyzer （AAA）.     

Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin

In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression.     

应用反向传播神经网络预测化合物脑血分配系数

选用27种三维结构性质描述符对脑血分配系数预测建立神经网络模型.网络模型选用典型的适合函数逼近的两层结构神经网络对脑血分配系数(lgBB,BB为脑血浓度比)进行预测,计算中采用的模型具有一个双曲正切型激活函数的隐含层和一个线性激活函数的输出层.计算表明,使用小心选择的反向传播神经网络模型对化合物脑血分配系数具有较好的预测能力.