胆碱酯酶抑制剂(S)-卡巴拉汀及其类似物的不对称合成与活性研究

以对羟基苯甲醛或间羟基苯甲醛为原料,用(R)或(S)-叔丁基亚磺酰胺为手性引发剂,设计合成了(S)-卡巴拉汀及其12个未见文献报道的类似物,其结构通过IR,1HNMR,13CNMR和HRMS确证.以Ellman法进行化合物的活性测试,结果表明合成的化合物都有较好的对乙酰胆碱酯酶以及丁酰胆碱酯酶抑制活性,部分化合物的活性甚至比卡巴拉汀(rivastigmine)更好.     

A Novel Labeling Reagent of 2-(12-Benzo[b]acridin-5-(12H)-yl)-acetohydrazide for Determination of Saturated and Unsaturated Fatty Acids in Traditional Chinese Herbs by HPLC-APCI-MS

A new fluorescence labeling reagent 2-(12-benzo[b]acridin-5(12H)-yl)-acetohydrazide (BAAH) has been designed for fatty acids labeling. Eleven fatty acids containing seven saturated and four unsaturated fatty acids were used to evaluate the analytical potential of this reagent. The labeling reaction of BAAH with fatty acids was completed at 85?°C for 60?min using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC·HCl) as the condensing agent. Separation of the derivatized fatty acids was carried out on a reversed-phase Thermo Hypersil Gold C18 column (4.6?mm?×?250?mm, 5?μm) in combination with a gradient elution with a good baseline resolution. The fluorescence excitation and emission wavelengths were set at λ_ex 280 and λ_em 510?nm, respectively. The identification was carried out by the online APCI-MS in positive-ion detection mode. Linear correlation coefficients for all fatty acid derivatives were of >0.9994. Detection limits, at a signal-to-noise ratio of 3:1, were 3.89–12.5?nmol?L^?1 for the labeled fatty acids. The developed method was successfully applied to the accurate determination of fatty acids in five traditional Chinese herbs with satisfactory results.     

Surface-plasmon-polaritons-assisted nanolithography with dual-wavelength illumination for high exposure depth

We propose a new direct writing nanolithography approach using a plasmonic focusing device and a nano silver mirror with dual-wavelength illumination for high exposure depth. Arrays of pyramid aperture are used to focus the incident light beams into 80 nm light spots. The pyramid combined with a thin silver film coated on the substrate constructs a surface plasmon polaritons (SPP) coupling cavity, which amplifies the intensity of the light field in it by SPP effect and resonance. The transmission depth of the standing wave formed by forward and reflected light could reach hundreds of nanometers. Two lasers with different wavelengths are used as illumination sources to homogenize the light field through complementation between the two standing waves. Simulation results show by using 355 nm and 441 nm wavelengths, a space of 44 nm at the bottom of the photoresist could be obtained after exposure and development. The feature size of resist patterns could be further scaled down, depending on the optimization of parameters of photoresist exposure and development, illumination wavelengths, etc.     

分子印迹固相萃取搅拌棒的制备及对复杂样品中双烯雌酚和己烷雌酚的萃取性能

以己烯雌酚为替代模板,利用整体材料的“原位”合成技术制备了分子印迹聚合物,并将其作为固相萃取搅拌棒的涂层(MIP-SBSE)制备了新的搅拌棒。详细考察了分子印迹聚合物制备条件中模板分子及功能单体用量对MIP-SBSE选择性萃取性能的影响,同时利用元素分析、扫描电镜和红外光谱对聚合物进行表征。以双烯雌酚(DS)和己烷雌酚(HS)为目标化合物,将MIP-SBSE与高效液相色谱-二极管阵列检测器联用,建立起复杂样品中DS和HS的分离分析方法。考察了吸附和解吸时间、解吸溶剂、离子强度和样品pH值等萃取条件对MIP-SBSE选择性萃取性能的影响。结果表明,在最佳萃取条件下,MIP-SBSE对DS和HS具有较高的选择性萃取性能,线性范围分别为1.0～400.0 μg/L和5.0～400.0 μg/L,利用氮吹再定容的方法,对DS和HS的检出限(S/N=3)分别可低至0.04和0.14 μg/L。在对实际污水、蜂蜜和牛尿样品的分析中取得了良好的加标回收率,其值为61.3%～120%。所建方法具有简便、高选择性和灵敏等特点,可用于复杂样品中双烯雌酚和己烷雌酚的分析监测。     

实现惯性约束聚变驱动器谐波分离的二元光学元件研究

针对惯性约束聚变驱动器的要求,基于二元光学深蚀刻的思想,设计并制作成功二元光学谐波分离器。测量表明,三倍频光的能量利用率达７５．７３％。     

新型羧甲基壳聚糖水凝胶流变性能,药物释放及细胞相容性研究

羧甲基壳聚糖含有丰富的羧基和氨基, 通过1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)共催化交联羧甲基壳聚糖形成新型水凝胶. 调节EDC/NHS用量, 制备不同交联度的羧甲基壳聚糖水凝胶(CMCS hydrogels). 研究水凝胶的流变行为, 结果表明, 高交联度的水凝胶具有较好的弹性形变能力, 较高的储存模量, 这是因为随着交联度的升高, 羧甲基壳聚糖水凝胶化学交联网络结构趋于完善. 以胸腺五肽(TP-5)为模型药物, 初步评价CMCS水凝胶药物释放行为, 结果表明水凝胶交联度越高, 胸腺五肽释放速度越慢. MTT法初步评价了水凝胶细胞毒性, 细胞形态和细胞相对增值速率, 结果表明水凝胶毒性很低. 由此可见, 水凝胶具有良好的生物相容性, 在药物缓释和组织工程领域具有广阔的应用前景.     

Cell-like structure of unstable oblique detonation wave from high-resolution numerical simulation

A comprehensive numerical study was carried out to investigate the unsteady cell-like structures of oblique detonation waves (ODWs) for a fixed Mach 7 inlet flow over a wedge of 30° turning angle. The effects of grid resolution and activation energy were examined systematically at a dimensionless heat addition of 10. The ODW front remains stable for a low activation energy regardless of grid resolution, but becomes unstable for a high activation energy featuring a cell-like wave front structure. Similar to the situation with an ordinary normal detonation wave (NDW), a continuous increase in the activation energy eventually causes the wave-front oscillation to transit from a regular to an irregular pattern. The wave structure of an unstable ODW, however, differs considerably from that of a NDW. Under the present flow condition, triple points and transverse waves propagate downstream, and the numerical smoke-foil record exhibits traces of triple points that rarely intersect with each other. Several instability-driving mechanisms were conjectured from the highly refined results. Since the reaction front behind a shock wave can be easily destabilized by disturbance inherent in the flowfield, the ODW front becomes unstable and displays cell-like structures due to the local pressure oscillations and/or the reflected shock waves originating from the triple points. The combined effects of various instability sources give rise to a highly unstable and complex flow structure behind an unstable ODW front.     

Tuning the Properties of Graphdiyne by Introducing Electron-Withdrawing/Donating Groups

The properties of graphdiyne (GDY), such as energy gap, morphology, and affinity to alkali metals, can be adjusted by including electron-withdrawing/donating groups. The push–pull electron ability and size differences of groups play a key role on the partial property adjusting of GDY derivatives MeGDY, HGDY, and CNGDY. Cyano groups (electron-withdrawing) and methyl groups (electron-donating) decrease the band gap and increase the conductivity of the GDY network. The cyano and methyl groups affects the aggregation of GDY, providing a higher number of micropores and specific surface area. These groups also endow the original GDY additional advantages: the stronger electronegativity of cyano groups increase the affinity of GDY frameworks to lithium atoms, and the larger atomic volume of methyl groups increases the interlayer distance and provides more storage space and diffusion tunnels.     

复合材料组分性能随机性识别的克里金随机分析方法

建立非均匀材料宏观力学性能与微结构参数之间的定量关系一直是人们所关心的问题,利用材料微结构参数和组分性能预报复合材料宏观力学性能,已经取得了很大的进展,然而已知复合材料宏观性能,如何开展组分性能的随机识别,目前的研究工作还不多见.论文考虑了复合材料的随机性,在已知复合材料宏观有效性能的随机性条件下,采用克里金随机分析方法,对复合材料组分性能的随机性进行识别,通过单向纤维复合材料的宏观有效性能的随机性,计算得到了纤维弹性模量的均值与方差,证明了该方法的有效性.