Monodispersed polymer particles with tunable surface structures: Droplet microfluidic-assisted fabrication and biomedical applications

Polymer particles are key materials in various biomedical applications, including drug delivery, cellular immunity, cell capture, biochip, etc. Droplets produced by microfluidics have been widely applied as templates for the fabrication of polymer particles with controllable sizes and narrow size distributions. Compared to smooth polymer particles, those with surface microstructures (e.g., tentacles, bubbles, wrinkles and pits) are more attractive due to their increased surface area and biomimetic structural characteristics. In this review, we summarized representative methods for the preparation of monodispersed polymer particles with various surface microstructures based on droplet microfluidics, as well as their typical bioapplications in drug delivery, cellular immunity and cell capture. Finally, the current challenges and further development in this research area are discussed.     

Monoterpene and tetrahydronaphthene derivatives from Senecio argunensis

Two new compounds,senarguines A and B,were isolated from Senecio argunensis.They were respectively identified as (Z)-3-ethylidene-9-hydroxyl-9-methyl-6,7-dioxaspiro [4.4]nonane-5,8--dione (1) and 3,6,6-trimethyl 6,7,8-tetrahydronaphtha-[1,2b]furan (2) on the basis of spectral data.     

The Thermokinetics of the Formation Reaction of Cobalt Histidine Complex

The enthalpy change of formation reaction of cobalt(II) histidine (His) complex in water has been determined by a microcalorimeter, using cobalt chloride with L-α-histidinein the temperature range of 25~50°C. On the basis of experimental and calculated results, three thermodynamics parameters (the activation enthalpies, the activation entropies, the activation free energies), the rate constant, three kinetic parameters (the activation energies, the pre-exponential constant and the reaction order) are obtained. The results show that the titled reaction easily took place in the studied temperature. This revised version was published online in August 2006 with corrections to the Cover Date.     

甲壳素类液晶高分子的研究V.取代基个数及长度对羟乙基壳聚糖液晶性的综合影响

采用碱壳聚糖的方法合成了一系列具有不同摩尔醚化度 (DME)的新的液晶性壳聚糖衍生物羟乙基壳聚糖 (HECS) .用酸氧化蚀刻的方法 ,在扫描电子显微镜 (SEM )下证实了其胆甾型的液晶织构 .以甲酸为溶剂 ,研究了摩尔醚化度对羟乙基壳聚糖溶致液晶性的影响 .结果表明 ,在该体系中 ,摩尔醚化度能综合取代基个数及长度两个结构因素的影响 ,当DME较低时 (<～ 2 0 ) ,这种影响关系类似于取代基个数 (即取代度 )的影响 ,当DME较高时 (>～ 2 0 ) ,则类似于取代基长度的影响 .前者对液晶临界浓度的影响很小 ,而后者却有显著影响 .此外还观察到当DME >～ 2 0时出现水溶性 ,HECS的水溶液也呈现典型的胆甾指纹状织构     

具有模糊信息的多目标运输问题求解

提出一种求解具有模糊信息的多目标运输问题的方法。利用专家意见通过模糊算法集给从各产地到各目的地运送单位物资的模糊综合指标值,运用一种对模糊数排序的方法,将模糊多目标运输问题转化为单目标的运输问题进行求解,最后给出了一个数值例子。     

围压条件下岩石断裂韧性的实验研究

研制了围压条件下内压式岩石断裂韧性测试仪,并对试样进行围压下岩石断裂韧性的测试,结合实验数据,利用断裂力学理论求得了不同围压条件下的断裂韧性,解决了水力压裂设计所需要的断裂韧性的这一重要参数的获取,有利于提高压裂设计,预测的精度。     

Effects of Surface Waves and Marine Soil Parameters on Seabed Stability

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5-Norbornene-2-carboxylic acid: Another catalytic mediator for Catellani-type reactions

Mediators play a central role in Catellani-type reactions. Herein we reported the discovery of inexpensive 5-norbornene-2-carboxylic acid (N⁴) as a general catalytic mediator (20?mol%) to facilitate ortho C–H activation and the following C–C bond formation of aryl iodides. Firstly, a cooperative catalytic system comprising N⁴ and a palladium/XPhos complex was developed for the novel Catellani/redox-relay Heck cascade to construct tetrahydronaphthalenes and indanes that contain a quaternary carbon stereogenic center. The striking feature of this work was the avoidance of stoichiometric NBE mediator that are usually required for Catellani-type reactions. Then, preliminary results demonstrated that N⁴ could act as a general catalytic mediator to replace NBE for other Catellani-type reactions, which will undoubtedly inspire future developments in the field of cooperative catalysis. Finally, control experiments indicated that the carboxylic acid moiety of N⁴ plays an essential role in its ability to serve as a superior mediator.     

Secoiridoid Sulfonates from the Sulfiting‐Processed Buds of Lonicera japonica

The new secoiridoid sulfonates 1 – 3 were isolated from the 50% EtOH/H₂O extract of the sulfiting‐processed Lonicera japonica Flos (LJF) by semi‐prep. HPLC, and their structures were identified on the basis of mass spectrometry and NMR spectroscopy. HPLC and LC‐DAD‐MS/MS analyses of the different samples of LJF obtained by various process techniques suggested that the sulfur fumigation led to the decrease of secologanic acid ( 4 ) and the formation of secologanic acid‐derived sulfonate 1 and its derivatives 2, 2a , and 3 in the crude materials, which revealed that sulfur fumigation, the traditional process technique, could alter the phytochemical profiles of some Chinese herbal medicines.