Cell lysis on a microfluidic CD (compact disc)

Cell lysis was demonstrated on a microfluidic CD (Compact Disc) platform. In this purely mechanical lysis method, spherical particles (beads) in a lysis chamber microfabricated in a CD, cause disruption of mammalian (CHO-K1), bacterial (Escherichia coli), and yeast (Saccharomyces cerevisiae) cells. Interactions between beads and cells are generated in the rimming flow established inside a partially filled annular chamber in the CD rotating around a horizontal axis. To maximize bead-cell interactions in the lysis chamber, the CD was spun forward and backwards around this axis, using high acceleration for 5 to 7 min. Investigation on inter-particle forces (friction and collision) identified the following parameters; bead density, angular velocity, acceleration rate, and solid volume fraction as having the most significant contribution to cell lysis. Cell disruption efficiency was verified either through direct microscopic viewing or measurement of the DNA concentration after cell lysing. Lysis efficiency relative to a conventional lysis protocol was approximately 65%. In the long term, this work is geared towards CD based sample-to-answer nucleic acid analysis which will include cell lysis, DNA purification, DNA amplification, and DNA hybridization detection.     

The Luminescence Properties and Intramolecular Energy Transfer of Rare Earth Complexes with Aromatic Carboxylic Acids

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Oxodiperoxo molybdenum modified mesoporous MCM-41 materials for the catalytic epoxidation of cyclooctene

A hybrid heterogeneous catalyst system, which has been synthesized by covalently anchoring oxodiperoxo molybdenum chelate complexes onto the surface of mesoporous MCM-41, is highly active and truly heterogeneous for the liquid-phase epoxidation of cyclooctene with tBuOOH as the oxygen source.     

Preparation of polymer-supported phosphine from ferrocene for palladium-catalyzed Suzuki-Miyaura cross-coupling reactions

Polymer-supported phosphine ligand 3b derived from ferrocene was prepared,and applied in palladium-catalyzed Suzuki- Miyaura reactions.A range of aryl bromides can couple with phenylboronic acid to obtain corresponding biaryls in excellent yields. The recycling of the polymer-bound catalyst was tested without adding palladium.     

组合电化学--电化学研究中的新策略

组合电化学是一种新的电化学研究策略，通过设计和构建大量多样性的电极阵列，并对其进行高通量筛选和表征，快速、高效地实现了体系的电化学研究。本文综述了近年来进行的组合电化学研究，重点介绍了组合光学筛选方法、组合电化学合成方法以及电化学平行筛选方法，并探讨了各种方法的优势和存在的问题。     

四君子汤和四物汤微量元素含量研究

通过了解中药“四君子汤”和“四物汤”中微量元素含量的异同,研讨了微量元素和中医“气血”理论之间的关系。实验表明,“四君子汤”和“四物汤”在微量元素的含量方面,有一定的类同和差异。该现象同中医的“气血”理论有非常相像的地方。同时发现中药中的微量元素在煎煮过程中,并不是同想象的一样匀速进入药液,而是不同的元素在不同的时间段不同的批次进入药液,这也提示中药煎法理论有一定依据。由于目前做的实验还少,本实验留下很多问题和疑点,值得进一步做有关的实验和研究。     

Plasmid DNA isolation using amino-silica coated magnetic nanoparticles (ASMNPs)

A simple and efficient approach for the rapid isolation of plasmid DNA from crude cell lysates has been described. The approach took advantage of the amino-modified silica coated magnetic nanoparticles (ASMNPs) with positive zeta potential at neutral pH and superparamagnetism under the external magnetic fields. As a demonstration, the pEGFP-N3 plasmid has been concentrated and isolated from the E. coli DH5α transformed with pEGFP-N3 plasmid through electrostatic binding between the positive charge of the amino group of ASMNPs and the negative charge of the phosphate groups of the plasmid DNA. Then the pEGFP-N3 plasmid has been released easily and quickly from the pEGFP-N3 plasmid-ASMNPs complexes with 3 M NaCl. The entire procedure could be carried out by the aid of external magnetic fields in 15 min and eliminate the need of phenol, cesium chloride gradients or other noxious reagents and complexes operation. Moreover, the pEGFP-N3 plasmid obtained by this approach retains biological activity that can be suitable for restriction enzyme digestion and cells transfection with expression of green fluorescence protein.     

Molecular basis for antifreeze activity difference of two insect antifreeze protein isoforms

The insect spruce budworm(Choristoneura fumiferana) produces antifreeze protein(AFP) to assist in the protection of the over-wintering larval stage and contains multiple isoforms. Structures for two isoforms,known as CfAFP-501 and CfAFP-337,show that both possess similar left-handed β-helical structure,although thermal hysteresis activity of the longer isoform CfAFP-501 is three times that of CfAFP-337. The markedly enhanced activity of CfAFP-501 is not proportional to,and cannot be simply accounted for,by the increased ice-binding site resulting from the two extra coils in CfAFP-501. In or-der to investigate the molecular basis for the activity difference and gain better understanding of AFPs in general,we have employed several different computational methods to systematically study the structural properties and ice interactions of the AFPs and their deletion models. In the context of intact AFPs,a majority of the coils in CfAFP-501 has better ice interaction and causes stronger ice lattice disruption than CfAFP-337,strongly suggesting a cooperative or synergistic effect among β-helical coils. The synergistic effect would play a critical role and make significant contributions to the anti-freeze activity β-helical antifreeze proteins. This is the first time that synergistic effect and its implica-tion for antifreeze activity are reported for β-helical antifreeze proteins.     

Asymmetric Synthesis of α-Substituted-γ-butyrolactone Empolying Prolinol Type of Auxiliaries

Eleven (S)-(-)-bishydrocarbyl-(l-alkanoylpyrrolidin-2_yl)_methanol derivatives of three types were synthesized from L-proline.asymmtncally selective alkylation products were obtained oy LDA treatment and alkylation using methyl 2-bromoethyl ether, and three types of chiral α-Substituted-γ-butyrolactones were obtained by hydrolyzing the alkylation products, with %e.e. beijing up to 89 percent.     

钴(Ⅱ)与5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯络合物吸附波及其应用

钴 (Ⅱ )在NH3·H2O -NH2OH·HCl-5_(5_硝基_2_吡啶偶氮)_2,4_二氨基甲苯体系中有一灵敏的极谱波 ,其峰电位Vp 为 -1.20V(vsSCE) ,钴质量浓度在0.25～25μg/L范围内与峰电流Ip′有良好的线性关系 ,检出限为0.12μg/L;经多种电化学方法证明该波为络合物吸附波 ,其电极过程为不可逆过程 ,电子转移数为2 ,此外还试验了多种离子对峰电流Ip′的影响;所拟方法已用于维生素B12 和模拟样中痕量钴的测定