Phenol biosensor based on electrochemically controlled integration of tyrosinase in a redox polymer

An amperometric biosensor for the detection of phenolic compounds was developed based on the immobilization of tyrosinase within an Os-complex functionalized electrodeposition polymer. Integration of tyrosinase within the redox polymer assures efficient catechol recycling between the enzyme and the polymer bound redox sites. The non-manual immobilization procedure improves the reproducibility of fabrication process, greatly reduces the desorption of the enzyme from the immobilization layer, and, most importantly prevents fast inactivation of the enzyme by its substrate due to fast redox cycling. A two-layer sensor architecture was developed involving ascorbic acid oxidase entrapped within an electrodeposition polymer in a second layer on top of the redox polymer/tyrosinase layer. Using this sensor architecture it was possible to eliminate the current interference arising from direct ascorbate oxidation up to a concentration of 630 μM ascorbic acid. The effects of the polymer thickness, the enzyme/polymer ratio, and the applied potential were evaluated with respect to optimal sensor properties. The sensitivity of the optimized sensors for catechol was 6.1 nA μM⁻¹ with a detection limit of 10 nM, and for phenol 0.15 nA μM⁻¹ with a detection limit of 100 nM.     

直接求线性规划可行基的一种方法

本文给出直接求线性规划问题基可行解的一种简易方法,该方法既避免了引入人工变量,减少存储,一般又能较快地得到一个较好的基可行解.     

A new convenient synthesis of phenanthrene alkaloids from 1-arylmethyl-1,2,3,4-tetrahydroisoquinolines

Hofmann degradation of 1-arylmethyl-1,2,3,4-tetrahydro-2,2-dimethylisoquinolinium iodides with methanolic KOH gave stilbene derivatives, for example, (E)-N-2{2-[2-(phenyl)ethenyl]-4,5-dimethoxyphenyl}ethyl-N,N-dimethylamine. Photochemical electrocyclization of these stilbenes afforded the corresponding phenanthrene alkaloids/phenanthrene derivatives.     

A Relationship Among Gentzen's Proof-Reduction,Kirby-Paris' Hydra Game and Buchholz's Hydra Game

We first note that Gentzen's proof-reduction for his consistency proof of PA can be directly interpreted as moves of Kirby-Paris' Hydra Game, which implies a direct independence proof of the game (Section 1 and Appendix). Buchholz's Hydra Game for labeled hydras is known to be much stronger than PA. However, we show that the one-dimensional version of Buchholz's Game can be exactly identified to Kirby-Paris' Game (which is two-dimensional but without labels), by a simple and natural interpretation (Section 2). Jervell proposed another type of a combinatorial game, by abstracting Gentzen's proof-reductions and showed that his game is independent of PA. We show (Section 3) that this Jervell's game is actually much stronger than PA, by showing that the critical ordinal of Jervell's game is φ_ω (0) (while that of PA or of Kirby-Paris' Game is φ₁ (0) = ?₀) in the Veblen hierarchy of ordinals.     

Creation of entangled states of excitons in coupled quantum dots

We present two methods for the creation of two-particle entangled states of excitons in a coupled quantum dot system. The system contains two identical quantum dots that are coupled by an inter-dot hopping process. The manipulation of the system is succeeded by proper application of an external laser field.     

The elimination of fast variables in complex chemical reactions. III. Mesoscopic level (irreducible case)

The master equation for a complex chemical reaction cannot always be reduced to a simpler master equation, even if there are fast and slow individual reaction steps. Nevertheless the elimination of intermediates can be carried out with the help of the-expansion. This is illustrated with a well-known complex reaction: the dissociation of N₂O₅. It is shown that the intrinsic fluctuations in the N₂O₅ decay are larger than those implied by the master equation suggested by the macroscopic rate law.     

芳烃金属配合物在有机合成中的应用

本文讨论了芳烃金属配合物中的芳香部份在与金属配合后性质上的变化,以及这些变化后的性质在有机合成中的应用。     

大鼠肾组织的超低温快速冷冻固定和冷冻置换研究

超低温快速冷冻固定以极高的冷冻速率（１００００Ｋ／ｓ）对生物组织进行物理固定，可使生物组织结构、组织内可溶性离子及游离性物质得到保存，使被固定后的生物组织保持最接近于原自然状态，这种样品制备方法大大优于化学制备法，因而在Ｘ－射线微分析及免疫细胞化学中得到广泛应用。生物样品超低温快速冷冻后，利用冷冻置换法，在低温下将生物组织内的结晶水缓慢置换出来，而后常规包埋切片，可获得理想的组织结构及组织内待分析成分。本文应用超低温快速冷冻固定技术及冷冻置换法对大鼠肾皮质部的快速冷冻固定及损伤进行探讨。     

碳酸及碳酸酯热消除反应的量子化学研究

用AM1方法研究了碳酸和碳酸酯的热消除反应．发现迁移基团R和基团R’共同制约这类吸热反应的活化能。     

A supported gold catalyst for the elimination of hydrogen from CO2 feed gas in the production of urea

Supported gold catalyst for eliminating hydrogen from CO₂ feed gas in the production of urea is found to be superior to other industrial catalysts (e.g. Pt/Al₂O₃ and PdPt/Al₂O₃) in catalytic activity and resistance to sulfur poisoning.