用pDS软件开发pLSI／ispLSI器件

本文介绍了用pDS软件实现pLSI／is-pLSI器件逻辑电路的设计过程。结合实际，提出了设计调试中应注意的问题，供大家参考、讨论。     

在系统可编程逻辑器件分析

在系统可编程(ISP)器件,消除了传统可编程器件的限制,实现了印制电路板、系统层设计、生产和编程的一体化流程,使得硬件像软件一样灵活和容易更改,设备升级方便、快捷.分析ISP器件的结构和性能,并介绍ISP下载方法.     

Continuous maximin knapsack problems with GLB constraints

This paper introduces the continuous minimax knapsack problem with generalized lower bound constraints and describes an algorithm that solves this problem in O(n logn) time. We also discuss the related problem with generalized upper bound constraints. This research is partially supported by the Natural Sciences and Engineering Council of Canada under Grant No. A5053.     

Synthesis of a New β-Galactosidase Inhibitor Displaying Pharmacological Chaperone Properties for GM1 Gangliosidosis

GM1 gangliosidosis is a rare lysosomal disease caused by the deficiency of the enzyme β-galactosidase (β-Gal; GLB1; E.C. 3.2.1.23), responsible for the hydrolysis of terminal β-galactosyl residues from GM1 ganglioside, glycoproteins, and glycosaminoglycans, such as keratan-sulfate. With the aim of identifying new pharmacological chaperones for GM1 gangliosidosis, the synthesis of five new trihydroxypiperidine iminosugars is reported in this work. The target compounds feature a pentyl alkyl chain in different positions of the piperidine ring and different absolute configurations of the alkyl chain at C-2 and the hydroxy group at C-3. The organometallic addition of a Grignard reagent onto a carbohydrate-derived nitrone in the presence or absence of a suitable Lewis Acid was exploited, providing structural diversity at C-2, followed by the ring-closure reductive amination step. An oxidation-reduction process allowed access to a different configuration at C-3. The N-pentyl trihydroxypiperidine iminosugar was also synthesized for the purpose of comparison. The biological evaluation of the newly synthesized compounds was performed on leucocyte extracts from healthy donors and identified two suitable β-Gal inhibitors, namely compounds 10 and 12. Among these, compound 12 showed chaperoning properties since it enhanced β-Gal activity by 40% when tested on GM1 patients bearing the p.Ile51Asn/p.Arg201His mutations.