结肠癌诱导分化基因表达差异的消减cDNA文库的建立

为保存和分析抑制性消减杂交 (SSH)获得的结肠癌经全反式维甲酸和 1 ,2 5-(OH) 2 D3联合诱导分化前、后的差异cDNA ,把消减产物与TA载体连接并转化到大肠杆菌中建立消减cDNA文库 .结果表明 :诱导前消减cDNA文库的容量为 1 .0 5× 1 0 4 pfu ,诱导后消减cDNA文库的容量为 1 .49× 1 0 4 pfu .本实验为进一步研究结肠癌的发病机制和诱导分化的机制提供了物质基础 .     

游客情感计算的文本大数据挖掘方法比较研究

旅游文本大数据以其方便、快捷和低门槛的特点为游客情感计算提供了极大便利,已经成为旅游大数据的主要来源之一。基于大数据理论和情感理论,以文本大数据为数据源,在全面梳理国内外情感计算相关成果的基础上,利用人工智能中的逻辑/算法编程方法、机器学习方法、深度学习方法对旅游文本大数据进行挖掘,探索最佳的基于文本大数据的游客情感计算方法。研究发现：（1）基于情感词典的游客情感计算模型,其核心是构建情感词典和设计情感计算规则,方法简单,容易实现,适用语料范围广。（2）机器学习,用统计学方法抽取文本中的特征项,具有非线性特征,可靠性较线性特征的情感词典方法高。（3）基于深度学习技术的游客情感计算,效果良好,准确率在85%以上。训练多领域的文本语料易于移植,实用性强,且泛化能力好,较适合大数据时代游客情感计算研究。     

Solution-phase combinatorial chemistry

The use of solution phase techniques has been explored as an alternative to solid-phase chemistry approaches for the preparation of arrays of compounds in the drug discovery process. Solution-phase work is free from some of the constraints of solid-phase approaches but has disadvantages with respect to purification. This article will also illustrate some of the advances made in recent years in solution phase array chemistry including using supported reagents and simple extractive protocols for the effective preparation of high quality samples.     

社区图书馆信息服务探讨

阐述了社区图书馆开展信息服务的必要性，探讨了社区信息服务的具体内容，提出文献、网络、休闲娱乐、特色信息服务以及信息咨询服务是当前社区图书馆开展信息服务的主要方式．     

Solid-supported syntheses of 3-thio-1,2,4-triazoles

Two solid-supported synthesis strategies for the preparation of 3-thio-1,2,4-triazoles are described. In the first, Rink amide resin is combined with Fmoc-protected ω-amino acids, acid hydrazides, and alkyl halides to provide diverse sets of starting materials from which numerous triazoles may be prepared. The second employs t-alkylcarbamateresin (Boc resin) which permits the use of additional pools of starting materials, including isothiocyanates and α- and ω-amino esters, resulting in triazoles with patterns of functional groups that are not possible from the initial route. The combination of multiple resins and resin attachment sites allows the preparation of a diverse library based upon the3-thio-1,2,4-triazole scaffold and avoids the pitfallof having a single linker functionality present at the same position in all library members. General synthetic procedures and representative products from each route are presented. A similarity analysis of representative sublibraries from each synthesis strategy concludes that variation of the solid-phase linker chemistry and attachment site can enhance molecular diversity of the combined triazole library. This revised version was published online in August 2006 with corrections to the Cover Date.     

The decomposition of Kv into K2×K5''''s

The decomposition of the complete graph Kv into Kr×Kc's, the products of Kr and Kc,is originated from the use of DNA library screening. In this paper, we consider the case where r=2 and c = 5, and show that such a decomposition exists if and only if v ≡ 1 (mod 25).     

Library generation through successive substitution of trichlorotriazine

Summary The decreasing reactivity of tri-, di- and monochlorotriazine was utilized for the solid-phase construction of a combinatorial library with three randomized positions, using 20 amino acids and 50 amines as building blocks. The first chlorine atom was selectively substituted by coupling a large excess of trichlorotriazine to the support-bound amino acid, thus avoiding simultaneous substitution of the second chlorine. The second and third diversity positions were selectively introduced by coupling amines at different temperatures. Mixtures of model compounds were synthesized and analyzed, showing the correct representation of all expected components. A library composed of 12 000 compounds was generated using this method.     

A new class of libraries

In this paper we give the stationary measure and a sufficient condition of positive recurrence for a new class of linear libraries. These libraries are built by juxtaposing McCabe's libraries and Tsetlins libraries in an appropriate way: Their policy is not classical, by the fact that instead of a circular permutation, ₁ can be the product of several disjoint circular permutations.     

Obtaining a family of high-affinity,high-specificity protein inhibitors of plasmin and plasma kallikrein

Summary Human lipoprotein-associated coagulation inhibitor (LACI) is a serum protein containing three Kunitz domains. We displayed the first domain (LACI-D1) on the III protein of phage M13 and made libraries of this domain. We iteratively varied 13 residues in the region corresponding to the BPTI-trypsin interface and selected for binding to human plasmin (PLA) and human plasma kallikrein (pKAL). For PLA, our first-round best binder, EPI-P211, had K_D=2 nM. Using information from the first selection, we made a PLA-biased library containing 500 000 proteins and selected from these a protein, EPI-P302, having a K_D for PLA of 87 pM. EPI-P302 inhibits pKAL with K_D=250 nM (2800-fold higher than for PLA) and K_D values for other proteases are higher yet. From the same initial LACI-D1 library, we selected an inhibitor of pKAL, EPI-K401, with a K_D for pKAL of 287 pM. We used information from this selection to construct a pKAL-biased library from which we selected EPI-K502, which has a K_D for pKAL of 40 pM. EPI-K502 inhibits PLA with K_D20 nM (500-fold higher than for pKAL); K_D values for other proteases are much higher. For both targets and for both selections, there are families of proteins having a few differences and a range of affinities for their targets. These proteins are candidate drugs and imaging agents for indications involving excess PLA or pKAL. Structure-activity relationships of PLA and pKAL binders will allow design of small molecules that are specific for these targets.Abbreviations APP-I-D1 Kunitz domain of amyloid precursor protein-I - BPTI bovine pancreatic trypsin inhibitor - F.VII_a Factor VII_a - F.XI_a Factor XI_a - FIR fraction of input recovered - hNE human neutrophil elastase - LACI-D1 lipoprotein-associated coagulation inhibitor, first Kunitz domain - pKAL human plasma kallikrein - PLA human plasmin - RT room temperature - THBN human thrombin - Vg variegated - w.t. wild-type - %RIA percent residual inhibitory activity - :: fusion (gene or protein)