The development of an integrated platform to identify breast cancer glycoproteome changes in human serum

Protein glycosylation represents one of the major post-translational modifications and can have significant effects on protein function. Moreover, changes in the carbohydrate structure are increasingly being recognized as an important modification associated with cancer etiology. In this report, we describe the development of a proteomics approach to identify breast cancer related changes in either concentration and/or the carbohydrate structures of glycoprotein(s) present in blood samples. Diseased and healthy serum samples were processed by an optimized sample preparation protocol using multiple lectin affinity chromatography (M-LAC) that partitions serum proteins based on glycan characteristics. Subsequently, three separate procedures, 1D SDS-PAGE, isoelectric focusing and an antibody microarray, were applied to identify potential candidate markers for future study. The combination of these three platforms is illustrated in this report with the analysis of control and cancer glycoproteomic fractions. Firstly, a molecular weight based separation of glycoproteins by 1D SDS-PAGE was performed, followed by protein, glycoprotein staining, lectin blotting and LC–MS analysis. To refine or confirm the list of interesting glycoproteins, isoelectric focusing (targeting sialic acid changes) and an antibody microarray (used to detect neutral glycan shifts) were selected as the orthogonal methods. As a result, several glycoproteins including alpha-1B-glycoprotein, complement C3, alpha-1-antitrypsin and transferrin were identified as potential candidates for further study.     

Effect of pH, temperature and solvent mole ratio on solubility of disodium 5′-guanylate in water + ethanol system

Solubility of disodium 5′-guanylate in water + ethanol binary solvent mixtures was determined by a gravimetric method in the temperature range from 283.15 K to 323.15 K, pH range from 8 to 10 and at different water/ethanol mole ratios. The effects of pH, temperature and water/ethanol mole ratio on the solubility were investigated in detail. The modified Apelblat model and the combined nearly ideal binary solvent (CNIBS)/Redlich-Kister model were selected to correlate the experimental data. The results showed that the experimental data was satisfactorily correlated by the (CNIBS)/Redlich-Kister model, but for the modified Apelblat model, the correlation was not so satisfactory in some cases.     

Correlation receiver of below-noise pulsed signals based on parametric interactions of spin waves in magnetic films

A correlation receiver capable of receiving pulsed microwave signals having amplitudes substantially below the noise level is proposed and experimentally realized. The device is based on the parametric interaction of two contra-propagating spin waves excited by the received microwave signal and the reference pulsed signal, containing information about the received signal shape, in a ferrite film waveguide. The output nonlinear correlation signal having the doubled carrier frequency and the signal-to-noise ratio enhanced by several orders of magnitude is received by a dielectric resonator coupled to an output microwave transmission line.     

基于结构元的复模糊数及其序列极限

复模糊数是模糊复分析中的基本概念,在模糊复分析中,它的运算是基于扩张原理的形式给出的,是对元素遍历某个条件所对应的结果进行运算,这种遍历过程给实际操作带来了很多的不便,因此,在一定程度上也阻碍了模糊复分析理论的应用.对此,本文基于模糊结构元的理论基础,探讨了复模糊数运算的另一种新的途径,这种方法简化了复模糊数的运算,也...     

The asymptotic estimate for the sum of two correlated classes of discounted aggregate claims with heavy tails

Consider a risk model with two correlated classes of insurance business and a constant force of interest. We assume that the correlation comes from a common shock and that the claim-size distribution is heavy-tailed. Under this setting, we investigate the tail behavior of the sum of the two correlated classes of discounted aggregate claims. We obtain the uniform asymptotic formulas for some subclass of subexponential distributions.     

The credit risk+ model with general sector correlations

We consider an enhancement of the credit risk⁺ model to incorporate correlations between sectors. We model the sector default rates as linear combinations of a common set of independent variables that represent macro-economic variables or risk factors. We also derive the formula for exact VaR contributions at the obligor level.     

Discriminant Analysis of Selected Organics Evaluated as Corrosion Inhibitors in 0.5 M HCL

Abstract

Discriminant analysis can be used to (1) find criteria to separate observations into groups and (2) to optimally assign a new observation to its correct group. It is rather exploratory in nature especially when causal relationships are not known. Twenty four selected organics were tested as corrosion inhibitors and both physical and structural features were encoded as criteria for discrimination. In addition, a narrower set of twelve nitrogen containing compounds was also studied. In both cases the carbon chain length was an important uncoded criterion. The physical factors such as boiling point, molecular weight, pKa, and molecular area were not as important as some of the structural parameters.     

Capillary isotachophoresis for the analysis of ionic liquid entities

Simple, selective and sensitive isotachophoretic methods for the analysis of ionic liquid (IL) compartments were developed in this study. A leading electrolyte containing 10 mM L ‐histidine + 10 mM histidine hydrochloride and a terminating electrolyte containing 5 mM glutamic acid + 5 mM L ‐histidine were selected to separate nitrate(V), chlorate(V), hexafluorophosphate, dicyanimide, trifluoromethanesulfonate, phosphate(V) and bis(trifluoromethanesulfonyl)imide in anionic mode. In contrast, seven short‐chain alkylimidazolium, alkylpyrrolidinium, alkylpyridinium and non‐chromophoric tetraalkylammonium and tetraalkylphosphonium IL cations were separated with 10 mM potassium hydroxide + 10 mM acetic acid as leading electrolyte, and 10 mM β‐alanine + 10 mM acetate as terminating electrolyte. Both methods were optimized and validated with good analytical performance parameters. LOD was about 3–5 μM, and the repeatability lay in the range of 1.06–5.59%. These methods were evaluated for their applicability to the analysis of soil samples and freshwater contaminated with ILs. In light of hitherto the absence of reports on the determination of non‐chromophoric IL cations, this study delivers for the first time a universal method enabling analysis of these species. Moreover, as there is still significant lack of methodologies of IL anion analysis, the obtained results offer an interesting alternative in that matter.     

Uncertainty calculations in the certification of reference materials

To serve as a measurement standard, a (certified) reference material must be stable. For this purpose, the material should undergo stability testing after it has been prepared. This paper looks at the statistical aspects of stability testing. Essentially, these studies can be described with analysis of variance statistics, including variant regression analysis. The latter is used in practice for both trend analysis and for the development of expressions for extrapolations. Extrapolation of stability data is briefly touched upon, as far as the combined standard uncertainty of the reference material is concerned. There are different options to validate the extrapolations made from initial stability studies, and some of them might influence the uncertainty of the reference material and/or the shelf-life. The latter is the more commonly observed consequence of what is called ’stability monitoring’. Received: 6 October 2000 Accepted: 4 December 2000