Testing successive regression approximations by large-scale two-stage problems

A heuristic procedure, called successive regression approximations (SRA) has been developed for solving stochastic programming problems. They range from equation solving to probabilistic constrained and two-stage models through a combined model of Prékopa. We show here, that due to enhancements in the computer program, SRA can be used to solve large-scale two-stage problems with 100 first stage decision variables and a 120 dimensional normally distributed random right hand side vector in the second stage problem. A FORTRAN source program and computational results for 124 problems are presented at .     

Rearrangements in Spiro-λ4-sulfane Chemistry

The reactions of possible spiro-λ⁴-sulfane precursor diaryl sulfoxides with dehydrating agents have been studied resulting in the formation of cyclic anhydride, spiro-λ⁴-sulfane, cyclic sulfonium-ylide, lactam-sulfoxide, cyclic sulfonimide and cyclic sulfilimine type of intermediates or products. The structures of the intermediates or products depend on the functional groups attached to the aryl rings at ortho positions and on the reaction conditions applied.     

Alkane isomers: presence in petroleum ether and complexity

The presence and absence of alkane isomers in petroleum and petroleum derivatives depend on the complexity of these structures. It was assumed that the more complex the structure is the less probable it is that that the molecule can be detected in any petroleum derivative. Complexity is a vague concept, which has not been defined in quantitative terms yet, and therefore there is no experimental method, which could be used to determine ‘complexity’. Mass spectrometry and infrared spectroscopy in combination with gas chromatography were used to identify the various structural isomers of alkanes in petroleum ether. The isomers were categorised in quantitative terms by using topological indices and linear discriminant analysis. It was found that alkanes possessing a more complex, highly branched structure are less probable to be detected in petroleum ether than isomers with a simpler backbone structure. It was proposed that the experimental ‘measure’ of the complexity of isomer_i should be proportional to 1/C_i , where C_i , denotes the concentration of isomer_i in a (primary) petroleum derivative.     

Syntheses,transformations and applications of aminonaphthol derivatives prepared via modified Mannich reactions

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Fractionation of the human plasma proteome for monoclonal antibody proteomics‐based biomarker discovery 2: Antigen identification by dot‐blot array screening

Immunization with complex mixtures, like the human plasma resulted in the generation of cloned mAb libraries (PlasmaScan? and QuantiPlasma? libraries, with >1000 individual mAbs) reacting with a nonredundant set of antigenic epitopes. mAb proteomics refers to quasi‐hypothesis‐free profiling of plasma samples with nascent or cloned mAb libraries for the discovery of disease‐specific biomarkers. Once mAbs with biomarker potential have been identified, the next task is the determination of cognate antigens recognized by the respective mAbs. To determine the cognate protein antigen corresponding to each individual mAbs in the cloned mAb libraries, we have separated human plasma by consecutive steps of desalting and various chromatography procedures. The process resulted in 783 fractions, which we termed “Analyte Library” (AL). The AL represents the human plasma proteome in relatively low‐protein complexity fractions. Here, to determine the utility of the AL, we selected ten plasma proteins and checked for their presence in the fractions. Among the ten cases, the distribution of four selected plasma proteins matched expectations, as these proteins were present only in a few fractions corresponding to their physical, chemical, and biochemical properties. However, in six cases, we observed “smear” ‐like distribution or complete absence of the proteins, suggesting that protein–protein interactions or protein variants may alter the observed plasma distribution profiles. Nevertheless, we conclude that the AL is an efficient, high throughput tool to complement the mAb biomarker discovery process with cognate protein antigen identification for each mAbs.     

Carbocyclic Ring Closure of an Aminodeoxy HEX-5-Enopyranoside

Ferrier's intramolecular carbocyclic ring closure reaction of methyl 3,4-di-O-acetyl-2-benzoyl-amino-2,6-dideoxy-α-O-xylo-hex-5-enopyranoside (2) led to 2L-2,4,513-2,3-di-O-acetyl-4-benzoylamino-5-hydroxy-cyclohexanone (4). Upon acetylation compound 4 underwent B-elimination to give the conjugated enone 5. The convenient preparation of these highly functionalized aminocyclohexanones offers an efficient route to monoamino- or 1,4-diaminocyclitol-type aminoglycoside antibiotic aglycones, starting from 2-amino-2-deoxy-O-glucose.     

An improved rapid method for the determination of actinides in water

A new rapid method has been developed for the determination of Th, Pu, Np, U, Am and Cm isotopes in water samples of about 1 L. Actinides are pre-concentrated by co-precipitation with Ca phosphate, sequentially separated on stacked TEVA and TK221 cartridges and measured by alpha spectrometry. The TK221 extraction chromatographic resin contains i.e. CMPO and DGA extractants. It has been characterized by measuring the weight distribution ratios (D_w) of actinides which are higher than 1000 for all actinides in 3 M HNO₃. The method has been optimized, applied for the analysis of tap and seawater samples and validated by participating in an IAEA proficiency test. Chemical recoveries for all actinides are better than 50%. The method can be performed within one day.