J Aggregation of Thiacarbocyanine in Aqueous Gelatin Solutions

The aggregation processes of 3,3′-disulfopropyl-4,4′,5,5′-dibenzo-9-ethylthiacarbocyanine betaine were studied in aqueous gelatin solutions. Gelatin molecules were shown to favor the formation of J aggregates from dye dimers according to the block mechanism. Acidic gelatins much stronger favor J aggregation of the dye than alkaline and, especially, modified gelatins. High contents of microgels and high-molecular-mass fractions in gelatin retard the formation of long-wavelength aggregates.     

Mössbauer investigation of the reaction between HCl and tin dopant ions located on the surface of Cr2O3 microcrystals

The chemical behavior of surface-located tin dopant ions depends strongly on their valence state. At room temperature all Sn(II) ions readily react with gaseous hydrogen chloride while, under similar conditions, the predominant part of Sn(IV) ions is not affected by this gas. The results of this study, along with those previously obtained for both valence states of tin dopant exposed to a H₂S atmosphere, suggest that lower reactivity of Sn(IV) ions is essentially due to their higher coordination number and concomitant steric hindrance effects.     

Optimization of the Aerosol Filter Parameters

Theoretical approach to the optimization of the parameters of two-stage fibrous aerosol filter is reported. The approach is based on earlier developed method for the calculation of the clogging of model filter where the particle deposit is approximated by the porous shell on the fibers. The values of optimal fiber radii are determined from the condition of maximal dust capacity of a filter at given limiting pressure drop and total initial efficiency. Optimization was performed with allowance for possible variation in the prefilter thickness.     

Using IMAP technology to identify kinase inhibitors: comparison with a substrate depletion approach and analysis of the nature of false positives

IMAP is a fluorescence polarisation-based assay method which can be applied to the measurement of protein kinase activity. Using a model serine/threonine kinase we found that IMAP generated a good assay window (Z' > 0.8), was very tolerant of DMSO, and was flexible with respect to sample processing (stopped reactions were stable over a period of several days). Using a set of six low molecular weight inhibitors of the kinase, we found a good correlation between IMAP and scintillation proximity assay (SPA) potency data. IMAP, which measures product accumulation, was compared in an HTS setting with a substrate depletion method (luminescence-based measurement of ATP concentration). There was a reasonable (approximately 50%) overlap in primary hits from a 17,000 compound set, but more apparent false positives were generated from the IMAP method. We followed up the compounds that showed activity in the IMAP method but not in the luminescence assay. Approximately 10% of these compounds displayed intrinsic fluorescence, suggesting that they were false actives by virtue of intrinsic spectroscopic properties. Compound activity by competition of phosphopeptide binding to IMAP beads can occur with high concentrations of chelating compounds, but did not occur with any of the false actives, suggesting that this form of interference is rare.     

Parity nonconservation in atomic cesium induced by nuclear anapole moment

Nuclear spin dependentP-odd effects in atomic cesium are calculated. The detection of these effects will allow to determine the nuclear anapole moment.     

Theoretical aspects of a preparative continuous chromatograph

Summary Equipment which has been used or suggested for preparative scale chromatography is reviewed. Particular attention is paid to one form of equipment for continuous counter-current chromatography which employs a moving mechanical seal. The theoretical effects of practical operating conditions and the mode of operation of this equipment are discussed. The influence of these effects on polymer fractionation is also considered. A theoretical model, based on the equilibrium stage concept, is proposed for the simulation of continuous gel permeation chromatography of a binary feed on such an apparatus. Examples of the results obtained from the computer simulation are given.     

The Nitrosation of Primary Aliphatic Diazocarbonyl Compounds: Formation of α-carbonyl nitrile oxides. Preliminary communication

Aqueous nitrosation of primary α-carbonyl diazo compounds (ethyl diazoacetate, diazoacetone, diazoacetophenones) yields α-carbonyl nitrile oxides, R? CO? CNO; their formation is demonstrated by 1,3-dipolar addition reactions.     

Über die flüchtigen Anteile der Ananas

A gas chromatographic investigation of the volatile part of a pineapple concentrate led to the identification of 59 substances, 35 of which were not previously found in pineapple. The identifications and syntheses of some esters (Δ³- and Δ⁴-unsaturated, β-hydroxy, β-acetoxy, and δ-acetoxy) and of a new sulfur compound are given.     

Decarbonylation of N-carbazolylacetyl chloride in the friedel-crafts acylation reaction

Reaction products of N-carbazolylacetyl chloride under Friedel-Crafts reaction conditions include carbon monoxide, the reaction product from carbazole and formaldehyde (CF condensate), and carbazole. It is postulated that decarbonylation of N-carbazolylacetyl chloride involves intermediate formation of a N-carbazolylmethyl cation.     

Analyse qualitative et quantitative de melanges complexes de chlorures de lanthanides,en utilisant la dispersion rotatoire magnetique

The general features of a new physical process for the qualitative and quantitative routine analysis of rare earth mixtures are given. The characteristic sharp lines in the magneto-optical rotation spectra of these elements are utilized. The recording photoelectric spectropolarimeter used is described briefly. A comparison is made with two other physical processes-absorption and X-ray fluorescence spectrometry. The proposed method appears to be the best when a mixture with more than 3 or 4 elements must be analysed. The sensitivity and accuracy are given for 9 rare earths. Improvements of the process are suggested.