LC-MS method development to evaluate major triterpenes in skins and cuticular waxes of grape berries

Predominant triterpenes (free oleanolic acid, β-sitosterol and β-sitosterol-3-O-β- d -glucoside) in skin and cuticular wax of grape berries have been analysed by liquid chromatography–mass spectrometry (LC-APCI-MS). The validity of the developed method was established by determining linearity, recovery, precision, accuracy, limit of detection and quantification. Detection limits were in the range of 0.12–0.25 mg L⁻¹, and linearity values ranged up to 105 mg L⁻¹. The repeatability of the method was good. High variability was found among the measured grape varieties based on triterpene content, quantitites of oleanolic acid of cuticular wax ranged from 31.53 mg kg⁻¹ to 162.01 mg kg⁻¹ of the twelve analysed samples. The highest sitosterol content was measured in the sample 'Othello' (73.12 mg kg⁻¹), while maximum sitosterol glucoside content was also found in 'Othello' variety (13.68 mg kg⁻¹). The results showed that the study on triterpenes could be an informative tool to characterise grape varieties.     

Effect of various phenol additives on viscosity of SRC blends

Coal-derived liquids are susceptible to oxidative degradation. Two different weight ratios of SRC-I/SRC-II blends, with or without phenol derivatives, have been subjected to accelerated ageing studies. Viscosity, infrared, elemental analysis, molecular weight determination, and solvent analysis are used to examine the properties of the degradation products. On ageing, there is a large increase in the amount of toluene-insoluble material, decrease in oil components, and a relatively constant amount of asphaltenes. The oxygen content increases in the aged toluene-insoluble and asphaltene fractions, and a new absorption at ≈1700 cm^?1 (the C = 0 group) appears in these two fractions only. On the addition of phenol itself and the less hindered phenol derivatives, the original hydrogen-bonding between the acidic and basic fuctional groups in the coal liquids is apparently disrupted because the added phenol can now interact with the proton-accepting species in the liquids, thus leading to a lower viscosity. This does not mean that the unhindered phenols retard the rate of ageing. The original hydrogen-bonding in the coal-derived liquid now gives way to a new hydrogen-bonding, and ageing occurs with the latter. The more hindered phenol derivatives are not as effective as phenol in disrupting the original hydrogen-bonding in the coal-derived liquids.     

Some effects of counselor profanity in counseling.

60 male and female 24–50 yr old recovering alcoholic counseling clients were assigned randomly to 1 of 3 male counselors and to 1 of 2 treatment conditions. In the nonstandard English condition, the counselor casually and passively introduced 4 profane words. The standard English condition was identical except in respect to the use of these specific words. On client self-report and behavioral measures, which cut across all schools of counseling, counselors who used nonstandard English were judged to be less effective and satisfying. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Der Schlanke mit der gro?en Bildfl?che

Firmen&;ProdukteNeuer 16-ZOLL-LCD-Monitor

Der Schlanke mit der gro?en Bildfl?che     

Reaction behaviour of monomeric β-ketoesters

Summary Polymerizable enamines were synthesized by the reaction of 2-acetoacetoxyethyl methacrylate (AAEMA) with various aliphatic mono- and diamines. The enamines were characterized by elemental analyses, IR,¹H NMR and¹³C NMR spectroscopy. Radical polymerization of synthesized enamines yielded polymers with pendant enamine groups which were also prepared by the reaction of poly(AAEMA) with the corresponding amines.     

Robust DNA microarray image analysis

DNA microarrays are an increasingly important tool that allow biologists to gain insight into the function of thousands of genes in a single experiment. Common to all array-based approaches is the necessity to analyze digital images of the scanned DNA array. The ultimate image analysis goal is to automatically quantify every individual array element (spot), providing information about the amount of DNA bound to a spot. Irrespective of the quantification strategy, the preliminary information to extract about a spot includes the mapping between its location in the digital image and its possibly distorted position in the spot array (gridding). We present a gridding approach divided into a spot-amplification step (matched filter), a rotation estimation step (Radon transform), and a grid spanning step. Quantification of the spots is performed by robustly fitting of a parametric model to pixel intensities with the help of M-estimators. The main advantage of parametric spot fitting is its ability to cope with overlapping spots. If the goodness-of-fit is too bad, a semiparametric spot fitting is employed. We show that our approach is superior to simple quantification strategies such as averaging of the pixel intensities. The system was extensively tested on 1740 images resulting from two DNA libraries.Received: 15 June 2001, Accepted: 21 July 2002, Published online: 3 June 2003 Correspondence to: Norbert Brändle