Online comprehensive RPLC × RPLC with mass spectrometry detection for the analysis of proteome samples

LC-MS-based shotgun proteomics relies both on the power of the separation techniques and the sensitivity of detection methods. As a viable alternative to classical approaches in this field, we developed a fully automated, comprehensive 2D LC system, in which RPLC × RPLC was coupled to MS detection, for the first time, and applied for the analysis of tryptic digests obtained from α-casein and dephosphorylated α-casein. The use of a significantly different pH in the two dimensions allowed us to attain high peak capacity, despite the employment of novel identical stationary phases. Furthermore, such a combination addresses compatibility issues, thus allowing straightforward interfacing in online 2D LC configuration, as well as direct linkage to a mass spectrometer. A theoretical peak capacity of ca. 8500 was calculated for the setup, employing four serially coupled C18 columns in the first dimension (600 × 2.1 mm, 2.7 μm d.p.), operated under basic conditions, and 3 cm length of the same stationary phase (30 × 4.6 mm, 2.7 μm d.p. column), under acidic conditions, for fast second dimension analysis.     

An unusual foreign body in the rectum

This is the report of an unusual foreign body in the rectum which was a complication of the migration of an esophageal Celestin's prosthesis.     

Quantifying the relevance and stage of disease with the Tau image technique

Discusses a complementary diagnostic imaging technique based on infrared functional imaging. It is concluded that the Tau images obtained with our method provide a large amount of information. The method, in fact, correctly depicts the ill and symptomatic situation; moreover, it is able to identify the surface projection onto the skin of the damaged areas and, by means of the evaluated value of the Tau time, the stage of the disease. Additionally, it is possible to evaluate the evolution of the clinical situation following a rehabilitation therapy and to quantitatively compare the different Tau images recorded at different times.     

A fuzzy approach to some classification problems

An appropriate algebraic structure was previously defined which can be regarded as a possible alternative to the theory of approximate reasoning, [A. Gisolfi, Fuzzy Sets Syst. 44 , 37–43 (1992)]. In this article we aim at extending the operations of the structure in order to cope with classification problems. the theoretical aspects are emphasized in order to give an adequate background to the possible applications. After defining the basic elements and the related operations, the structure is implemented by means of Prolog. Finally the relationship between the structure and the problems of classification is discussed in some detail. © 1993 John Wiley & Sons, Inc.     

SMOS REFLEX 2003: L-band emissivity characterization of vineyards

The goal of the Soil Moisture and Ocean Salinity mission over land is to infer surface soil moisture from multiangular L-band radiometric measurements. As the canopy affects the microwave emission of land, it is necessary to characterize different vegetation layers. This paper presents the Reference Pixel L-Band Experiment (REFLEX), carried out in June-July 2003 at the Vale/spl grave/ncia Anchor Station, Spain, to study the effects of grapevines on the soil emission and on the soil moisture retrieval. A wide range of soil moisture (SM), from saturated to completely dry soil, was measured with the Universitat Polite/spl grave/cnica de Catalunya's L-band Automatic Radiometer (LAURA). Concurrently with the radiometric measurements, the gravimetric soil moisture, temperature, and roughness were measured, and the vines were fully characterized. The opacity and albedo of the vineyard have been estimated and found to be independent on the polarization. The /spl tau/--/spl omega/ model has been used to retrieve the SM and the vegetation parameters, obtaining a good accuracy for incidence angles up to 55/spl deg/. Algorithms with a three-parameter optimization (SM, albedo albedo, and opacity) exhibit a better performance than those with one-parameter optimization (SM).     

Preparation, characterization and CO sensing of Au/iron oxide thin films

The preparation and characterization of Au-doped iron oxide thin films is reported. Doped-thin films have been prepared by a liquid-phase deposition (LPD) method from aqueous solutions in the presence of a reactive atmosphere containing NH₃. The morphology and microstructure of the prepared films are described. The effect of some process parameters (precursor solution concentration, calcination temperature) on the film formation, thickness and microstructure are investigated. Sensor devices based on Au/Fe₂O₃ thin films deposited on alumina by the LPD method, are sensitive to CO at operating temperatures between 200–400 °C.     

Simplified correlation models for CO/H2 chemical reaction times

This paper provides simplified correlation models for CO/H₂ chemical reaction times. The procedure used for the CO/H₂ simplified modeling utilized the full chemical kinetics mechanism run over a range of temperatures from 700 to 1800 K, pressures from 0.5 to 50 atm, mixtures from 0% to 95% CO, and equivalence ratios from 0.2 to 2.0 to determine ignition (or reaction) time. The correlations for ignition times are given in formulas as functions of equivalence ratio, temperature, and pressure. Two different forms of correlations were obtained, one being a single, overall correlation and the other a two-stage correlation representing regions of high and low temperatures. These correlations are shown to work well over a range of chemical time scales spanning ten orders of magnitude. The correlations are also compared with measured data from the literature.     

Purification from Bothrops lanceolatus (fer de lance) venom of a fibrino(geno)lytic enzyme with esterolytic activity

Bothrops lanceolatus venom has high caseinolytic, phospholipasic, esterolytic and hemorrhagic activities. In spite of having no coagulant effect on plasma, this venom contains a thrombin-like enzyme. Using gel filtration and ion-exchange chromatographies, we have purified an esterolytic fraction (F-II-1a) from this venom with a protein yield of 4% and a 58% recovery in enzyme activity. SDS-PAGE in the presence of beta-mercaptoethanol showed that the enzyme is a single chain polypeptide with a MW=38,100. Immunodiffusion and immunoelectrophoresis of fraction F-II-1a against serum from horses immunized with B. lanceolatus venom and against rabbit antiserum prepared using fraction F-II-1a both showed a single immunoprecipitin line. The Km and Vmax values for TAME hydrolysis were 0.85 mM and 38.6 micromol/min/mg, respectively. The esterolytic activity was completely inhibited by PMSF (10 mM) but not by EDTA (20 mM). Fraction F-II-1a hydrolyzed the alpha and beta chains of fibrinogen. Degradation of the alpha chain occurred within 10 min while that of the beta-chain was slower. The enzyme had no effect on the gamma-chain even after 4 h of hydrolysis.     

Conformational changes of Mal d 2, a thaumatin-like apple allergen,induced by food processing

Mal d 2, a thaumatin-like protein from apple was previously described to react to almost 75% of the apple allergic patient sera. Based on the molecular structure of this protein, the present study focused on the conformational stability of Mal d 2 in relation to in vitro IgE-binding under different physico-chemical conditions and proteolysis. The structural integrity of Mal d 2 was monitored using SDS–PAGE, Western blotting using polyclonal antibodies and human sera, fluorescence spectrometry and circular dichroism. Results confirmed the stability of Mal d 2. However, Mal d 2 was reactive to human serum IgEs mainly after reduction of disulphide bridges fixing the α-helical domain II. Contrary to previous assumptions, the current findings suggest that the allergenic epitopes of Mal d 2 are hidden inside the protein structure and none of the rigorous conditions applied in industrial juice processing or digestive proteolysis enhance or reduce the binding to IgE molecules.