HILIC-UPLC-MS for exploratory urinary metabolic profiling in toxicological studies

Hydrophilic interaction ultra performance liquid chromatography (HILIC-UPLC) permits the analysis of highly polar metabolites, providing complementary information to reversed-phase (RP) chromatography. HILIC-UPLC-TOF-MS was investigated for the global metabolic profiling of rat urine samples generated in an experimental hepatotoxicity study of galactosamine (galN) and the concomitant investigation of the protective effect of glycine. Within-run repeatability and stability over a large sample batch (>200 samples, 60 h run-time) was assessed through the repeat analysis of a quality control sample. Following system equilibration, excellent repeatability was observed in terms of retention time (CV < 1.7%), signal intensity (CV < 14%), and mass variability (<0.005 amu), providing a good measure of reproducibility. Classification of urinary metabolic profiles according to treatment was observed, with significant changes in specific metabolites after galN exposure, including increased urocanic acid, N-acetylglucosamine, and decreased 2-oxoglutarate. A novel finding from this HILIC-UPLC-MS approach was elevated urinary tyramine in galN-treated rats, reflecting disturbed amino acid metabolism. These results show HILIC-UPLC-MS to be a promising method for global metabolic profiling, demonstrating high within-run repeatability, even over an extended run time. Retention of polar endogenous analytes and xenobiotic metabolites was improved compared with RP studies, including galN, N-acetylglucosamine, oxoglutarate, and urocanic acid, enhancing metabolome coverage and potentially improving biomarker discovery.     

The methods of complex potentials, singular integral equations and integral transformations in a series of problems for the reinforcement of cracked plates

We study the initiation and propagation of a vertical crack in an elastic semi-infinite plate, reinforced on its boundary by an infinite discontinuous stringer within the limits of the theory of brittle failure. The plate is subjected to uniform distributed tensile forces at infinity, as well as to contact stresses due to application of forces to the stringer. We find the appropriate loading of the coherent stringer, and consequently we consider a problem where the stringer is cracked and a vertical crack has developed within the plate. We deduce the exact analytical solution for the principal singular integral equation for this case; hence the stringer is perfectly rigid and we calculate characteristic parameters of the problem. The results show that the crack tip has a logarithmic singularity, and the tangential contact stresses under the stringer at that end point are finite and generally differ from zero.     

Methods for the Assessment of NET Formation: From Neutrophil Biology to Translational Research

Several studies have indicated that a neutrophil extracellular trap (NET) formation, apart from its role in host defense, can contribute to or drive pathogenesis in a wide range of inflammatory and thrombotic disorders. Therefore, NETs may serve as a therapeutic target or/and a diagnostic tool. Here, we compare the most commonly used techniques for the assessment of NET formation. Furthermore, we review recent data from the literature on the application of basic laboratory tools for detecting NET release and discuss the challenges and the advantages of these strategies in NET evaluation. Taken together, we provide some important insights into the qualitative and quantitative molecular analysis of NETs in translational medicine today.     

A quantitative analysis of the European Automakers’ voluntary commitment to reduce CO2 emissions from new passenger cars based on independent experimental data

The reduction of CO₂ emissions and fuel consumption from road transportation constitutes an important pillar of the European Union strategy for implementing the Kyoto Protocol. The commitment to reduce passenger car average CO₂ emissions at 140 g/km in 2008 signed by European car manufacturers and the European Commission is up to now the most important initiative towards limiting CO₂ emissions from road transportation and particularly from passenger cars. Until today, annual reports show the manufacturers’ efforts in limiting CO₂ emissions is within the intermediate target set by the commitment and these results are incorporated in emissions estimations and scientific studies. This paper analyses the origin of the progress achieved so far in CO₂ emissions and attempts an assessment of the commitment using independent experimental emission data. Additionally, the applicability of the commitment-monitoring data into policy and decision-making tools is being examined. The results indicate that a significant part of the reductions achieved so far is due to a market shift towards diesel vehicle sales and that no reduction factors should be applied yet in CO₂ emissions estimation models.     

Pseudo-Satellitefilm Using Fractal Clouds to Enhance Animated Weather Forecasting

We have developed a system enabling the National German Meteorological Office to generate pseudo-satellite images and video sequences based on their weather forecasting simulation data. With our system meteorologists can visualize the past and the current weather situation, evaluate their simulation results, and produce animated weather forecast videos broadcasted by several television stations. Realistic images are generated by interpolating the extremely coarse weather simulation data grid and enhancing the result using fractal clouds. It also enables the meteorologists to interactively change the forecast data in order to compensate the lack of accuracy or the known errors in their simulation models. Our system TRITON enables the visualization of complex weather simulations in a more natural way by presenting an intuitively understandable forecast.     

Hydrology and Nutrient Enrichment at Two Coastal Lagoon Systems in Northern Greece

The lagoons of N.E. Greece, located on the western side of NestosRiver, and of N.W. Greece, located at the lower reaches of Kalamas River, are among the most important shallow, semi-enclosed ecosystems in Northern Greece. The temporal variability of nutrients at both lagoonal systems shows the strong influence of fresh water discharge on water quality. Nutrient enrichment factors showed that nitrites and ammonium were six times higher at the lagoons of N.W. Greece than those observed at N.E. Greece, while phosphates were forty times higherat Nestos River lagoons. The flushing half-life was calculatedbased on a combination of hydrological and tidal processes, foreach lagoon of these two systems, allowing for the assessment ofwater quality changes. Proper management measures for both systems should focus on the control of fresh water quality entering the lagoons, the reduction of phosphoric fertilizers used by agriculture and the better oxygenation of the water column. One way to eliminate massive fish deaths during the winter in N.E. Greece is also the transfer of fresh, warm groundwater, while bathymetric modifications and channel wideningare needed at the lagoons of N.W. Greece.     

On the road to psychotherapy integration: A student's journey.

This article presents the integrative journey of a doctoral student across two continents. The development and aspirations of a student integrationist from the "get go" are outlined, and some thoughts on the future of the integration movement are offered. The role of self-direction, integrative role models, flexible training environments, and the support of the integrative community in one's integrative development are highlighted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The simultaneous use of 4×4 and 2×2 bilinear stress elements for viscoelastic flows

Mixed finite elements for viscoelastic flows based on a 4×4 sub-linear interpolation for the extra stress components satisfy the Babuska-Brezzi condition and are highly stable. They have been proved to be quite satisfactory in solving problems with strong stress boundary layers. In this work, we examine the simultaneous use of 4×4 and 2×2 bilinear stress elements in an attempt to reduce the computational cost without sacrificing the accuracy. The 4×4 bilinear elements are employed in regions where the stress field is anticipated to be steep while the 2×2 elements carry the burden elsewhere with a much smaller number of stress nodes. Additional constraints along the sides shared by different elements are necessary in order to preserve conformity. The method is applied to the creeping flow of a Maxwell fluid around a sphere falling along the axis of a cylindrical tube. Results are given for three mixed finite element formulations: the Galerkin method, the consistent streamline-upwind/Petrov-Galerkin method (SUPG) and the non-consistent streamline-upwind method (SU). Particular emphasis is given on the calculated drag correction factors. The effect of the sphere/cylinder diameter ratio is also examined.