An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study

Background

An association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i) to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii) to evaluate a possible association between the changes in plasma sodium concentration ([Na⁺]) and changes in feet volume.

Methods

In seventy-six 100-km ultra-marathoners, body mass, plasma [Na⁺], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography.

Results

Body mass decreased by 1.8 kg (2.4%) (p < 0.0001); plasma [Na⁺] increased by 1.2% (p < 0.0001). Haematocrit decreased (p = 0.0005). The volume of the feet remained unchanged (p > 0.05). Plasma volume and urine specific gravity increased (p < 0.0001). Fluid intake was positively related to the change in the volume of the feet (r = 0.54, p < 0.0001) and negatively to post-race plasma [Na⁺] (r = -0.28, p = 0.0142). Running speed was negatively related to both fluid intake (r = -0.33, p = 0.0036) and the change in feet volume (r = -0.23, p = 0.0236). The change in the volume of the feet was negatively related to the change in plasma [Na⁺] (r = -0.26, p = 0.0227). The change in body mass was negatively related to both post-race plasma [Na⁺] (r = -0.28, p = 0.0129) and running speed (r = -0.34, p = 0.0028).

Conclusions

An increase in feet volume after a 100-km ultra-marathon was due to an increased fluid intake.     

Co-gasification of coal and wood in a dual fluidized bed gasifier

In the last decade the reduction of CO₂ emissions from fossil fuels became a worldwide topic. Co-gasification of coal and wood provides an opportunity to combine the advantages of the well-researched usage of fossil fuels such as coal with CO₂-neutral biomass. Gasification itself is a technology with many advantages. The producer gas can be used in many ways; for electric power generation in a gas engine or gas turbine, for Fischer-Tropsch synthesis of liquid fuels and also for production of gaseous products such as synthetic natural gas (bio SNG). Moreover, the use of the producer gas in fuel cells is under investigation. The mixture of coal and wood leads to the opportunity to choose the gas composition as best befits the desired process. Within this study the focus of investigation was of gasification of coal and wood in various ratios and the resulting changes in producer gas composition. Co-gasification of coal and wood leads to linear producer gas composition changes with linear changing load ratios (coal/wood). Hydrogen concentrations rise with increasing coal ratio, while CO concentrations decrease. Due to the lower sulfur and nitrogen content of wood, levels of the impurities NH₃ and H₂S in the producer gas fall with decreasing coal ratio. It is also shown that the majority of sulfur is released in the gasification zone and, therefore, no further cleaning of the flue gas is necessary. All mixture ratios, from 100 energy% to 0 energy% coal, performed well in the 100 kW dual fluidized bed gasifier. Although the gasifier was originally designed for wood, an addition of coal as fuel in industrial sized plants based on the same technology should pose no problems.     

Gel Casting of Free‐Shapeable Ceramic Membranes with Adjustable Pore Size for Ultra‐ and Microfiltration

The growing demand of reliable high‐performance membrane materials for separation processes requires new simple, straightforward, environmental friendly, sustainable approaches for membrane fabrication. In this study, we present an environmentally friendly gel‐casting, one‐pot process based on ionotropic‐gelation for obtaining alumina membranes. A slurry of alumina particles and the biopolymer alginate, which acts in combination with calcium iodate like a resin, was gelled in a controllable temperature dependent manner. Alumina membranes are obtained by three different shaping routes (extrusion, free‐forming, casting). The suitability of extruded capillaries in a polymer‐ceramic hybrid state (green body) and after sintering (1150°C for 2 h) for potential application in micro‐ and ultrafiltration is evaluated by monitoring the chemical and mechanical stability, permeability and separation behavior. Varying the initial alumina particle size from 200 to 900 nm, membranes with a narrow pore size distribution, predictable and tunable average pore diameters from 70 up to 480 nm and a constant open porosity of ~40%, are obtained. The permeability behavior is tested with fluorescence labeled submicron‐ and nano‐particles. Our novel colloidal processing route represents a very versatile tool for designing and manufacturing ceramic membranes with complex shapes for micro‐ (>0.1 μm) and ultrafiltration (0.1–0.01 μm).     

Catalytic steam reforming of model biogas

Catalytic steam reforming of a model biogas (CH₄/CO₂ = 60/40) is investigated to produce H₂-rich synthesis gas. Gas engines benefit from synthesis gas fuel in terms of higher efficiency and lower NO_x production when compared to raw biogas or CH₄. The process is realized in a fixed bed reactor with a Ni-based catalyst on CaO/Al₂O₃ support. To optimize the performance, the reactor temperature and the amount of excess steam are varied. The experimental results are compared to the theoretical values from thermodynamic calculation and the main trends of CH₄ conversion and H₂ yield are analyzed and verified. Finally, optimal reactor temperature is pointed out and a range of potential steam to methane ratios is presented. The experimental results will be applied to design a steam reformer at an existing anaerobic biomass fermentation plant in Strem, Austria.     

Single beam optical tweezers setup with backscattered light detection for three-dimensional measurements on DNA and nanopores

We introduce a versatile and high precision three-dimensional optical tweezers setup with minimal optical interference to measure small forces and manipulate single molecules in the vicinity of a weak reflective surface. Our tweezers system integrates an inverted optical microscope with a single IR-laser beam that is spatially filtered in an appropriate way to allow force measurements in three dimensions with remarkably high precision when operated in backscattered light detection mode. The setup was tested by overstretching a lambda-DNA in x and z directions (perpendicular and along the optical axis), and by manipulating individual lambda-DNA molecules in the vicinity of a nanopore that allowed quantitative single molecule threading experiments with minimal optical interference.     

Screening of protease inhibitors as antiplasmodial agents. Part I: Aziridines and epoxides

A broad protease-based and cell-based screening of protease inhibitors yielded the aziridine-2-carboxylic acid derivative 2 a and the N-acylated aziridine-2,3-dicarboxylic acid derivatives 32 a and 34 b as the most potent inhibitors of falcipain-2 and falcipain-3 (IC(50) falcipain-2: 0.079-5.4 microM, falcipain-3: 0.25-39.8 microM). As the compounds also display in vitro activity against the P. falciparum parasite in the submicromolar and low micromolar range, these compound classes are leads for new antiplasmodial falcipain inhibitors.     

Verkehrstelematik

Ohne Zusammenfassung     

Process components of the Implicit Association Test: A diffusion-model analysis.

The authors present a diffusion-model analysis of the Implicit Association Test (IAT). In Study 1, the IAT effect was decomposed into 3 dissociable components: Relative to the compatible phase, (a) ease and speed of information accumulation are lowered in the incompatible phase, (b) more cautious speed-accuracy settings are adopted, and (c) nondecision components of processing require more time. Studies 2 and 3 assessed the nature of interindividual differences in these components. Construct-specific variance in the IAT relating to the construct to be measured (such as implicit attitudes) was concentrated in the compatibility effect on information accumulation (Studies 2 and 3), whereas systematic method variance in the IAT was mapped on differential speed-accuracy settings (Study 3). Implications of these dissociations for process theories of the IAT and for applications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)