The KDEL receptor, ERD2, regulates intracellular traffic by recruiting a GTPase-activating protein for ARF1

The small GTPase ADP-ribosylation factor 1 (ARF1) is a key regulator of intracellular membrane traffic. Regulators of ARF1, its GTPase-activating protein (GAP) and its guanine nucleotide exchange factor have been identified recently. However, it remains uncertain whether these regulators drive the GTPase cycle of ARF1 autonomously or whether their activities can be regulated by other proteins. Here, we demonstrate that the intracellular KDEL receptor, ERD2, self-oligomerizes and interacts with ARF1 GAP, and thereby regulates the recruitment of cytosolic ARF1 GAP to membranes. Because ERD2 overexpression enhances the recruitment of GAP to membranes and results in a phenotype that reflects ARF1 inactivation, our findings suggest that ERD2 regulates ARF1 GAP, and thus regulates ARF1-mediated transport.     

Serological comparison of tospoviruses with polyclonal antibodies produced against the main structural proteins of tomato spotted wilt virus

The perfect bladder substitute has not been devised yet. The ileal orthotopic bladder substitute, however, provides adequate capacity, convenient voiding patterns, optimal continence rate, preservation of renal function, acid-base balance, and calcium metabolism. The authors describe important surgical details based on experience with more than 200 patients. To achieve a good functional result, patient selection, postoperative voiding reeducation, and meticulous follow-up are important.     

Zur Problematik der selektiven Erfassung von PSP-Toxinen aus Muscheln

Zusammenfassung Die Messung der PSP-Belastung (paralytic shellfish poisoning) von Schalentieren erfolgt vor allem mit Hilfe des Maus-Biotestes. Um PSP-Toxine sowohl qualitativ als auch quantitativ besser bestimmen zu können, wurden chromatographische Verfahren mit Fluorescenzdetektion entwickelt. Diese HPLC-Methoden sowie die Kopplung HPLC/MS gelangten zum Einsatz, um in spanischen Muschelkonserven ein neben Saxitoxin vermutetes zweites PSP-Toxin nachzuweisen. Es zeigte sich, daß in den 1986 in der Bundesrepublik Deutschland wegen zu hoher PSP-Konzentrationen beanstandeten Muschelkonserven vor allem Decarbamoyl-Saxitoxin enthalten war.

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The problem of the selective determination of PSP-toxins in mussels

Summary Levels of paralytic shellfish poisoning (PSP) toxins in shellfish are routinely determined by mouse bioassay: In order to improve the qualitative and quantitative determination of PSP toxins, Chromatographic techniques with fluorescence detection have been developed. These HPLC methods and the HPLC/MS coupling were used to determine a second PSP toxin which was found, in addition to saxitoxin, in canned Spanish mussels. These canned mussels were rejected in 1986 by the German food control because PSP concentrations were too high. It has been shown that these samples contained mainly dc-saxitoxin.

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Herrn Professor Dr. A. Montag zum 60. Geburtstag gewidmet     

The Physical Influence Scheme applied to staggered unstructured grids for solving fluid flow problems

Abstract

In this article, a finite volume formulation for solving the Navier-Stokes equations using unstructured hybrid grids and a staggered arrangement of variable pressure and velocity is presented. In this manner, a tight spatial pressure-velocity coupling is ensured without compromising geometrical flexibility. A second contribution of this work lays upon proposing a suitable interpolation function for the convected velocities in the momentum equations. For this purpose, we employ the so-called “Physical Influence Scheme (PIS),” which fully incorporates all physical phenomena involved, namely convection, diffusion, and pressure effects. Each term corresponding to each physical phenomenon is carefully addressed. We present numerical experiments that show the suitability of the PIS for the staggered finite volume formulation and highlight the importance of including diffusion and pressure effects (in addition to convection) into the interpolation function.     

Long-term stability at fuel processing of diesel and kerosene

The long-term stability at autothermal reforming of diesel fuel and kerosene was studied using Juelich's autothermal reformer ATR 9.2, which is equipped with a commercial proprietary RhPt/Al₂O₃–CeO₂ catalyst. The experiment was run for 10,000 h of time on stream at constant reaction conditions with an O₂/C molar ratio of 0.47, a H₂O/C molar ratio of 1.9, and a gas hourly space velocity of 30,000 h⁻¹. Kerosene produced via the gas-to-liquid process and diesel fuel synthesized via the bio-to-liquid route were used. Both fuels were almost free of mass fractions of sulfur and aromatics. The trends for the desired main products of autothermal reforming H₂, CO, CO₂, and CH₄ were almost stable when kerosene was used. When the fuel mass flow was switched to diesel fuel however, different modes of catalyst deactivation occurred (active sites blocked by carbonaceous deposits, sintering processes), leading to a decrease in the concentrations of H₂ and CO₂ with a simultaneous increase in the CO content. This paper defines carbon conversion as the decisive criterion for evaluating the long-term stability during autothermal reforming of kerosene and diesel fuel. Carbon conversion was diminished via three different pathways during the long-term experiment. Undesired byproducts found in the gas phase leaving the reactor had the strongest impact on carbon conversion. These byproducts included ethene, propene, and benzene. Furthermore, a liquid oily residue was detected floating on the condensed unconverted mass flow of water. This happened once during the whole experiment. Finally, undesired organic byproducts were dissolved in the mass flow of unconverted water. These were found to be straight-chain and branched paraffins, esters, alcohols, acids, aldehydes, ketones, etc. Nevertheless, at the end of the long-term experiment, carbon conversion still amounted to more than 98.2%.     

Inhibition effect of CO on hydrogen permeability of Pd–Ag membrane applied in a microchannel module configuration

The surface adsorption effect of CO on the hydrogen permeability of a 12.5 micron-thick Pd₇₇Ag₂₃ membrane has been evaluated quantitatively under experimental conditions close to the operating conditions of the highly-efficient membrane reformer (MRF) system developed by Tokyo Gas. The permeability of the membrane was measured in the conditions of CO concentration between 1 and 5 vol.% at a temperature and pressure of up to 500 °C and 0.6 MPa, respectively. High feed flow rates and a microchannel module configuration were applied in the flux measurements to ensure that the results are obtained with limited influence of concentration polarization adjacent to the membrane surface and hydrogen depletion along the microchannel length. While the CO inhibition effect was close to negligible at 500 °C, it was significant at lower temperatures. At a feed pressure of 0.2 MPa, the CO inhibition effect was only 0.2% at a CO concentration of 1 vol.% and the effect was 3.6% at a CO concentration of 5 vol.% at 500 °C. The CO inhibition effect were 3.4% for 1 vol.% CO and 14.1% for 5 vol.% CO at 400 °C. Measurements were also carried out at a high feed pressure of 0.6 MPa to evaluate the pressure dependence of the CO inhibition effect. The CO inhibition effect decreased to 0.7% at a CO feed concentration of 5 vol.% at 500 °C. Lower CO inhibition effect were also observed at 450 and 400 °C compared to the data obtained with the feed pressure of 0.2 MPa, while the inhibition levels were almost the same at 350 °C. Though the CO inhibition effect is larger at a lower feed pressure of 0.2 MPa, the effect was only 0.2% at 1 vol.% CO at 500 °C, which is close to the operating conditions of the MRF system. This study quantitatively revealed that the CO inhibition effect on hydrogen flux is extremely small when the membrane is operated at temperatures equal to or higher than 500 °C, even for state-of-the-art thin membranes. The performance of the Tokyo Gas MRF seems thus mainly limited by concentration polarization effects.     

Catalytic burner with internal steam generation for a fuel-cell-based auxiliary power unit for middle distillates

A catalytic burner (CAB) was developed, which utilizes the anode off-gas of a high temperature polymer electrolyte fuel cell (HT-PEFC). This CAB has two functions within the HT-PEFC-system: It has to convert completely all combustible components including methane and carbon monoxide, even in the low ppm range and it has to provide steam to the autothermal reformer (ATR). Thereby it increases the system's overall efficiency.     

Operational behavior and reforming kinetics over Ni/YSZ of a planar type pre-reformer for SOFC systems

At Forschungszentrum Jülich GmbH, a multi-component SOFC design based on planar stacks has been developed, in which all hot system components are scaled to a nominal SOFC stack power of 5 kW. To optimize the SOFC system it is necessary to investigate the effects of design and operating parameters on the system components like pre-reformer and afterburner. A special designed 5-layer planar type steam pre-reformer on basis of Ni/YSZ has been built and tested for operational behavior and kinetics of steam reforming with methane. This paper summarizes and discusses the experimental results on the global reaction kinetics of a Jülich planar pre-reformer in the temperature range between 350 °C and 620 °C at ambient pressure (1 bar). The species compositions of product gas at different feed compositions, flow rates and temperatures are determined by using gas-chromatographic methods and dew-point measurements. The reproducibility of experiments in the low temperature range (especially less than 430 °C) was only assured, when the catalyst has been reduced before every kinetic experiment. The proposed kinetic expression of Arrhenius type (second order with respect to mole fraction of methane and first order with respect to mole fraction of water) gives a good agreement with the experimental results of the methane steam reforming. It is general effective for different steam to carbon ratios. The temperature distribution in the pre-reformer and the loss of heat are also discussed.     

The problem of selective determination of PSP toxins in mussels

Levels of paralytic shellfish poisoning (PSP) toxins in shellfish are routinely determined by mouse bioassay. In order to improve the qualitative and quantitative determination of PSP toxins, chromatographic techniques with fluorescence detection have been developed. These HPLC methods and the HPLC/MS coupling were used to determine a second PSP toxin which was found, in addition to saxitoxin, in canned Spanish mussels. These canned mussels were rejected in 1986 by the German food control because PSP concentrations were too high. It has been shown that these samples contained mainly dc-saxitoxin.     

Prediction of laboratory and in situ protein fractions in legume and grass silages using near-infrared reflectance spectroscopy

Legume and grass silage samples (n = 121) were collected from commercial forage testing laboratories (trial 1). Samples were dried at 55 degrees C for 48 h, ground, scanned on a near-infrared reflectance spectrophotometer, and analyzed for crude protein (CP), soluble CP, acid detergent fiber (ADF) CP, and neutral detergent fiber (NDF) CP by wet chemistry methods. Sixty samples were selected for calibration development, and the remaining samples were used for equation validation. Near-infrared reflectance spectroscopy accurately predicted the CP content of the silages (R2 = 0.96), but prediction of soluble CP, ADF CP, and NDF CP was markedly less accurate. The coefficients of determination and standard errors of calibration for CP, ADF CP, NDF CP (percentage of DM), and soluble CP (percentage of CP) were as follows (0.96 and 0.80, 0.77 and 0.24, 0.72 and 0.71, and 0.82 and 4.40). In a second study, legume and grass silage samples (n = 32) were dried at 55 degrees C and ground (2 mm). Duplicate dacron bags containing 5 g of silage were incubated in the ventral rumen of three ruminally cannulated cows for 0, 3, 6, 12, 24, 48, and 72 h. In situ protein fractions, including rapidly degraded protein, slowly degraded protein, undegradable protein, degradation rate, and rumen-undegradable protein, were determined. Original samples were reground (1 mm) and scanned. Previously defined near-infrared spectroscopy calibration procedures were conducted. Coefficients of determination for in situ CP fractions were R2 > 0.92 with the exception of degradation rate (R2 = 0.87). Data suggest that in situ protein fractions are better predicted by near-infrared reflectance spectroscopy than by laboratory protein fractions.