Comparison of the group V and VI transition metal carbides for methane dry reforming and thermodynamic prediction of their relative stabilities

The DME‐SCR activity was suppressed upon exposure of a γ-alumina catalyst to SO₂, in contrast to methanol‐SCR, which remains active at the same surface sulphate coverage. This difference in behaviour is attributed to the limited availability of surface methoxy, which may be regarded as a prerequisite for NOx- reduction over γ-alumina under lean conditions, in the case of dimethyl ether in the presence of SO₂. This revised version was published online in July 2006 with corrections to the Cover Date.     

直击劲爆演出现场

相信很多人都为摇滚现场演出的效果所震撼,何不拿起你的相机,把这激动人心的时刻定格下来,作为永久的纪念呢?我们英国的编辑Ed Godden前往摇滚圣地——普利茅斯展馆剧场,拍下了休克摇滚之父AliceCooper的狂野演出。     

Determination of vitamin K in the edible part of fish by high-performance liquid chromatography

 A highly sensitive high-performance liquid chromatography method for measuring endogenous phylloquinone (K₁) and several menaquinones (MK-4 to MK-10) in the edible part of fish was developed. The procedure consists of three chromatographic steps, a preliminary purification of crude lipid extracts on silica cartridges, a semipreparative stage using normal-phase HPLC, and a final analytical reversed-phase HPLC stage that uses postcolumn chemical reduction of the vitamin followed by fluorimetric detection. The accuracy of this method was evaluated by recovery experiments. The investigated fish included most of the important fish species consumed in Germany. Phylloquinone and MK-4 were the two dominant forms of vitamin K in fish. Relatively high concentrations were found in muscle of marine and freshwater fish with high fat content and in the liver of cod. Fish with low fat content contained only very small amounts. The main part of the vitamin K in fishery products like fish sticks and canned tuna in oil was of plant origin. Received: 31 March 2000 / Revised version: 20 July 2000     

Analytical performance of the Tandem-R free PSA immunoassay measuring free prostate-specific antigen

The analytical performance of the Tandem-R free PSA assay available from Hybritech Inc. was evaluated. Comparison of recoveries of purified free (unbound) prostate-specific antigen (PSA) diluted in female serum in the Tandem-R free PSA assay and the Tandem-R (total) PSA assay demonstrated a link in calibration between the assays and an accurate determination of percent free PSA. The cross-reactivity of the assay to purified PSA-alpha 1-antichymotrypsin was determined to be < 1%. The minimum-detectable concentration was < 0.05 microgram/L. The within-run and between-day CVs were < or = 5% for samples with > 0.3 microgram/L free PSA. Dilution and recovery showed no significant deviations from linearity across the assay range. The assay was insensitive to interference from blood components. The Tandem-R free PSA kit was shown to be an accurate, precise, and reliable assay for the measurement of free PSA.     

Cellular automata method for macroscopic surface and friction dynamics in brake systems

The friction dynamics in the boundary layer of a brake system is closely linked with the growth and the destruction of typical structures on the brake pad. These processes are caused by an interaction of friction and wear and determine the (as well measured) time-dependence of global parameters, such as the friction coefficient μ or the temperature. Based on the simulation with a set of differential equations, this equilibrium of flow has also already been described with a cellular-automaton-discretization. This paper will show new results and fundamental conclusions with respect to the surface topography dynamics and the friction behaviour of a brake system.     

Chronic d-fenfluramine treatment reduces fat intake independent of macronutrient preference

The origin of hematopoietic stem cells (HSCs) and their growth factor requirement are poorly understood. Here we describe a new in vitro culture system of the aorta-gonad-mesonephros (AGM) region, where long-term repopulating HSCs first arise. We demonstrate that oncostatin M (OSM) is expressed in the AGM and is absolutely required for the expansion of multipotential hematopoietic progenitors in vitro. In addition, OSM enhances the formation of endothelial cell clusters. Thus, OSM appears to be a key cytokine for the development of multipotential hematopoietic progenitors in the AGM, possibly acting on common precursor cells between HSCs and endothelial cells. By using the AGM culture derived from macrophage colony-stimulating factor (M-CSF)-deficient op/op mutant embryos, we also show a pivotal role for M-CSF in fetal myelopoiesis.     

Effects of vocal loudness on nasalance measures

The effect of storage and high temperatures on the stability of Saccharomyces cerevisiae allergens was studied by immunoblotting. Saccharomyces cerevisiae allergic serum pool and 125I- and galactosidase-labelled anti-IgE were used in the assays. Freeze-dried extracts were reconstituted with saline and with 50% glycerol and then stored at room (+20 degrees C) and refrigerator temperature (+6 degrees C) for different time periods. The stability was better in 50% glycerol at +6 degrees C than at room temperature without glycerol. However, after 1 month, two of the most important allergens of S. cerevisiae, the 48 and 32 kDa protein allergens, lost their IgE-binding capacity even in the extracts stored with 50% glycerol at +6 degrees C. The 45 kDa allergen was, on the other hand, quite stable after storage for 9 months at +6 degrees C. Although the beneficial effect of 50% glycerol was clear, storage at +6 degrees C, even with 50% glycerol should not exceed 1 month for S. cerevisiae extracts. Two commercially available S. cerevisiae extracts in solution with valid expiry dates were also analysed. They had only little allergenic potency, while a freeze-dried extract stored for 8 years showed good allergenic potency. Heating S. cerevisiae extracts resulted in precipitation, the precipitated fraction contained almost all the specific proteins as judged by electrophoresis and IgE detection. The supernatant fraction contained only a few allergens.     

Reexamining psychokinesis: Comment on B?sch, Steinkamp, and Boller (2006).

H. B?sch, F. Steinkamp, and E. Boller's (see record 2006-08436-001) review of the evidence for psychokinesis confirms many of the authors' earlier findings. The authors agree with B?sch et al. that existing studies provide statistical evidence for psychokinesis, that the evidence is generally of high methodological quality, and that effect sizes are distributed heterogeneously. B?sch et al. postulated the heterogeneity is attributable to selective reporting and thus that psychokinesis is "not proven." However, B?sch et al. assumed that effect size is entirely independent of sample size. For these experiments, this assumption is incorrect; it also guarantees heterogeneity. The authors maintain that selective reporting is an implausible explanation for the observed data and hence that these studies provide evidence for a genuine psychokinetic effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)