Structure control of silica-supported mono and bimetallic Au–Pt catalysts via mercapto capping synthesis

Cataloged from PDF version of article.SiO2-supported monometallic and bimetallic platinum-gold catalysts are prepared by deposition of metal nanoparticles stabilized by mercaptopropyltriethoxysilane (MPTES) after different aging time of the solution containing metal ions and MPTES. The materials are tested in the hydrodesulfurization (HDS) reaction of thiophene and compared with corresponding catalysts prepared by the conventional deposition-precipitation (DP) method. The monometallic Pt and the bimetallic Au-Pt prepared by DP have comparable activity. With respect to the platinum catalyst prepared by DP, the corresponding platinum catalyst prepared by MPTES particle stabilization exhibits a substantial enhancement of the activity regardless the solution aging time. On the contrary, the MPTES-assisted Au-Pt catalysts have different activities, depending on the solution aging time, with the most active being the one obtained with the 5-day-aged solution. In accord with XRD, XPS, and FTIR, the aging time of the solution, through the different interaction of Pt or Au precursors with the mercapto groups, has a crucial effect on the structure and on the surface of the catalysts. The observed differences in the catalytic activity are related to the structural and compositional changes of the bimetallic particles. (C) 2012 Elsevier Inc. All rights reserved

Association of polymorphic markers rs243865 and rs3025058 with the development of arterial hypertension

Association of polymorphic markers rs243865 and rs3025058 with the development of arterial hypertension Essential hypertension is a multifactorial polygenic disease with a highest incidence in the world. The purpose of the study was to assess the relationship between gene polymorphisms MMP2-1586S>T (rs243865) and -1612 5A/6A MMP3 (rs3025058) with the development of arterial hypertension in population of the Central Chernozem region of Russi

Associations of cytokines genetic polymorphisms with hypertension progress

The article presents results of comparative analysis of cytokines genes polymorphous variants occurrence among hypertension patients with burdened familial history regarding this disease and in a control grou

Linux kernel compaction through cold code swapping

There is a growing trend to use general-purpose operating systems like Linux in embedded systems. Previous research focused on using compaction and specialization techniques to adapt a general-purpose OS to the memory-constrained environment, presented by most, embedded systems. However, there is still room for improvement: it has been shown that even after application of the aforementioned techniques more than 50% of the kernel code remains unexecuted under normal system operation. We introduce a new technique that reduces the Linux kernel code memory footprint, through on-demand code loading of infrequently executed code, for systems that support virtual memory. In this paper, we describe our general approach, and we study code placement algorithms to minimize the performance impact of the code loading. A code, size reduction of 68% is achieved, with a 2.2% execution speedup of the system-mode execution time, for a case study based on the MediaBench II benchmark suite

Effect of treatment with enrofloxacin and Lactobacillus probiotics on ABCB1, ABCC2 and ABCG2 mRNA expression in poultry

Poultry feed is often supplemented by Lactobacillus probiotics which may alter drug bioavailability by affecting the expression of intestinal ATP-binding cassette (ABC) efflux transporters. Therefore the effect of probiotics, administered alone or in combination with enrofloxacin, on the expression of ABCB1, ABCC2 and ABCG2 mRNAs in chickens was evaluated. Day-old Ross chicks (n=24) were divided in four equal groups. Control group was not treated. The second group received feed with addition of probiotics Lactobacillus brevis, L. plantarum and L. bulgaricus 5 days after hatching, for 15 days. The third group received probiotics as described above and enrofloxacin at the age of 15 days (10 mg/kg, via drinking water for 5 days). The last group received enrofloxacin at age of 15 days (10 mg/kg, via drinking water for 5 days). Expression of ABC transporters in liver, duodenum and jejunum was determined by qRT-PCR. Down-regulation of ABCG2 mRNA in the liver (P<0.05), its up-regulation in the duodenum (P<0.05) and increased ABCB1 mRNA levels in the jejunum (P<0.05) can be attributed to enrofloxacin treatment. Decrease in ABCC2 mRNA expression in the duodenum can be associated with enrofloxacin administration. The observed changes were related to enrofloxacin administration and to lesser extent to Lactobacillus supplementation

Independent Component Analysis-motivated Approach to Classificatory Decomposition of Cortical Evoked Potentials

BACKGROUND: Independent Component Analysis (ICA) proves to be useful in the analysis of neural activity, as it allows for identification of distinct sources of activity. Applied to measurements registered in a controlled setting and under exposure to an external stimulus, it can facilitate analysis of the impact of the stimulus on those sources. The link between the stimulus and a given source can be verified by a classifier that is able to "predict" the condition a given signal was registered under, solely based on the components. However, the ICA's assumption about statistical independence of sources is often unrealistic and turns out to be insufficient to build an accurate classifier. Therefore, we propose to utilize a novel method, based on hybridization of ICA, multi-objective evolutionary algorithms (MOEA), and rough sets (RS), that attempts to improve the effectiveness of signal decomposition techniques by providing them with "classification-awareness." RESULTS: The preliminary results described here are very promising and further investigation of other MOEAs and/or RS-based classification accuracy measures should be pursued. Even a quick visual analysis of those results can provide an interesting insight into the problem of neural activity analysis. CONCLUSION: We present a methodology of classificatory decomposition of signals. One of the main advantages of our approach is the fact that rather than solely relying on often unrealistic assumptions about statistical independence of sources, components are generated in the light of a underlying classification problem itself

Statistics of magnetic field measurements in OBA stars and the evolution of their magnetic fields

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim We review the measurements of magnetic fields of OBA stars. Based on these data, we confirm that magnetic fields are distributed according to a lognormal law with mean log B = − 0.5 (B in kG) with a standard deviation σ = 0.5. The shape of the magnetic field distribution (MFD) is similar to that for neutron stars. This finding favors the hypothesis that the magnetic field of a neutron star is determined mainly by the magnetic field of its predecessor, namely the massive OB star. Further, we model the evolution of an ensemble of magnetic massive stars in the Galaxy. We use our own population synthesis code to obtain the distribution of stellar radii, ages, masses, temperatures, effective magnetic fields, and magnetic fluxes from the pre-main-sequence (PMS) via zero-age main sequence (ZAMS) up to the terminal-age main sequence stages. A comparison of the MFD obtained in our model with that obtained from the recent measurements of the stellar magnetic field allows us to conclude that the evolution of magnetic fields of massive stars is slow if not absent. The shape of the real MFD shows no indications of the magnetic desert proposed previously. Based on this finding, we argue that the observed fraction of magnetic stars is determined by physical conditions at the PMS stage of stellar evolution