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

Infant nutrition and allergy

The correct nutrition in the first year of a child’s life is an important factor determining the physical and intellectual capabilities of a person at a later age and has an important meaning to the risk of developing a food allergy. The aim of our study was to determine whether breastfeeding practices, including exceptional breastfeeding, and using hydrolysed milk alter the risk of developing a food allergy in infants. Material and Methods: We tracked 180 healthy infants up to the age of one year old and 94 – with manifestations of allergy. The statistical processing and visualisation of the results were done with the products Statgraphics Plus and Microsoft Excel. Results: The success of breastfeeding in the monitored mothers in terms of duration of breastfeeding was influenced by the level of education, ethnicity and current place of residence. In normal birth and caesarean delivery, healthy children are breastfed over 7 months of age, while children with manifestations of allergy – up to 1-2 months of age. Among the monitored by us children food allergy was seen more frequently in infants with low birth weight.  More commonly during the first year we observed skin-gastrointestinal form toward cow’s milk proteins. Among the observed children with allergic manifestation we found elevated levels of immunoglobin E(36,5IU/ml), eosinophiles – over 7%, anaemic syndrome – 40,5%. About 93% of children with initial manifestations of allergy were fed milk for infants, 4,3% were on mixed feeding (breast milk and supplementation with infant milk), 2,1 - on exceptional breastfeeding. Conclusion: The frequent clinical manifestation of allergic colitis and confirmation of allergy to cow's milk with immunoglobulin E and eosinophils require the introduction of an elimination diet and prolonged feeding with protein hydrolysate 6-12 months

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

Guest Editorial Special Issue on Cardiovascular System Monitoring and Therapy: Innovative Technologies and Internet of Things

The papers in this special section focus on cardiovascular system monitoring and therapy. The number of devices for the measurement and interpretation of biological systems that describe performance of the cardiovascular system is growing. Among others, this is due to the improvement of circuit and system design that renders the devices wearable and easy to use. Moreover, internetworking enables these devices to exchange data. Their true impact on patient care is highly dependent on the quality and relevancy of the data acquired. The design of circuits and systems to answer the growing demand and the necessity to have portable and connected devices lead to a focus on designing ultra-low power apparatus, mixed-signal devices, using nanoscale electronics. Microelectronic issues are therefore at the heart of the demand. All this requires inter-disciplinary collaborations between scientists, engineers, medical researchers, and practitioners. The interconnection of these embedded devices, known as Internet of Things, is expected to usher in the medical field, among others to study the cardiovascular system of patients. Data processing and storage will also take place in the healthcare information technology. Furthermore, key issues such as data security and privacy will be determinants of the utility of these systems and impact in healthcare monitoring and management. This special issue aimed to provide a forum for both established experts and newinvestigators to share their developments, knowledge, and insights for the further design of circuits and systems aiming at being integrated in sensors to monitor or treat the cardiovascular system

Investigation of melt-grown dilute GaAsN and GaInAsN nanostructures for photovoltaics

AbstractThe present work demonstrates the possibility to use liquid phase epitaxy to incorporate nitrogen in epitaxial GaAsN/GaAs and GaInAsN/GaAs heterostructures, including nanoscaled ones. The structures are grown from Ga - and GaIn - melts containing polycrystalline GaN as a nitrogen source. The red shift of the absorption spectra corresponds to nitrogen content in the epitaxial layers near or less than 0.2 at %. Photoluminescence spectra of dilute nitride GaAsN and GaInAsN show emission from localized nitrogen states - N-nanoclusters of more than two N atoms. These studies show that the melt grown dilute GaAsN and GaInAsN nanostructures can be used for solar cells with extended long wavelength edge

An enhanced CRISPR repressor for targeted mammalian gene regulation.

The RNA-guided endonuclease Cas9 can be converted into a programmable transcriptional repressor, but inefficiencies in target-gene silencing have limited its utility. Here we describe an improved Cas9 repressor based on the C-terminal fusion of a rationally designed bipartite repressor domain, KRAB-MeCP2, to nuclease-dead Cas9. We demonstrate the system's superiority in silencing coding and noncoding genes, simultaneously repressing a series of target genes, improving the results of single and dual guide RNA library screens, and enabling new architectures of synthetic genetic circuits

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