3,060 research outputs found
Adrenomedullin suppresses migration inhibitory factor production and cytokine response of rat macrophages to lipopolysaccharide
published_or_final_versio
Free energies of molecular clusters determined by guided mechanical disassembly
The excess free energy of a molecular cluster is a key quantity in models of the nucleation of droplets from a metastable vapor phase; it is often viewed as the free energy arising from the presence of an interface between the two phases. We show how this quantity can be extracted from simulations of the mechanical disassembly of a cluster using guide particles in molecular dynamics. We disassemble clusters ranging in size from 5 to 27 argonlike Lennard-Jones atoms, thermalized at 60 K, and obtain excess free energies, by means of the Jarzynski equality, that are consistent with previous studies. We only simulate the cluster of interest, in contrast to approaches that require a series of comparisons to be made between clusters differing in size by one molecule. We discuss the advantages and disadvantages of the scheme and how it might be applied to more complex systems
The copular construction with a comparative interpretation in mandarin and Cantonese
2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Public knowledge of how to use an automatic external defibrillator in out-of-hospital cardiac arrest in Hong Kong
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Regulation of human cardiac KCNQ1/KCNE1 channel by epidermal growth factor receptor kinase
The aim of the present study was to investigate whether/how the recombinant human cardiac I Ks could be regulated by epidermal growth factor receptor kinase in HEK 293 cells stably expressing hKCNQ1/hKCNE1 genes using the approaches of perforated patch clamp technique, immunoprecipitation and Western blot analysis. It was found that the broad spectrum isoflavone tyrosine kinase inhibitor genistein and the selective epidermal growth factor receptor kinase inhibitor tyrphostin AG556 suppressed the recombinant I Ks, and their inhibition was countered by the protein tyrosine phosphatase inhibitor orthovanadate. The Src-family kinase inhibitor PP2 reduced the current, but the effect was not antagonized by orthovanadate. Immunoprecipitation and Western blot analysis revealed that tyrosine phosphorylation level of hKCNQ1 protein was decreased by genistein or AG556, but not by PP2. These results provide the novel information that epidermal growth factor receptor kinase, but not Src-family kinases, regulates the recombinant cardiac I Ks stably expressed in HEK 293 cells via phosphorylating KCNQ1 protein of the channel. © 2009 Elsevier B.V. All rights reserved.postprin
Highly Selective Conversion of CH4 to High Value-Added C1 Oxygenates over Pd Loaded ZnTi-LDH
The selective oxidation of methane to high value-added liquid oxygenated compounds under mild conditions is of great significance to promote the efficient utilization of the carbon source, but it also faces the dilemma of low activity and over-oxidation. Here, ZnTi-layered double hydroxides (LDH)-A200 photocatalysts with Pd loading are prepared to achieve efficient oxidation of methane, with O2 as an oxidant under ambient condition. The highest generation rate of C1 liquid products (methanol and formaldehyde) reaches 4924.47 µmol g−1 h−1 with a selectivity close to 100% over 0.5Pd-ZnTi-LDH-A200, which is 20 times higher than that of bare ZnTi-LDH-A200. The photochemical results show that the modified photocatalysts present much higher generation and separation efficiency of electron-hole pairs. In situ X–ray photoelectron spectroscopy indicates that Pd nanoparticles are the hole acceptor, which is beneficial to charge separation in the photocatalysis. Furthermore, electron spinresonance spectroscopy and temperature–programmed–desorption analysis prove that Pd loading is helpful to the adsorption of methane and oxygen on the surface of ZnTi-LDH-A200, promoting the production of reactive oxygen species and activation of methane. All these factors work together to promote the efficient conversion of CH4 to high value-added C1 oxygenates
On the effect of turbulent fluctuations on precipitation: A direct numerical simulation – population balance study
The objective of the present paper is to investigate the effect of turbulent fluctuations on precipitation and the implications for modelling. To this end, a coupled direct numerical simulation (DNS) - population balance study is conducted on the experiments of Schwarzer et al. (2006) on BaSO4 precipitation in a Tmixer. The unclosed terms in the averaged population balance equation are identified and evaluated via DNS. A comparison of the average nucleation and growth rates with those computed with the average values shows significant deviations indicative of the importance of fluctuations in precipitation modelling. Furthermore, the correlation between growth and number density is analysed, as well as its contribution to the reactant consumption. The study is performed at Sc ¼ 1 as it is, at present, not possible to resolve the sub-Kolmogorov scales at high Reynolds and Schmidt numbers. However, an attempt to investigate the effect of sub-Kolmogorov scales is made by performing a simulation of precipitation in a similar T-mixer at a lower (but still turbulent) Reynolds number and at Sc ¼ 1 and Sc ¼ 10. The findings indicate the presence of thinner reaction zones at higher Sc, but the effect on the product particle size distribution is marginal. An analysis of the results indicates that this is due to a compensation of the effect of thinner reaction zones by higher reaction rates occurring therei
Optimization of RAPD-PCR reaction system for genetic relationships analysis of 15 camellia cultivars
With orthogonal analysis by L27(36), the random amplified polymorphic DNA (RAPD)-PCR optimization reaction system for camellia were obtained. Results showed that the optimization system was 10×PCR Buffer (2.5 L), 25 mM MgCl2 (2.5 L), 2.5 mM dNTPs (2.0 L), 20 M primer (1.0 L), Tag (1.5 U), temple DNA (40 ng or so) and added ddH2O to the total volume 25 uL; suitable annealing temperature was 36°C. With the optimized system and fifteen 10 nt random primers, we analyzed 15 camellia cultivars and observed 102 clear amplified loci, in which polymorphic loci were 79 while the percentage of polymorphic loci were 77.54%. Cluster analysis showed that the four groups were divided at the point 0.75 of similarity coefficient, indicating relatively high genetic diversity. We also found that the gene controlling petal color may play an important role in RAPD analysis. Moreover, genetic diversities based on RAPD analysis could be clearly reflected by morphological traits among 15 camellia cultivars. This study showed the RAPD optimization system was suitable and RAPD molecular marker was effective and useful tool for detection of genetic relationships among camellia cultivars
Tissue kallikrein mediates pro-inflammatory pathways and activation of protease-activated receptor-4 in proximal tubular epithelial cells.
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