Showing papers by "Xiamen University published in 2008"
TL;DR: A general rule is preliminarily proposed that the atomic radius, bond dissociation energy, and electronegativity of the core and shell metals play key roles in determining the conformal epitaxial layered growth mode.
Abstract: With octahedral Au nanocrystals as seeds, highly monodisperse Au@Pd and Au@Ag core-shell nanocubes were synthesized by a two-step seed-mediated method in aqueous solution. Accordingly, we have preliminarily proposed a general rule that the atomic radius, bond dissociation energy, and electronegativity of the core and shell metals play key roles in determining the conformal epitaxial layered growth mode.
689 citations
TL;DR: It is found that the extent analysis method cannot estimate the true weights from a fuzzy comparison matrix and has led to quite a number of misapplications in the literature.
628 citations
TL;DR: Great efforts have been made to comprehensively understand SERS and analyze EC-SERS spectra on the basis of the chemical and physical enhancement mechanisms in order to provide meaningful information for revealing the mechanisms of electrochemical adsorption and reaction.
Abstract: This tutorial review first describes the early history of SERS as the first SERS spectra were obtained from an electrochemical cell, which led to the discovery of the SERS effect in mid-1970s. Up to date, over 500 papers have been published on various aspects of SERS from electrochemical systems. We then highlight important features of electrochemical SERS (EC-SERS). There are two distinctively different properties of electric fields, the electromagnetic field and static electrochemical field, co-existing in electrochemical systems with various nanostructures. Both chemical and physical enhancements can be influenced to some extent by applying an electrode potential, which makes EC-SERS one of the most complicated systems in SERS. Great efforts have been made to comprehensively understand SERS and analyze EC-SERS spectra on the basis of the chemical and physical enhancement mechanisms in order to provide meaningful information for revealing the mechanisms of electrochemical adsorption and reaction. The EC-SERS experiments and applications are then discussed from preparation of nanostructured electrodes to investigation of SERS mechanisms and from characterization of adsorption configuration to elucidation of electrochemical reaction mechanisms. Finally, prospective developments of EC-SERS in substrates, methods and theory are discussed.
519 citations
TL;DR: The Natural Science Foundation of China as discussed by the authors [20673091, 20433060, 20503023, 20873113, 20833005], Mnistry of Science and Technology of China [2009CB220102, 2007DFA40890]
Abstract: Natural Science Foundation of China [20673091, 20433060, 20503023, 20873113, 20833005]; Mnistry of Science and Technology of China [2009CB220102, 2007DFA40890]
512 citations
TL;DR: A facile nonaqueous synthetic route to prepare anatase nanosheets with exposed {001} facets and high-quality rhombic-shaped anatase Nanocrystals with a large percentage of exposed {010} facets is reported.
Abstract: Although solution-based synthesis is the most powerful and economic method to create nanostructured anatase TiO2, under those synthesis conditions the {101} facets are the most thermodynamically stable, making it difficult to create anatase nanomaterials with a large percentage of high-energy {001} or {010} facets exposed. Here, we report a facile nonaqueous synthetic route to prepare anatase nanosheets with exposed {001} facets and high-quality rhombic-shaped anatase nanocrystals with a large percentage of exposed {010} facets. Including adscititious water in the nonaqueous synthesis and eliminating the use of carboxylic acid type capping agents are the two keys to integrating the structural diversity from aqueous systems into large-quantity synthesis in nonaqueous systems. The nanostructured TiO2 that we prepared exhibits conspicuous activity in the photocatalytic degradation of organic contaminants.
391 citations
TL;DR: Wang et al. as discussed by the authors investigated the relationship between environmental pollution and economic growth in China based on the environmental Kuznets curve hypothesis, using Chinese provincial data over 1985-2005, and found that panel cointegration estimation is preferable for all pollutants except for solid wastes.
369 citations
TL;DR: National Natural Science Foundation of China [20433040, 20573085, 20673091]; "973" Program [2009CB220102]
Abstract: National Natural Science Foundation of China [20433040, 20573085, 20673091]; "973" Program [2009CB220102]
366 citations
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, as to provide real-time information about concrete mechanical properties such as E-modulus and compressive strength to describe the response of the immune system to EMTs.
Abstract: National Natural Science Foundation of China [20725310, 20721001, 20673085, 20671079, J0630429]; National Basic Research Program of China [2007CB815303, 2009CB939804]; Fujian Province of China [2005HZ013]
303 citations
TL;DR: The successful synthesis of a highly catalytically active gold bilayer may lead to the design and synthesis of practically active Au nanofilm catalysts, and the key issues of catalysis by nanostructured Au, effects of oxide support and active site/structure are discussed in detail.
Abstract: Almost two decades have passed since supported Au nanoparticles were found to be active for CO oxidation. This discovery inspired extensive research addressing the origin of the unique properties of supported Au nanoparticles, the design and synthesis of potentially technical Au catalysts, and the extension of Au catalysis to other reactions. This tutorial review summarises the current understanding of the origin of the unique properties of titania-supported Au catalysts for carbon monoxide oxidation. The key issues of catalysis by nanostructured Au, effects of oxide support and active site/structure, especially those provided from model studies are discussed in detail. The successful synthesis of a highly catalytically active gold bilayer may lead to the design and synthesis of practically active Au nanofilm catalysts.
300 citations
TL;DR: In this paper, National Basic Research Program of China (973 Program) [2007CB209702] and National Natural Science Foundation (NNSFC) [20433060, 20473068, 29925310]
Abstract: National Basic Research Program of China (973 Program) [2007CB209702]; National Natural Science Foundation of China (NNSFC) [20433060, 20473068, 29925310]
291 citations
TL;DR: This review summarizes the origin, structure and clinical symptoms of PSP, NSP, CFP, AZP, yessotoxin and palytoxin produced by marine dinoflagellates, as well as their molecular mechanisms of action on voltage-gated ion channels.
Abstract: Dinoflagellates are not only important marine primary producers and grazers, but also the major causative agents of harmful algal blooms. It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents. Consumption of seafood contaminated by algal toxins results in various seafood poisoning syndromes: paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), ciguatera fish poisoning (CFP) and azaspiracid shellfish poisoning (ASP). Most of these poisonings are caused by neurotoxins which present themselves with highly specific effects on the nervous system of animals, including humans, by interfering with nerve impulse transmission. Neurotoxins are a varied group of compounds, both chemically and pharmacologically. They vary in both chemical structure and mechanism of action, and produce very distinct biological effects, which provides a potential application of these toxins in pharmacology and toxicology. This review summarizes the origin, structure and clinical symptoms of PSP, NSP, CFP, AZP, yessotoxin and palytoxin produced by marine dinoflagellates, as well as their molecular mechanisms of action on voltage-gated ion channels.
TL;DR: The octaketide cytosporone B (Csn-B) is a naturally occurring agonist for Nur77 that induced apoptosis and retarded xenograft tumor growth by inducing Nur77 expression, translocating Nur77 to mitochondria to cause cytochrome c release and may be useful as a reagent to increase understanding of Nur77 biological function.
Abstract: Nuclear orphan receptor Nur77 has important roles in many biological processes. However, a physiological ligand for Nur77 has not been identified. Here, we report that the octaketide cytosporone B (Csn-B) is a naturally occurring agonist for Nur77. Csn-B specifically binds to the ligand-binding domain of Nur77 and stimulates Nur77-dependent transactivational activity towards target genes including Nr4a1 (Nur77) itself, which contains multiple consensus response elements allowing positive autoregulation in a Csn-B-dependent manner. Csn-B also elevates blood glucose levels in fasting C57 mice, an effect that is accompanied by induction of multiple genes involved in gluconeogenesis. These biological effects were not observed in Nur77-null (Nr4a1-/-) mice, which indicates that Csn-B regulates gluconeogenesis through Nur77. Moreover, Csn-B induced apoptosis and retarded xenograft tumor growth by inducing Nur77 expression, translocating Nur77 to mitochondria to cause cytochrome c release. Thus, Csn-B may represent a promising therapeutic drug for cancers and hypoglycemia, and it may also be useful as a reagent to increase understanding of Nur77 biological function.
TL;DR: In this paper, the authors examined how regional diversification affects firm performance and found that it has linear and curvilinear effects on firm performance, and that firms of developed countries maximize their performance when they operate across a moderate number of developed regions and a strictly limited number of developing regions.
Abstract: This study examines how regional diversification affects firm performance. The results indicate that regional diversification has linear and curvilinear effects on firm performance. Regional diversification enhances firm performance linearly up to a certain threshold, and then its impact becomes negative. The results also show that firms of developed countries maximize their performance when they operate across a moderate number of developed regions and a strictly limited number of developing regions. This explains why internationalization by most international firms is regional rather than global.
TL;DR: This research presents a probabilistic method to estimate the intensity of the response of the immune system to earthquake-triggered landslides in the Northern Hemisphere.
TL;DR: A series of cross-linked quaternized poly(vinyl alcohol) (PVA) membranes have been prepared and characterized for alkaline direct methanol fuel cell (DMFC) applications as mentioned in this paper.
15 Jul 2008
TL;DR: In this article, the authors examined the occurrence of seasonal hypoxia (O 2 < 2 mg l(-1)) in the bottom waters of four river-dominated ocean margins (off the Changjiang, Mississippi, Pearl and Rhone Rivers) and compared the processes leading to the depletion of oxygen.
Abstract: We examined the occurrence of seasonal hypoxia (O-2 < 2 mg l(-1)) in the bottom waters of four river-dominated ocean margins (off the Changjiang, Mississippi, Pearl and Rhone Rivers) and compared the processes leading to the depletion of oxygen. Consumption of oxygen in bottom waters is linked to biological oxygen demand fueled by organic matter from primary production in the nutrient-rich river plume and perhaps terrigenous inputs. Hypoxia occurs when this consumption exceeds replenishment by diffusion, turbulent mixing or lateral advection of oxygenated water. The margins off the Mississippi and Changjiang are affected the most by summer hypoxia, while the margins off the Rhone and the Pearl rivers systems are less affected, although nutrient concentrations in the river water are very similar in the four systems. Spring and summer primary production is high overall for the shelves adjacent to the Mississippi, Changjiang and Pearl (1-10g C m(-2) d(-1)), and lower off the Rhone River (< 1 g C m(-2) d(-1)), which could be one of the reasons of the absence of hypoxia on the Rhone shelf The residence time of the bottom water is also related to the occurrence of hypoxia, with the Mississippi margin showing a long residence time and frequent occurrences of hypoxia during summer over very large spatial scales, whereas the East China Sea (ECS)/Changjiang displays hypoxia less regularly due to a shorter residence time of the bottom water. Physical stratification plays an important role with both the Changjiang and Mississippi shelf showing strong thermohaline stratification during summer over extended periods of time, whereas summer stratification is less prominent for the Pearl and Rhone partly due to the wind effect on mixing. The shape of the shelf is the last important factor since hypoxia occurs at intermediate depths (between 5 and 50 m) on broad shelves (Gulf of Mexico and ECS). Shallow estuaries with low residence time such as the Pearl River estuary during the summer wet season when mixing and flushing are dominant features, or deeper shelves, such as the Gulf of Lion off the Rhone show little or no hypoxia. (c) 2008 Elsevier Ltd. All rights reserved. (Less)
TL;DR: In this article, the structure and morphology of the coated Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 samples were characterized and compared.
TL;DR: A comparative approach is now further aided by the biokinetic modeling approach which can be used to predict the rates and routes of metal bioaccumulation and assist in the interpretation of accumulated body metal concentrations in aquatic animals.
Abstract: Over the past decades, comparative physiology and biochemistry approaches have played a significant role in understanding the complexity of metal bioaccumulation in aquatic animals. Such a comparative approach is now further aided by the biokinetic modeling approach which can be used to predict the rates and routes of metal bioaccumulation and assist in the interpretation of accumulated body metal concentrations in aquatic animals. In this review, we illustrate a few examples of using the combined comparative and biokinetic modeling approaches to further our understanding of metal accumulation in aquatic animals. We highlight recent studies on the different accumulation patterns of metals in different species of invertebrates and fish, and between various aquatic systems (freshwater and marine). Comparative metal biokinetics can explain the differences in metal bioaccumulation among bivalves, although it is still difficult to explain the evolutionary basis for the different accumulated metal body concentrations (e.g., why some species have high metal concentrations). Both physiological/biochemical responses and metal geochemistry are responsible for the differences in metal concentrations observed in different populations of aquatic species, or between freshwater and marine species. A comparative approach is especially important for metal biology research, due to the very complicated and potentially variable physiological handling of metals during their accumulation, sequestration, distribution and elimination in different aquatic species or between different aquatic systems.
TL;DR: In this paper, the spatial distribution and seasonal variation of dissolved inorganic nitrogen in a large perturbed estuary, the Pearl River Estuary, based on three cruises conducted in winter (January 2005), summer (August 2005) and spring (March 2006).
Abstract: . We investigated the spatial distribution and seasonal variation of dissolved inorganic nitrogen in a large perturbed estuary, the Pearl River Estuary, based on three cruises conducted in winter (January 2005), summer (August 2005) and spring (March 2006). On-site incubation was also carried out for determining ammonium and nitrite oxidation rates (nitrification rates). We observed a year-round pattern of dramatic decrease in NH4+, increase in NO3−, but insignificant change in NO2− in the upper estuary at salinity ~0–5. However, species and concentrations of inorganic nitrogen at upper estuary significantly changed with season. In winter, with low runoff, the most upper reach of the Pearl River Estuary showed relatively low rates of ammonia oxidation (0–5.4 μmol N L−1 d−1) and nitrite oxidation (0–5.2 μmol N L−1 d−1), accompanied by extremely high concentrations of ammonia (up to >800 μmol L−1) and nitrate (up to >300 μmol L−1). In summer, the upper estuary showed higher nitrification rates (ammonia oxidation rate ~1.5–33.1 μmol N L−1 d−1, nitrite oxidation rate ~0.6–32.0 μmol N L−1 d−1) with lower concentrations of ammonia (
TL;DR: In this paper, general relationship of riverine bicarbonate concentrations and fluxes as a function of drainage basin mineral content and runoff are examined using a database of the 25 largest rivers in the world.
TL;DR: In this paper, a detailed analysis of the influence of chemical enhancement effects on the SERS signals is presented, which shows that the relative Raman intensities of SERS spectra depend strongly on the binding interaction between pyridine and SERS active centers, the electronic property of metal materials, and the incident wavelengths.
Abstract: Using density functional theory, we have studied the interactions between pyridine (Py) and coinage metals (silver, copper, and gold) as well as the transition metal platinum. We present here a detailed analysis of the influence of chemical enhancement effects on the SERS signals. We analyze the differential Raman scattering cross sections of the a1 vibrational modes related to Py. The results show that the relative Raman intensities of SERS spectra depend strongly on the binding interaction between Py and the SERS active centers, the electronic property of metal materials, and the incident wavelengths. When the bonding between Py and a SERS site is very weak, analogous to physical adsorption, the Raman spectra of the adsorbed Py are similar to that of free Py. For Py interacting strongly with copper, gold, and platinum clusters, we find that the Raman intensities of the v1, v6a, v9a, and v8a modes of Py are enhanced, whereas the intensity of the v12 mode decreases. To check the enhancement effect of the ...
TL;DR: The identification of a Nur77-derived Bcl-2-converting peptide with 9 amino acids (NuBCP-9) and its enantiomer, which induce apoptosis of cancer cells in vitro and in animals.
TL;DR: In this article, the performance of commercial lithium ion cells with LiCoO 2 as cathode, artificial graphite as anode and 1.M LiPF 6/EC-DEC-EMC (ethylene carbonate,diethyl carbonate-dimethyl carbonate) with additives (1.1% propylene sulfite (PS)) as electrolyte were aged at 60% and 100% state of charge (SOC) for 6 months at room temperature and the corresponding cycle performance was measured.
TL;DR: The data suggest that miR-21 may play a key role during embryo implantation, and it is shown that Reck was the target gene of MiRNAs, and miRNA microarray was used to examine differential expression of miRNAs in the mouse uterus between implantation sites and inter-implantation sites.
TL;DR: In this article, a method of separating variables is effectively implemented for solving a time-fractional telegraph equation (TFTE), and the analytical solution of the TFTE with three kinds of nonhomogeneous boundary conditions, namely, Dirichlet, Neumann and Robin boundary conditions.
TL;DR: A mechanism has been proposed to explain the formation of superhydrophobic TiO2 films with distinct adhesion and the significant increase of adhesion by introducing nitrocellulose is ascribed to the combination of hydrogen bonding between the nitro groups and the hydroxyl groups at the solid/liquid interfaces.
Abstract: A simple electrochemical and self-assembly method was adopted for the fabrication of superhydrophobic spongelike nanostructured TiO2 surfaces with markedly controllable adhesion. Water adhesion ranging from ultralow (5.0 μN) to very high (76.6 μN) can be tuned through adjusting the nitro cellulose dosage concentrations. The detailed experiments and analyses have indicated that the significant increase of adhesion by introducing nitrocellulose is ascribed to the combination of hydrogen bonding between the nitro groups and the hydroxyl groups at the solid/liquid interfaces and the disruption of the densely packed hydrophobic 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PTES) molecule. A mechanism has been proposed to explain the formation of superhydrophobic TiO2 films with distinct adhesion.
TL;DR: The Intelligent Malware Detection System (IMDS) is an integrated system consisting of three major modules: PE parser, OOA rule generator, and rule based classifier, and an OOA_Fast_FP-Growth algorithm is adapted to efficiently generate OOA rules for classification.
Abstract: The proliferation of malware has presented a serious threat to the security of computer systems. Traditional signature-based anti-virus systems fail to detect polymorphic/metamorphic and new, previously unseen malicious executables. Data mining methods such as Naive Bayes and Decision Tree have been studied on small collections of executables. In this paper, resting on the analysis of Windows APIs called by PE files, we develop the Intelligent Malware Detection System (IMDS) using Objective-Oriented Association (OOA) mining based classification. IMDS is an integrated system consisting of three major modules: PE parser, OOA rule generator, and rule based classifier. An OOA_Fast_FP-Growth algorithm is adapted to efficiently generate OOA rules for classification. A comprehensive experimental study on a large collection of PE files obtained from the anti-virus laboratory of KingSoft Corporation is performed to compare various malware detection approaches. Promising experimental results demonstrate that the accuracy and efficiency of our IMDS system outperform popular anti-virus software such as Norton AntiVirus and McAfee VirusScan, as well as previous data mining based detection systems which employed Naive Bayes, Support Vector Machine (SVM) and Decision Tree techniques. Our system has already been incorporated into the scanning tool of KingSoft’s Anti-Virus software.
TL;DR: In this article, the mean size of the Pd particles over the SiO 2 -Al 2 O 3 support was found to depend on the Si/Al ratio, and a decrease in the Si /Al ratio resulted in an increase in the mean number of Pd nanoparticles.
Abstract: Silica-alumina (SiO 2 -Al 2 O 3 )-supported palladium catalysts prepared by adsorption of the tetrachloropalladate anion (PdCl 4 2- ) followed by calcination and reduction with either hexanol or hydrogen were studied for the aerobic oxidation of alcohols. The mean size of the Pd particles over the SiO 2 -Al 2 O 3 support was found to depend on the Si/Al ratio, and a decrease in the Si/Al ratio resulted in a decrease in the mean size of the Pd nanoparticles. By changing the Si/Al ratio, we obtained supported Pd nanoparticles with mean sizes ranging from 2.2 to 10 nm. The interaction between the Pd precursor and the support was proposed to play a key role in tuning the mean size of the Pd nanoparticles. The Pd/SiO 2 -Al 2 O 3 catalyst with an appropriate mean size of Pd particles could catalyze the aerobic oxidation of various alcohols to the corresponding carbonyl compounds, and this catalyst was particularly efficient for the solvent-free conversion of benzyl alcohol. The intrinsic turnover frequency per surface Pd atom depended significantly on the mean size of Pd particles and showed a maximum at a medium mean size (3.6-4.3 nm), revealing that the aerobic oxidation of benzyl alcohol catalyzed by the supported Pd nanoparticles was structure-sensitive.
TL;DR: A significant linear relationship between antioxidant potency, free radical-scavenging ability and the content of phenolic compounds of leaf extracts supported this observation.
Abstract: The antioxidant activity of Syzygium cumini leaf extracts was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging and ferric-reducing antioxidant power (FRAP) assays. The methanolic extract and its four water, ethyl acetate, chloroform, and n-hexane fractions were prepared and subjected to antioxidant evaluation. The results showed that the ethyl acetate fraction had stronger antioxidant activity than the other ones. HPLC data indicated that S. cumini leaf extracts contained phenolic compounds, such as ferulic acid and catechin, responsible for their antioxidant activity. A significant linear relationship between antioxidant potency, free radical-scavenging ability and the content of phenolic compounds of leaf extracts supported this observation.