Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells

We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic nanoparticle (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet scanning electron microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both cases, the backscattered electron (BSE) detector was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution transmission electron microscopy (TEM) images and scanning Auger electron spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens.     

Temporal and spatial differences in deposition of organic matter and black carbon in Lake Michigan sediments over the period 1850–2010

Inorganic carbon (IC), total organic carbon (OC), and black carbon (BC) were analyzed in eight sediment cores obtained from deep water (>30 m) sediments in the Chippewa and south Chippewa basins, as well as Green Bay in Lake Michigan. These cores were segmented at high resolution and radio-dated to reconstruct a detailed history of deposition to the lake both spatially and temporally since ca. 1850 CE. To help interpret the depositional record, cores were also characterized for stable isotopes (¹³C and ¹⁵N), as well as particle size distribution, density, organic matter (OM), and other parameters. Fine (silt and clay) sediment particles contained OM of primarily lacustrine algal biomass origin. Sedimentation fluxes showed large increases in OM and OC fluxes through much of the lake during the onset of industrialization and the period of rapid industrialization to onset of Great Lakes environmental legislation. In contrast, fluxes and loading of BC increased dramatically in the southern basin until the 1930's, then decreased substantially after the 1940's. This observation was due largely to results from site M009 nearest the steel mills and industrial zones of Chicago and northern Indiana. Together, whole lake loadings of OM and BC provide evidence that changing industrial activity and legislation intended to curb air pollution in the Great Lakes region have had a fairly rapid and dramatic impact. In contrast, legislation intended to decrease eutrophication through reductions in nutrient loading to the lake have not had a similar impact on sedimentation of OM in the lake.     

Numerical investigation of continuous processes for catalytic hydrogenation of nitrile butadiene rubber

Dynamic behavior of continuous processes was numerically investigated for the catalytic hydrogenation of nitrile butadiene rubber, based on developed models, which took into account the coupling between kinetics and mass transfer. The evolution of hydrogenation reaction trajectories in both cases were analyzed. It is proposed that the coupling behavior between the catalytic hydrogenation and mass transfer was completely determined by the ability of the catalyst in activating hydrogen, carbon‐carbon double bond loading level and the relative capacity of reaction to mass transfer as well as the residence time in the reactor. Four dimensionless parameters were derived to characterize these aspects. The effects of operation conditions on the hydrogenation processes were investigated. The application of the ideal flow models to non‐ideal flows was in addition discussed. It is suggested that the optimal reactor for such a hydrogenation system would be a plug flow reactor with an instantaneous well‐mixing component in the inlet of it, and a reasonable approach to the proposed optimal reactor should be with the flow behavior of at least three continuous stirred tank reactors in series. Further research directions are suggested.     

Hydrogenation of cis‐1,4‐poly(isoprene) catalyzed by OsHCl(CO)(O2)(PCy3)2

The quantitative hydrogenation of cis‐1,4‐poly(isoprene) (CPIP) provides an easy entry to the alternating copolymer of ethylene–propylene, which is difficult to prepare by conventional polymerization. The homogeneous hydrogenation of CPIP, in the presence of OsHCl(CO)(O₂)(PCy₃)₂ as catalyst, has been studied by monitoring the amount of hydrogen consumed during the reaction. The final degree of olefin conversion measured by computer‐controlled gas uptake apparatus was confirmed by infrared spectroscopy and ¹H nuclear magnetic resonance analysis. Kinetic experiments for CPIP hydrogenation in toluene solvent indicate that the hydrogenation rate is first order with respect to catalyst and carbon–carbon double bond concentration. A second‐order dependence on hydrogen concentration for low values and a zero‐order dependence for higher values of the hydrogen concentration was observed. The apparent activation energy for the hydrogenation of CPIP over the temperature range of 115–140°C was 109.3 kJ/mole. Mechanistic aspects of this catalytic process are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 142–152, 2003     

Predicting the determinants of the NFC-enabled mobile credit card acceptance: A neural networks approach

The main aim of this study is to determine the factors influencing the adoption of Near Field Communication (NFC)-enabled mobile credit card, an innovation in contactless payment for the future generation. Constructs from psychological science, trust-based and behavioral control theories were incorporated into the parsimonious TAM. Using empirical data and Structural Equation Modeling-Artificial Neural Networks approach together with multi group analysis, the effects of social influence, personal innovativeness in information technology, trust, perceived financial cost, perceived usefulness and perceived ease of use were examined. The significance of indirect effects was examined using the bias-corrected percentile with two-tailed significance through bootstrapping. Gender, age, experience and usage were introduced as the moderator variables with industry being the control variable in the research model. The scarcity in studies regarding the moderating effects of these variables warranted the needs to further investigate their impacts. The mediating effect of perceived usefulness was examined using the Baron–Kenny’s technique. The findings of this study have provided invaluable theoretical, methodological and managerial implications and will contribute to the decision making process by CEOs, managers, manufacturers and policy makers from the mobile manufacturing industry, businesses and financial institutions, mobile commerce, mobile telecommunication providers, mobile marketers, private or government practitioners and etc.     

The moderating role of subordinate political skill on supervisors' impressions of subordinate ingratiation and ratings of subordinate interpersonal facilitation.

Nearly 2 decades ago, social influence theorists called for a new stream of research that would investigate why and how influence tactics are effective. The present study proposed that political skill affects the style of execution of influence attempts. It utilized balance theory to explain the moderating effect of employee political skill on the relationships between self- and supervisor-reported ingratiation. Additionally, supervisor reports of subordinate ingratiation were hypothesized to be negatively related to supervisor ratings of subordinate interpersonal facilitation. Results from a combined sample of 2 retail service organizations provided evidence that subordinates with high political skill were less likely than those low in political skill to have their demonstrated ingratiation behavior perceived by targets as a manipulative influence attempt. Also, when subordinates were perceived by their supervisors to engage in more ingratiation behavior, the subordinates were rated lower on interpersonal facilitation. Implications of these findings, limitations, and future research directions are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

稳步发展的“下半球”数字印刷业

<正>2009年11月下旬,作为中国政府邀请的嘉宾,我参加了在北京召开的"第二届中国服务贸易大会"。这一国际盛会旨在促进中国与相关服务贸易国家和地区的进一步信息交流和接触。在会议期间,我有幸与中国印刷科学技术研究所的管理团队进行了交流,并受到来自他们的热情接待。     

Active Sites of a NiSO4/γ-Al2O3 Catalyst for the Oligomerization of Isobutene

Structural characterization, the mechanism of catalytic activity generation and the nature of active sites of a NiSO₄/γ-Al₂O₃ catalyst for isobutene oligomerization were studied by temperature programmed reduction (TPR), X-ray diffraction (XRD), diffuse reflectance infrared fourier transformed (DRIFTS) and X-ray photoelectron spectroscopy (XPS) techniques. The TPR measurements together with the XRD data indicated that calcination of the catalyst at 500 °C did not form either nickel oxide or nickel aluminate. The presence of only one type of surface nickel species formed by the incorporation of nickel ions into the surface vacant sites of γ-alumina lattice was indicated by XPS with Ar⁺ ions sputtering and TPR measurements. XPS analysis of the calcined catalyst suggested that the oxidation state of nickel ions in the calcined catalyst was (+2) and after calcination the nickel ions were coordinated to relatively more basic ligands. The surface acid centers of the catalyst were found to be only Lewis type. SO₄ ^2? ions were found to be present as a chelating bidentate ligand and enhanced the acidity of metal ( $ {\text{Al}}^{3 + } $ and/or $ {\text{Ni}}^{2 + } $ ) Lewis acid centers. The results suggested that the combined effects of the presence of the bidentate SO₄ ^2? ligand and dehydroxylation generate coordinatively unsaturated $ {\text{Ni}}^{2 + } $ that interact with isobutene during the oligomerization reaction. The formation of lower-valent nickel ions ( $ {\text{Ni}}^{x + } ,x\; \le\; 1 $ ) was demonstrated by in situ DRIFTS using CO as a probe molecule and by XPS measurements. Formation of a binuclear bridging carbonyl complex, $ [{\text{Ni}}({\text{CO}})^{ + } ]_{2} $ suggested that some lower-valent nickel species were formed via in situ reduction by isobutene. Analysis of Ni 2p photolines indicated the appearance of a new lower-valent nickel species ( $ {\text{Ni}}^{x + } ,x \;\le\; 1 $ ) during the course of isobutene oligomerization. Hence it is plausible that lower-valent nickel species might act as the active center for the oligomerization reaction, while the SO₄ ^2? ions enhance the acidity of the Lewis acid sites on the surface and assist in the adsorption of reactant molecules on the surface.     

Hydrogenation of a Tri-layer High Performance Elastomer: Substrate Synthesis,Catalytic Latex Hydrogenation,and Catalyst Recovery

A whole set of “green” nano-processes providing hydrogenated PMMA-PS-NBR tri-layer core–shell nanostructured high performance rubbers was developed in this research, which involved the synthesis of diene elastomers as the substrate, followed by the catalytic hydrogenation reaction, and finally catalyst recovery. This study may contribute to the development of hydrogenated high performance elastomers in latex form and recovery of catalyst from the polymer matrix.