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21.
This study reports a multifunctional electrode approach which directly implements electrokinetic enhancement on a self-assembled-monolayer-based electrochemical sensor for point-of-care diagnostics. Using urinary tract infections as a model system, we demonstrate that electrokinetic enhancement, which involves in situ stirring and heating, can enhance the sensitivity of the strain specific 16S rRNA hybridization assay for 1 order of magnitude and accelerate the time-limiting incubation step with a 6-fold reduction in the incubation time. Since the same electrode platform is used for both electrochemical signal enhancement and electrochemical sensing, the multifunctional electrode approach provides a highly effective strategy toward fully integrated lab-on-a-chip systems for various biomedical applications. 相似文献
22.
Kuo‐Hui Wu Yi‐Yin Kuo Chien‐An Chen Yi‐Ling Huang Han‐Mou Gau 《Advanced Synthesis \u0026amp; Catalysis》2013,355(5):1001-1008
Aryl addition reactions of ArTi(O‐i‐Pr)3 to aromatic, heteroaromatic, or α,β‐unsaturated ketones are described, producing tertiary alcohols in good to excellent enantioselectivities of up to 97% ee. The structure of the dititanium complex [(i‐PrO)2Ti{μ‐(S)‐BINOLate}(μ‐O‐i‐Pr)TiPh(O‐i‐Pr)2] [(S)‐ 4 ] that simultaneously bears a chiral directing ligand and a nucleophile is reported. Complex (S)‐ 4 possesses a pocket structure and has been illustrated as the key active species for addition reactions of both aldehydes and ketones. Mechanistic and stereochemical insights concerning addition reactions of organometallic reagents to organic carbonyls are rationalized based on the pocket structure and pocket size of (S)‐ 4 . 相似文献
23.
24.
In the course of a more general study on vertical pneumatic transport catalytic reactors we have been led to investigate more particularly the aerodynamics of concentrated gas-solid suspensions at low velocities. Here we describe the various flow regimes encountered under these conditions. The prediction of choking flowrates and concentrations can be made from a mathematical model based on a single stability criterium. This model is a good agreement with our experimental results and the data of other authors. 相似文献
25.
Steady state kinetics of the oxidation reaction have been determined with the help of a gradientless semi-differential, fixed-bed reactor. The Mars and van Krevelen phenomenological model satisfactorily correlates the experimental data but a modification of the Langmuir-Hinshelwood model taking into account partial coverage of the catalyst surface with reaction intermediates is preferred. Transient kinetics have been studied with a new automated periodic-pulse reactor, directly connected to a gas chromatograph. The response of a catalyst (essentially V2O5–MoO3) to reduction and oxidation has been investigated. The rate of bulk (lattice) oxygen utilization as well as the degree of carbon coverage are estimated by this technique. Selectivity is dependent on the oxidation state of the catalyst: high partial pressure of either benzene or oxyen and high temperatures are detrimental to selectivity. 相似文献
26.
Three series of self‐synthesized poly(vinyl acetate)‐based low‐profile additives (LPAs) with different chemical structures and molecular weights, including poly(vinyl acetate), poly(vinyl chloride‐co‐vinyl acetate), and poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride), were studied. Their effects on the volume shrinkage characteristics and internal pigmentability for low‐shrink unsaturated polyester (UP) resins during cure were investigated. The experimental results were examined with an integrated approach involving measurements of the static phase characteristics of the ternary styrene/UP/LPA system, the reaction kinetics, the cured sample morphology, and microvoid formation by using differential scanning calorimetry, scanning electron microscopy, optical microscopy, and image analysis. Based on the Takayanagi mechanical model, factors leading to both good volume shrinkage control and acceptable internal pigmentability for the molded parts were explored. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3336–3346, 2003 相似文献
27.
Jenn-Terng Gau Adam D. Dye Yashwanth Gaddam Chet Arciuch 《The International Journal of Advanced Manufacturing Technology》2007,35(5-6):423-433
In this study, FEA simulations were conducted to analyze the forming and springback of a split dowel forming process. Through
96 simulations, the best dimensional quality product from the current production tooling was obtained. However, it still cannot
meet the customer’s geometrical requirement, so a metal finish process (secondary operation) is required. In order to minimize
manufacturing cost and time, the secondary operation is not desired. Therefore, a new forming process and die design were
developed through many iterative FEA simulations. This new design adds a short coin bead on the seam line area of the split
dowel. It has been found that the springback amount is almost eliminated and the product quality exceeds the customer’s geometry
requirement. Through this real industry case study, it is shown that FEA simulation can be used to not only optimize the current
process but also design a new process and tooling. 相似文献
28.
Michael Nemec Christian Behm Vera Maierhofer Jonas Gau Anastasiya Kolba Erwin Jonke Xiaohui Rausch-Fan Oleh Andrukhov 《International journal of molecular sciences》2022,23(17)
Nano- and microparticles are currently being discussed as potential risk factors for peri-implant disease. In the present study, we compared the responses of human gingival mesenchymal stromal cells (hG-MSCs) on titanium and zirconia nanoparticles (<100 nm) in the absence and presence of Porphyromonas gingivalis lipopolysaccharide (LPS). The primary hG-MSCs were treated with titanium and zirconia nanoparticles in concentrations up to 2.000 µg/mL for 24 h, 72 h, and 168 h. Additionally, the cells were treated with different nanoparticles (25–100 µg/mL) in the presence of P. gingivalis LPS for 24 h. The cell proliferation and viability assay and live–dead and focal adhesion stainings were performed, and the expression levels of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1 were measured. The cell proliferation and viability were inhibited by the titanium (>1000 µg/mL) but not the zirconia nanoparticles, which was accompanied by enhanced apoptosis. Both types of nanoparticles (>25 µg/mL) induced the significant expression of IL-8 in gingival MSCs, and a slightly higher effect was observed for titanium nanoparticles. Both nanoparticles substantially enhanced the P. gingivalis LPS-induced IL-8 production; a higher effect was observed for zirconia nanoparticles. The production of inflammatory mediators by hG-MSCs is affected by the nanoparticles. This effect depends on the nanoparticle material and the presence of inflammatory stimuli. 相似文献
29.
Rung-Hung Gau 《Communications Letters, IEEE》2008,12(2):140-142
In this paper, we propose an analytical approach for evaluating the performance of finite-user slotted Aloha in wireless networks with multiple packet reception and random traffic. We derive the exact values of the throughput, the average system size, the packet blocking probability, and the average system delay. Our analysis is based on probability theory. We show that our numerical results are identical to simulation results. 相似文献
30.
Experiments have been performed to study and obtain the adiabatic-wall film cooling effectiveness and the heat transfer over a film-cooled surface that is made inclined at various angles with respect to a highly turbulent flow. The film-cooled air is injected from a tangential slot. The normal temperature distributions were measured to infer the flow structure and the rate of mixing of film jet with the freestream. The freestream turbulence intensity is controlled to range from 1.0% to 26.4%, the inclination or the convergent angle of the film-cooled surface ranges from 0° to 20°, the blowing parameter from 0.5 to 2.0. It is found that the mixing of the film jet with the freestream is significantly enhanced by both the freestream turbulence intensity and the convergent angle of the film-cooled surface, which leads to the decrease in the film cooling effectiveness and the increase in the heat transfer when the inclination angle of the film-cooled surface is not large. This is attributed to the two competition mechanisms of impinging effect and the stabilization due to acceleration of the mainstream. The normal temperature distribution at several locations along the flow direction is also measured and used to infer the flow structure of the mixing of film jet with the mainstream. More detailed discussion is presented. Correlations for both the film cooling effectiveness and the heat transfer under the film-cooled surface have been very successful and are provided. 相似文献