Biofunctionalized quantum dots (QDs), especially protein-coated QDs, are known to be useful targeted fluorescent labels for cellular and deep-tissue imaging. These nanoparticles can also serve as efficient energy dono...
Biofunctionalized quantum dots (QDs), especially protein-coated QDs, are known to be useful targeted fluorescent labels for cellular and deep-tissue imaging. These nanoparticles can also serve as efficient energy donors in fluorescence resonance energy transfer (FRET) binding assays for the multiplexed sensing of tumor markers. However, current preparation processes for protein-functionalized QDs are laborious and require multiple synthesis steps (e.g. preparing them in high temperature, making them dispersible in water, and functionalizing them with surface ligands) to obtain a high quality and quantity of QD formulations, significantly impeding the progress of employing QDs for clinical diagnostics use such as a QD-based immunohistofluorescence assay. Herein, we demonstrate a one-step synthesis approach for preparing protein-functionalized QDs using a microfluidic (MF) chip setup. Using bovine serum albumin (BSA) molecules as the surface ligand model, we first studied and optimized the MF reaction synthesis parameters (e.g. reaction temperature, and channel width and length) for making protein-functionalized QDs using COMSOL simulation modeling, followed by experimental verification. Moreover, in comparison with the BSA-functionalized QDs synthesized using the conventional bench-top method, BSA-QDs prepared using the MF approach exhibit a significantly higher protein-functionalization efficiency, photostability and colloidal stability. The proposed one-step MF synthesis approach provides a rapid, cost effective, and a small-scale production of nanocrystals platform for developing new QD formulations in applications ranging from cell labeling to biomolecular sensing. Most importantly, this approach will considerably reduce the amount of chemical waste generated during the trial-and-error stage of developing and perfecting the desired physical and optical properties of new QD materials.
Several dibenzocyclooctatetraene derivatives (5-7) and related biphenyls (8-11) were designed, synthesized, and evaluated for inhibition of cancer cell growth and the NF-kappa B signaling pathway. Compound 5a, a diben...
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Several dibenzocyclooctatetraene derivatives (5-7) and related biphenyls (8-11) were designed, synthesized, and evaluated for inhibition of cancer cell growth and the NF-kappa B signaling pathway. Compound 5a, a dibenzocyclooctatetraene succinimide, was discovered as a potent inhibitor of the NF-kappa B signaling pathway with significant antitumor activity against several human tumor cell lines (GI(50) 1.38-1.45 mu M) and was more potent than paclitaxel against the drug-resistant KBvin cell line. Compound 5a also inhibited LPS-induced NF-kappa B activation in RAW264.7 cells with an IC50 value of 0.52 mu M, prevented I kappa B-alpha degradation and p65 nuclear translocation, and suppressed LPS-induced NO production in a dose-dependent manner. The antitumor data in cellular assays indicated that relative positions and types of substituents on the dibenzocyclooctatetraene or acyclic biphenyl as well as torsional angles between the two phenyls are of primary importance to antitumor activity. (C) 2013 Elsevier Ltd. All rights reserved.
In allusion to the problem of data sampling interpolation error which exists in continuous micro-line segments interpolation algorithm with acceleration /deceleration control, this paper proposes a high-precision posi...
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This paper proposes an improved adaptive NURBS curve interpolation scheme, which keeps a constant feedrate most of the time and adaptively changes feedrate with consideration of machine dynamics. It reserves the advan...
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ISBN:
(纸本)9780878492220
This paper proposes an improved adaptive NURBS curve interpolation scheme, which keeps a constant feedrate most of the time and adaptively changes feedrate with consideration of machine dynamics. It reserves the advantages of adaptive planning, which has a shorter machining time and a better machining performance, and removes abrupt feedrate changes at the beginning and end of sensitive corner. Furthermore, this method reuses the previous interpolation values during look-ahead planning rather than discard them.
In this paper, the jerk-limited feedrate planning is used to adaptively change feedrate with consideration of machine dynamics in the sensitive corners. The curvature is introduced to detect sensitive corner by the lo...
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ISBN:
(纸本)9783037850312
In this paper, the jerk-limited feedrate planning is used to adaptively change feedrate with consideration of machine dynamics in the sensitive corners. The curvature is introduced to detect sensitive corner by the look-ahead module to avoid the situation that the curvature is zero. The parameters of every deceleration stages are solved with a series of formula first, and then the feedrate profile is discretized with consideration of the deceleration time, which must be an integer multiple of the interpolation sample time. In addition, the deceleration start point estimation method is described in detail, and a number of deceleration terminal speeds are added into the discrete feedrate profile to drive the machine tool to the right position.
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