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It is of extreme importance to engineer the structural characteristics of carbon dots (CDs) to satisfy their practical applications in imaging and medical treatments. Here, Cu,N-doped CDs ( Cu,N -CDs) are a new class of near-infrared-(NIR) light-induced therapeutic agents that were prepared by a one-step hydrothermal method using EDTA·2Na and CuCl 2 . Specifically, Cu ΙΙ was located in the inner of Cu,N -CDs via N-Cu-N complexation, endowing NIR absorption for the production of heat and reactive oxygen species. The relationships between the hydrothermal temperature, NIR absorption, and intrinsic biological activity of the Cu,N -CDs were examined. The hydrothermal temperature significantly affected the latter two when the Cu content in the Cu,N -CDs was changed. The Cu,N -CDs at 180 °C were examined for cancer phototherapeutics in vitro and in vivo . The Cu,N -CDs markedly inhibited cancer via synergistic photothermal/photodynamic therapies. In addition, the Cu,N -CDs could also act as one kind of fluorescence cell-imaging agent and IR thermal imaging agent to visualize the in vitro and in vivo treatment process, respectively. Thus, the present study provides a promising new method to prepare CDs with NIR absorption feature for multifunctional cancer theranostic applications. [ABSTRACT FROM AUTHOR]

Highlights • A two-bed VPSA process was developed for CH 4 /N 2 separation. • Effects of three kinds of disturbances on VPSA process performances were analyzed. • PID and MPC controller were designed for VPSA system with disturbances. • The performance of MPC controller was superior to PID controller. Abstract This work presents a detailed study for the systematic design and analysis of effective VPSA process control for the separation of methane–nitrogen mixture. A rigorous mathematic model of VPSA process was developed in prior to simulate the real VPSA process and to reflect its cyclic dynamic behaviours more exactly. Moreover, a powerful optimization of VPSA process for methane-nitrogen separation has been conducted to obtain a better base with superior performances for the exploration of design of VPSA controller. Subsequently, three kinds of disturbances scenarios have been introduced into VPSA system and the deterioration of process performances were significantly observed under open-loop operation. In order to get performance indicators back to the set point, PID and MPC controllers have been designed and tested. Results under close-loop operation demonstrated that the traditional PID controller can be used to regulate process performance but it would typically result in an over-saturation of target point with a slower response. In contrast, the MPC controller performed a more rapid and efficient response with less oscillatory behaviour in target tracking, which has indicated that it is more suitable for the regulation and control of VPSA process for methane–nitrogen separation. [ABSTRACT FROM AUTHOR]

The surface functionalization of carbon dots (CDs) can introduce an additional dimension for the control of their photoluminescence properties and effective promotion of the applications of CDs such as imaging, sensing, etc . In this study, a simple one-step carbonization using Tween 80 as the sole carbon source is described for directly synthesizing white-emitting CDs (WCDs) in high yield. The results revealed the presence of several long alkyl chains on the surface of the as-fabricated WCDs, which effectively suppress the aggregation-caused quenching (ACQ) effect and emit bright white luminescence under an UV illumination of 365 nm in the solution and solid states. Besides, together with the surface protection of long alkyl chains, WCDs preferentially interact with lipophilic fatty residues and are beneficial for the label-free imaging of latent fingerprints. This study provides a promising new method to not only effectively inhibit the intrinsic ACQ effect of CDs but also develop the surface engineering of functionalized white-emitting CDs for practical applications via facile synthesis. [ABSTRACT FROM AUTHOR]