Dendritic polyurethane-based prodrug as unimolecular micelles for precise ultrasound-activated localized drug delivery

Ultrasound has been recognized as an exciting tool to enhance the therapeutic efficacy in tumor chemotherapy owing to the triggered drug release, facilitated intracellular drug delivery, and improved spatial precision. Aiming for a precise localized drug delivery, novel dendritic polyurethane-based prodrug (DOX-DPU-PEG) was fabricated with a drug content of 18.9% here by conjugating DOX onto the end groups of the functionalized dendritic polyurethane via acid-labile imine bonds. It could easily form unimolecular micelles around 38 nm. Compared with the non-covalently drug-loaded unimolecular micelles (DOX@Ph-DPU-PEG), they showed excellent pH/ultrasound dual-triggered drug release performance, with drug leakage of only 4% at pH 7.4, but cumulative release of 14% and 88% at pH 5.0 without and with ultrasound, respectively. The ultrasound responsiveness was attributed to the unique strawberry-shaped topological structure of the DOX-DPU-PEG, in which DOX was embedded in the skin layer of the hydrophobic DPU cores. With ultrasound, the DOX-DPU-PEG unimolecular micelles possessed enhanced tumor growth inhibition than free DOX but showed no obvious cytotoxicity on the tumor cells without ultrasound. Such feature makes them promising potential for precise localized drug delivery.     

High-performance nonfused ring electron acceptor with a steric hindrance induced planar molecular backbone

Three nonfused ring electron acceptors (NFREAs) TTC6,TT-C8T and TT-TC8 were purposefully designed and synthesized.The molecular geometry can be adjusted by the steric hindrance of lateral substituents.According to the DFT calculations,from TTC6 to TT-C8T and TT-TC8,planarity of the molecular backbone is gradually improved,accompanying with the enhancing of intramolecular charge transfer effect.As for TT-TC8,the two phenyl substituents are almost perpendicular to the molecular backbone,which endues the acceptor with good solubility and suppresses it to form over-aggregation.Multidirectional regular molecular orientation and closer molecular stacking are formed in TT-TC8 film.As a result,TT-TC8 based devices afford the highest PCE of 13.13%,which is much higher than that of TTC6 (4.41%) and TT-C8T (10.42%) and among the highest PCE values based on NFREAs.     

基于电化学老化衰退模型的锂离子动力电池外特性

当前锂离子动力电池电化学模型存在模型复杂、建模难度大、计算效率低、老化评估效果差的问题,本文提出一种考虑电池衰退老化的机理模型(ADME).本文首先通过有限差分法对伪二维(P2D)电化学模型进行离散降阶处理,得到简化伪二维(SP2D)模型.在SP2D模型的基础上,基于阴阳两极发生的副反应导致的衰退老化现象,提出一种考虑电池衰退老化的机理模型.其次,使用多变量偏差补偿最小二乘法实现模型参数辨识.最后通过动力电池衰退老化性能循环实验,对比分析了恒流、脉冲工况下SP2D模型和ADME模型的终端电压输出.结果表明:ADME模型较为简单、计算效率和估算精度高,可以有效评估电池容量老化衰退,得到理想的锂离子动力电池外特性曲线.     

Enhanced thermoelectric performance of PEDOT:PSS films via ionic liquid post-treatment

Thermoelectric(TE)energy harvesting can effectively convert waste heat into electricity,which is a crucial technology to solve energy concerns.As a promising candidate for energy conversion,poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)has gained significant attention owing to its easy doping,high transparency,and solution processability.However,the TE performance of PEDOT:PSS still needs to be further enhanced.Herein,different approaches have been applied for tuning the TE properties:(i)direct dipping PEDOT:PSS thin films in ionic liquid;(ii)post-treatment of the films with concentrated sulfuric acid(H₂SO₄),and then dipping in ionic liquid.Besides,the same bis(trifluoromethanesulfonyl)amide(TFSI)anion and different cation salts,including 1-ethyl-3-methylimidazolium(EMIM+)and lithium(Li+),are selected to study the influence of varying cation types on the TE properties of PEDOT:PSS.The Seebeck coefficient and electrical conductivity of the PEDOT:PSS film treated with H2SO4EMIM:TFSI increase simultaneously,and the resulting maximum power factor is 46.7μW·m^-1·K^-2,which may be attributed to the ionic liquid facilitating the rearrangement of the molecular chain of PEDOT.The work provides a reference for the development of organic films with high TE properties.     

General Decay for a Thermoelastic Problem of a Microbeam with Gurtin-Pipkin Thermal Law

In this paper, we study the well-posedness and the asymptotic stability of a one-dimensional thermoelastic microbeam system, where the heat conduction is given by Gurtin-Pipkin thermal law. We first establish the well-posedness of the system by using the semigroup arguments and Lumer-Phillips theorem. We then obtain an explicit and general formula for the energy decay rates through perturbed energy method and some properties of the convex functions.     

Output feedback regulation of large-scale feedforward systems with discrete and distributed delays

Nonlinear Dynamics - This paper proposes an output feedback control strategy to achieve the global regulation of a class of large-scale feedforward nonlinear systems with discrete and distributed...     

Convergence of the viscosity solution of non-autonomous Hamilton-Jacobi equations

In this paper,we investigate the non-autonomous Hamilton-Jacobi equation ■ where H is 1-periodic with respect to t and M is a compact Riemannian manifold without boundary.We obtain the viscosity solution denoted by T_(t_0)~tφ(x) and show T_(t_0)~tφ(x) converges uniformly to a time-periodic viscosity solution u~*(x,t) of ?_tu+H(t,x,?_xu,u)=0.     

The Preparation of Cu(II)- and Ag(I)-responsive Carbon Nanodots from the Right Amino-acid Carbon Source

Journal of Fluorescence - Carbon nanodots (CDs) have exhibited excellent sensing capability for various metal ions. However, it is difficult to determine the selectivity of CDs to metal ions. In...