HepG2 Cell Resistance against Camptothecin from a Lysosomal Drug Delivery

A galactose‐appended drug delivery system released camptothecin (CPT) to lysosomes of HepG2 hepatoma cells, resulting in the cell resistance to the anticancer drug. We found that the resistance to CPT is caused by alteration of the drug release from the prodrug in lysosomes, emphasizing that the final delivery locations may critically influence drug efficacy.     

Kinetically Controlled Layer-by-Layer Stacking of Metal Oxide 2D Nanosheets

An efficient chemical way to finely control the layer-by-layer stacking of inorganic nanosheets (NS) is developed by tuning the type and composition of intercalant ion, and the reaction temperature for restacking process. The finely controlled stacking of NS relies on a kinetic control of the self-assembly of NS in the presence of coordinating organic cations. A critical role of organic cations in this assembly highlights the importance of the appropriate activation energy. Of prime importance is that a fine-control of the interstratification of 2D NS is highly effective not only in tailoring its pore structure but also in enhancing its electrode activity. The present study clearly demonstrates that the kinetically controlled restacking of NS provides a facile and powerful method to tailor their stacking number and functionality.     

基于权重比的民航飞行员安全行为指标权重算法

确定飞行员安全行为指标的权重,对发现民航飞行员飞行安全风险的短板,提高民航飞行安全性具有重要意义.基于指标权重比,提出了一种飞行员安全行为指标权重算法.并以此算法分析了职业安全意识、飞行情景意识、特情应变能力以及机组资源管理能力等指标对飞行员安全行为的影响程度,研究可为飞行员安全行为风险管理提供依据,对安全飞行具有积极的指导意义.     

Solving the robust two-stage capacitated facility location problem with uncertain transportation costs

In this study, we start from a multi-source variant of the two-stage capacitated facility location problem (TSCFLP) and propose a robust optimization model of the problem that involves the uncertainty of transportation costs. Since large dimensions of the robust TSCFLP could not be solved to optimality, we design a memetic algorithm (MA), which represents a combination of an evolutionary algorithm (EA) and a modified simulated annealing heuristic (SA) that uses a short-term memory of undesirable moves from previous iterations. A set of computational experiments is conducted to examine the impact of different protection levels on the deviation of the objective function value. We also investigate the impact of variations of transportation costs that may occur on both transhipment stages on the total cost for a fixed protection level. The obtained results may help in identifying a sustainable and efficient strategy for designing a two stage capacitated transportation network with uncertain transportation costs, and may be applicable in the design and management of similar transportation networks.     

In Situ Polymerized 1,3-Dioxolane Electrolyte for Integrated Solid-State Lithium Batteries

Solid-state lithium batteries are promising and safe energy storage devices for mobile electronics and electric vehicles. In this work, we report a facile in situ polymerization of 1,3-dioxolane electrolytes to fabricate integrated solid-state lithium batteries. The in situ polymerization and formation of solid-state dioxolane electrolytes on interconnected carbon nanotubes (CNTs) and active materials is the key to realizing a high-performance battery with excellent interfacial contact among CNTs, active materials and electrolytes. Therefore, the electrodes could be tightly integrated into batteries through the CNTs and electrolyte. Electrons/ions enable full access to active materials in the whole electrode. Electrodes with a low resistance of 4.5 Ω □⁻¹ and high lithium-ion diffusion efficiency of 2.5×10⁻¹¹ cm² s⁻¹ can significantly improve the electrochemical kinetics. Subsequently, the batteries demonstrated high energy density, amazing charge/discharge rate and long cycle life.     

Oxidation-Reduction Molecular Junction Covalent Organic Frameworks for Full Reaction Photosynthesis of H2O2

The full reaction photosynthesis of H₂O₂ that can combine water-oxidation and oxygen-reduction without sacrificial agents is highly demanded to maximize the light-utilization and overcome the complex reaction-process of anthraquinone-oxidation. Here, a kind of oxidation-reduction molecular junction covalent-organic-framework (TTF-BT-COF) has been synthesized through the covalent-coupling of tetrathiafulvalene (photo-oxidation site) and benzothiazole (photo-reduction site), which presents visible-light-adsorption region, effective electron-hole separation-efficiency and photo-redox sites that enables full reaction generation of H₂O₂. Specifically, a record-high yield (TTF-BT-COF, ≈276 000 μM h⁻¹ g⁻¹) for H₂O₂ photosynthesis without sacrificial agents has been achieved among porous crystalline photocatalysts. This is the first work that can design oxidation-reduction molecular junction COFs for full reaction photosynthesis of H₂O₂, which might extend the scope of COFs in H₂O₂ production.     

Solvent-Free Heterogeneous Catalytic Hydrogenation of Polyesters to Diols

The utilization of carbon resources stored in plastic polymers through chemical recycling and upcycling is a promising approach for mitigating plastic waste. However, most current methods for upcycling suffer from limited selectivity towards a specific valuable product, particularly when attempting full conversion of the plastic. We present a highly selective reaction route for transforming polylactic acid (PLA) into 1,2-propanediol utilizing a Zn-modified Cu catalyst. This reaction exhibits excellent reactivity (0.65 g g_cat⁻¹ h⁻¹) and selectivity (99.5 %) towards 1,2-propanediol, and most importantly, can be performed in a solvent-free mode. Significantly, the overall solvent-free reaction is an atom-economical reaction with all the atoms in reactants (PLA and H₂) fixed into the final product (1,2-propanediol), eliminating the need for a separation process. This method provides an innovative and economically viable solution for upgrading polyesters to produce high-purity products under mild conditions with optimal atom utilization.     

Dual Photosensitizer Coupled Three-Dimensional Metal-Covalent Organic Frameworks for Efficient Photocatalytic Reactions

In this work, we innovatively assembled two types of traditional photosensitizers, that is pyridine ruthenium/ferrum (Ru(bpy)₃²⁺/Fe(bpy)₃²⁺) and porphyrin/metalloporphyrin complex (2HPor/ZnPor) by covalent linkage to get a series of dual photosensitizer-based three-dimensional metal-covalent organic frameworks (3D MCOFs), which behaved strong visible light-absorbing ability, efficient electron transfer and suitable band gap for highly efficient photocatalytic hydrogen (H₂) evolution. Rubpy-ZnPor COF achieved the highest H₂ yield (30 338 μmol g⁻¹ h⁻¹) with apparent quantum efficiency (AQE) of 9.68 %@420 nm, which showed one of the best performances among all reported COF based photocatalysts. Furthermore, the in situ produced H₂ was successfully tandem used in the alkyne hydrogenation with ≈99.9 % conversion efficiency. Theoretical calculations reveal that both the two photosensitizer units in MCOFs can be photoexcited and thus contribute optimal photocatalytic activity. This work develops a general strategy and shows the great potential of using multiple photosensitive materials in the field of photocatalysis.     

Acidic Media Impedes Tandem Catalysis Reaction Pathways in Electrochemical CO2 Reduction

Electrochemical CO₂ reduction (CO₂R) in acidic media with Cu-based catalysts tends to suffer from lowered selectivity towards multicarbon products. This could in principle be mitigated using tandem catalysis, whereby the *CO coverage on Cu is increased by introducing a CO generating catalyst (e.g. Ag) in close proximity. Although this has seen significant success in neutral/alkaline media, here we report that such a strategy becomes impeded in acidic electrolyte. This was investigated through the co-reduction of ¹³CO₂/¹²CO mixtures using a series of Cu and CuAg catalysts. These experiments provide strong evidence for the occurrence of tandem catalysis in neutral media and its curtailment under acidic conditions. Density functional theory simulations suggest that the presence of H₃O⁺ weakens the *CO binding energy of Cu, preventing effective utilization of tandem-supplied CO. Our findings also provide other unanticipated insights into the tandem catalysis reaction pathway and important design considerations for effective CO₂R in acidic media.