Abstract
Colloidal quantum dots have been emerging as promising photocatalysts to convert CO
2
into fuels by using solar energy. However, the above photocatalysts usually suffer from low CO
2
...adsorption capacity because of their nonporous structures, which principally reduces their catalytic efficiency. Here, we show that synchronizing imine polycondensation reaction to self-assembly of colloidal CdSe/CdS nanorods can produce micro-meso hierarchically porous nanocomposites with double-shelled nanocomposites. Owing to their hierarchical pores and the ability to separate photoexcited electrons, the self-assembled porous nanocomposites exhibit remarkably higher activity (≈ 64.6 μmol g
−1
h
−1
) toward CO
2
to CO in solid-gas regime than that of nonporous solids from self-assembled CdSe/CdS nanorods under identical conditions. Importantly, the length of the nanorods is demonstrated to be crucial to correlate their ability to long-distance separation of photogenerated electrons and holes along their axial direction. Overall, this approach provides a rational strategy to optimize the CO
2
adsorption and conversion by integrating the inorganic and organic semiconductors.
Abstract
The development of mechanochemistry substantially expands the traditional synthetic realm at the molecular level. Here, we extend the concept of mechanochemistry from atomic/molecular solids ...to the nanoparticle solids, and show how the macroscopic grinding is being capable of generating chirality in self-assembled nanorod (NR) assemblies. Specifically, the weak van der Waals interaction is dominated in self-assembled NR assemblies when their surface is coated with aliphatic chains, which can be overwhelmed by a press-and-rotate mechanic force macroscopically. The chiral sign of the NR assemblies can be well-controlled by the rotating directions, where the clockwise and counter-clockwise rotation leads to the positive and negative Cotton effect in circular dichroism and circularly polarized luminescence spectra, respectively. Importantly, we show that the present approach can be applied to NRs of diverse inorganic materials, including CdSe, CdSe/CdS, and TiO
2
. Equally important, the as-prepared chiral NR assemblies could be served as porous yet robust chiral substrates, which enable to host other molecular materials and induce the chirality transfer from substrate to the molecular system.
Brain metastases are a most disturbing situation for breast cancer patients as there is basically no adequate treatment available. Any potential drug formulation has to be able to cross the ...blood-brain barrier (BBB) and specific to metastatic brain tumors without causing unacceptable adverse effects. Here, we developed transferrin-functionalized chimeric polymersomes carrying siRNA against polo-like kinase 1 (Tf@TBP-CPs-siPLK1) for treating brain metastatic MDA-MB 231 triple negative breast cancer (TNBC) xenografts in mice. To facilitate the loading of siPLK1, chimaeric polymersomes (CPs) were designed with spermine in the watery core and transferrin-binding peptide (TBP) at the surface, enabling attachment of transferrin after the siRNA loading step and thereby circumventing interference of transferrin with siRNA loading. Tf@TBP-CPs-siPLK1 encapsulating 3.8 wt% siRNA had a mean size of about 50 nm and a neutral zeta potential in phosphate buffer (PB). By virtue of the presence of transferrin, Tf@TBP-CPs demonstrated greatly (ca. 5-fold) enhanced internalization in MDA-MB 231 cells and transcytosis in the endothelial (bEnd.3) monolayer model in vitro as well as markedly improved accumulation in the orthotopically xenografted MDA-MB 231 tumor in the brain in vivo compared with control CPs lacking transferrin, supporting that transferrin mediates efficient BBB penetration and high specificity towards MDA-MB 231 cells. As a result, Tf@TBP-CPs-siPLK1 effectively inhibited tumor progression and prolonged the lifespan of the mice significantly. Selective transferrin coating appears to be a particularly facile strategy to fabricate BBB-permeable and targeted vesicles for potent RNAi therapy of brain metastatic breast cancer.
Transferrin-binding peptide (TBP)-functionliazed chimaeric polymersomes (TBP-CPs) enable robust loading of PLK1 siRNA into its watery core and specific surface coating with transferrin, leading to effcient BBB transcytosis and targeted RNAi therapy for intracranial MDA-MB 231 breast tumors. Display omitted
•Selective transferrin coating offers a new strategy to fabricate targeted vesicles for siRNA delivery.•Transferrin-coated polymersomal siPLK1 (Tf@TBP-CPs-siPLK1) boosts BBB transcytosis and breast tumor uptake.•Tf@TBP-CPs-siPLK1 effectively retards brain metastatic MDA-MB 231 breast tumor with little toxicity.•Tf@TBP-CPs-siPLK1 induces significant survival benefits in brain metastatic breast tumor-bearing mice.
Although a great achievement has been made in the field of electrochemistry, the exploration of high-efficiency catalysts for the generation of hydrogen and oxygen via overall water splitting is ...still a grand challenge. We herein report the successful construction of a new class of hierarchical catalysts with defect-enriched nickel-molybdenum phosphide nanosheets anchored on the surface of carbon nanotubes for efficient water splitting. Via the construction of a hierarchical nanostructure, more efficient electron mobility and mass transfer occurrence were achieved, resulting in a substantial enhancement of electrocatalytic performances. Interestingly, overpotentials of only 255 and 135 mV are required for the optimized Ni1Mo1P NSs@MCNTs to afford a current of 10 mA cm–2 for oxygen evolution reaction and hydrogen evolution reaction, respectively. More significantly, the introduction of molybdenum and phosphorus is also significant for exposing surface active sites and modifying the bonding energy between hydrogen and metals; all of these advantages have endowed the Ni1Mo1P NSs@MCNTs//Ni1Mo1P NSs@MCNTs couple to display highly efficient water electrocatalysis property with a relatively low overall potential of 1.601 V at 10 mA cm–2, shedding bright light for large-scale overall water electrocatalysis.
•Feasibility and potential of PSB wastewater treatment was evaluated.•Important influencing factors in wastewater treatment process were summarized.•PSB membrane bioreactor is the most effective ...means of biomass recovery.
A paradigm shift is underway in wastewater treatment from pollution removal to resource or energy recovery. However, conventional activated sludge (CAS) as the core technology of wastewater treatment is confronted with severe challenges on high energy consumption, sludge disposal and inevitable greenhouse gas emission, which are posing a serious impact on the current wastewater industry. It is urgent to find new alternative methods to remedy these defects.
Photosynthetic bacteria (PSB) have flexible metabolic modes and high tolerance, which enhance the removal of nutrients, heavy metals and organic contaminants efficiency in different wastewater. The unique phototrophic growth of PSB breaks the restriction of nutrient metabolism in the CAS system. Recent studies have shown that PSB-based technologies can not only achieve the recovery of nutrient and energy, but also improve the degradation efficiency of refractory substances. If the application parameters can be determined, there will be great prospects and economic effects. This review summarizes the research breakthroughs and application promotion of PSB-based wastewater treatment technology in recent years. Comparing discussed the superiority and inferiority from the perspective of application range, performance differences and recovery possibility. Pathways involved in the nutrient substance and the corresponding influencing parameters are also described in detail. The mode of PSB biodegradation processes presented a promising alternative for new wastewater treatment scheme. In the future, more mechanical and model studies, deterministic operating parameters, revolutionary process design is need for large-scale industrial promotion of PSB-based wastewater treatment.
In the face of smart and varied jamming, intelligent radar anti-jamming technologies are urgently needed. Due to the variety of radar electronic counter-countermeasures (ECCMs), it is necessary to ...efficiently optimize ECCMs in the high-dimensional knowledge base to ensure that the radar achieves the optimal anti-jamming effect. Therefore, an intelligent radar anti-jamming decision-making method based on the deep deterministic policy gradient (DDPG) and the multi-agent deep deterministic policy gradient (MADDPG) (DDPG-MADDPG) algorithm is proposed. Firstly, by establishing a typical working scenario of radar and jamming, we designed the intelligent radar anti-jamming decision-making model, and the anti-jamming decision-making process was formulated. Then, aiming at different jamming modes, we designed the anti-jamming improvement factor and the correlation matrix of jamming and ECCM. They were used to evaluate the jamming suppression performance of ECCMs and to provide feedback for the decision-making algorithm. The decision-making constraints and four different decision-making objectives were designed to verify the performance of the decision-making algorithm. Finally, we designed a DDPG-MADDPG algorithm to generate the anti-jamming strategy. The simulation results showed that the proposed method has excellent robustness and generalization performance. At the same time, it has a shorter convergence time and higher anti-jamming decision making accuracy.
Nanoscale curvature‐dependent interactions are of paramount importance in biological systems. Here, we report that nanoscale curvature plays an important role in regulating the chirality of ...self‐assembled nanocomposites from chiral organic molecules and achiral nanoparticles. Specifically, we show that the supramolecular chirality of the nanocomposites markedly depends on the nanoparticle curvature, where small‐sized nanoparticles of high curvature and large‐sized nanoparticles of low curvature lead to nanocomposites with opposite chirality. Quantitative kinetic experiments and molecular dynamics simulations reveal that nanoparticle curvature plays a key role in promoting the pre‐nucleation oligomerization of chiral molecules, which consequently regulates the supramolecular chirality of the nanocomposites. We anticipate that this study will aid in rational design of an artificial cooperative system giving rise to emergent assembling phenomena that can be surprisingly rich and often cannot be understood by studying the conventional noncooperative systems.
An active role of achiral nanoparticles in regulating supramolecular chirality of the nanocomposites is reported. Nanoparticle‐curvature‐dependent supramolecular chirality in nanotubular composites was discovered, where small‐sized nanoparticles of high curvature and large‐sized nanoparticles of low curvature lead to nanotubular composites with opposite chirality.
The surface chemistry in colloidal nanocrystals on the final crystalline structure of binary superlattices produced by self-assembly of two sets of nanocrystals is hereby demonstrated. By mixing ...nanocrystals having two different sizes and the same coating agent, oleylamine (OAM), the binary nanocrystal superlattices that are produced, such as NaCl, AlB2, NaZn13, and MgZn2, are well in agreement with the crystalline structures predicted by the hard-sphere model, their formation being purely driven by entropic forces. By opposition, when large and small nanocrystals are coated with two different ligands OAM and dodecanethiol (DDT), respectively while keeping all other experimental conditions unchanged, the final binary structures markedly change and various structures with lower packing densities, such as Cu3Au, CaB6, and quasicrystals, are observed. This effect of the nanocrystals’ coating agents could also be extended to other binary systems, such as Ag–Au and CoFe2O4–Ag supracrystalline binary lattices. In order to understand this effect, a mechanism based on ligand exchange process is proposed. Ligand exchange mechanism is believed to affect the thermodynamics in the formation of binary systems composed of two sets of nanocrystals with different sizes and bearing two different coating agents. Hence, the formation of binary superlattices with lower packing densities may be favored kinetically because the required energetic penalty is smaller than that of a denser structure.
Despite business model innovation being the object of much interest, limited attention has paid on how and when knowledge management capabilities enhance business model innovation in the literature. ...Build upon institutional theory and knowledge-based view, we seek to investigate how knowledge management capabilities affect the business model innovation by exploring the dual role of different types of legitimation motivations in triggering knowledge management capabilities, and moderating the relationship between knowledge management capabilities, and business model innovation. The data collected from the 236 Chinese new ventures running their businesses across a variety of sectors. The results indicate the both political and market legitimation motivation positively affect knowledge management capabilities. The relationship between knowledge management capabilities and business model innovation are more strongly in high motivation to achieve market legitimacy. However, the positive effect of knowledge management capabilities stimulate business model innovation is more strongly in moderately motivation to achieve political legitimacy than in low or highly political legitimation motivation. The paper has significantly contributed to advancing the body of knowledge of institutional and business model innovation theory and providing deeper insights on the correlation between firm's motivation to achieve legitimacy and knowledge management capabilities for business model innovations.
This study aimed to investigate the effect of bone marrow-derived mesenchymal stem cells (BMSCs) on silica-induced lung fibrosis in a rat model. Thirty SD rats were randomly divided into three ...groups: control group, silica group, and BMSC group (n = 10 rats per group). BMSCs were injected successively into rats on the 14th, 28th, and 42nd days after silica exposure. All rats were sacrificed 56 days after silica exposure. We detected the pathological and fibrotic changes, apoptosis, autophagy, and pyroptosis in their lung tissue by histopathological examination, hydroxyproline content assays, real-time quantitative polymerase chain reactions, western blot assays, immunohistochemistry staining, immunofluorescence staining, and enzyme-linked immunosorbent assays. We found that BMSCs significantly relieved lung inflammatory infiltrates, collagen deposition, hydroxyproline content, and the mRNA and protein levels of collagen 1 and fibronectin. Compared to the silica group, in the BMSC group, apoptosis-associated proteins, including cleaved caspase 3 and Bax, were significantly downregulated, and Bcl-2/Bax was significantly upregulated; pyroptosis-related proteins, including Nlrp3, cleaved caspase 1, IL-1β, and IL-18, were significantly reduced. However, the BMSCs had no significant impact on autophagy-related proteins, including Beclin 1, P62, and LC3. In summary, BMSCs protected lung tissue against severe fibrosis by inhibiting apoptosis and pyroptosis but not autophagy.
•Bone marrow-derived mesenchymal stem cells (BMSCs) relieve pulmonary fibrosis induced by silica.•BMSCs transplantation suppresses apoptosis in a rat pulmonary fibrosis model.•BMSCs cannot rescue autophagy activation in silica-induced pulmonary fibrosis.•BMSCs attenuate pyroptosis in silica-induced pulmonary fibrosis.
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