Red-Light-Responsive Supramolecular Valves for Photocontrolled Drug Release from Mesoporous Nanoparticles

Red-light-responsive supramolecular valves constructed by tetra-<i>ortho</i>-methoxy-substituted azobenzene (mAzo) and β-cyclodextrin (β-CD) were used to control drug release from mesoporous silica nanoparticles (MSNs). Doxorubicin (DOX) was used as a model drug and loaded into nanopores of mAzo modified MSNs. β-CD formed supramolecular valves with mAzo by host–guest interaction and closed the nanopores. Red light was able to open the supramolecular valves and induce DOX release even in deep tissue

Visible-Light-Responsive Azopolymers with Inhibited π–π Stacking Enable Fully Reversible Photopatterning

Photoswitchable polymers are promising candidates for information storage. However, two general problems for photoswitchable polymers used in rewritable optical storage are photobleaching and inefficient switching processes in solid state. To overcome both of these obstacles, we demonstrate the synthesis of a new visible-light-switchable azobenzene-containing polymer (azopolymer) with nonstackable azo chromophores for reversible and stable information storage. The new azopolymer (PmAzo) contains ortho-methoxy-substituted azobenzene (mAzo) groups on the polymer side chains and shows reversible trans-to-cis or cis-to-trans isomerization by using distinct wavelengths of visible light. PmAzo is better suited for reversible optical storage than conventional UV-responsive azopolymers because visible light avoids the photodamage caused by UV light. Additionally, mAzo groups do not π–π stack in solid state, making photopatterning of PmAzo fully reversible. Moreover, photoinduced patterns on PmAzo can be stored for more than half a year. These properties distinguish PmAzo as a promising candidate for rewritable and stable information storage

Complete Removal of Organic Contaminants from Hypersaline Wastewater by the Integrated Process of Powdered Activated Carbon Adsorption and Thermal Fenton Oxidation

The feasibility of reusing hypersaline wastewater containing a high concentration of organic contaminants by a combined process of powdered activated carbon (PAC) adsorption and Fenton oxidation was investigated in this study. Operating conditions of the integrated process were optimized by jar tests. According to the results of molecular weight (MW) and full wavelength scanning analysis, most of the aromatic compounds with high MW (>1000 Da) were removed after adsorption pretreatment, but the effects of PAC adsorption on hydrophilic organic pollutants of low MW were rather limited. The adsorption followed a pseudo-second-order kinetic equation. Additionally, the strategy for maximizing the efficiency of both H₂O₂ and organic removal in saline wastewater was proposed. The Fenton efficiency was strongly dependent on both reaction conditions and feeding modes of reagents. Organic removal was significantly enhanced by slowing down the feeding rate of Fenton’s reagents. Moreover, rapid acidification of the wastewater was observed after adding a small amount of Fenton’s reagents, and the H₂O₂ dosage required for achieving a sufficient organic removal (effluent total organic carbon (TOC) < 200 mg/L) decreased by 22.2% with pH 3.0 maintained throughout oxidation process. Under the optimal oxidation conditions (reaction temperature = 80–90 °C, pH = 3, Fe²⁺/H₂O₂ molar ratio = 0.03), overall TOC removal efficiency of the integrated process was more than 95% of which 30% corresponds to the adsorption of PAC and 65% to the Fenton oxidation process. Furthermore, a pilot test indicated that the final effluent of the integrated process could conform to the standard for saline water recycle, confirming that this process provided a more economical and feasible alternative for reusing the hypersaline water contaminated with a high concentration of organic compounds

Control-Oriented Modeling and Real-Time Control for the Ozone Dosing Process of Drinking Water Treatment

Ozonation is one of the most important steps during drinking water treatment. To improve the efficiency of ozonation and to stabilize the quality of the treated water, control-oriented modeling and a real-time control method for the ozone dosing process are developed in this study. Compared with existing ozonation models developed by bench-scale and pilot-scale batch experiments, the model reported herein is control-oriented and based on plant-scale batch experiments. A real-time control strategy for maintaining a constant ozone exposure is attempted to meet primary disinfection requirements. An internal model control scheme is proposed to maintain a constant ozone exposure by adjusting the ozone dosage. The proposed real-time control method can cope with changing water quality, water flow rate, and process operational conditions. Both simulations and experimental studies have been carried out and implemented for the ozone dosing process control system, and the results demonstrate the effectiveness and practicality of this real-time control method

Effect of Dispersion on Adsorption of Atrazine by Aqueous Suspensions of Fullerenes

With the widespread application of fullerenes, it is critical to assess their environmental behaviors and their impacts on the transport and bioavailability of organic contaminants. The effects of fullerene particle size, chemistry of the solution, and natural organic matter on the adsorption of atrazine by aqueous dispersions of fullerenes (C60) were investigated in this work. The results showed that the Polanyi-Manes model could fit the adsorption isotherms well. Smaller sizes of fullerene particles led to increased available sites and, consequently, enhanced the adsorption of atrazine on C60. However, intensely dispersed C60 systems might not possess suitably high adsorptive capacities due to surface chemistry change. Adsorption of atrazine by aqueous dispersions of C60 increased with a decrease in the pH of the solution. Introduction of humic acid significantly reduced the size of the C60 particles, and resulted in the increase of the adsorption amount. Fullerene materials, once released into the aquatic environment, are inclined to form aqueous suspensions with different degrees of dispersion, which would greatly affect the transport and fate of organic contaminants

Data_Sheet_1_Species Classification for Neuroscience Literature Based on Span of Interest Using Sequence-to-Sequence Learning Model.PDF

Large-scale neuroscience literature call for effective methods to mine the knowledge from species perspective to link the brain and neuroscience communities, neurorobotics, computing devices, and AI research communities. Structured knowledge can motivate researchers to better understand the functionality and structure of the brain and link the related resources and components. However, the abstracts of massive scientific works do not explicitly mention the species. Therefore, in addition to dictionary-based methods, we need to mine species using cognitive computing models that are more like the human reading process, and these methods can take advantage of the rich information in the literature. We also enable the model to automatically distinguish whether the mentioned species is the main research subject. Distinguishing the two situations can generate value at different levels of knowledge management. We propose SpecExplorer project which is used to explore the knowledge associations of different species for brain and neuroscience. This project frees humans from the tedious task of classifying neuroscience literature by species. Species classification task belongs to the multi-label classification which is more complex than the single-label classification due to the correlation between labels. To resolve this problem, we present the sequence-to-sequence classification framework to adaptively assign multiple species to the literature. To model the structure information of documents, we propose the hierarchical attentive decoding (HAD) to extract span of interest (SOI) for predicting each species. We create three datasets from PubMed and PMC corpora. We present two versions of annotation criteria (mention-based annotation and semantic-based annotation) for species research. Experiments demonstrate that our approach achieves improvements in the final results. Finally, we perform species-based analysis of brain diseases, brain cognitive functions, and proteins related to the hippocampus and provide potential research directions for certain species.</p

Flocculation–Dewatering Behavior of Microalgae at Different Growth Stages under Inorganic Polymeric Flocculant Treatment: The Relationships between Algal Organic Matter and Floc Dewaterability

An algal bloom is a naturally occurring phenomenon in freshwaters due to discharge of wastewater containing nitrogen and phosphate. Coagulation-flocculation was widely used in removal of cyanobacteria and algae organic matter (AOM) from water. Microalgae and AOM differ greatly in physiochemical properties at different growth stages, which are likely to have important effects on their coagulation behavior. In this study, the interacting mechanisms between polymeric aluminum chloride (PACl) and microalgae cells and AOM at the different growth stages were investigated by characterizing morphology and AOM properties of microalgae flocs formed from PACl treatment. The results showed that PACl coagulation exhibited better removal efficiency for the microalgae cells and AOM in exponential and stationary phase than that in decline phase. The protein and humic acid content in loose bound AOM (LB-AOM) were found to be key constituents affecting floc dewatering behavior, and complexation adsorption of hydrolyzed products for proteins and humic substances in LB-AOM was responsible for microalgae floc dewatering improvement. These results provide a novel insight into optimization of flocculation and dewatering of cyanobacteria at different growth stages with PACl treatment

Designing a Photoresponsive Molecularly Imprinted System on a Silicon Wafer Substrate Surface

A photoresponsive molecularly imprinted system was prepared on a silicon wafer substrate surface via the host–guest complex of grafted 4-(3-triethoxysilylpropyiureido)­azobenzene (TSUA) and mono-6-deoxy-6-((p-chlorosulfonyl)-benzoic acid)-β-cyclodextrin (CBA−β-CD), and the acid–base pair interactions/hydrogen bonds between CBA−β-CD and the template molecules, including theophylline (TPE) and 4-hydroxybenzoic acid (4-HA). A molecular imprinting cycle “imprinting → extracting → uptaking → shuffling” was also defined in the study, the processes of uptaking and shuffling were investigated in detail by equilibrium binding experiments, and the Langmuir adsorption isotherm and Scatchard equation were used to evaluate the binding affinity and the theoretical binding sites of the molecularly imprinted (MIS), nonimprinted (NIS), and pure (PS) silicon wafer substrates. Compared with the NISs and PSs, the MISs showed a significantly higher adsorption capacity for the template molecules. More importantly, the MISs showed a reimprinted ability; after the process of shuffling, the molecularly imprinted systems on the substrate surface were destroyed, and new imprinted systems could be fabricated for the recognition of other template molecules after washing the substrates under irradiation at 450 nm. Moreover, the selective adsorption for the MISs was investigated, which indicated that the MISs showed specific affinity to the template molecules (TPE or 4-HA)

Tuning Active Species in N‑Doped Carbon with Fe/Fe₃C Nanoparticles for Efficient Oxygen Reduction Reaction

Transition metal–nitrogen–carbon (M–N–C) catalysts (M = Fe, Co, etc.) are the most promising substituents of Pt-based catalysts for oxygen reduction reaction (ORR). However, the insufficient active species in catalysts inevitably hamper their widespread applications. Herein, we report the regulation of the active species in the catalysts of multicomponent N-doped carbon with Fe/Fe3C nanoparticles by polydopamine (PDA) coating. It is found that the PDA is conducive to increasing the pyridinic, graphitic, and total N content in the carbon matrix. Benefiting from the chelating effects, the PDA further profits the formation of Fe–Nx structures and the implantation of Fe/Fe3C nanoparticles in the matrix during the pyrolysis. As expected, the resultant catalysts exhibit over 15 times mass activity toward ORR than nitrogen-doped carbon. Moreover, our developed catalysts show long-term stability as well as high methanol tolerance, which is superior to that of the commercial Pt/C electrode. This work provides a new avenue to explore a wider range of high-performance ORR electrocatalysts by regulating the active species

Ionic Liquid Surface Treatment-Induced Crystal Growth of CsPbIBr₂ Perovskite for High-Performance Solar Cells

Inorganic CsPbIBr2 perovskite has been attracting ever-increasing attention in the photovoltaic field owing to its high stability and good optoelectronic properties. The high-quality CsPbIBr2 perovskite is an essential prerequisite for fabricating efficient inorganic CsPbIBr2 perovskite solar cells. Herein, we report the preparation of high-quality CsPbIBr2 perovskites through an ionic liquid surface treatment-induced crystal growth strategy. The CsPbIBr2 precursor is deposited on the substrate by a spin-coating method and then treated through spin-coating the isopropanol solution of 1-ethyl-3-methylimidazolium iodide ionic liquid atop it. This surface treatment results in the formation of perovskite crystals with a well-developed structure within the obtained precursor film. These well-developed perovskite crystals can induce perovskite crystallization during the subsequent annealing process and lead to the formation of a dense and high-crystallinity CsPbIBr2 perovskite film with reduced defect density. The fabricated carbon-based CsPbIBr2 cell achieves a conversion efficiency of up to 10.13% and displays a good long-term stability while retaining ∼88% of the original efficiency after being stored for 816 h in ambient air