In the Big Data era, targeted advertising occurs some changes in increasing the marketing accurateness and its valuation model. When the low-carbon product traders adopt targeted advertising, ...consumer preference information also gets their attentions. In this process, the pricing rules and coordination issues become their attention problems considering targeted advertising and consumer performance information in the new background, but efforts about it are still a gap. Thus, to explore these problem, a low-carbon supply chain with one retailer and one low-carbon manufacturer was chosen. Afterwards, the demand function was revised considering the targeted advertising and the carbon emission level, and four common cost-sharing models and its pricing rules were put forward and analyzed. Finally, revenue-sharing contract was used to coordinate supply chain in the proposed four models. Results indicates that sharing the BDAT inputs, the costs for obtaining consumer preference information and the carbon emission reduction costs can help the retailer obtain a low wholesale price and gain more benefits. When the value of revenue-sharing coefficient is bigger than 0.25 and lower than 0.5, the revenue-sharing contract can achieve the low-carbon supply chain coordinate.
It is challenging to remove polar organic micropollutants from water through adsorption‐mediated processes. Macrocycle‐crosslinked polymers were recently shown to be effective adsorbents for nonpolar ...or charged organic micropollutants through specific host–guest binding, but are rarely used for the treatment of neutral and polar organic micropollutants. This is due to the challenge of recognizing polar molecules in water by macrocyclic hosts. In this research, we report two amide naphthotube‐crosslinked polymers which can effectively and rapidly adsorb a wide scope of polar organic micropollutants from water through biomimetic molecular recognition. Amide naphthotubes possess hydrogen bonding sites in their deep hydrophobic cavities and can effectively bind polar organic micropollutants in water through the hydrophobic effects and shielded hydrogen bonds. The cross‐linked polymers containing amide naphthotubes are even able to remove a complex mixture of organic micropollutants from water and the used materials can be easily regenerated through washing with MeOH or EtOH. This research provides a solution for the treatment of polar organic micropollutants by using biomimetic molecular recognition in water.
The cross‐linked polymers containing the biomimetic macrocyclic hosts, amide naphthotubes, are able to effectively and rapidly adsorb polar organic micropollutants from water by employing host–guest binding. The polymers can be readily regenerated through washing with MeOH or EtOH at room temperature.
Phenol‐based macrocyclic arenes have been widely used in supramolecular chemistry, significantly enriching the toolbox of the field. In contrast, naphthol‐based macrocyclic arenes are rather ...underdeveloped. Very recently, Gaeta and co‐workers successfully synthesized such macrocycles (referred to as prismnarenes) with good guest‐binding ability by reacting 2,6‐dimethoxynaphthalene with paraformaldehyde under optimized conditions. In view of the simple synthesis and good host–guest chemistry, we anticipate that this macrocycle will find similar success and wide applications as the phenol‐based macrocyclic arenes.
New macrocyclic arenes, so‐called prismnarenes, are readily synthesized from 2,6‐dimethoxynaphthalene and paraformaldehyde in the presence of templates. They adopt a prism‐like structure with an electron‐rich cavity and show excellent binding affinities towards organic cations. In view of the simple synthesis and good host–guest chemistry, they should find many uses in supramolecular chemistry.
Urea electrolysis is a prospective technology for simultaneous H2 production and nitrogen suppression in the process of water being used for energy production. Its sustainability is currently founded ...on innocuous N2 products; however, we discovered that prevalent nickel‐based catalysts could generally over‐oxidize urea into NO2− products with ≈80 % Faradaic efficiencies, posing potential secondary hazards to the environment. Trace amounts of over‐oxidized NO3− and N2O were also detected. Using 15N isotopes and urea analogues, we derived a nitrogen‐fate network involving a NO2−‐formation pathway via OH−‐assisted C−N cleavage and two N2‐formation pathways via intra‐ and intermolecular coupling. DFT calculations confirmed that C−N cleavage is energetically more favorable. Inspired by the mechanism, a polyaniline‐coating strategy was developed to locally enrich urea for increasing N2 production by a factor of two. These findings provide complementary insights into the nitrogen fate in water–energy nexus systems.
A systematic investigation of the nitrogen network during the nickel‐catalyzed urea oxidation reaction was carefully performed. It revealed a dominant NO2− production rather than innocuous N2 present on various nickel‐based catalysts. Accordingly, polymer‐surface modification was put forward to increase the efficiency of harmless N2 products.
Heterogeneous catalysts are often composite materials synthesized via several steps of chemical transformation, and thus the atomic structure in composite is a black-box. Herein with ...machine-learning-based atomic simulation we explore millions of structures for MFI zeolite encapsulated PtSn catalyst, demonstrating that the machine-learning enhanced large-scale potential energy surface scan offers a unique route to connect the thermodynamics and kinetics within catalysts' preparation procedure. The functionalities of the two stages in catalyst preparation are now clarified, namely, the oxidative clustering and the reductive transformation, which form separated Sn
O
and PtSn alloy clusters in MFI. These confined clusters have high thermal stability at the intersection voids of MFI because of the formation of "Mortise-and-tenon Joinery". Among, the PtSn clusters with high Pt:Sn ratios (>1:1) are active for propane dehydrogenation to propene, ∼10
in turnover-of-frequency greater than conventional Pt
Sn metal. Key recipes to optimize zeolite-confined metal catalysts are predicted.
Macrocyclic hosts with a well‐defined cavity are particularly appealing for supramolecular chemistry, but they are still rare. In this research, we reported a new class of macrocyclic hosts, namely ...methylene‐bridged naphthotubes, with well‐defined cavities. They were synthesized through TFA‐catalyzed Friedel–Crafts reactions between alkoxy‐substituted bisnaphthalenes and paraformaldehyde. A configurational selection was observed. Three‐membered macrocycles possess a single cavity, while four‐membered macrocycles adopt a double‐cavity conformation or a self‐filling conformation depending on the alkoxy length. The small homologue shows quite strong binding affinities (up to 108 M−1) to organic cations, which is better than structurally similar but flexible macrocycles. This demonstrates the advantage of a well‐defined cavity in molecular recognition. Moreover, these naphthotubes can be used as chirality sensors for chiral organic cations through different chirality transfer mechanisms.
Methylene‐bridged naphthotubes have been successfully developed. The three‐membered naphthotubes possess a rigid and well‐defined cavity, while four‐membered naphthotubes possess a double‐cavity conformation or a self‐filling conformation depending on the alkoxy length. They show quite strong binding affinities (up to 108 M−1) to organic cations and can be used as chirality sensors for chiral organic cations.
Macrocyclic hosts are the principal tools used in supramolecular chemistry because they can recognize other small molecules through non-covalent interactions. However, in terms of recognition ...ability, known macrocyclic hosts are often not comparable to bioreceptors. This may be due to the lack of functional groups inside the deep cavity, which is a common feature of bioreceptors. Most of the known macrocyclic hosts contain either a hydrophobic cavity or polar binding sites only. Macrocyclic hosts with functional groups inside a hydrophobic cavity are rare. In 2004, Glass and co-workers reported a pair of water-soluble naphthalene-based molecular tubes with amide protons in the well-defined deep cavity. The cavity feature is very similar to that of bioreceptors. However, the amide protons were not used in molecular recognition and were replaced in 2012 with allyl groups in order to improve the hydrophobic effect. We started our work on the basis of the Glass molecular tubes but paid close attention to the functional groups in the deep cavity. In this Account, we summarize our results on these biomimetic receptors, which we call naphthotubes. The inward-directed functional groups endow the corresponding naphthotubes with unique recognition abilities. Naphthotubes with hydrogen-bond acceptors (ether, ester, and imine) prefer to bind organic cations; naphthotubes with hydrogen-bond donors (urea, thiourea, and amide) can bind neutral molecules; amine naphthotubes are stimuli-responsive to acid/base. In particular, the water-soluble amide naphthotubes are able to selectively recognize highly hydrophilic molecules in water-a generally accepted challenge in supramolecular chemistry. The unique recognition ability of these naphthotubes provides the basis for their applications in sensing, self-assembly, and molecular machines. Fluorescent sensing of environmental contaminants in water, chiroptical sensing of small chiral molecules, allosteric cooperative self-assembly, dissipative self-assembly, and directional molecular shuttles have been demonstrated with these naphthotubes. Overall, we hope to convey the message that these naphthotubes have unique recognition properties and promising applications in diverse fields. We believe that further exploration of this class of macrocycles may lead to practical applications in, for example, biomedical science, environmental science, and other related fields.
Cancer stem cells (CSCs) are thought to play an important role in tumor recurrence and drug resistance, and present a major challenge in cancer therapy. The tumor microenvironment such as growth ...factors, nutrients and oxygen affect CSC generation and proliferation by providing the necessary energy sources and growth signals. The side population (SP) analysis has been used to detect the stem-like cancer cell populations based on their high expression of ABCG2 that exports Hoechst-33342 and certain cytotoxic drugs from the cells. The purpose of this research is to investigate the effect of a main nutrient molecule, glutamine, on SP cells and the possible underlying mechanism(s).
Biochemical assays and flow cytometric analysis were used to evaluate the effect of glutamine on stem-like side population cells in vitro. Molecular analyses including RNAi interfering, qRT-PCR, and immunoblotting were employed to investigate the molecular signaling in response to glutamine deprivation and its influence on tumor formation capacity in vivo.
We show that glutamine supports the maintenance of the stem cell phenotype by promoting glutathione synthesis and thus maintaining redox balance for SP cells. A deprivation of glutamine in the culture medium significantly reduced the proportion of SP cells. L-asparaginase, an enzyme that catalyzes the hydrolysis of asparagine and glutamine to aspartic acid and glutamate, respectively, mimics the effect of glutamine withdrawal and also diminished the proportion of SP cells. Mechanistically, glutamine deprivation increases intracellular ROS levels, leading to down-regulation of the β-catenin pathway.
Glutamine plays a significant role in maintaining the stemness of cancer cells by a redox-mediated mechanism mediated by β-catenin. Inhibition of glutamine metabolism or deprivation of glutamine by L-asparaginase may be a new strategy to eliminate CSCs and overcome drug resistance.
Benzene hydrogenation is an important industrial process. The reaction is incomplete, resulting in a mixture of benzene, cyclohexane, and/or cyclohexene that have to be separated before any further ...reactions. The currently used extractive and azeotropic distillations are operationally complex and energy intensive. Adsorptive separation provides an alternative energy‐efficient method. However, the separation of the ternary mixture by adsorptive separation has not yet been reported. In the present research, we report two macrocyclic hosts with hydrogen‐bonding sites in their cavities that are able to separate the ternary mixture of benzene, cyclohexene, and cyclohexane. N−H⋅⋅⋅π interactions were found to play a key role in the selective separation. In addition, fast adsorption, high loading ratios, and easy recycling are achieved with the present system, which is promising for practical applications.
Mixtures of benzene, cyclohexene, and cyclohexane can be separated through solid‐vapor adsorption by using the activated solids of amide naphthotubes. N−H⋅⋅⋅π interactions are found to play a key role in the adsorption selectivity among the three structurally similar molecules.
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