Biomass‐derived carbon is a promising electrode material in energy storage devices. However, how to improve its low capacity and stability, and slow diffusion kinetics during lithium storage remains ...a challenge. In this research, we propose a “self‐assembly‐template” method to prepare B, N codoped porous carbon (BN‐C) with a nanosandwich structure and abundant pyridinic N‐B species. The nanosandwich structure can increase powder density and cycle stability by constructing a stable solid electrolyte interphase film, shortening the Li+ diffusion pathway, and accommodating volume expansion during repeated charging/discharging. The abundant pyridinic N‐B species can simultaneously promote the adsorption/desorption of Li+/PF6− and reduce the diffusion barrier. The BN‐C electrode showed a high lithium‐ion storage capacity of above 1140 mAh g−1 at 0.05 A g−1 and superior stability (96.5% retained after 2000 cycles). Moreover, owing to the synergistic effect of the nanosandwich structure and pyridinic N‐B species, the assembled symmetrical BN‐C//BN‐C full cell shows a high energy density of 234.7 W h kg−1, high power density of 39.38 kW kg−1, and excellent cycling stability, superior to most of the other cells reported in the literature. As the density functional theory simulation demonstrated, pyridinic N‐B shows enhanced adsorption activity for Li+ and PF6−, which promotes an increase in the capacity of the anode and cathode, respectively. Meanwhile, the relatively lower diffusion barrier of pyridinic N‐B promotes Li+ migration, resulting in good rate performance. Therefore, this study provides a new approach for the synergistic modulation of a nanostructure and an active site simultaneously to fabricate the carbon electrode material in energy storage devices.
B, N codoped porous carbon (BN‐C) with a nanosandwich structure and abundant pyridinic N‐B species was prepared using the “self‐assembly‐template” method. Owing to the synergistic effect of the nanostructure and pyridinic N‐B sites, the assembled symmetrical BN‐C//BN‐C full cell shows high capacity and ultralong cycling stability, superior to most of the other cells reported in the literature.
Pemetrexed (PEM) inhibits DNA and RNA synthesis and is currently one of the first‐line agents for mesothelioma. PEM suppresses the activities of several enzymes involved in purine and pyrimidine ...synthesis, and elevated activity of these enzymes in tumors is often linked with resistance to PEM. The agent also stimulates AMP‐activated protein kinase (AMPK) and consequently influences the mammalian target of rapamycin complex 1 (mTORC1) pathways. Nevertheless, it remains unclear whether PEM resistance is linked to the AMPK or mTORC1 pathways. Here, we established two independent PEM‐resistant mesothelioma cell lines in which expression of the PEM‐target enzymes was not elevated, and found that levels of phosphorylated AMPK and p70S6K and, to a lesser extent, levels of phosphorylated AKT and p53, were increased in these cells as compared with the respective parent cells. PEM stimulation also augmented phosphorylation of AMPK, p70S6K, AKT and p53 in most cases. An AMPK activator increased phosphorylation and PEM resistance in parental cells, and the inhibitor decreased the resistance of PEM‐resistant cells. In contrast, inhibitors for p70S6K and AKT did not influence PEM resistance; furthermore, increased levels of endogenous p53 did not affect PEM sensitivity. These data collectively indicate that constitutive activation of AMPK is associated with PEM resistance, and that this is unconnected with elevated DNA and RNA synthesis.
Pemetrexed (PEM), an anti‐cancer agent, inhibits the activity of enzymes involved in DNA/RNA synthesis and AICART. Suppressed AICART activity increases the substrate, ZMP, an AMP analog, and consequently augments AMPK function, which in turn influences mTORC1 responses. The current study showed that PEM‐resistant mesothelioma exhibited constitutively activated AMPK and that the increased AMPK activity was linked with PEM‐resistance, which was unconnected to DNA/RNA synthetic enzymes.
Single atom catalysts (SACs) are widely researched in various chemical transformations due to the high atomic utilization and catalytic activity. Carbon‐supported SACs are the largest class because ...of the many excellent properties of carbon derivatives. The single metal atoms are usually immobilized by doped N atoms and in some cases by C geometrical defects on carbon materials. To explore the catalytic mechanisms and improve the catalytic performance, many efforts have been devoted to modulating the electronic structure of metal single atomic sites. Doping with polynary metals and heteroatoms has been recently proposed to be a simple and effective strategy, derived from the modulating mechanisms of metal alloy structure for metal catalysts and from the donating/withdrawing heteroatom doping for carbon supports, respectively. Polynary metals SACs involve two types of metal with atomical dispersion. The bimetal atom pairs act as dual catalytic sites leading to higher catalytic activity and selectivity. Polynary heteroatoms generally have two types of heteroatoms in which N always couples with another heteroatom, including B, S, P, etc. In this Review, the recent progress of polynary metals and heteroatoms SACs is summarized. Finally, the barriers to tune the activity/selectivity of SACs are discussed and further perspectives presented.
Carbon‐supported single atoms catalysts (SACs) are the most widely researched electrocatalysts. Polynary metals and polynary heteroatoms doping strategies are the simple and effective ways to modulate the electronic structure of metal sites that play the leading role for catalyzing activity and product distribution. This Review provides a reference for the electronic structure modulation of other SACs.
Soxhlet extraction (SE), ultrasonic-assisted extraction (UAE), and microwave-assisted extraction (MAE) were carried out on Daxing coal with carbon tetrachloride. The extracted components were ...analyzed by GC-MS while the residues of the coal after extractions were analyzed by FT-IR spectroscopy. The obtained IR spectra indicated that the functional groups were barely changed in strength for the coal before and after extractions concluding that the macromolecular structures of coal were not destroyed in the extraction processes. XRD diagrams showed the peak around θ = 47 was totally disappeared by all the three extractions, indicating that the graphite-like structural substances in the coal were totally destroyed in the extraction processes. GC/MS analysis showed that: (1) The SE method extracted the least number of substances from the coal; on the other hand, the extracted compounds are largely chlorinated which can be explained by the free radical mechanism. (2) MAE extracted 75 organic compounds of which 53 are oxygen-containing substances. A small portion of non-alkanes (1.19%) was found, which is in contrast to the other two extraction methods. Moreover, a few biomarker compounds were also identified including hexaoxane, 2-methylcholest-3-ene, 6,9,12-tripropylheptadecane, and 17α-21β-28,30-bisnorhopane. (3) The three extraction methods gave totally different extraction patterns for the same coal, highlighting that the extraction method can dominate the outcome of the extracted products. The mechanisms behind these extraction processes are discussed. This study provides a base for the future choice of the extraction methods in terms of outcomes of the extraction products.
Carbon material is a promising electrocatalyst for the oxygen reduction reaction (ORR). Doping of heteroatoms, the most widely used modulating strategy, has attracted many efforts in the past decade. ...Despite all this, the catalytic activity of heteroatoms‐modulated carbon is hard to compare to that of metal‐based electrocatalysts. Here, a “double‐catalysts” (Fe salt, H3BO3) strategy is presented to directionally fabricate porous structure of crystal graphene nanoribbons (GNs)/amorphous carbon doped by pyridinic NB pairs. The porous structure and GNs accelerate ion/mass and electron transport, respectively. The N percentage in pyridinic NB pairs accounts for ≈80% of all N species. The pyridinic NB pair drives the ORR via an almost 4e− transfer pathway with a half‐wave potential (0.812 V vs reversible hydrogen electrode (RHE)) and onset potential (0.876 V vs RHE) in the alkaline solution. The ORR catalytic performance of the as‐prepared carbon catalysts approximates commercial Pt/C and outperforms most prior carbon‐based catalysts. The assembled Zn–air battery exhibits a high peak power density of 94 mW cm−2. Density functional theory simulation reveals that the pyridinic NB pair possesses the highest catalytic activity among all the potential configurations, due to the highest charge density at C active sites neighboring B, which enhances the interaction strength with the intermediates in the p‐band center.
The dominantly pyridinic NB pair is rationally fabricated on hierarchically structure of crystal graphene nanoribbons/amorphous carbon by a “double‐catalysts” strategy. As experiments and density functional theory demonstrated, the pyridinic NB plays a key role for the highly catalytic performance (half‐wave potential, 0.812 V vs reversible hydrogen electrode, electron transfer number, ≈3.94), comparable to commercial Pt/C and superior to most of carbon‐based electrocatalysts.
Driven by its excellent physical and chemical properties, BC (bacterial cellulose) has achieved significant progress in the last decade, rendering with many novel applications. Due to its resemblance ...to the structure of extracellular matrix, BC-based biomaterials have been widely explored for biomedical applications such as tissue engineering and drug delivery. The recent advances in nanotechnology endow further modifications on BC and generate BC-based composites for different applications. This article presents a review on the research advancement on BC-based biomaterials from fabrication methods to biomedical applications, including wound dressing, artificial skin, vascular tissue engineering, bone tissue regeneration, drug delivery, and other applications. The preparation of these materials and their potential applications are reviewed and summarized. Important factors for the applications of BC in biomedical applications including degradation and pore structure characteristic are discussed in detail. Finally, the challenges in future development and potential advances of these materials are also discussed.
Based on its unique structure and properties like high elastic modulus, high specific surface area, low density, non-abrasive nature, ease of surface functionalization, high purity and crystallinity, high degree of polymerization, excellent biocompatibility and biodegradability, bacterial cellulose-based functional materials show a wide applications in biomedical materials, including wound dressing materials, artificial skin, vascular tissue engineering, bone tissue regeneration, drug delivery, and other applications in tissue engineering, et al. Display omitted
•Advances in fabrication and application of bacterial cellulose-based biomaterials are described.•Conclusion relating to the progress in interesting and important fields is given.•Challenges for future development of these materials and potential future advances are discussed.
A new direction for China in exploring sustainable development is the Innovative City Pilot Policy (ICPP), which provides policy guidance for accelerating carbon peaking and carbon neutrality by ...reducing carbon emissions. With data from 282 cities spanning 2006–2018, this paper examines ICPP's effect on carbon intensity (CI) through a multi-period difference-in-differences (DID) model, as well as exploring the mediating effect, moderating effect, heterogeneity, and spatial spillover effects. The results show that ICPP reduces CI significantly by enhancing technology innovation (TI), and when industrial structure (IS) is added, the effect of ICPP is expanded. The ICPP gains additional advantages in reducing CI by optimizing the efficiency of resource allocation (ERA). Compared with the concentration of human capital (HCL), the amount of scientific research institutes (SRI) has a slightly greater moderating effect. ICPP impacts considering location, size, and hierarchy heterogeneity. ICPP has a greater impact on mitigating CI in the western, larger size, and provincial capital cities. There are positive spillover effects of the ICPP on neighboring CI. To support the idea that ICPP can effectively contribute to CI reduction, this paper provides empirical evidence and theoretical guidelines.
•Innovative city pilot policy (ICPP) has a significant positive effect on Carbon intensity (CI).•Technology innovation and industrial structure mediate the effect of ICPP on CI.•Carbon reduction can be positively moderated by the efficiency of resource allocation (ERA).•The effect of ICPP on CI is heterogeneous in terms of geographical location, size, and hierarchy.
Carbon materials are considered promising 2/4 e− oxygen reduction reaction (ORR) electrocatalysts for synthesizing H2O2/H2O via regulating heteroatom dopants and functionalization. Here, various ...doped and functionalized graphene quantum dots (GQDs) are designed to reveal the crucial active sites of carbon materials for ORR to produce H2O2. Density functional theory (DFT) calculations predict that the edge structure involving edge N, B dopant pairs and further OH functionalization to the B (NBOH) is an active center for 2e− ORR. To verify the above predication, GQDs with an enriched density of NBOH (NBO‐GQDs) are designed and synthesized by the hydrothermal reaction of NH2 edge‐functionalized GQDs with H3BO3 forming six‐member heterocycle containing the NBOH structure. When dispersed on conductive carbon substrates, the NBO‐GQDs show H2O2 selectivity of over 90% at 0.7 –0.8 V versus reversible hydrogen electrode in the alkaline solution in a rotating ring‐disk electrode setup. The selectivity retains 90% of the initial value after 12 h stability test. In a flow cell setup, the H2O2 production rate is up to 709 mmol gcatalyst−1 h−1, superior to most reported carbon‐ and metal‐based electrocatalysts. This work provides molecular insight into the design and formulation of highly efficient carbon‐based catalysts for sustainable H2O2 production.
Density functional theory calculations predict that the edge structure involving edge N, B dopant pairs and further OH functionalization to the B is an active center for 2 e− ORR. GQDs with an enriched density of NBOH show high H2O2 selectivity (over 90%), stability and H2O2 production rate (709 mmol gcatalyst−1 h−1), superior to most reported carbon‐ and metal‐based electrocatalysts.
The EGFR family play a significant role in cell signal transduction and their overexpression is implicated in the pathogenesis of numerous human solid cancers. Inhibition of the EGFR-mediated ...signaling pathways by EGFR inhibitors is a widely used strategy for the treatment of cancers. In most cases, the EGFR inhibitors used in clinic were only effective when the cancer cells harbored specific activating EGFR mutations which appeared to preserve the ligand–dependency of receptor activation but altered the pattern of downstream signaling pathways. Moreover, cancer is a kind of multifactorial disease, and therefore manipulating a single target may result in treatment failure. Although drug combinations for the treatment of cancers proved to be successful, the use of two or more drugs concurrently still was a challenge in clinical therapy owing to various dose-limiting toxicities and drug-drug interactions caused by pharmacokinetic profiles changed. Therefore, a single drug targeting two or multiple targets could serve as an effective strategy for the treatment of cancers. In recent, drugs with diverse pharmacological effects have been shown to be more advantageous than combination therapies due to their lower incidences of side effects and more resilient therapies. Accordingly, dual target-single-agent strategy has become a popular field for cancer treatment, and researchers became more and more interest in the development of novel dual-target drugs in recent years. In this review, we briefly introduce the EGFR family proteins and synergisms between EGFR and other anticancer targets, and summarizes the development of potential dual target inhibitors based on wild-type and/or mutant EGFR for the treatment of solid cancers in the past five years. Additionally, the rational design and SARs of these dual target agents are also presented in detailed, which will lay a significant foundation for the further development of novel EGFR-based dual inhibitors with excellent druggability.
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•The development of novel dual target inhibitors based on EGFR were summarized.•The rational design and SARs of novel dual target agents were presented in detailed.•Over ten different pharmacophores were included in the dual target agents.
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