Replacement of CC unit with its isoelectronic BN unit in aromatics provides a new class of molecules with appealing properties, which have attracted great attention recently. In this Concept, we ...focus on BN‐substituted polycyclic aromatics with fused structures, and review their synthesis, photophysical, and redox properties, as well as their applications in organic electronics. We also present challenging synthetic targets, large BN‐ substituted polycyclic aromatics, such as regioregular BN heterosuperbenzenes, which can be viewed as BN‐doped nanographenes. Finally, we propose an atomically precise bottom‐up synthesis of structurally well‐defined BN‐doped graphenes.
A new super hero! BN substitution in aromatic systems could provide a new family of interesting compounds. In this Concept, the development of BN‐substituted polycyclic aromatics is reported, and their synthesis, properties and electronic applications are summarized. From monocyclic BN‐substituted benzene to polycyclic BN heteroaromatics (like BN heterosuperbenzene), the possible ways to structurally well‐defined BN‐doped graphenes are proposed.
Although it is known that the expression and activity of sirtuin 1 (SIRT1) significantly decrease in doxorubicin (DOX)-induced cardiomyopathy, the role of interaction between SIRT1 and sestrin 2 ...(SESN2) is largely unknown. In this study, we investigated whether SESN2 could be a crucial target of SIRT1 and the effect of their regulatory interaction and mechanism on DOX-induced cardiac injury. Here, using DOX-treated cardiomyocytes and cardiac-specific Sirt1 knockout mice models, we found SIRT1 deficiency aggravated DOX-induced cardiac structural abnormalities and dysfunction, whereas the activation of SIRT1 by resveratrol (RES) treatment or SIRT1 overexpression possessed cardiac protective effects. Further studies indicated that SIRT1 exerted these beneficial effects by markedly attenuating DOX-induced oxidative damage and apoptosis in a SESN2-dependent manner. Knockdown of Sesn2 impaired RES/SIRT1-mediated protective effects, while upregulation of SESN2 efficiently rescued DOX-induced oxidative damage and apoptosis. Most importantly, SIRT1 activation could reduce DOX-induced SESN2 ubiquitination possibly through reducing the interaction of SESN2 with mouse double minute 2 (MDM2). The recovery of SESN2 stability in DOX-impaired primary cardiomyocytes by SIRT1 was confirmed by Mdm2-siRNA transfection. Taken together, our findings indicate that disrupting the interaction between SESN2 and MDM2 by SIRT1 to reduce the ubiquitination of SESN2 is a novel regulatory mechanism for protecting hearts from DOX-induced cardiotoxicity and suggest that the activation of SIRT1-SESN2 axis has potential as a therapeutic approach to prevent DOX-induced cardiotoxicity.
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•DOX-induced cardiotoxicity is based on decreased SIRT1 and SESN2 levels.•SIRT1 activation improves DOX-induced cardiac oxidative stress and apoptosis.•The benefits of SIRT1 in DOX-impaired cardiac function require the activation of SESN2.•SIRT1 reduces ubiquitination and degradation of SESN2 via MDM2.
Proton exchange membrane fuel cells (PEMFCs) are considered to be an important low-carbon energy conversion technology, which has shown impressive performance improvement in the past decades. ...However, the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode has been an impediment to the successful commercialization of the technology. Novel highly active electrocatalysts for the ORR are highly desired to meet the US DOE performance targets. In recent years, polyhedron-engineered Pt-alloy nanocrystals have demonstrated unprecedented electrocatalytic activity. Different from previous reviews on shape-manipulated Pt-based ORR catalysts, this review focuses on 3D polyhedron-engineered Pt-based nanocrystal electrocatalysts with an in-depth comparison of different active facet-tailored geometric configurations and their advanced electrocatalytic properties. The review carefully examines and criticizes the aggregated data in this area, and provides an important overview as well as a critical insight into the topic. Understanding the catalytic mechanism taking place with polyhedron-designed Pt-based nanocrystals helps to unlock the door to highly active ORR electrocatalysts for PEMFC applications.
This review focuses on polyhedron-engineered Pt-based nanocrystals as highly active ORR catalysts for PEMFCs.
Doxorubicin (DOX) is an anthracycline chemotherapy drug used in the treatment of various types of cancer. However, short-term and long-term cardiotoxicity limits the clinical application of DOX. ...Currently, dexrazoxane is the only approved treatment by the United States Food and Drug Administration to prevent DOX-induced cardiotoxicity. However, a recent study found that pre-treatment with dexrazoxane could not fully improve myocardial toxicity of DOX. Therefore, further targeted cardioprotective prophylaxis and treatment strategies are an urgent requirement for cancer patients receiving DOX treatment to reduce the occurrence of cardiotoxicity. Accumulating evidence manifested that Sirtuin 1 (SIRT1) could play a crucially protective role in heart diseases. Recently, numerous studies have concentrated on the role of SIRT1 in DOX-induced cardiotoxicity, which might be related to the activity and deacetylation of SIRT1 downstream targets. Therefore, the aim of this review was to summarize the recent advances related to the protective effects, mechanisms, and deficiencies in clinical application of SIRT1 in DOX-induced cardiotoxicity. Also, the pharmaceutical preparations that activate SIRT1 and affect DOX-induced cardiotoxicity have been listed in this review.
In the past several decades, conducting polymers have achieved remarkable progress and have been widely applied as the active materials for optoelectronics. So far, p-type conducting polymers exhibit ...high conductivities over 1000 S cm–1 and thermoelectric performance comparable to that of inorganic materials; however, only a few n-type conducting polymers showed conductivities over 1 S cm–1 after doping. The low conductivity of n-type conducting polymers is considered as the major barrier for further enhancing their thermoelectric performances. In this perspective, we highlight the scientific and engineering challenges to enhance the conductivity of n-type polymer thermoelectric materials, including n-doping efficiency in n-type polymers, factors influencing charge carrier mobilities after doping, and stability of n-type conducting polymers. Recent development and strategies to address these issues and enhance the conductivity of n-type conjugated polymers are summarized and discussed, providing materials and device engineering guidelines for the future high-performance polymer thermoelectric materials research and development.
In the past couple of years, remarkable progress has been made in solution-processable organic semiconducting materials for optoelectronics. The development of novel π-conjugated backbones has always ...been the central issue in this field. In contrast, flexible side chains are less developed and usually used only as solubilizing groups. In this Perspective, we highlight the effects of the flexible chains in organic semiconductors, including the influences of length, odd–even effect, substitution position, terminal groups, branching position, and chirality of alkyl chains, as well as some significant features of oligo(ethylene glycol) and fluoroalkyl chains. Although the roles of flexible chains in organic semiconducting materials are complex and differ when corresponding conjugated skeleton changes, in this Perspective, we emphasize the synergy of conjugated backbones and flexible side chains, which might significantly facilitate the understanding of the roles of flexible chains in structure–property relationship and promote the development of high-performance organic semiconductors.
Solid‐state materials with efficient room‐temperature phosphorescence (RTP) emissions have found widespread applications in materials science, while liquid or solution‐phase pure organic RTP emission ...systems has been rarely reported, because of the nonradiative decay and quenchers from the liquid medium. Reported here is the first example of visible‐light‐excited pure organic RTP in aqueous solution by using a supramolecular host‐guest assembly strategy. The unique cucurbit8uril‐mediated quaternary stacking structure allows tunable photoluminescence and visible‐light excitation, enabling the fabrication of multicolor hydrogels and cell imaging. The present assembly‐induced emission approach, as a proof of concept, contributes to the construction of novel metal‐free RTP systems with tunable photoluminescence in aqueous solution, providing broad opportunities for further applications in biological imaging, detection, optical sensors, and so forth.
True colors: An assembly‐induced emission strategy was utilized to endow a simple dye molecule with room‐temperature phosphorescence and tunable photoluminescence in aqueous solution. The obtained supramolecular assembly structure has intriguing photophysical properties and enables the fabrication of multicolor hydrogels and cell imaging.
Since ever-increasing energy demands stimulated intensive research activities on lithium-ion batteries (LIBs), biomass as an earth-abundant renewable energy source has played an intriguing and ...promising role in developing sustainable biomass-derived carbons and their composite materials for high-performance LIB anodes. Different from other materials (
e.g.
, silicon, tin, metal oxides,
etc.
), biomass-derived carbons and their composite materials have been applied more and more to LIBs due to their advantages such as low cost, green and eco-friendly synthesis, easy accessibility, sustainable strategy, and improved battery performance, including capacity, cycling property, and stability/durability. This tutorial review focusing on biomass-derived carbons and their composites in the application of LIB anodes will act as a strategic guide to build a close connection between renewable materials and electrochemical energy storage devices. Also, this review provides a critical analysis and comparison of biomass-derived carbons and their composites for LIB anodes, coupled with an important insight into the remaining challenges and future directions in the field.
This review focuses on the derivation of nanostructured carbons and their composite materials from biomass materials for lithium ion battery anodes.