The precise modification of redox species on the inner and outer surfaces of hollow nanostructures is relevant in catalysis, surface science, and nanotechnology, but has proven difficult to achieve. ...Herein, we develop a facile approach to specifically fabricate Pt and Co3O4 nanoparticles (NPs) onto the interior and exterior surface of hollow carbon nitride spheres (HCNS), respectively, to promote the surface redox functions of the polymer semiconductors. The photocatalytic water splitting activities of HCNS with spatially separated oxidation and reduction centers at their nanodomains were enhanced. The origin of the enhanced activity was attributed to the spatially separated reactive sites for the evolution of H2 and O2 and also to the unidirectional migration of the electron and hole on the Janus surfaces, thereby preventing the unwanted reverse reaction of water splitting and decreasing charge recombination.
Interior design: A hollow conjugated carbon nitride semiconductor nanosphere with Pt and Co3O4 nanoparticles on the interior and exterior surfaces, respectively, has been prepared by a precise nanofabrication technology. The nanoparticle co‐catalysts enable the Janus hollow structure to photocatalyze water splitting by promoting charge separation and inhibiting the unwanted reverse reaction.
Carbon‐based catalysts have demonstrated great potential for the aerobic oxidative dehydrogenation reaction (ODH). However, its widespread application is retarded by the unavoidable deactivation ...owing to the appearance of coking or combustion under ODH conditions. The synthesis and characterization of porous structure of BCN nanosheets as well as their application as a novel catalyst for ODH is reported. Such BCN nanosheets consist of hybridized, randomly distributed domains of h‐BN and C phases, where C, B, and N were confirmed to covalent bond in the graphene‐like layers. Our studies reveal that BCN exhibits both high activity and selectivity in oxidative dehydrogenation of ethylbenzene to styrene, as well as excellent oxidation resistance. The discovery of such a simple chemical process to synthesize highly active BCN allows the possibility of carbocatalysis to be explored.
The porous structure of two‐dimension BCN nanosheets, consisting of hybridized h‐BN and C domains, were constructed for aerobic oxidative dehydrogenation reactions. The high porosity, novel pore structure, and abundant oxygen‐containing functional groups endow the BCN with more active sites.
As the most dominant cell type in the skin, keratinocytes play critical roles in wound repair not only as structural cells but also exerting important immune functions. This review focuses on the ...communications between keratinocytes and immune cells in wound healing, which are mediated by various cytokines, chemokines, and extracellular vesicles. Keratinocytes can also directly interact with T cells via antigen presentation. Moreover, keratinocytes produce antimicrobial peptides that can directly kill the invading pathogens and contribute to wound repair in many aspects. We also reviewed the epigenetic mechanisms known to regulate keratinocyte immune functions, including histone modifications, non-protein-coding RNAs (e.g., microRNAs, and long noncoding RNAs), and chromatin dynamics. Lastly, we summarized the current evidence on the dysregulated immune functions of keratinocytes in chronic nonhealing wounds. Based on their crucial immune functions in skin wound healing, we propose that keratinocytes significantly contribute to the pathogenesis of chronic wound inflammation. We hope this review will trigger an interest in investigating the immune roles of keratinocytes in chronic wound pathology, which may open up new avenues for developing innovative wound treatments.
The ability to rapidly restore the integrity of a broken skin barrier is critical and is the ultimate goal of therapies for hard-to-heal-ulcers. Unfortunately effective treatments to enhance healing ...and reduce scarring are still lacking. A deeper understanding of the physiology of normal repair and of the pathology of delayed healing is a prerequisite for the development of more effective therapeutic interventions. Transition from the inflammatory to the proliferative phase is a key step during healing and accumulating evidence associates a compromised transition with wound healing disorders. Thus, targeting factors that impact this phase transition may offer a rationale for therapeutic development. This review summarizes mechanisms regulating the inflammation–proliferation transition at cellular and molecular levels. We propose that identification of such mechanisms will reveal promising targets for development of more effective therapies.
Silicon‐containing compounds are widely used as synthetic building blocks, functional materials, and bioactive reagents. In particular, silyl radicals are important intermediates for the synthesis ...and transformation of organosilicon compounds. Herein, we describe the first protocol for the generation of silyl radicals by photoinduced decarboxylation of silacarboxylic acids, which can be easily prepared in high yield on a gram scale and are very stable to air and moisture. Irradiation of silacarboxylic acids with blue LEDs (455 nm) in the presence of a commercially available photocatalyst releases silyl radicals, which can further react with various alkenes to give the corresponding silylated products in good‐to‐high yields with broad functional‐group compatibility. This reaction proceeds in the presence of water, enabling efficient deuterosilylation of alkenes with D2O as the deuterium source. Germyl radicals were similarly obtained.
Generation of silyl radicals by photoinduced decarboxylation of silacarboxylic acids is described. The reaction proceeds smoothly in the presence of a commercially available photocatalyst with broad functional‐group compatibility. This reaction could also be performed in the presence of water, enabling the use of D2O as the deuteration reagent. Germyl radicals were similarly obtained.
Solar steam generation is emerging as a promising technology, for its potential in harvesting solar energy for various applications such as desalination and sterilization. Recent studies have ...reported a variety of artificial structures that are designed and fabricated to improve energy conversion efficiencies by enhancing solar absorption, heat localization, water supply, and vapor transportation. Mushrooms, as a kind of living organism, are surprisingly found to be efficient solar steam‐generation devices for the first time. Natural and carbonized mushrooms can achieve ≈62% and ≈78% conversion efficiencies under 1 sun illumination, respectively. It is found that this capability of high solar steam generation is attributed to the unique natural structure of mushroom, umbrella‐shaped black pileus, porous context, and fibrous stipe with a small cross section. These features not only provide efficient light absorption, water supply, and vapor escape, but also suppress three components of heat losses at the same time. These findings not only reveal the hidden talent of mushrooms as low‐cost materials for solar steam generation, but also provide inspiration for the future development of high‐performance solar thermal conversion devices.
Mushrooms can, surprisingly, enable efficient solar steam generation (≈78% under 1 sun illumination), as their natural structures possess the excellent properties of light absorption, thermal management with minimized heat loss, efficient water supply, and vapor escape.
Carbon dots (CDs), a kind of carbon material discovered accidentally, exhibit unexpected advantages in fluorescence imaging/sensing such as photostability, biocompatibility, and low toxicity. For ...emerging theranostics, an interdiscipline created by integrating therapy and diagnostics, CDs are good candidates when they are combined with targeted chemo/gene/photodynamic/photothermal therapeutic moieties. Here, the development of CDs in nanomedicine is reviewed from their use as original imaging agents and/or drug carriers to multifunctional theranostic systems. Finally, the challenges and prospects of the next‐generation of CD‐based theranostics for clinical applications are also discussed.
Carbon dots (CDs) in nanomedicine are gradually developed from original imaging agents and/or drug carriers to smart multifunctional theranostic systems. In addition to having the common advantages of stability, biocompatibility, and low toxicity, CDs with special photothermal therapy/ photodynamic therapy capability are successfully exploited. This work addresses recent encouraging progress in the development of CD‐based multifunctional nanomedicinal agents in theranostics.
Herein we report a versatile Mizoroki–Heck‐type photoinduced C(sp3)−N bond cleavage reaction. Under visible‐light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzky salts react ...smoothly with alkenes in a 1:1 molar ratio in the presence of 1.0 mol % of commercially available photoredox catalyst without the need for any base, affording the corresponding alkyl‐substituted alkenes in good yields with broad functional‐group compatibility. Notably, the E/Z‐selectivity of the alkene products can be controlled by an appropriate choice of photoredox catalyst.
Under visible‐light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzky salts react smoothly with alkenes in a 1:1 molar ratio in the presence of 1.0 mol % of commercially available photoredox catalyst without the need for any base, affording the corresponding alkyl‐substituted alkenes in good yields with broad functional‐group compatibility (see scheme).
A review of the research activities and achievements at Shenzhen University is conducted in this paper concerning the creation and further development of novel microcapsule based self-resilience ...systems for their application in concrete structures. After a brief description of pioneering works in the field starting about 10 years ago, the principles raised in the relevant research are examined, where fundamental terms related to the concept of resilience are discussed. Several breakthrough points are highlighted concerning the three adopted comprehensive self-resilience systems, namely physical, chemical and microbial systems. The major challenges regarding evaluation are emphasized and further development concerning self-resilience in concrete structures will be addressed.
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