Development of easy‐to‐make, highly active, and stable bifunctional electrocatalysts for water splitting is important for future renewable energy systems. Three‐dimension (3D) porous Ni/Ni8P3 and ...Ni/Ni9S8 electrodes are prepared by sequential treatment of commercial Ni‐foam with acid activation, followed by phosphorization or sulfurization. The resultant materials can act as self‐supported bifunctional electrocatalytic electrodes for direct water splitting with excellent activity toward oxygen evolution reaction and hydrogen evolution reaction in alkaline media. Stable performance can be maintained for at least 24 h, illustrating their versatile and practical nature for clean energy generation. Furthermore, an advanced water electrolyzer through exploiting Ni/Ni8P3 as both anode and cathode is fabricated, which requires a cell voltage of 1.61 V to deliver a 10 mA cm−2 water splitting current density in 1.0 m KOH solution. This performance is significantly better than that of the noble metal benchmark—integrated Ni/IrO2 and Ni/Pt–C electrodes. Therefore, these bifunctional electrodes have significant potential for realistic large‐scale production of hydrogen as a replacement clean fuel to polluting and limited fossil‐fuels.
Three‐dimension nickel‐based electrocatalytic electrodes (Ni/Ni8P3 and Ni/Ni9S8) are developed for application in water splitting. The as‐obtained Ni/Ni8P3 catalytic electrode, particularly exhibiting excellent electrocatalytic activity and stability due to its advanced structure effects, can serve as a highly efficient and stable bifunctional catalyst for overall water splitting.
Hybrid organic–inorganic perovskites (HOIPs) with chiral organic ligands exhibit highly spin-dependent transport and strong natural optical activity (NOA). Here we show that these remarkable features ...can be traced to a chirality-induced spin–orbit coupling (SOC), H so = ατk z σ z , which connects the carrier’s spin (σ z ), its wave vector (k z ), and the material’s helicity (τ) along the screw direction with strength α controlled by the geometry of the organic ligands. This SOC leads to a macroscopic spin polarization in the presence of an electrical current and is responsible for the observed spin-selective transport. NOA originates from a coupling between the exciton’s center-of-mass wave vector K z and its circular polarization j z ex, H so ′ = α′τK z j z ex, contributed jointly from the electron’s and the hole’s SOCs in an exciton. Our model provides a roadmap to achieve a strong and tunable chirality in HOIPs for novel applications utilizing carrier spin and photon polarization.
Compared with conventional tumor photothermal therapy (PTT), mild‐temperature PTT brings less damage to normal tissues, but also tumor thermoresistance, introduced by the overexpressed heat shock ...protein (HSP). A high dose of HSP inhibitor during mild‐temperature PTT might lead to toxic side effects. Glucose oxidase (GOx) consumes glucose, leading to adenosine triphosphate supply restriction and consequent HSP inhibition. Therefore, a combinational use of an HSP inhibitor and GOx not only enhances mild‐temperature PTT but also minimizes the toxicity of the inhibitor. However, a GOx and HSP inhibitor‐encapsulating nanostructure, designed for enhancing its mild‐temperature tumor PTT efficiency, has not been reported. Thermosensitive GOx/indocyanine green/gambogic acid (GA) liposomes (GOIGLs) are reported to enhance the efficiency of mild‐temperature PTT of tumors via synergistic inhibition of tumor HSP by the released GA and GOx, together with another enzyme‐enhanced phototherapy effect. In vitro and in vivo results indicate that this strategy of tumor starvation and phototherapy significantly enhances mild‐temperature tumor PTT efficiency. This strategy could inspire people to design more delicate platforms combining mild‐temperature PTT with other therapeutic methods for more efficient cancer treatment.
Thermosensitive liposomes made of DPPC and DSPE‐PEG2000 encapsulating GOx, ICG, and GA are presented. This system is used for synergistic starvation therapy, EEPT, and enhanced mild‐temperature PTT against tumors.
A novel SARS-related coronavirus (SARS-CoV-2) has recently emerged as a serious pathogen that causes high morbidity and substantial mortality. However, the mechanisms by which SARS-CoV-2 evades host ...immunity remain poorly understood. Here, we identified SARS-CoV-2 membrane glycoprotein M as a negative regulator of the innate immune response. We found that the M protein interacted with the central adaptor protein MAVS in the innate immune response pathways. This interaction impaired MAVS aggregation and its recruitment of downstream TRAF3, TBK1, and IRF3, leading to attenuation of the innate antiviral response. Our findings reveal a mechanism by which SARS-CoV-2 evades the innate immune response and suggest that the M protein of SARS-CoV-2 is a potential target for the development of SARS-CoV-2 interventions.
Coronavirus disease 2019 (COVID‐19) is a novel type of highly contagious pneumonia caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Despite the strong efforts taken to ...control the epidemic, hundreds of thousands of people were infected worldwide by 11 March, and the situation was characterized as a pandemic by the World Health Organization. Pregnant women are more susceptible to viral infection due to immune and anatomic alteration, though hospital visits may increase the chance of infection, the lack of medical care during pregnancy may do more harm. Hence, a well‐managed system that allows pregnant women to access maternal health care with minimum exposure risk is desired during the outbreak. Here, we present the managing processes of three pregnant women who had fever during hospitalization in the gynecology or obstetrics department, and then, we further summarize and demonstrate our maternal health care management strategies including antenatal care planning, patient triage based on the risk level, admission control, and measures counteracting emergencies and newly discovered high‐risk cases at in‐patient department. In the meantime, we will explain the alterations we have done throughout different stages of the epidemic and also review relative articles in both Chinese and English to compare our strategies with those of other areas. Although tens of COVID‐19 cases were confirmed in our hospital, no nosocomial infection has occurred and none of the pregnant women registered in our hospital was reported to be infected.
Highlights
Demonstration of three cases of pregnant women who developed a fever during hospitalization.
Soft woods have attracted enormous interest due to their anisotropic cellular microstructure and unique flexibility. The conventional wood-like materials are usually subject to the conflict between ...the superflexibility and robustness. Inspired by the synergistic compositions of soft suberin and rigid lignin of cork wood which has good flexibility and mechanical robustness, an artificial soft wood is reported by freeze-casting the soft-in-rigid (rubber-in-resin) emulsions, where the carboxy nitrile rubber confers softness and rigid melamine resin provides stiffness. The subsequent thermal curing induces micro-scale phase inversion and leads to a continuous soft phase strengthened by interspersed rigid ingredients. The unique configuration ensures crack resistance, structural robustness and superb flexibility, including wide-angle bending, twisting, and stretching abilities in various directions, as well as excellent fatigue resistance and high strength, overwhelming the natural soft wood and most wood-inspired materials. This superflexible artificial soft wood represents a promising substrate for bending-insensitive stress sensors.
Vinylcyclopropane (VCP) derivatives participate in a variety of transition-metal-catalyzed multicomponent cycloadditions to produce five- to eight-membered carbocycles. Various cycloaddition modes ...provide novel approaches to mono-, bi-, and polycyclic molecules. In this Synopsis, recent advances in transition-metal-catalyzed VCP cycloadditions are discussed, with a particular emphasis on the influence of VCP substitution pattern on cycloaddition modes. A tabular summary of applications of the VCP cycloadditions in natural product synthesis is also presented.
Cellulose aerogels are plagued by intermolecular hydrogen bond‐induced structural plasticity, otherwise rely on chemicals modification to extend service life. Here, we demonstrate a ...petrochemical‐free strategy to fabricate superelastic cellulose aerogels by designing hierarchical structures at multi scales. Oriented channels consolidate the whole architecture. Porous walls of dehydrated cellulose derived from thermal etching not only exhibit decreased rigidity and stickiness, but also guide the microscopic deformation and mitigate localized large strain, preventing structural collapse. The aerogels show exceptional stability, including temperature‐invariant elasticity, fatigue resistance (∼5 % plastic deformation after 105 cycles), high angular recovery speed (1475.4° s−1), outperforming most cellulose‐based aerogels. This benign strategy retains the biosafety of biomass and provides an alternative filter material for health‐related applications, such as face masks and air purification.
A new type of cellulose aerogels with anisotropic and hierarchical porous architecture are developed via a petrochemical‐free method. The aerogels display temperature‐invariant elasticity (∼5 % plastic deformation after 105 compressive cycles at 50 % strain), large‐strain recoverability (folding and twisting), angular recovery speed high up to 1475.4° s−1, and exceptional fatigue resistance.
Practical syntheses of natural products and their analogues with eight-membered carbocyclic skeletons are important for medicinal and biological investigations. However, methods and strategies to ...construct the eight-membered carbocycles are limited. Therefore, developing new methods to synthesize the eight-membered carbocycles is highly desired. In this Account, we describe our development of three rhodium-catalyzed cycloadditions for the construction of the eight-membered carbocycles, which have great potential in addressing the challenges in the synthesis of medium-sized ring systems. The first reaction described in this Account is our computationally designed rhodium-catalyzed two-component 5 + 2 + 1 cycloaddition of ene–vinylcyclopropanes (ene–VCPs) and CO for the diastereoselective construction of bi- and tricyclic cyclooctenones. The design of this reaction is based on the hypothesis that the C(sp3)–C(sp3) reductive elimination of the eight-membered rhodacycle intermediate generated from the rhodium-catalyzed cyclopropane cleavage and alkene insertion, giving Wender’s 5 + 2 cycloadduct, is not easy. Under CO atmosphere, CO insertion may occur rapidly, converting the eight-membered rhodacycle into a nine-membered rhodacycle, which then undergoes an easy C(sp2)–C(sp3) reductive elimination process and furnishes the 5 + 2 + 1 product. This hypothesis was supported by our preliminary DFT studies and also served as inspiration for the development of two 7 + 1 cycloadditions: the 7 + 1 cycloaddition of buta-1,3-dienylcyclopropanes (BDCPs) and CO for the construction of cyclooctadienones, and the benzo/7 + 1 cycloaddition of cyclopropyl-benzocyclobutenes (CP-BCBs) and CO to synthesize the benzocyclooctenones. The efficiency of these rhodium-catalyzed cycloadditions can be revealed by the application in natural product synthesis. Two eight-membered ring-containing natural products, (±)-asterisca-3(15),6-diene and (+)-asteriscanolide, have been synthesized using the 5 + 2 + 1 cycloaddition as the key step. In the latter case, excellent asymmetric induction was obtained using a chiral substrate. The efficiency of the 5 + 2 + 1 reaction was further demonstrated by the synthesis of four sesquiterpene natural products, (±)-pentalenene, (+)-hirsutene, (±)-1-desoxyhypnophilin, and (±)-hirsutic acid C, containing linear or branched triquinane skeletons utilizing the tandem or stepwise 5 + 2 + 1 cycloaddition/aldol reaction strategy. With the success of 5 + 2 + 1 cycloaddition in natural product synthesis, application of the 7 + 1 and benzo/7 + 1 cycloadditions in target- and function-oriented syntheses can be envisioned.
Developing new transition metal‐catalyzed asymmetric cycloadditions for the synthesis of five‐membered carbocycles (FMCs) is a research frontier in reaction development due to the ubiquitous presence ...of chiral FMCs in various functional molecules. Reported here is our discovery of a highly enantioselective intramolecular 3+2 cycloaddition of yne‐alkylidenecyclopropanes (yne‐ACPs) to bicyclo3.3.0octadiene and bicyclo4.3.0nonadiene molecules using a cheap Co catalyst and commercially available chiral ligand (S)‐Xyl‐BINAP. This reaction avoids the use of precious Pd and Rh catalysts, which are usually the choices for 3+2 reactions with ACPs. The enantiomeric excess in the present reaction can be up to 92 %. Cationic cobalt(I) species was suggested by experiments as the catalytic species. DFT calculations showed that this 3+2 reaction starts with oxidative cyclometallation of alkyne and ACP, followed by ring opening of the cyclopropyl (CP) group and reductive elimination to form the cycloadduct. This mechanism is different from previous 3+2 reactions of ACPs, which usually start from CP cleavage, not from oxidative cyclization.
The first Co‐catalyzed asymmetric intramolecular 3+2 reaction of yne‐alkylidenecyclopropanes (yne‐ACPs) using a commercially available ligand has been realized for the synthesis of 5/5 and 6/5 bicycles. This reaction avoids the use of precious Pd and Rh catalysts usually used for these reactions. Mechanistic studies suggest that the reaction takes places via oxidative cyclometallation of the alkyne and the ACP, ring opening of the cyclopropyl group, and reductive elimination.
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