Although self-healing gels with structural resemblance to biological tissues attract great attention in biomedical fields, it remains a dilemma for combination between fast self-healing properties ...and high mechanical toughness. On the basis of the design of dynamic reversible cross-links, we incorporate rigid tannic acid-coated cellulose nanocrystal (TA@CNC) motifs into the poly(vinyl alcohol) (PVA)–borax dynamic networks for the fabrication of a high toughness and rapidly self-healing nanocomposite (NC) hydrogel, together with dynamically adhesive and strain-stiffening properties that are particularly indispensable for practical applications in soft tissue substitutes. The results demonstrate that the obtained NC gels present a highly interconnected network, where flexible PVA chains wrap onto the rigid TA@CNC motifs and form the dynamic TA@CNC–PVA clusters associated by hydrogen bonds, affording the critical mechanical toughness. The synergetic interactions between borate–diol bonds and hydrogen bonds impart a typical self-healing behavior into the NC gels, allowing the dynamic cross-linked networks to undergo fast rearrangement in the time scale of seconds. Moreover, the obtained NC hydrogels not only mimic the main feature of biological tissues with the unique strain-stiffening behavior but also display unique dynamic adhesiveness to nonporous and porous substrates. It is expected that this versatile approach opens up a new prospect for the rational design of multifunctional cellulosic hydrogels with remarkable performance to expand their applications.
High kinetics oxygen reduction reaction (ORR) electrocatalysts under low temperature are critical and highly desired for temperature‐tolerant energy conversion and storage devices, but remain ...insufficiently investigated. Herein, oxygen vacancy‐rich porous perovskite oxide (CaMnO3) nanofibers coated with reduced graphene oxide coating (V‐CMO/rGO) are developed as the air electrode catalyst for low‐temperature and knittable Zn–air batteries. V‐CMO/rGO exhibits top‐level ORR activity among perovskite oxides and shows impressive kinetics under low temperature. Experimental and theoretical calculation results reveal that the synergistic effect between metal atoms and oxygen vacancies, as well as the accelerated kinetics and enhanced electric conductivity and mass transfer over the rGO coated nanofiber 3D network contribute to the enhanced catalytic activity. The desorption of ORR intermediate is promoted by the regulated electron filling. The V‐CMO/rGO drives knittable and flexible Zn–air batteries under a low temperature of −40 °C with high peak power density of 56 mW cm−2 and long cycle life of over 80 h. This study provides insight of kinetically active catalyst and facilitates the ZABs application in harsh environment.
The oxygen reduction reaction kinetics of a perovskite oxide is significantly promoted by a facile metal–vacancy strategy. The newly developed vacancy‐rich porous perovskite nanofibers exhibit comparable activities to the commercial Pt/C and even surpass it under low temperature. The developed catalyst can drive knittable fibrous‐type and sandwich‐type zinc–air batteries under low temperature of −40 °C with impressive performance.
Bladder cancer (BC) is one of the most prevalent cancers worldwide. However, the recurrence rate and five-year survival rate have not been significantly improved in advanced BC, and new therapeutic ...strategies are urgently needed. The anticancer activity of stellettin B (SP-2), a triterpene isolated from the marine sponge
sp., was evaluated with the MTT assay as well as PI and Annexin V/7-AAD staining. Detailed mechanisms were elucidated through an NGS analysis, protein arrays, and Western blotting. SP-2 suppressed the viability of BC cells without severe toxicity towards normal uroepithelial cells, and it increased apoptosis with the activation of caspase 3/8/9, PARP, and γH2AX. The phosphorylation of FGFR3 and its downstream targets were downregulated by SP-2. Meanwhile, it induced autophagy in BC cells as evidenced by LC3-II formation and p62 downregulation. The inhibition of autophagy using pharmacological inhibitors or through an ATG5-knockout protected RT-112 cells from SP-2-induced cell viability suppression and apoptosis. In addition, the upregulation of DAPK2 mRNA and protein expression also contributed to SP-2-induced cytotoxicity and apoptosis. In RT-112 cells, an FGFR3-TACC3-knockout caused the downregulation of DAPK2, autophagy, and apoptosis. In conclusion, this is the first study demonstrating that SP-2 exhibits potent anti-BC activity by suppressing the FGFR3-TACC3/Akt/mTOR pathway, which further activates a novel autophagy/DAPK2/apoptosis signaling cascade.
Abstract
Designing novel single‐atom catalysts (SACs) supports to modulate the electronic structure is crucial to optimize the catalytic activity, but rather challenging. Herein, a general strategy ...is proposed to utilize the metalloid properties of supports to trap and stabilize single‐atoms with low‐valence states. A series of single‐atoms supported on the surface of tungsten carbide (M‐WC
x
, M=Ru, Ir, Pd) are rationally developed through a facile pyrolysis method. Benefiting from the metalloid properties of WC
x
, the single‐atoms exhibit weak coordination with surface W and C atoms, resulting in the formation of low‐valence active centers similar to metals. The unique metal‐metal interaction effectively stabilizes the low‐valence single atoms on the WC
x
surface and improves the electronic orbital energy level distribution of the active sites. As expected, the representative Ru‐WC
x
exhibits superior mass activities of 7.84 and 62.52 A mg
Ru
−1
for the hydrogen oxidation and evolution reactions (HOR/HER), respectively. In‐depth mechanistic analysis demonstrates that an ideal dual‐sites cooperative mechanism achieves a suitable adsorption balance of H
ad
and OH
ad
, resulting in an energetically favorable Volmer step. This work offers new guidance for the precise construction of highly active SACs.
Anodic organic upgrading offers a promising strategy to produce value-added chemicals and to facilitate coupled hydrogen production but it is still challenging in terms of long-term stability and ...high activity of the electrocatalysts at large current densities. Herein, highly dispersed FeNi oxide heterojunctions anchored on nickel foam (Fe
2
O
3
/NiO) as efficient catalysts are synthesized
via
an ultrafast solution combustion strategy. In methanol electrooxidation, a large absolute current density (500 mA cm
2
at 1.654 V
vs.
RHE) with a high faradaic efficiency (>98%) is achieved.
In situ
infrared spectroscopy and theoretical calculations indicate that the heterostructure modulates the electronic state of NiO through strong electronic interactions, providing unique collaborative active sites for the favorable dynamic conversion of methanol to formate and inhibiting further oxidation. Furthermore, the interface confinement effect also stabilizes the metastable nickel active site, which ensures the stability of the catalyst structure during the reversible redox cycling, resulting in a steady and dynamically-enhanced catalytic process.
The ultrafast solution combustion synthesis of heterogeneous interface is developed to boost anodic organic upgrading reaction, which exhibits remarkable current density and faradaic efficiency benefiting from the strong electronic interaction.
The continuous oxidation and leachability of active sites in Ru‐based catalysts hinder practical application in proton‐exchange membrane water electrolyzers (PEMWE). Herein, robust inter‐doped ...tungsten–ruthenium oxide heterostructures (Ru–W)Ox fabricated by sequential rapid oxidation and metal thermomigration processes are proposed to enhance the activity and stability of acidic oxygen evolution reaction (OER). The introduction of high‐valent W species induces the valence oscillation of the Ru sites during OER, facilitating the cyclic transition of the active metal oxidation states and maintaining the continuous operation of the active sites. The preferential oxidation of W species and electronic gain of Ru sites in the inter‐doped heterostructure significantly stabilize RuOx on WOx substrates beyond the Pourbaix stability limit of bare RuO2. Furthermore, the asymmetric Ru–O–W active units are generated around the heterostructure interface to adsorb the oxygen intermediates synergistically, enhancing the intrinsic OER activity. Consequently, the inter‐doped (Ru–W)Ox heterostructures not only demonstrate an overpotential of 170 mV at 10 mA cm−2 and excellent stability of 300 h in acidic electrolytes but also exhibit the potential for practical applications, as evidenced by the stable operation at 0.5 A cm−2 for 300 h in PEMWE.
The robust inter‐doped (Ru–W)Ox heterostructures enhance the activity and stability of acidic oxygen evolution reaction (OER) by inducing valence oscillation and stabilizing RuOx on WOx substrates. The asymmetric Ru–O–W units synergistically adsorb oxygen intermediates, resulting in improved intrinsic activity and demonstrating potential for practical applications with low overpotential and excellent stability.
Arabidopsis mutants produced by constitutive overexpression of the CRISPR/Cas9 genome editing system are usually mosaics in the T1 generation. In this study, we used egg cell-specific promoters to ...drive the expression of Cas9 and obtained non-mosaic T1 mutants for multiple target genes with high efficiency. Comparisons of 12 combinations of eight promoters and two terminators found that the efficiency of the egg cell-specific promoter-controlled CRISPR/Cas9 system depended on the presence of a suitable terminator, and the composite promoter generated by fusing two egg cell-specific promoters resulted in much higher efficiency of mutation in the T1 generation compared with the single promoters.
Hepatitis D virus (HDV) is a defective virus that completes its life cycle only with hepatitis B virus (HBV). The HBV with HDV super-infection has been considered as one of the most severe forms of ...the chronic viral hepatitis. However, there is a scarcity of data on the global burden of HDV infection.
We searched PubMed, Embase, Cochrane Library and China Knowledge Resource Integrated databases from 1 January 1977 to 31 December 2016. We included studies with a minimum sample size of 50 patients. Our study analysed data from a total of 40 million individuals to estimate the prevalence of HDV by using Der-Simonian Laird random-effects model. The data were further categorised according to risk factors.
From a total of 2717 initially identified studies, only 182 articles from 61 countries and regions met the final inclusion criteria. The overall prevalence of HDV was 0.98% (95% CI 0.61 to 1.42). In HBsAg-positive population, HDV pooled prevalence was 14.57% (95% CI 12.93 to 16.27): Seroprevalence was 10.58% (95% CI 9.14 to 12.11) in mixed population without risk factors of intravenous drug use (IVDU) and high-risk sexual behaviour (HRSB). It was 37.57% (95% CI 29.30 to 46.20) in the IVDU population and 17.01% (95% CI 10.69 to 24.34) in HRSB population.
We found that approximately 10.58% HBsAg carriers (without IVDU and HRSB) were coinfected with HDV, which is twofold of what has been estimated before. We also noted a substantially higher HDV prevalence in the IVDU and HRSB population. Our study highlights the need for increased focus on the routine HDV screening and rigorous implementation of HBV vaccine programme.
Neutral oxygen evolution reaction (OER) with unique reactive environments exhibits extremely slow reaction kinetics, posing significant challenges in the design of catalysts. Herein, a built‐in ...electric field between the tungstate (Ni‐FeWO4) with adjustable work function and Lewis acid WO3 is elaborately constructed to regulate asymmetric interfacial electron distribution, which promotes electron accumulation of Fe sites in the tungstate. This decelerates the rapid dissolution of Fe under the OER potentials, thereby retaining the active hydroxyl oxide with the optimized OER reaction pathway. Meanwhile, Lewis acid WO3 enhances hydroxyl adsorption near the electrode surface to improve mass transfer. As expected, the optimized Ni‐FeWO4@WO3/NF self‐supporting electrode achieves a low overpotential of 235 mV at 10 mA cm−2 in neutral media and maintains stable operation for 200 h. Furthermore, the membrane electrode assembly constructed by such self‐supporting electrode exhibits robust stability for 250 h during neutral seawater electrolysis. This work deepens the understanding of the reconstruction of OER catalysts in neutral environments and paves the way for development of the energy conversion technologies.
A built‐in electric field between Ni‐FeWO4 and WO3 simultaneously achieves the electron‐rich state of the Fe sites in tungstate and improvement of the local reaction environment to suppress Fe leaching and accelerate mass transfer during neutral water oxidation, which endows the membrane electrode assembly constructed of Ni‐FeWO4@WO3/NF with low cell voltages and robust stability for neutral seawater electrolysis.
The gut microbiota-derived metabolite, trimethylamine N-oxide (TMAO) plays an important role in cardiovascular disease (CVD). The fasting plasma TMAO was shown as a prognostic indicator of CVD ...incident in patients and raised the interest of intervention targeting gut microbiota. Here we develop a clinically applicable method called oral carnitine challenge test (OCCT) for TMAO-related therapeutic drug efforts assessment and personalising dietary guidance.
A pharmacokinetic study was performed to verify the design of OCCT protocol. The OCCT was conducted in 23 vegetarians and 34 omnivores to validate gut microbiota TMAO production capacity. The OCCT survey was integrated with gut microbiome, host genotypes, dietary records and serum biochemistry. A humanised gnotobiotic mice study was performed for translational validation.
The OCCT showed better efficacy than fasting plasma TMAO to identify TMAO producer phenotype. The omnivores exhibited a 10-fold higher OR to be high TMAO producer than vegetarians. The TMAO-associated taxa found by OCCT in this study were consistent with previous animal studies. The TMAO producer phenotypes were also reproduced in humanised gnotobiotic mice model. Besides, we found the faecal
gene was not associated with TMAO production; therefore, other key relevant microbial genes might be involved. Finally, we demonstrated the urine TMAO exhibited a strong positive correlation with plasma TMAO (r=0.92, p<0.0001) and improved the feasibility of OCCT.
The OCCT can be used to identify TMAO-producer phenotype of gut microbiota and may serve as a personal guidance in CVD prevention and treatment.
NCT02838732; Results.
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