Transition metal single‐atom catalysts (SACs) are currently a hot area of research in the field of electrocatalytic oxygen reduction reaction (ORR). In this review, the recent advances in transition ...metal single‐atom supported by 2D materials as catalysts for ORR with high performance are reported. Due to their large surface area, uniformly exposed lattice plane, and adjustable electronic state, 2D materials are ideal supporting materials for exploring ORR active sites and surface reactions. The rational design principles and synthetic strategies of transition metal SACs supported by 2D materials are systematically introduced while the identification of active sites, their possible catalytic mechanisms as well as the perspectives on the future of transition metal SACs supported by 2D materials for ORR applications are discussed. Finally, according to the current development trend of ORR catalysts, the future opportunities and challenges of transition metal SACs supported by 2D materials are summarized.
In this review, the rational design and synthesis of transition metal single‐atom catalysts supported by 2D materials are systematically summarized while the identification of active sites, their possible catalytic mechanisms, and the future perspectives for the oxygen reduction reaction (ORR) are provided. Finally, the opportunities and challenges are also discussed according to the current development trends in ORR catalysts.
Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes ...(MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor.
Immune checkpoint inhibitors had a great effect in triple-negative breast cancer (TNBC); however, they benefited only a subset of patients, underscoring the need to co-target alternative pathways and ...select optimal patients. Herein, we investigated patient subpopulations more likely to benefit from immunotherapy and inform more effective combination regimens for TNBC patients.
We conducted exploratory analyses in the FUSCC cohort to characterize a novel patient selection method and actionable targets for TNBC immunotherapy. We investigated this in vivo and launched a phase 2 trial to assess the clinical value of such criteria and combination regimen. Furthermore, we collected clinicopathological and next-generation sequencing data to illustrate biomarkers for patient outcomes.
CD8-positivity could identify an immunomodulatory subpopulation of TNBCs with higher possibilities to benefit from immunotherapy, and angiogenesis was an actionable target to facilitate checkpoint blockade. We conducted the phase II FUTURE-C-Plus trial to assess the feasibility of combining famitinib (an angiogenesis inhibitor), camrelizumab (a PD-1 monoclonal antibody) and chemotherapy in advanced immunomodulatory TNBC patients. Within 48 enrolled patients, the objective response rate was 81.3% (95% CI, 70.2-92.3), and the median progression-free survival was 13.6 months (95% CI, 8.4-18.8). No treatment-related deaths were reported. Patients with CD8- and/or PD-L1- positive tumors benefit more from this regimen. PKD1 somatic mutation indicates worse progression-free and overall survival.
This study confirms the efficacy and safety of the triplet regimen in immunomodulatory TNBC and reveals the potential of combining CD8, PD-L1 and somatic mutations to guide clinical decision-making and treatments.
ClinicalTrials.gov: NCT04129996 . Registered 11 October 2019.
Flexible fibers and textiles featuring photothermal conversion and storage capacities are ideal platforms for solar‐energy utilization and wearable thermal management. Other than using ...fossil‐fuel‐based synthetic fibers, re‐designing natural fibers with nanotechnology is a sustainable but challenging option. Herein, advanced core–shell structure fibers based on plant‐based nanocelluloses are obtained using a facile co‐axial wet‐spinning process, which has superior photothermal and thermal‐regulating performances. Besides serving as the continuous matrix, nanocelluloses also have two other important roles: dispersing agent when exfoliating molybdenum disulfide (MoS2), and stabilizer for phase change materials (PCM) in the form of Pickering emulsion. Consequently, the shell layer contains well‐oriented nanocelluloses and MoS2, and the core layer contains a high content of PCM in a leak‐proof encapsulated manner. Such a hierarchical cellulosic supportive structure leads to high mechanical strength (139 MPa), favorable flexibility, and large latent heat (92.0 J g−1), surpassing most previous studies. Furthermore, the corresponding woven cloth demonstrates satisfactory thermal‐regulating performance, high solar‐thermal conversion and storage efficiency (78.4–84.3%), and excellent long‐term performance. In all, this work paves a new way to build advanced structures by assembling nanoparticles and polymers for functional composite fibers in advanced solar‐energy‐related applications.
Photothermal and thermal‐regulating fibers with a unique core–shell structure are obtained using a facile co‐axial wet‐spinning process. Beyond assembling into a continuous matrix, cellulose nanofibrils also serve as in situ stabilizers for photothermal nanoparticles in the shell layer and phase change materials in the core layer to enable advanced structural design.
Ferroptosis, triggered by discoordination of iron, thiols and lipids, leads to the accumulation of 15-hydroperoxy (Hp)-arachidonoyl-phosphatidylethanolamine (15-HpETE-PE), generated by complexes of ...15-lipoxygenase (15-LOX) and a scaffold protein, phosphatidylethanolamine (PE)-binding protein (PEBP)1. As the Ca2+-independent phospholipase A2β (iPLA2β, PLA2G6 or PNPLA9 gene) can preferentially hydrolyze peroxidized phospholipids, it may eliminate the ferroptotic 15-HpETE-PE death signal. Here, we demonstrate that by hydrolyzing 15-HpETE-PE, iPLA2β averts ferroptosis, whereas its genetic or pharmacological inactivation sensitizes cells to ferroptosis. Given that PLA2G6 mutations relate to neurodegeneration, we examined fibroblasts from a patient with a Parkinson’s disease (PD)-associated mutation (fPDR747W) and found selectively decreased 15-HpETE-PE-hydrolyzing activity, 15-HpETE-PE accumulation and elevated sensitivity to ferroptosis. CRISPR-Cas9-engineered Pnpla9R748W/R748W mice exhibited progressive parkinsonian motor deficits and 15-HpETE-PE accumulation. Elevated 15-HpETE-PE levels were also detected in midbrains of rotenone-infused parkinsonian rats and α-synuclein-mutant SncaA53T mice, with decreased iPLA2β expression and a PD-relevant phenotype. Thus, iPLA2β is a new ferroptosis regulator, and its mutations may be implicated in PD pathogenesis.Ca2+-independent phospholipase A2β cleaves an oxidized form of phosphatidylethanolamine (PE) involved in ferroptosis such that increases in PE sensitize cells to ferroptosis. A mutant allele of the enzyme links neurodegeneration and ferroptosis.
Aromatic heterocycles are ubiquitous building blocks in bioactive natural products, pharmaceutical and agrochemical industries. Accordingly, the carborane-fused heterocycles would be potential ...candidates in drug discovery, nanomaterials, metallacarboranes, as well as photoluminescent materials. In recent years, the transition metal catalyzed B-H activation has been proved to be an effective protocol for selective functionalization of B-H bond of
-carboranes, which has been further extended for the synthesis of polyhedral borane cluster-fused heterocycles via cascade B-H functionalization/annulation process. This article summarizes the recent progress in construction of polyhedral borane cluster-fused heterocycles via B-H activation.
Continuous filaments obtained through the wet spinning of nanocellulose have promising mechanical properties with sustainable features. To guarantee proper spinnability for wet spinning, freshly made ...cellulose nanofibril (CNF) suspension needs to be concentrated to have a concentration above 1 wt%, resulting in energy- and time-consuming, and inferior mechanical properties of the final filaments owing to decreasing the CNF alignment against shear flows. In this study, a CNF spinning suspension at a low concentration (0.4 wt%) can be used right after the fibrillation process without further treatments. The effects of the concentration and re-concentrating process are studied by carefully characterizing the rheological behavior and filament solidification processes, which provides more fundamental understandings on the spinnability and CNF network formation of such colloidal CNF suspensions. Combined with a post stretching process, the final dried CNF filaments have superior mechanical properties with Young's modulus and tensile strength of 35 GPa and 567 MPa, surpassing most literature data. Moreover, different functional particles can be easily incorporated to prepare functional filaments. With facile preparation and superior properties, these CNF filaments may be suitable for advanced composite filler and special textile applications.
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We demonstrate, for the first time, a new method of fabricating hybrid MoS2/poly(ethyleneimine)-modified graphene oxide (PEI-GO) composites assembled through electrostatically charged interaction ...between the negatively charged MoS2 nanosheets and positively charged PEI-GO in an aqueous solution. The GO can not only improve the electronic conductivity of the MoS2/PEI-GO composites, leading to an excellent charge-transfer network, but also hamper the restacking of MoS2 nanosheets. The composition ratios between MoS2 and PEI-GO were also optimized with the highest specific capacitance of 153.9 F g–1 where 96.0% of the initial specific capacitance remains after 6800 cycles. The specific capacitance of only 117.5 F g–1 was observed for the pure MoS2 nanosheets, and 68.2% of the initial specific capacitance was achieved after 5000 cycles. The excellent electrochemical performance of the hybrid MoS2/PEI-GO composites was demonstrated by establishing an asymmetric supercapacitor with a MoS2/PEI-GO-based negative electrode and an activated-carbon positive electrode. The asymmetric supercapacitor provided a maximum capacitance of 42.9 F g–1, and 93.1% of the initial capacitance was maintained after 8000 cycles. Furthermore, a MoS2/PEI-GO//activated-carbon asymmetric supercapacitor delivered an energy density of 19.3 W h kg–1 and a power density of 4500 W kg–1, indicating the potential of the hybrid MoS2/PEI-GO composites in electrochemical energy storage applications.
A highly efficient nitrogen-doped carbon nanotubes (N-CNTs) electrocatalyst derived from nitrogen-doped carbon dots (N-Cdots) and metal-organic frameworks (MOFs) for oxygen reduction reaction (ORR) ...was demonstrated successfully for the first time. The N-Cdots with plenty of hydroxyl and amine groups can favor the formation of N-CNTs through the catalytic decomposition of MOFs in a lower temperature. On the other hand, the N-Cdots serve as inducers of the graphitic structure and supply extra nitrogen, extending a potential electrocatalytic activity of N-CNTs. Results show that the N-CNTs provided an excellent ORR electrocatalytic performance, yielding a positive onset potential of 0.88 V vs. RHE and a high kinetic current density of up to 5.58 mA cm−2 at 0.2 V. In addition, the slope of N-CNTs being ∼81 mV/dec can be found to be much lower than that of the Pt/C catalyst (∼132 mV/dec). These superior performances are attributed to defects in the graphitic crystal structure and the synergistic coupling effects of N-Cdots and N-CNTs. In addition, a slight loss in activity for the N-CNTs catalyst can be found whereas the Pt/C catalyst decreases nearly 45% of its initial activity, which exhibit highly catalytic durability and tolerance to methanol in an alkaline media.
Nitrogen-doped carbon nanotubes (N-CNTs) electrocatalyst derived from nitrogen-doped carbon dots (N-Cdots) and metal-organic frameworks (MOFs) was demonstrated for the oxygen reduction reaction (ORR), yielding a positive onset potential of 0.88 V vs. RHE and a high kinetic current density of up to 5.58 mA cm−2 at 0.2 V, a highly catalytic durability, and tolerance to methanol in an alkaline media. Display omitted
•Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized by a direct pyrolysis of ZIF-67 and N-Cdots mixture simultaneously in a lower temperature for the first time.•N-Cdots not only serve as the inducer of the graphitic structure and the extra nitrogen supplier, but also favor the N-CNTs formation through catalytic decomposition of ZIF-67.•The defects of graphitic crystal structure and synergic effect of N-Cdots greatly outperforms the ORR electrocatalytic performance.•An efficient 4e-dominated ORR process and an outstanding cyclic stability were paramount for N-CNTs exhibiting an excellent electrocatalytic performance than N-Cdots and Co–N–C nanohybrids.
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