Thermoelectric technology enables the harvest of waste heat and its direct conversion into electricity. The conversion efficiency is determined by the materials figure of merit
Here we show a maximum
...of ~2.8 ± 0.5 at 773 kelvin in n-type tin selenide (SnSe) crystals out of plane. The thermal conductivity in layered SnSe crystals is the lowest in the out-of-plane direction two-dimensional (2D) phonon transport. We doped SnSe with bromine to make n-type SnSe crystals with the overlapping interlayer charge density (3D charge transport). A continuous phase transition increases the symmetry and diverges two converged conduction bands. These two factors improve carrier mobility, while preserving a large Seebeck coefficient. Our findings can be applied in 2D layered materials and provide a new strategy to enhance out-of-plane electrical transport properties without degrading thermal properties.
A 3D hierarchical meso‐ and macroporous Na3V2(PO4)3‐based hybrid cathode with connected Na ion/electron pathways is developed for ultra‐fast charge and discharge sodium‐ion batteries. It delivers an ...excellent rate capability (e.g., 86 mA h g−1 at 100 C) and outstanding cycling stability (e.g., 64% retention after 10 000 cycles at 100 C), indicating its superiority in practical applications.
Microstructure engineering is an effective strategy to reduce lattice thermal conductivity (κl) and enhance the thermoelectric figure of merit (zT). Through a new process based on melt‐centrifugation ...to squeeze out excess eutectic liquid, microstructure modulation is realized to manipulate the formation of dislocations and clean grain boundaries, resulting in a porous network with a platelet structure. In this way, phonon transport is strongly disrupted by a combination of porosity, pore surfaces/junctions, grain boundaries, and lattice dislocations. These collectively result in a ≈60% reduction of κl compared to zone melted ingot, while the charge carriers remain relatively mobile across the liquid‐fused grains. This porous material displays a zT value of 1.2, which is higher than fully dense conventional zone melted ingots and hot pressed (Bi,Sb)2Te3 alloys. A segmented leg of melt‐centrifuged Bi0.5Sb1.5Te3 and Bi0.3Sb1.7Te3 could produce a high device ZT exceeding 1.0 over the whole temperature range of 323–523 K and an efficiency up to 9%. The present work demonstrates a method for synthesizing high‐efficiency porous thermoelectric materials through an unconventional melt‐centrifugation technique.
The melt‐centrifugation technique is demonstrated to be able to decrease the thermal conductivity while preserving the good electrical properties. By introducing a unique porous structure with microscale dislocation, ≈60% reduction in lattice thermal conductivity compared to conventional zone melted ingots is achieved. Such a method paves a new way for top‐down introduction of large porosity and dense dislocations in bulk materials.
Individuals with high anti-citrullinated protein antibody (ACPA) titers have an increased risk of developing rheumatoid arthritis (RA). Although our knowledge of the generation and production of ...ACPAs has continuously advanced during the past decade, our understanding on the pathogenic mechanisms of how ACPAs interact with immune cells to trigger articular inflammation is relatively limited. Citrullination disorders drive the generation and maintenance of ACPAs, with profound clinical significance in patients with RA. The loss of tolerance to citrullinated proteins, however, is essential for ACPAs to exert their pathogenicity. N-linked glycosylation, cross-reactivity and the structural interactions of ACPAs with their citrullinated antigens further direct their biological functions. Although questions remain in the pathogenicity of ACPAs acting as agonists for a receptor-mediated response, immune complex (IC) formation, complement system activation, crystallizable fragment gamma receptor (FcγR) activation, cross-reactivity to joint cartilage and neutrophil extracellular trap (NET)-related mechanisms have all been suggested recently. This paper presents a critical review of the characteristics and possible biological effects and mechanisms of the immunopathogenesis of ACPAs in patients with RA.
Self‐supported nanotube arrays of sulfur‐doped TiO2 on metal substrates are fabricated using electrochemical anodization and subsequent sulfidation. The nanotube arrays can serve as an efficient ...anode for sodium storage, enabling ultrastable cycling (retaining 91% of the 2nd capacity up to 4400 cycles) and robust rate capability (167 mA h g−1 at 3350 mA g−1), remarkably outperforming any other reported TiO2‐based electrodes.
Chronic exercise has been reported to improve cognitive function. However, whether and how different types of exercise affect
various learning and memory tasks remain uncertain. To address this ...issue, male BALB/c mice were trained for 4 weeks under
two different exercise protocols: moderate treadmill running or voluntary wheel running. After exercise training, their spatial
memory and aversive memory were evaluated by a Morris water maze and by one-trial passive avoidance (PA), respectively. Levels
of neural plasticity-related proteins, i.e. brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB)
and synaptotagmin I (Syt I), in hippocampus and amygdala were determined by ELISA or immunoblotting. Finally, the functional
roles of these proteins in the basolateral amygdala were verified by locally blocking them with K252a (a TrkB kinase inhibitor),
or lentivirus expressing Syt I shRNA. We found that (1) although both moderate treadmill running and wheel running improved
the Morris water maze performance, only the former improved PA performance; (2) likewise, both exercise protocols upregulated
the BDNFâTrkB pathway and Syt I in the hippocampus, whereas only treadmill exercise upregulated their expression levels in
the amygdala; (3) local injection of K252a abolished the treadmill exercise-facilitated PA performance and upregulation of
amygdalar TrkB and Syt I; and (4) local administration of Syt I shRNA abolished the treadmill exercise-facilitated PA performance
and upregulation of amygdalar Syt I. Therefore, our results support the notion that different forms of exercise induce neuroplasticity
changes in different brain regions, and thus exert diverse effects on various forms of learning and memory.
Summary
Fruit ripening is a critical phase in the production and marketing of fruits. Previous studies have indicated that fruit ripening is a highly coordinated process, mainly regulated at the ...transcriptional level, in which transcription factors play essential roles. Thus, identifying key transcription factors regulating fruit ripening as well as their associated regulatory networks promises to contribute to a better understanding of fruit ripening. In this study, temporal gene expression analyses were performed to investigate banana fruit ripening with the aim to discern the global architecture of gene regulatory networks underlying fruit ripening. Eight time points were profiled covering dynamic changes of phenotypes, the associated physiology and levels of known ripening marker genes. Combining results from a weighted gene co‐expression network analysis (WGCNA) as well as cis‐motif analysis and supported by EMSA, Y1H, tobacco‐, banana‐transactivation experimental results, the regulatory network of banana fruit ripening was constructed, from which 25 transcription factors were identified as prime candidates to regulate the ripening process by modulating different ripening‐related pathways. Our study presents the first global view of the gene regulatory network involved in banana fruit ripening, which may provide the basis for a targeted manipulation of fruit ripening to attain higher banana and loss‐reduced banana commercialization.
A 3D yolk–shell‐like electrode material composed of a porous interconnected graphene network and embedded Ni2P nanoparticles is designed and fabricated by an assembly and self‐template strategy. This ...novel nanoarchitecture integrates the advantages of nanostructure and microstructure, and provides highly efficient and stable electrochemical circuits involving the active nanoparticles, leading to excellent electrochemical performance in terms of reversibility, rate capability, and cycle stability.
Sodium‐ion batteries (SIBs) have attracted increasing attention in the past decades, because of high overall abundance of precursors, their even geographical distribution, and low cost. Apart from ...inherent thermodynamic disadvantages, SIBs have to overcome multiple kinetic problems, such as fast capacity decay, low rate capacities and low Coulombic efficiencies. A special case is sodium super ion conductor (NASICON)‐based electrode materials as they exhibit – besides pronounced structural stability – exceptionally high ion conductivity, rendering them most promising for sodium storage. Owing to the limiting, comparatively low electronic conductivity, nano‐structuring is a prerequisite for achieving satisfactory rate‐capability. In this review, we analyze advantages and disadvantages of NASICON‐type electrode materials and highlight electrode structure design principles for obtaining the desired electrochemical performance. Moreover, we give an overview of recent approaches to enhance electrical conductivity and structural stability of cathode and anode materials based on NASICON structure. We believe that this review provides a pertinent insight into relevant design principles and inspires further research in this respect.
Sodium super ion conductor (NASICON)‐based electrode materials, exhibiting pronounced structural stability and exceptionally high ion conductivity are promising materials for sodium storage. Challenges and perspectives of NASICON‐type electrode materials are discussed, and electrode structure design principles for obtaining the desired electrochemical performance are highlighted. Recent progress in enhancing electrical conductivity and structural stability of NASICON materials is summarized.
An emerging hallmark of cancer is reprogrammed cellular metabolism, and several cancers involve increased glucose intake and glutamine addiction. Hepatocellular carcinoma (HCC) is one of the most ...fatal cancers, and its molecular basis needs to be delineated to identify biomarkers for its potential treatment without resection. Therefore, this study aimed to determine the metabolism status of HCC by evaluating the expression of the glucose transporter GLUT1 and glutamine transporter ASCT2. We enrolled 192 patients with surgically resected HCC in this study. Their tissue samples were subjected to immunohistochemistry to detect GLUT1 and ASCT2 expression. The prognostic value of GLUT1 and ASCT2 expression and their combined metabolic index was determined by Kaplan-Meier analysis and the Cox proportional hazards model. We found that GLUT1 and ASCT2 expression was significantly upregulated in tumor tissues as compared to adjacent non-tumor tissues and was positively associated with tumor size. Survival analysis revealed that patients with high GLUT1 or ASCT2 expression had poor overall survival (OS) and recurrence-free survival (RFS). In HCC patients, ASCT2 expression was an independent negative prognostic factor for OS (hazard ratio HR, 1.760; 95% confidence interval CI = 1.124-2.755; p = 0.013) and the metabolic index was an independent negative prognostic factor for OS (HR = 1.672, 95% CI = 1.275-2.193, p < 0.001) and RFS (HR = 1.362, 95% CI = 1.066-1.740, p = 0.013). In conclusion, the tumor metabolism status determined by expression of GLUT1 and ASCT2 and their metabolic index is a promising prognostic predictor for HCC patients.
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