Recycling and reusing spent graphite have become urgent tasks, with massive numbers of lithium-ion batteries (LIBs) from hybrid electric vehicles (HEVs)/electric vehicles (EVs) retired every year. ...Meanwhile, interlayer designs based on carbon materials have attracted widespread attention to suppress the polysulfide shuttle effect in high-energy-density lithium-sulfur (Li-S) batteries. Nevertheless, designing simple and low-cost carbon-derived interlayers still remains a great challenge. Spent graphite possesses a porous structure, defects, and polar functional groups that were formed
in situ
, which can significantly confine polysulfides through a combination of physical and chemical adsorption. Meanwhile, transition metals introduced due to the dissolution of cathode active materials can also anchor polysulfides
via
S-TM bonding, as well as improving electrical conductivity and boosting polysulfide conversion kinetics. Herein, spent graphite recycled from waste LIBs was employed for the first time as a functional interlayer for Li-S batteries based on its intrinsic properties. The spent-graphite-derived interlayer exhibited remarkably enhanced trapping and catalytic performance toward polysulfides. A high discharge capacity of 968 mA h g
−1
with a low decay rate of 0.08% per cycle over 500 cycles at 1 C can be obtained. The present work not only provides a promising strategy for the design of interlayers, but it also shows a high-value application of spent graphite.
A spent-graphite-based functional interlayer was developed for the first time for use in Li-S batteries, utilizing the intrinsic properties of recovered graphite.
Despite recent advances in the assembly of organic nanotubes, conferral of sequence-defined engineering and dynamic response characteristics to the tubules remains a challenge. Here we report a new ...family of highly designable and dynamic nanotubes assembled from sequence-defined peptoids through a unique "rolling-up and closure of nanosheet" mechanism. During the assembly process, amorphous spherical particles of amphiphilic peptoid oligomers crystallize to form well-defined nanosheets before folding to form single-walled nanotubes. These nanotubes undergo a pH-triggered, reversible contraction-expansion motion. By varying the number of hydrophobic residues of peptoids, we demonstrate tuning of nanotube wall thickness, diameter, and mechanical properties. Atomic force microscopy-based mechanical measurements show peptoid nanotubes are highly stiff (Young's Modulus ~13-17 GPa). We further demonstrate the precise incorporation of functional groups within nanotubes and their applications in water decontamination and cellular adhesion and uptake. These nanotubes provide a robust platform for developing biomimetic materials tailored to specific applications.
Due to the highest theoretical specific capacity of 4200 mA h g−1 for Li4.4Si, silicon(Si)-based materials could fulfill the increasing demands of high-energy lithium-ion batteries (LIBs). However, ...the intrinsic huge volume expansion during the lithiation/delithiation process results in rapid capacity decay and short cycle life and restricts the satisfactory electrical performance of Si-based anodes. Binder plays an important role of maintaining the contact integrity between active material, conductive additive and the current collector, thereby reducing the pulverization of the Si particles during charge/discharge. Here, the review systematically summarizes the synthesis methods, design principles and working mechanisms, including chemical composition, superstructure, and various interactions between different functional moieties of synthetic binders and natural biomass binders, to reveal the structure-composition-performance relationship, offer practical solutions to challenging problems associated with defects of Si-based electrode materials in LIBs and aim at exploiting new family of binders that could be used in industrial level as well as providing design principles for other electrode binders in rechargeable batteries.
Display omitted
•Working mechanisms and design principles of Si-based anodes binders are presented.•Synergistic strategy of combining binders with anode structure design is discussed.•Synthesis methods, applied anodes, ICE and cycling performance are listed.
Obesity-induced adipose dysfunction is a major contributor to atherosclerosis. Cold exposure has been reported to affect atherosclerosis through regulation of adipose function, but the mechanism has ...not been well clarified. Here, adipocyte hypoxia-inducible factor 2α (HIF-2α) was upregulated after mild cold exposure at 16°C and mediated cold-induced thermogenesis. Adipocyte HIF-2α deficiency exacerbated Western-diet-induced atherosclerosis by increasing adipose ceramide levels, which blunted hepatocyte cholesterol elimination and thermogenesis. Mechanistically, Acer2, the gene encoding alkaline ceramidase 2, was identified as a novel target gene of HIF-2α, triggering ceramide catabolism. Adipose overexpression of ACER2 rescued adipocyte HIF-2α-deficiency-induced exacerbation of atherosclerosis. Furthermore, activation of adipose HIF-2α by the HIF prolyl hydroxylase inhibitor FG-4592 had protective effects on atherosclerosis, accompanied by a reduction in adipose and plasma ceramide and plasma cholesterol levels. This study highlights adipocyte HIF-2α as a putative drug target against atherosclerosis.
To address the challenges associated with the weak affinity and difficult separation of biochar, we developed chitosan–biochar hydrogel beads (CBHBs) as an efficient solution for removing reactive ...brilliant blue (RBB KN-R) from wastewater. The adsorption behavior and mechanism of RBB KN-R onto CBHBs were extensively studied. Notably, the adsorption capacity of RBB KN-R showed pH-dependence, and the highest adsorption capacity was observed at pH 2. The adsorption process was well fitted with the pseudo-second-order kinetic model and the intraparticle diffusion model. Film diffusion and intraparticle diffusion were both responsible for the adsorption of RBB KN-R onto CBHBs. At 298.15 K, the maximum adsorption capacity qm was determined to be 140.74 mg/g, with higher temperatures favoring the adsorption process. A complex mechanism involving π–π interactions, electrostatic attraction, hydrophobic interaction, and hydrogen bonding was found to contribute to the overall adsorption process. The experimental data discovered the coexisting substances and elevated ionic strength hindered the adsorption capacity. Significantly, after three cycles of adsorption–desorption, the CBHBs maintained an adsorption capacity above 95% for RBB KN-R. These promising results imply that CBHBs are a durable and cost-effective adsorbent for efficient removal of dyes from wastewater.
Sodium-ion batteries (SIBs) possess enormous development potential and broad market prospects in the field of large-scale energy storage and low-speed electric vehicles with low cost and abundant ...resources. The current cycle life of SIBs is only 1000-2000 cycles, which can meet the basic needs of low-speed electric vehicles, but it is insufficient for large-scale energy storage applications. The energy density, rate capability, cycle life and cost of SIBs depend largely on the cathode material used. Among the cathode materials for SIBs, the development of a layered oxide route is the most mature and promising strategy to take the lead in industrialization. Thus, the cycle life of a layered oxide cathode will directly affect the economy and practicability of SIBs. According to previous studies, the cycle life of layered oxide cathodes is mainly limited by irreversible phase transformation, the Jahn-Teller effect and the interface deterioration of materials during charging and discharging. In this review, the latest progress on layered oxide cathode materials is summarized, with emphasis on the problems of poor cycle life caused by irreversible phase transition, the Jahn-Teller effect and interface deterioration, and several strategies are proposed to alleviate these problems (multi-phase combination, morphology and structure optimization, chemical element substitution and surface coating). Furthermore, opportunities and challenges in the practical application of electrode materials are elucidated, which will guide the development of layered oxide cathodes in the future.
In this review, research progress on layered oxide cathodes for SIBs in recent years is summarized, with emphasis on the problems of poor cycle life caused by irreversible phase transition, Jahn-Teller effect and interface deterioration, and several strategies are proposed to alleviate these issues.
Although circular RNAs (circRNA) are known to modulate tumor initiation and progression, their role in hepatocellular carcinoma (HCC) metastasis remains poorly understood. Here, three ...metastasis-associated circRNAs identified in a previous circRNA-sequencing study were screened and validated in two HCC cohorts. CircRPN2 was downregulated in highly metastatic HCC cell lines and HCC tissues with metastasis. Patients with HCC with lower circRPN2 levels displayed shorter overall survival and higher rates of cumulative recurrence. Mechanistic studies in vitro and in vivo revealed that circRPN2 binds to enolase 1 (ENO1) and accelerates its degradation to promote glycolytic reprogramming through the AKT/mTOR pathway, thereby inhibiting HCC metastasis. CircRPN2 also acted as a competing endogenous RNA for miR-183-5p, which increases forkhead box protein O1 (FOXO1) expression to suppress glucose metabolism and tumor progression. In clinical samples, circRPN2 expression negatively correlated with ENO1 and positively correlated with FOXO1, and expression of circRPN2, either alone or in combination with ENO1 and FOXO1, was a novel indicator of HCC prognosis. These data support a model wherein circRPN2 inhibits HCC aerobic glycolysis and metastasis via acceleration of ENO1 degradation and regulation of the miR-183-5p/FOXO1 axis, suggesting that circRPN2 represents a possible therapeutic target in HCC.
The circRNA circRPN2 is a potential prognostic biomarker and therapeutic target in hepatocellular carcinoma that suppresses aerobic glycolysis and metastasis.
Background/Aims: Cerebral ischemia-reperfusion (I/R) injury involves multiple independently fatal terminal pathways. CK2α/NADPH oxidase is an important signaling pathway associated with ...ischemia-reperfusion injury, and miR-125b can regulate oxidative stress-related injury. In this study, we investigated whether the effect of miR-125b in rat brain I/R injury occurs through its modulation of the CK2α/NADPH oxidase pathway. Methods: Rats were subjected to 2 h of cerebral ischemia followed by 24 h of reperfusion to establish an I/R injury model. Neurological deficit was evaluated using a five-point score. Infarct volume was evaluated with 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and RT-PCR was used to detect expressions of miR125b and CK2α. We then examined the association between miR-125b expression and the CK2α/NADPH oxidative signaling pathway in a PC-12 cell oxygen-glucose deprivation and reoxygenation (OGD/R) injury model. Transfection with miR-125b mimics, an miR-125b inhibitor, and luciferase reporter gene plasmid was accomplished using commercial kits. In these cells, Western blots were used to detect the levels of expression of CK2α, cleaved caspase-3, NOX2, and NOX4. RT-PCR was used to detect the expressions of CK2α, miR125b, NOX2, and NOX4. We evaluated Lactate Dehydrogenase (LDH) level, NADPH oxidase activity, and caspase-3 activity using commercial kits. Mitochondrial reactive oxygen species (ROS) were measured by fluorescence microscopy. For both PC-12 cells and rat brains, histological analyses were conducted to observe morphological changes, and apoptosis was measured using a commercial kit. Results: I/R rats exhibited an increase in neurological deficit score, infarct volume, and cellular apoptosis, along with miR-125b elevation and CK2α downregulation. OGD/R treatment increased PC-12 cells’ injuries, cellular apoptosis, and ROS levels. These changes were associated with miR-125b elevation, CK2α downregulation and activations of NOX2 and NOX4, mimicking our in vivo findings. All of these effects were reversed by the inhibition of miR-125b, confirming a strong correlation between miR-125b activity and the CK2α/NADPH oxidase signaling pathway. Conclusions: Based on these observations, we conclude that inhibition of miR-125b protects the rat brain from I/R injury by regulating the CK2α/NADPH oxidative signaling pathway.
Agar is a polysaccharide mixture extracted from red algae. Agar has been widely used in food, medicine and biochemistry, because of its gelling properties and stability. However, sulfate groups in ...the structure of agar weaken the gel strength of agar; hence, sulfate removal is necessary to improve the agar quality. The commonly used alkali desulfation greatly pollutes the environment, and enzymatic desulfation is costly due to the need for a large amount of the enzyme. In this work, microorganisms were for the first time used for agar desulfation, taking advantage of the sulfur demand of microorganisms themselves. This allows the removal of agar sulfate groups to be eco-friendly and effective. Firstly, microorganism strains were screened with agar as the sole sulfur source. Then 4 microorganism-based agar desulfation techniques, sulfate removal from agar liquid at 60 °C, from an solid agar plate at 37 °C, from freshly-prepared agar slices in liquid medium, and from agar strips without pretreatment (ASWP) in liquid medium, were established and compared. Finally, by using
Priestia megaterium
WMX, the sulfate removal rate from ASWP reached 74.67%, and the gel strength increased by 187%, reaching 1173 g cm
−2
. Therefore, the agar quality was greatly improved by sulfate removal with microorganisms. The microorganism-based agar desulfation technique established in this work is easy-to-perform, cost effective, and an eco-friendly way to improve agar quality and has the potential to be applied on the industrial scale.
Microorganisms were for the first time used for agar desulfation, taking advantage of the sulfur demand of microorganisms themselves.
PDF
