A novel DDIT3 activator dehydroevodiamine effectively inhibits tumor growth and tumor cell stemness in pancreatic cancer.

BACKGROUND: The existence of pancreatic cancer stem cells (PCSCs) results in limited survival benefits from current treatment options. There is a scarcity of effective agents for treating pancreatic cancer patients. Dehydroevodiamine (DeHE), a quinazoline alkaloid isolated from the traditional Chinese herb Evodiae fructus, exhibited potent inhibition of pancreatic ductal adenocarcinoma (PDAC) cell proliferation and tumor growth both in vitro and in vivo. METHODS: The cytotoxic effect of DeHE on PDAC cells was assessed using CCK-8 and colony formation assays. The antitumor efficacy of DeHE were appraised in human PANC-1 xenograft mouse model. Sphere formation assay and flow cytometry were employed to quantify the tumor stemness. RNA-Seq analysis, drug affinity responsive target stability assay (DARTS), and RNA interference transfection were conducted to elucidate potential signaling pathways. Western blotting and immunohistochemistry were utilized to assess protein expression levels. RESULTS: DeHE effectively inhibited PDAC cell proliferation and tumor growth in vitro and in vivo, and exhibited a better safety profile compared to the clinical drug gemcitabine (GEM). DeHE inhibited PCSCs, as evidenced by its suppression of self-renewal capabilities of PCSCs, reduced the proportion of ALDH+ cells and downregulated stemness-associated proteins (Nanog, Sox-2, and Oct-4) both in vitro and in vivo. Furthermore, there is potential involvement of DDIT3 and its downstream DDIT3/TRIB3/AKT/mTOR pathway in the suppression of stemness characteristics within DeHE-treated PDAC cells. Additionally, results from the DARTS assay indicated that DeHE interacts with DDIT3, safeguarding it against degradation mediated by pronase. Notably, the inhibitory capabilities of DeHE on PDAC cell proliferation and tumor stemness were partially restored by siDDIT3 or the AKT activator SC-79. CONCLUSION: In summary, our study has identified DeHE, a novel antitumor natural product, as an activator of DDIT3 with the ability to suppress the AKT/mTOR pathway. This pathway is intricately linked to tumor cell proliferation and stemness characteristics in PDAC. These findings suggest that DeHE holds potential as a promising candidate for the development of innovative anticancer therapeutics.

Network pharmacology and experimental verification study on the mechanism of Hedyotis diffusa Willd in treating colorectal cancer.

This study aimed to evaluate the pharmacological mechanism of Hedyotis diffusa Willd against CRC (colorectal cancer) using network pharmacological analysis combined with experimental validation. The active components and potential targets of Hedyotis diffusa Willd were screened from the tax compliance management program public database using network pharmacology. The core anti-CRC targets were screened using a protein-protein interaction (PPI) network. The mRNA and protein expression of core target genes in normal colon and CRC tissues and their relationship with overall CRC survival were evaluated using The Cancer Genome Atlas (TCGA), Human Protein Atlas (HPA), and Gene Expression Profiling Interactive Analysis (GEPIA) databases. Functional and pathway enrichment analyses of the potential targets were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The first six core targets with stable binding were molecular-docked with the active components quercetin and ß-sitosterol. Finally, the results of network pharmacology were verified using in vitro experiments. In total, 149 potential targets were identified by searching for seven types of active components and the intersection of all potential and CRC targets. PPI network analysis showed that ten target genes, including tumor protein p53 (TP53) and recombinant cyclin D1 (CCND1), were pivotal genes. GO enrichment analysis involved 2043 biological processes, 52 cellular components, and 191 molecular functions. KEGG enrichment analysis indicated that the anticancer effects of H. alba were mediated by tumor necrosis factor, interleukin-17, and nuclear factor-κB (NF-κB) signaling pathways. Validation of key targets showed that the validation results for most core genes were consistent with those in this study. Molecular docking revealed that the ten core target proteins could be well combined with quercetin and ß-sitosterol and the structure remained stable after binding. The results of the in vitro experiment showed that ß-sitosterol inhibited proliferation and induced apoptosis in SW620 cells. This study identified a potential target plant for CRC through network pharmacology and in vitro validation.

Development of a 5-mRNAsi-related gene signature to predict the prognosis of colon adenocarcinoma.

Aim: To create a prognosis model based on mRNA-based stem index (mRNAsi) for evaluating the prognostic outcomes of colon adenocarcinoma (COAD). Background: Generation of heterogeneous COAD cells could be promoted by the self-renewal and differentiation potential of cancer stem cells (CSCs). Biomarkers contributing to the development of COAD stem cells remained to be discovered. Objective: To develop and validate an mRNAsi-based risk model for estimating the prognostic outcomes of patients suffering from COAD. Methods: Samples were collected from Rectal Adenocarcinoma (TCGA-READ) PanCancer Atlas datasets, The Cancer Genome Atlas Colon Adenocarcinoma (TCGA-COAD), and the GSE87211 dataset. MRNAsi was calculated by one-class logistic regression (OCLR) algorithm. Under the criterion of correlation greater than 0.4, genes related to mRNAsi were screened and clustered. Meanwhile, differentially expressed genes (DEGs) between molecular subtypes were identified to establish a risk model. According to the median risk score value for immunotherapy and results from immune cell infiltration and clinicopathological analyses, clusters and patients were divided into high-RiskScore and low-RiskScore groups. Cell apoptosis and viability were detected by flow cytometer and Cell Counting Kit-8 (CCK-8) assay, respectively. Results: A negative correlation between mRNAsi and clinical stages was observed. Three clusters of patients (C1, C2, and C3) were defined based on a total of 165 survival-related mRNAsi genes. Specifically, C1 patients had greater immune cell infiltration and a poorer prognosis. A 5-mRNAsi-gene signature (HEYL, FSTL3, FABP4, ADAM8, and EBF4) served as a prediction index for COAD prognosis. High-RiskScore patients had a poorer prognosis and higher level of immune cell infiltration. In addition, the five genes in the signature all showed a high expression in COAD cells. Knocking down HEYL promoted COAD cell apoptosis and inhibited viability. Conclusion: Our mRNAsi risk model could better predict the prognosis of COAD patients.

Effective Removal of Dyes from Wastewater by Osmanthus Fragrans Biomass Charcoal.

The exploration of low-cost, high-performance adsorbents is a popular research issue. In this work, a straightforward method that combined hydrothermal with tube firing was used to produce Osmanthus fragrans biomass charcoal (OBC) from low-cost osmanthus for dye adsorption in water. The study examined the parameters of starting concentration, pH, and duration, which impacted the process of adsorption of different dyes by OBC. The analysis showed that the adsorption capacities of OBC for six dyes: malachite green (MG, C0 = 800 mg/L, pH = 7), Congo red (CR, C0 = 1000 mg/L, pH = 8), rhodamine B (RhB, C0 = 500 mg/L, pH = 6), methyl orange (MO, C0 = 1000 mg/L, pH = 7), methylene blue (MB, C0 = 700 mg/L, pH = 8), and crystalline violet (CV, C0 = 500 mg/L, pH = 7) were 6501.09, 2870.30, 554.93, 6277.72, 626.50, and 3539.34 mg/g, respectively. The pseudo-second-order model and the Langmuir isotherm model were compatible with the experimental findings, which suggested the dominance of ion exchange and chemisorption. The materials were characterized by using XRD, SEM, FTIR, BET, and XPS, and the results showed that OBC had an outstanding specific surface area (2063 m2·g-1), with potential adsorption mechanisms that included electrostatic mechanisms, hydrogen bonding, and π-π adsorption. The fact that the adsorption capacity did not drastically decrease after five cycles of adsorption and desorption suggests that OBC has the potential to be a dye adsorbent.

Constructing a Prognostic Gene Signature for Lung Adenocarcinoma Based on Weighted Gene Co-Expression Network Analysis and Single-Cell Analysis.

Purpose: Lung adenocarcinoma (LUAD) has a high degree of intratumor heterogeneity. Advanced single-cell RNA sequencing (scRNA-seq) technologies have offered tools to analyze intratumor heterogeneity, which improves the accuracy of identifying biomarkers based on single-cell expression data, and thus helps in predicting prognosis of cancer patients and assisting decision-makings for cancer treatment. Patients and Methods: ScRNA-seq data containing two LUAD and two para-cancerous tissue samples were included to identify different cell clusters in tumor tissues. To identify the most relevant modules and important cell subpopulations (clusters) in LUAD tissues, weighted gene co-expression network analysis (WGCNA) was performed. Subsequently, LUAD molecular subtypes were constructed by unsupervised consensus clustering based on genes in key modules. Using differential analysis, univariate Cox regression analysis, and least absolute shrinkage and selection operator (LASSO) regression analysis, a prognostic model of LUAD was established. Results: A total of 14 cell clusters belonging to 10 cell types in LUAD were identified. The turquoise module was the most relevant to LUAD among all the modules; cluster 10 (C10, lung epithelial cells) was found to be the most strongly associated with the turquoise module. LUAD samples were divided into two groups of distinct molecular subtypes. Based on the 165 shared genes between the turquoise module and C10, 511 DEGs between the two molecular subtypes were obtained, and five of them were selected to construct the gene signature, which was validated to be an independent prognostic marker of LUAD. Conclusion: Fourteen cell clusters co-existed in LUAD, which contributed to its intratumor heterogeneity. Two molecular subtypes of LUAD were identified and a five-gene signature was developed and validated to be significantly associated with prognostic and clinical characteristics of LUAD patients.

Multi-Role Surface Modification of Single-Crystalline Nickel-Rich Lithium Nickel Cobalt Manganese Oxides Cathodes with WO3 to Improve Performance for Lithium-Ion Batteries.

Compared with the polycrystalline system, the single-crystalline ternary cathode material has better cycle stability because the only primary particles without grain boundaries effectively alleviate the formation of micro/nanocracks and retain better structural integrity. Therefore, it has received extensive research attention. There is no consistent result whether tungsten oxide acts as doping and/or coating from the surface modification of the polycrystalline system. Meanwhile, there is no report on the surface modification of the single-crystalline system by tungsten oxide. In this paper, multirole surface modification of single-crystalline nickel-rich ternary cathode material LiNi0.6Co0.2Mn0.2O2 by WO3 is studied by a simple method of adding WO3 followed by calcination. The results show that with the change in the amount of WO3 added, single-crystalline nickel-rich ternary cathode material can be separately doped, separately coated, and both doped and coated. Either doping or coating effectively enhances the structural stability, reduces the polarization of the material, and improves the lithium-ion diffusion kinetics, thus improving the cycle stability and rate performance of the battery. Interestingly, both doping and coating (for SC-NCM622-0.5%WO3) do not show a more excellent synergistic effect, while the single coating (for SC-NCM622-1.0%WO3) after eliminating the rock-salt phase layer performs the most excellent modification effect.

One-Pot Synthesis of Glucose-Derived Carbon Coated Ni3S2 Nanowires as a Battery-Type Electrode for High Performance Supercapacitors.

We report a novel Ni3S2 carbon coated (denoted as NCC) rod-like structure prepared by a facile one-pot hydrothermal method and employ it as a binder free electrode in supercapacitor. We coated carbon with glucose as carbon source on the surface of samples and investigated the suitable glucose concentration. The as-obtained NCC rod-like structure demonstrated great performance with a huge specific capacity of 657 C g-1 at 1 A g-1, preeminent rate capability of 87.7% retention, the current density varying to 10 A g-1, and great cycling stability of 76.7% of its original value through 3500 cycles, which is superior to the properties of bare Ni3S2. The result presents a facile, general, viable strategy to constructing a high-performance material for the supercapacitor applications.

Exploring the mechanism of aidi injection for lung cancer by network pharmacology approach and molecular docking validation.

BACKGROUND: Aidi injection (ADI) is an effective Traditional Chinese medicine preparation widely used for lung cancer. However, the pharmacological mechanisms of ADI on lung cancer remain to be elucidated. METHODS: A network pharmacology (NP)-based approach and the molecular docking validation were conducted to explore underlying mechanisms of ADI on lung cancer. The compounds and target genes were screened by Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (Batman-TCM) database. The STRING database was utilized for protein interaction network construction. The R package clusterProfiler was used for bioinformatics annotation of hub target genes. The gene expression analysis and survival analysis were performed based on The Cancer Genome Atlas (TCGA) database. The Autodock Vina was used for molecular docking validation. RESULTS: A total of five key compounds with 324 putative target genes were screened out, and 14 hub target genes were identified for treating lung cancer. Six hub genes could influence the survival of non-small cell lung cancer (NSCLC) patients. Of these hub genes, the expression pattern of EGFR, MYC, PIK3CA, and SMAD3 were significantly higher in the LUSC, while PIK3CA and RELA expressed lower in the LUAD group and LUSC group, respectively. These six hub genes had good docking affinity with the key compounds of ADI. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that ADI may exert therapeutic effects on lung cancer by regulating critical pathways including the thyroid hormone signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. CONCLUSIONS: The present study explored the potential pharmacological mechanisms of ADI on lung cancer, promoting the clinical application of ADI in treating lung cancer, and providing references for advanced researches.

Elevated CDK5R1 predicts worse prognosis in hepatocellular carcinoma based on TCGA data.

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumor with rapid progression, high recurrence rate and poor prognosis. The objective of our investigation was to explore the prognostic value of CDK5R1 in HCC. METHODS: The raw data of HCC raw data were downloaded from The Cancer Genome Atlas (TCGA) database. The Wilcoxon signed-rank test, Kruskal-Wallis test and logistic regression were applied to investigate the relevance between the CDK5R1 expression and clinicopathologic characteristics in HCC. Kaplan-Meier and Cox regression analysis were employed to examine the association between clinicopathologic features and survival. Gene set enrichment analysis (GSEA) was applied to annotate the biological function of CDK5R1. RESULTS: CDK5R1 was highly expressed in HCC tissues. The high expression of CDK5R1 in HCC tissues was significantly associated with tumor status (P=0.00), new tumor event (P=0.00), clinical stage (P=0.00) and topography (P=0.00). Elevated CDK5R1 had significant correlation with worse overall survival (OS; P=7.414e-04), disease-specific survival (DSS; P=5.642e-04), disease-free interval (DFI; P=1.785e-05) and progression-free interval (PFI; P=2.512e-06). Besides, univariate and multivariate Cox regression analysis uncovered that increased CDK5R1 can independently predict adverse OS (P=0.037, hazard ratio [HR]= 1.7 (95% CI [1.0-2.7])), DFI (P=0.007, hazard ratio [HR]= 3.0 (95% CI [1.4-6.7])), PFI (P=0.007, hazard ratio [HR]= 2.8 (95% CI [1.3-5.9])). GSEA disclosed that notch signaling pathway and non-small cell lung cancer were prominently enriched in CDK5R1 high expression phenotype. CONCLUSIONS: Increased CDK5R1 may act as a promising independent prognostic factor of poor survival in HCC.

Durable Clinical Response of Advanced Lung Adenocarcinoma Harboring EGFR-19del/T790M/BRAFV600E Mutations After Treating with Osimertinib and Dabrafenib Plus Trametinib: A Case Report.

EGFR-T790M and BRAFV600E are the common resistance mechanisms to EGFR-tyrosine kinase inhibitors (TKIs). Standard treatment for the triple mutations of EGFR-19del, T790M, and BRAFV600E is still under debate. Herein, we present a case of therapeutic efficacy of osimertinib and dabrafenib plus trametinib on a 63-year-old man with advanced lung adenocarcinoma. This patient reached a remarkable progression-free survival of 9 months without any serious adverse reaction. At the progression of the disease, C797S mutation in cis was detected by liquid biopsy. Subsequently, brigatinib with cetuximab was administered but no curative effect was observed. Then, therapy was changed to apatinib combined with osimertinib. The subsequent CT scan showed that the lesions reached stable disease (SD), and the survival benefit has been evaluated. This case showed that the combination treatment of osimertinib and dabrafenib plus trametinib might be a great treatment option for NSCLC patients with triple mutations (EGFR-19del/T790M/BRAFV600E).

A Comprehensive Network Pharmacology-Based Strategy to Investigate Multiple Mechanisms of HeChan Tablet on Lung Cancer.

BACKGROUND: HeChan tablet (HCT) is a traditional Chinese medicine preparation extensively prescribed to treat lung cancer in China. However, the pharmacological mechanisms of HCT on lung cancer remain to be elucidated. METHODS: A comprehensive network pharmacology-based strategy was conducted to explore underlying mechanisms of HCT on lung cancer. Putative targets and compounds of HCT were retrieved from TCMSP and BATMAN-TCM databases; related genes of lung cancer were retrieved from OMIM and DisGeNET databases; known therapeutic target genes of lung cancer were retrieved from TTD and DrugBank databases; PPI networks among target genes were constructed to filter hub genes by STRING. Furthermore, the pathway and GO enrichment analysis of hub genes was performed by clusterProfiler, and the clinical significance of hub genes was identified by The Cancer Genome Atlas. RESULT: A total of 206 compounds and 2,433 target genes of HCT were obtained. 5,317 related genes of lung cancer and 77 known therapeutic target genes of lung cancer were identified. 507 unique target genes were identified among HCT-related genes of lung cancer and 34 unique target genes were identified among HCT-known therapeutic target genes of lung cancer. By PPI networks, 11 target genes AKT1, TP53, MAPK8, JUN, EGFR, TNF, INS, IL-6, MYC, VEGFA, and MAPK1 were identified as major hub genes. IL-6, JUN, EGFR, and MYC were shown to associate with the survival of lung cancer patients. Five compounds of HCT， quercetin, luteolin, kaempferol, beta-sitosterol, and baicalein were recognized as key compounds of HCT on lung cancer. The gene enrichment analysis implied that HCT probably benefitted patients with lung cancer by modulating the MAPK and PI3K-Akt pathways. CONCLUSION: This study predicted pharmacological and molecular mechanisms of HCT against lung cancer and could pave the way for further experimental research and clinical application of HCT.

Arenobufagin Promoted Oxidative Stress-Associated Mitochondrial Pathway Apoptosis in A549 Non-Small-Cell Lung Cancer Cell Line.

Arenobufagin (ARE) has demonstrated potent anticancer activity in various types of tumor, but the role and mechanism of ARE for lung cancer remain unclear. Oxidative stress exists under normal conditions and is an inevitable state in the body. A variety of noxious stimuli can break the equilibrium state of oxidative stress and promote apoptosis. Here, we used a CCK-8 assay to examine cell viability. We determined oxidative stress damage by measuring levels of intracellular ROS and levels of GSH, SOD, and MDA. Annexin V-FITC/PI double staining assay, as well as the Hoechst 33258 staining, was used to detect ARE-induced apoptosis in A549 cell. Evaluation of the expression level of the specified molecule was indicated by Western blot and qRT-PCR. Loss of function experiment was carried out using NAC pretreatment. The experimental results show that ARE significantly declines in the viability of A549 cells and increases the apoptosis rate of A549 cells. As reflected in cell morphology, the A549 cells showed features of shrinkage and had incompletely packed membranes; the same phenomenon is manifested in Hoechst 33258 staining. Following ARE treatment, the ROS level in A549 cells was rising in a concentration-dependent manner, and so were MDA and GSH levels, while the SOD level was decreasing. Moreover, we found that ARE can decrease mitochondrial membrane potential (MMP), and a cascade of apoptotic processes can be triggered by decreased MMP. Importantly, we found significant changes in protein expression levels and mRNA levels of apoptosis-related proteins. Furthermore, when we used NAC to restrain oxidative stress, the expression levels of apoptosis-related proteins have also changed accordingly. Our data demonstrate that apoptosis in the non-small-cell lung cancer (NSCLC) cell line A549 is caused by oxidative stress due to ARE. Our research also shows that ARE may have the potential to become a targeted therapeutic for the treatment of NSCLC in the future.

One-Step Synthesis of Self-Supported Ni3S2/NiS Composite Film on Ni Foam by Electrodeposition for High-Performance Supercapacitors.

Herein, a facile one-step electrodeposition route was presented for preparing Ni3S2/NiS composite film on Ni foam substrate (denoted as NiSx/NF). The NiSx granular film is composed of mangy interconnected ultra-thin NiSx nanoflakes with porous structures. When applied as electrodes for supercapacitors, the ultra-thin nanoflakes can provide more active sites for redox reaction, and the interconnected porous structure has an advantage for electrolyte ions to penetrate into the inner space of active materials quickly. As expected, the obtained NiSx/NF sample exhibited high gravimetric capacitance of 1649.8 F·g-1 and areal capacitance of 2.63 F·cm-2. Furthermore, a gravimetric capacitance of 1120.1 F·g-1 can be maintained at a high current density of 20 mA·cm-2, suggesting a good rate capability. The influence of the different molar ratios of electrodeposition electrolyte (NiNO3 and thiourea) on the morphology and electrochemical properties of NiSx/NF sample was investigated to provide an optimum route for one-step electrodeposition of Ni3S2/NiS composite film. The outstanding performance indicated the Ni3S2/NiS composite film on Ni foam has great potential as an electrode material for supercapacitors.

Ferrocene as a Novel Additive to Enhance the Lithium-Ion Storage Capability of SnO2/Graphene Composite.

Improving the reversibility of conversion reaction is a promising way to enhance the lithium-ion storage capability of SnO2-based anodes. Herein, we report ferrocene as a novel additive to improve the Li-ion storage performance of the SnO2/graphene (SnO2/G) composite. Through a simple mixing method, ferrocene can be uniformly dispersed into the SnO2/G electrode. It is found that the ferrocene additive can effectively suppress the agglomeration of Sn/SnO2 and retain the nanoscale Sn/Li2O interface. Furthermore, metallic Fe is formed from ferrocene in the discharge process and acts as a catalyst to promote the reversible conversion between Sn/Li2O and SnO2. As a result, the SnO2/G electrode with the addition of 10 wt % ferrocene (10%Fc-SnO2/G) exhibits a superior Li-ion storage performance. It displays a reversible capacity of up to 1084.5 mAh g-1 at 0.1 A g-1 after 150 cycles with a good rate capability (752 mAh g-1 at 1 A g-1). In addition, the 10%Fc-SnO2/G electrode can retain a capacity of 787.2 mAh g-1 at 0.5 A g-1 after 220 cycles. This work demonstrates the promising additive of ferrocene in enhancing the reversible capacity of SnO2-based anodes for lithium-ion batteries.

NH3 assisted photoreduction and N-doping of graphene oxide for high performance electrode materials in supercapacitors.

Nitrogen-doped graphene was synthesized by simple photoreduction of graphene oxide (GO) deposited on nickel foam under NH3 atmosphere. The combination of photoreduction and NH3 not only reduces the GO in a shorter time but also induces nitrogen doping easily. The nitrogen doped content of N-rGO@NF reaches a high of 5.99 at% with 15 min of irradiation. The nitrogen-doped graphene deposited on Ni foam (N-rGO@NF) can be directly used as an electrode for supercapacitors, without any conductive agents and polymer binders. In the electrochemical measurement, N-rGO@NF displays remarkable electrochemical performance. In particular, the N-rGO@NF irradiated for 45 min at a high current density of 92.3 A g(-1) retained about 77% (190.4 F g(-1)) of its initial specific capacitance (247.1 F g(-1) at 0.31 A g(-1)). Furthermore, the stable voltage window could be extended to 2.0 and 1.5 V by using Li2SO4 and a mixed Li2SO4/KOH electrolyte, and the maximum energy density was high up to 32.6 and 21.2 Wh kg(-1), respectively. The results show that compared to Li2SO4, a mixed electrolyte (Li2SO4/KOH) more efficiently balances the relationship between the high energy densities and high power densities.

Direct formation of reduced graphene oxide and 3D lightweight nickel network composite foam by hydrohalic acids and its application for high-performance supercapacitors.

Here, a novel graphene composite foam with 3D lightweight continuous and interconnected nickel network was successfully synthesized by hydroiodic (HI) acid using nickel foam as substrate template. The graphene had closely coated on the backbone of the 3D nickel conductive network to form nickel network supported composite foam without any polymeric binder during the HI reduction of GO process, and the nickel conductive network can be maintained even in only a small amount of nickel with 1.1 mg/cm(2) and had replaced the traditional current collector nickel foam (35 mg/cm(2)). In the electrochemical measurement, a supercapacitor device based on the 3D nickel network and graphene composite foam exhibited high rate capability of 100 F/g at 0.5 A/g and 86.7 F/g at 62.5 A/g, good cycle stability with capacitance retention of 95% after 2000 cycles, low internal resistance (1.68 Ω), and excellent flexible properties. Furthermore, the gravimetric capacitance (calculated using the total mass of the electrode) was high up to 40.9 F/g. Our work not only demonstrates high-quality graphene/nickel composite foam, but also provides a universal route for the rational design of high performance of supercapacitors.

Facile synthesis of nickel network supported three-dimensional graphene gel as a lightweight and binder-free electrode for high rate performance supercapacitor application.

Here we report a simple strategy to prepare three-dimensional graphene gel coated on nickel foam for supercapacitor applications by a simple 'dipping and drying' process. The supercapacitors based on three-dimensional graphene gel (G-gel@NF-1) exhibited high rate capability of 152 F g(-1) at 0.36 A g(-1) and 107 F g(-1) at 90.9 A g(-1), good cycle stability with capacitance retention of 89% after 2000 cycles and low internal resistance (0.58 Ω). Furthermore, a flexible electrode (G-gel@NF-2) was obtained by etching most of the nickel foam but maintains the conductive backbone of the nickel foam, which greatly reduces the total mass of the electrode (can be reduced from 30 mg cm(-2) to less than 5 mg cm(-2)), and can be compressed from a thickness of 1 mm to ∼30 µm. With the aid of a conductive network composed of a small amount of nickel, G-gel@NF-2 still has good performance in high rate capability and displays excellent flexible properties. The specific capacitance when the mass density of the electrode was only 5.4 mg cm(-2) still reached ∼115 F g(-1). This strategy can improve the rate capability performance, greatly reduce the mass of the electrode, and lower the fabrication cost of supercapacitors.