Oxidation-Etching Preparation of MnO₂ Tubular Nanostructures for High-Performance Supercapacitors

1D hierarchical tubular MnO₂ nanostructures have been prepared through a facile hydrothermal method using carbon nanofibres (CNFs) as sacrificial template. The morphology of MnO₂ nanostructures can be adjusted by changing the reaction time or annealing process. Polycrystalline MnO₂ nanotubes are formed with a short reaction time (e.g., 10 min) while hierarchical tubular MnO₂ nanostructures composed of assembled nanosheets are obtained at longer reaction times (>45 min). The polycrystalline MnO₂ nanotubes can be further converted to porous nanobelts and sponge-like nanowires by annealing in air. Among all the types of MnO₂ nanostructures prepared, tubular MnO₂ nanostructures composed of assembled nanosheets show optimized charge storage performance when tested as supercapacitor electrodes, for example, delivering an power density of 13.33 kW·kg^–1 and a energy density of 21.1 Wh·kg^–1 with a long cycling life over 3000 cycles, which is mainly related to their features of large specific surface area and optimized charge transfer pathway

Controlled Soft-Template Synthesis of Ultrathin C@FeS Nanosheets with High-Li-Storage Performance

We report a facile approach to prepare carbon-coated troilite FeS (C@FeS) nanosheets <i>via</i> surfactant-assisted solution-based synthesis. 1-Dodecanethiol is used as both the sulfur source and the surfactant, which may form different-shaped micelles to direct the growth of nanostructures. Under appropriate growth conditions, the iron and sulfur atoms react to form thin layers of FeS while the hydrocarbon tails of 1-dodecanethiol separate the thin FeS layers, which turn to carbon after annealing in Ar. Such an approach can be extended to grow C@FeS nanospheres and nanoplates by modifying the synthesis parameters. The C@FeS nanosheets display excellent Li storage properties with high specific capacities and stable charge/discharge cyclability, especially at fast charge/discharge rates

Epidermal Growth Factor-Like Domain-Containing Protein 7 (EGFL7) Enhances EGF Receptor−AKT Signaling, Epithelial−Mesenchymal Transition, and Metastasis of Gastric Cancer Cells

<div><p>Epidermal growth factor-like domain-containing protein 7 (EGFL7) is upregulated in human epithelial tumors and so is a potential biomarker for malignancy. Indeed, previous studies have shown that high EGFL7 expression promotes infiltration and metastasis of gastric carcinoma. The epithelial–mesenchymal transition (EMT) initiates the metastatic cascade and endows cancer cells with invasive and migratory capacity; however, it is not known if EGFL7 promotes metastasis by triggering EMT. We found that EGFL7 was overexpressed in multiple human gastric cancer (GC) cell lines and that overexpression promoted cell invasion and migration as revealed by scratch wound and transwell migration assays. Conversely, shRNA-mediated EGFL7 knockdown reduced invasion and migration. Furthermore, EGFL7-overexpressing cells grew into larger tumors and were more likely to metastasize to the liver compared to underexpressing CG cells following subcutaneous injection in mice. EGFL7 overexpression protected GC cell lines against anoikis, providing a plausible mechanism for this enhanced metastatic capacity. In excised human gastric tumors, expression of EGFL7 was positively correlated with expression levels of the mesenchymal marker vimentin and the EMT-associated transcription repressor Snail, and negatively correlated with expression of the epithelial cell marker E-cadherin. In GC cell lines, EGFL7 knockdown reversed morphological signs of EMT and decreased both vimentin and Snail expression. In addition, EGFL7 overexpression promoted EGF receptor (EGFR) and protein kinase B (AKT) phospho-activation, effects markedly suppressed by the EGFR tyrosine kinase inhibitor AG1478. Moreover, AG1478 also reduced the elevated invasive and migratory capacity of GC cell lines overexpressing EGFL7. Collectively, these results strongly suggest that EGFL7 promotes metastasis by activating EMT through an EGFR−AKT−Snail signaling pathway. Disruption of EGFL7−EGFR−AKT−Snail signaling may a promising therapeutic strategy for gastric cancer.</p></div

EGFL7 induces anoikis resistance of GC cells in suspension culture.

<p>(A) Effect of EGFL7 underexpression on anoikis resistance. Representative cytograms from flow cytometry analysis of apoptotic cells revealed by Annexin V-PE/7-AAD staining of BGC823, BGC-NC, and BGC2-13 cells after 24 h in suspension culture. A greater percentage of BGC2-13 cells (22.95±1.72%) were apoptotic compared to BGC823 (11.83% ±0.99%) and BGC-NC cells (9.36% ±1.65%). (B) Effect of EGFL7 overexpression on anoikis resistance. Representative cytograms from flow cytometry analysis of apoptotic cells revealed by Annexin V-PE/7-AAD staining of MKN28-EGFL7, MKN28-NC, and MKN28 cells after 24 h of suspension culture. The number of apoptotic MKN28-EGFL7 cells (5.13% ±0.65%) was lower than the number of apoptotic MKN28 (29.53% ±0.68%) and MKN28-NC cells (35.98% ±1.77%). (C) and (D) Flow cytometry results plotted as the mean ± SD of triplicate experiments. *<i>P</i><0.05 considered significant. All experiments were performed in triplicate and repeated at least three times.</p

EGFL7 modulates the growth and metastasis of GC xenograft tumors in nude mice.

<p>(A) Subcutaneous xenograft tumors were significantly smaller in BGC2-13 cell-injected mice compared to BGC823 cell- and BGC-NC cell-injected mice, while MKN28-EGFL7 cell-injected mice exhibited significantly larger tumors than MKN28 cell- and MKN28-NC cell-injected mice. Tumor volume was calculated according to tumor volume (mm³) = 0.5×length×width² (*<i>P</i><0.05, **<i>P</i><0.01). (B) Subcutaneous xenograft tumors were analyzed by H&E staining. Liver metastasis was observed in mice injected with high EGFL7-expressing cells (BGC823, BGC-NC, and MKN28-EGFL7). Black arrow, metastatic cancer cells in the liver tissues of nude mice (H&E staining, original magnification×200). (C) Average MVD of tumors was lower in the BGC2-13 group compared to the BGC823 and BGC-NC groups (4±1.2 <i>vs.</i> 15±2 and 13±1, *<i>P</i><0.05), while the average MVD of tumors was higher in the MKN28-EGFL7 group than the MKN28 and MKN28-NC groups (28.7±6.02 <i>vs.</i> 4.3±1.53 and 5.0±2.0, **<i>P</i><0.05).</p

An EGFR tyrosine kinase inhibitor (Tyrphostin AG1478) blocks the effect of EGFL7 on EGFR phosphorylation, AKT phosphorylation, and cell motility.

<p>(A) Western blots showing that expression of EMT-related proteins changed significantly in BGC823 and MKN28-EGFL7 cells after treatment with the EGFR inhibitor Tyrphostin AG1478 (20 µM) for 1 h compared to vehicle (0.25% DMSO). E-cadherin protein expression levels increased in BGC823 and MKN28-EGFL7 cells after Tyrphostin AG1478 treatment, while expression levels of the mesenchymal marker proteins vimentin and Snail decreased. pEGFR and pAKT expression levels were significantly lower in BGC823 and MKN28-EGFL7 cells treated with Tyrphostin AG1478 than in BGC823 and MKN28-EGFL7 cells treated with 0.25% DMSO. No changes in EGFL7 protein expression levels were observed in BGC823 and MKN28-EGFL7 cells after treatment with Tyrphostin AG1478. (B) Migration of BGC823 and MKN28-EGFL7 cells was inhibited by Tyrphostin AG1478 treatment in the scratch wound assay (79% <i>vs.</i> 49%, *<i>P</i><0.05; 97% <i>vs.</i> 26%, **<i>P</i><0.05). (C) Tyrphostin AG1478 also reduced migration in the transwell assay (37±3.9 <i>vs.</i> 18±1.5, *<i>P</i><0.05; 58±3.7 <i>vs.</i> 15±4.0, **<i>P</i><0.05; vehicle-treated <i>vs.</i> Tyrphostin AG1478-treated).</p

EGFL7 promotes Epithelial−Mesenchymal transition (EMT) of GC cells through the EGFR–AKT signaling pathway.

<p>(A) Immunohistochemistry showing EGFL7, E-cadherin, vimentin, and Snail expression in gastric carcinoma tissues. (B) Cellular morphology of EGFL7-underexpressing cells (BGC2-13, MKN28, and MKN28-NC) was distinct from that of EGFL7-overexpressed cells (BGC823, BGCNC, and MKN28-EGFL7). BGC823, BGCNC, and MKN28-EGFL7 cells exhibited loss of intercellular contacts and typical spindle-shaped mesenchymal cell morphology, whereas BGC2-13, MKN28, and MKN28-NC cells exhibited an epithelial cell-like morphology with small cell size and cobblestone-like shape with tightly arranged intercellular contacts. (C) and (D) Expression levels of EMT-related molecules in cell lines analyzed by qRT-PCR (*<i>P</i><0.05, **<i>P</i><0.05, ***<i>P</i><0.05). (E) Western blot was used to confirm changes in expression of EMT-related molecules. qRT-PCR and Western blot results showed higher E-cadherin mRNA and protein expression levels in BGC2-13 cells and lower mRNA and protein expression levels of the mesenchymal markers vimentin and Snail. GAPDH served as an internal control for qRT-PCR reactions and Western blot. Error bars represent SD of triplicate experiments (*<i>P</i><0.05, **<i>P</i><0.05, ***<i>P</i><0.05 compared to BGC823 and BGC-NC cells). Conversely, qRT-PCR and Western blot results showed lower E-cadherin mRNA and protein expression levels in MKN28-EGFL7 cells and higher mRNA and protein expression levels of mesenchymal markers vimentin and Snail. Error bars represent SD of triplicate experiments (*<i>P</i><0.05, **<i>P</i><0.05, ***<i>P</i><0.05, compared to MKN28 and MKN28-NC cells). (F) Western blots showing both total and phosphorylated levels of EGFR, ERK1/2, and AKT in BGC823, BGC-NC, BGC2-13, MKN28-EGFL7, MKN28-NC, and MKN28 cells. Phosphorylated EGFR and AKT levels (pEGFR and pAKT) were significantly lower in BGC2-13 cells than in BGC823 and BGC-NC cells, while pEGFR and pAKT expression levels were significantly higher in MKN28-EGFL7 cells compared to MKN28 and MKN28-NC cells. Total EGFR and AKT levels did not differ significantly among cell lines. Neither total ERK1/2 nor pERK1/2 differed significantly. Western blots were performed in triplicate.</p

Fe-Based Metallopolymer Nanowall-Based Composites for Li–O₂ Battery Cathode

Metallopolymer nanowalls were prepared through a simple wet-chemical process using reduced graphene oxides as heterogeneous nucleation aids, which also help to form conductive electron paths. The nanowalls grow vertically on graphene surface with 100 -200 nm in widths and ∼20 nm in thickness. The Fe-based metallopolymer nanowall-based electrode shows best performance as O₂ cathode exhibiting high round-trip efficiencies and stable cycling performance among other transition metal containing metallopolymer counterparts. The electrode delivers discharge–charge capacities of 1000 mAh/g for 40 cycles and maintains round-trip efficiencies >78 % at 50 mA/g. The 1^st-cycle round-trip efficiencies are 79%, 72%, and 65% at current densities of 50, 200, and 400 mA/g, respectively. The NMR analysis of the Fe-based metallopolymer based electrode after 40 cycles reveals slow formation of the side products, CH₃CO₂Li and HCO₂Li

Relationship between EGFL7 and EMT-Related Molecule Protein Expressions in Gastric Cancer.

<p><i>Note</i>: <i>r</i> is Spearman’s rank correlation coefficient; two-tailed significances,</p><p>*<i>P</i><0.05.</p

EGFL7 expression does not alter GC cell proliferation.

<p>(A) Effect of EGFL7 underexpression on cell proliferation as determined by the adherent plate colony formation assay. BGC823, BGC-NC, and BGC2-13 cells were plated at low density and colonies counted after 10 days. There was no significant difference in the number of colonies formed (52±1.1 <i>vs.</i> 58±2.2 and 55±0.8, *<i>P</i>>0.05) (mean ± SD from three independent experiments). (B) Effect of EGFL7 overexpression on cell proliferation. MKN28-EGFL7, MKN28-NC, and MKN28 cells were treated as above. There was no significant difference in the number of colonies formed (42±1.91 <i>vs.</i> 39±1.04 and 45±3.00, *<i>P</i>>0.05) (mean ± SD from three independent experiments). (C) Effect of EGFL7 underexpression on cell proliferation as measured by MTT assay. There was no significant difference in proliferation rate among BGC823, BGC-NC, and BGC2-13 cells. (D) Effect of EGFL7 overexpression on cell proliferation. There were also no significant differences in proliferation rates among the MKN28-EGFL7, MKN28-NC, and MKN28 cells. All data were expressed as mean ± SD and were obtained from three independent experiments.</p