(00<i>l</i>)‑Facet-Exposed Planelike ABi₂Nb₂O₉ (A = Ca, Sr, Ba) Powders with a Single-Crystal Grain for Enhancement of Photocatalytic Activity

(00<i>l</i>)-facet-exposed planelike ABi₂Nb₂O₉ (A = Ca, Sr, Ba) powders with a single-crystal grain were obtained successfully by the molten salt method. The planelike grains were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. With modification by platinum nanoparticles as a cocatalyst, these materials were tested as photocatalysts for water splitting under full arc light irradiation. The H₂ evolution activities of the planelike ABi₂Nb₂O₉ (A = Ca, Sr, Ba) prepared by the molten salt method were almost an order of magnitude higher than those of the ABi₂Nb₂O₉ (A = Ca, Sr, Ba) prepared by traditional solid-state method. The planelike ABi₂Nb₂O₉ (A = Ca, Sr, Ba) powders also have higher O₂ evolution activities than the ABi₂Nb₂O₉ (A = Ca, Sr, Ba) powders prepared by the traditional solid-state method. The oxidation and reduction catalytic sites on the planelike ABi₂Nb₂O₉ (A = Ca, Sr, Ba) are discussed in detail. With increasing temperature of the molten salt, the variation tendencies of the photocatalytic activities of CaBi₂Nb₂O₉, SrBi₂Nb₂O₉, and BaBi₂Nb₂O₉ for water splitting were different from each other due to the different growth rhythm of the planelike ABi₂Nb₂O₉ (A = Ca, Sr, Ba) grains. The CaBi₂Nb₂O₉ and SrBi₂Nb₂O₉ with an orthorhombic lattice had a higher photocatalytic activity than BaBi₂Nb₂O₉ with a tetragonal lattice because of the strong distortion of NbO₆ octahedra in the perovskite-like slabs of CaBi₂Nb₂O₉ and SrBi₂Nb₂O₉

Dual-Functional Graphene Carbon as Polysulfide Trapper for High-Performance Lithium Sulfur Batteries

The lithium sulfur (Li–S) battery has attracted much attention due to its high theoretical capacity and energy density. However, its cycling stability and rate performance urgently need to improve because of its shuttle effect. Herein, oxygen-doped carbon on the surface of reduced graphene oxide (labeled as ODC/rGO) was fabricated to modify the separators of Li–S batteries to limit the dissolution of the lithium polysulfides. The mesoporous structure in ODC/rGO can not only serve as the physical trapper, but also provide abundant channels for fast ion transfer, which is beneficial for effective confinement of the dissoluble intermediates and superior rate performance. Moreover, the oxygen-containing groups in ODC/rGO are able to act as chemical adsorption sites to immobilize the lithium polysulfides, suppressing their dissolution in electrolyte to enhance the utilization of sulfur cathode in Li–S batteries. As a result, because of the synergetic effects of physical adsorption and chemical interaction to immobilize the soluble polysulfides, the Li–S batteries with the ODC/rGO-coated separator exhibit excellent rate performance and good long-term cycling stability with 0.057% capacity decay per cycle at 1.0 C after 600 cycles

Additional file 1 of Hypertoxic self-assembled peptide with dual functions of glutathione depletion and biosynthesis inhibition for selective tumor ferroptosis and pyroptosis

Additional file 1. Hypertoxic self-assembled peptide with dual functions of glutathione depletion and biosynthesis inhibition for selective tumor ferroptosis and pyroptosis

mPGES-1-selective inhibitor CAY10526 concentration-dependently attenuated LPS-induced PGE₂ production in BMDM.

<p>BMDM was pretreated with mPGES-1-selective inhibitor CAY10526 at 5, 10, or 20 µM for 0.5 hr prior to LPS (1 µg/ml) treatment for either 16 hrs or 7.5 hrs. CAY10526 concentration-dependently inhibited the LPS-induced PGE₂ production at 16 hrs (<b><i>A</i></b>) and 7.5 hrs (<i>F</i>) as measured by LC-MS-MS assay. Results are the mean of at least 3 independent experiments.. Western blot assays showed CAY10526 concentration-dependently attenuated the LPS-induced mPGES-1 and iNOS protein expression at either 16 hrs (<b><i>B</i></b>) or 7.5 hrs (<i>E</i>) in BMDM, but had no inhibitory effect on the protein expression of mPGES-2, c-PGES or COX-2. Representative blots and the densitometry of iNOS/mPGES-1/COX-2 protein expression were showed from at least 3 independent experiments. <b><i>C–D.</i></b> Real time RT-PCR results showed the efforts of CAY10526 pretreatment (10 µM, 0.5 hr prior to LPS treatment) significantly attenuated the LPS-induced (16 hrs) iNOS mRNA expression in BMDM (<b><i>D</i></b>); whereas LPS-induced (16 hrs) mPGES-1 mRNA expression in BMDM was significantly increased after CAY10526 treatment (<b><i>C</i></b>), confirming that CAY10526 selectively inhibited the translation step of mPGES-1 mRNA into proteins. Results shown were mean from 4 independent experiments.</p

LPS induces increased expression of iNOS/COX-2/mPGES-1/PU.1 in BMDM.

<p>Primary cultured mouse BMDM was treated with or without 1 µg/ml LPS for various time points from 2 to 24 hrs. <b><i>A</i></b>. The protein expression of targeted proteins in BMDM cell lysates was detected by Western blot assays. Representative blots and the densitometry of iNOS/COX-2/mPGES-1/PU.1 protein expression are showed from 5 independent experiments. Protein expression of COX-2 and iNOS was detected within 2 to 4 hrs post-LPS treatment; whereas increased protein expression of mPGES-1 and PU.1 was detected after 8 hrs of LPS treatment. In contrast, the protein expression of COX-1, mPGES-2, c-PGES or H-PGDS was not affected by LPS treatment. The protein loading in each experiment was normalized by β-actin. <b><i>B–G</i></b>. The LPS-stimulated (16 hrs) mRNA expression of COX-2 (<b><i>B</i></b>), iNOS (<b><i>C</i></b>), PU.1 (<b><i>D</i></b>), mPGES-1 (<b><i>E</i></b>), mPGES-2 (<b><i>F</i></b>), or c-PGES (<b><i>G</i></b>) in BMDM was confirmed by real-time quantitative RT-PCR. The mRNA of each gene was normalized to the β-actin mRNA expression level in the same sample. The results shown are mean of at least 4 independent experiments for each gene, * <i>p</i><0.05 vs. control.</p

Selective inhibition of COX-2 abolished LPS-induced PGs production, but didn't affect LPS-induced mPGES-1 expression.

<p>BMDM were pretreated with COX-2-selective inhibitor NS-398 (20 µM, 0.5 hr) prior to the treatment of 1 µg/ml LPS for 16 hrs, the PGE₂ and PGD₂ levels in culture medium were measured by LS-MC-MC. <b><i>A</i></b>. NS-398 completely prevented LPS-induced both PGE₂ and PGD₂ production (n = 3). <b><i>B</i></b>. NS-398 also partially inhibited LPS-induced protein expression of COX-2 and iNOS, but had no inhibitory effect on the expression of COX-1/PU.1/mPGES-1/mPGES-2/c-PGES by Western blot assay. The representative blots and the densitometry of iNOS/COX-2/mPGES-1/PU.1 protein expression were from 3 independent experiments.</p

LPS stimulates PGE₂ and PGD₂ production in BMDM.

<p>Equal amount of BMDM was treated with or without 1 µg/ml LPS for various time points from 2 to 24 hrs. The BMDM culture medium was collected and the concentrations of PGE₂ and PGD₂ in the sample media were quantified using LC-MS-MS. LPS induced both PGE₂ and PGD₂ production at a similar lower level in the first 8 hrs of treatment. In contrast, the production of PGE₂ in BMDM continuously increased after LPS treatment for 12 hrs; whereas the production of PGD₂ kept at a relatively stable level after 12 hrs of LPS treatment (n = 5).</p

The enzyme activities of expressed COX-2 and mPGES-1 enzymes between early and late phase of LPS treatment were not different.

<p>The induced COX-2 and mPGES-1 enzymes were immunoprecipitated (IP, 2 hrs at 4°C) separately from equal amount of BMDM lysates at either 8 or 16 hrs of LPS treatment under the same experimental condition. The IP COX-2 or mPGES-1 enzyme concentrations were determined, and equal amount of IP COX-2 or mPGES-1 enzymes from each time point was used to determine their enzyme activity of PGE₂ production from their substrates (either arachidonic acid or PGH₂) <i>in vitro</i>. No significant difference in either COX-2 or mPGES-1 enzyme activity of PGE₂ production was detected between 8 and 16 hrs of LPS treatment (n = 3).</p

Confocol fluorescent microscopy detects the expression and intracellular distribution of iNOS/COX-2/PU.1/mPGES-1 induced by LPS treatment.

<p>Primary cultured mouse BMDM was treated with or without 1 µg/ml LPS for 16 hrs. The protein expression of iNOS (<b><i>A</i></b>), COX-2 (<b><i>B</i></b>), PU.1 (<b><i>C</i></b>), and mPGES-1 (<b><i>D</i></b>) was determined by immunostaining followed by confocol fluorescent microscopy. In each sample group, BMDM was stained with the green fluorescent-labeled antibody for the targeted protein and the blue fluorescent-labeled DAPI for nucleus; the overlay image of each targeted protein and nucleus are shown (magnification: ×200, scale bar: 10 µM). LPS stimulation significantly increased cytosolic expression of iNOS, COX-2, mPGES-1 and PU.1 in BMDM, suggesting newly synthesized protein expression in cytosol. PU.1 also showed strong nuclear staining (i.e., nuclear translocation) after LPS treatment; whereas both COX-2 and mPGES-1 showed similar enhanced perinuclear localization in LPS-treated groups. The results shown are representative images from 3 independent experiments.</p

Selective siRNA inhibition of mPGES-1, but not mPGES-2 or c-PGES, attenuated LPS-induced late-phase PGE₂ production.

<p>BMDM were transfected with siRNA's for mPGES-1, mPGES-2, c-PGES mRNA, or a control siRNA for 36 hrs, and were then treated with 1 µg/ml LPS for 16 hrs. <b><i>A</i></b>. The PGE₂ level in culture medium was determined by LS-MC-MC. mPGES-1 siRNA significantly attenuated LPS-induced PGE₂ production at 16 hrs in BMDM compared to that of BMDM transfected with the control siRNA. In contrast, the siRNA for either mPGES-2 or c-PGES did not affect the LPS-induced PGE₂ production in BMDM compared to the control siRNA group. <b><i>B</i></b>. Western blot results showed that mPGES-1 siRNA not only selectively inhibit the protein expression of mPGES-1, but also that of iNOS. <b><i>C</i></b>. In contrast, transfection of BMDM with siRNA's for either mPGES-2 or c-PGES selectively attenuated the expression of its targeted protein expression accordingly, but had no inhibitory effect on LPS-induced expression of iNOS, COX-2, or mPGES-1. <b><i>D</i></b>. Real-time RT-PCR result confirmed that mPGES-1 siRNA significantly attenuated the LPS-induced mRNA expression of iNOS in BMDM at 16 hrs. <b><i>E–G</i></b>. Real-time RT-PCR results showed that siRNA's for mPGES-1 (<b><i>E</i></b>), mPGES-2 (<b><i>F</i></b>), or c-PGES (<b><i>G</i></b>) specifically inhibited the mRNA expression of its targeted PGES isoform compared to the control siRNA group, but did not affect the mRNA expression of the other two PGES isoforms in BMDM.</p