Primordial Magnetic Field from Gravitationally Coupled Electrodynamics in Bouncing Scenario

We in this paper study the generation of primordial magnetic field (PMF) in the non-singular bouncing scenario, through the coupling of the electromagnetic field to gravity. We adopt an electrodynamic model with a coupling coefficient as a function of the scale factor $a$, i.e. $f=1+(a/a_\star)^{-n}$, with $a_\star$ and $n>0$ being constants. The result implies that in this mechanism, the power spectrum of PMF today is always blue tilted on large scales from $1$ Mpc to the Hubble length, and the observational constraints favor the ekpyrotic-bounce scenario. Furthermore, the back reaction of the energy density of PMF at the bouncing point yields theoretical constraints on the bouncing model

Selective Formation of Cu Active Sites with Different Coordination States on Pseudospinel CuAl₂O₄ and Their NO Reduction Catalysis

In the spinel framework, copper (Cu) in two distinct coordination states exhibits catalytic activity for NO reduction through different mechanisms. However, detailed exploration of their respective catalytic properties, such as the redox behavior of Cu and substrate molecule adsorption, has been challenging due to difficulties in their separate formation. In this study, we present the controlled formation of pseudospinel CuAl2O4, containing exclusively tetrahedrally or octahedrally coordinated Cu, achieved by manipulating aging temperature and O2 concentration. Through these materials, we observed that in the CO–NO reaction, the step primarily determining the rate differs: NO reduction dominates with octahedrally coordinated Cu, whereas carbon monoxide (CO) oxidation is prominent with tetrahedrally coordinated Cu. The lower coordination number of Cu significantly benefits NO reduction but negatively impacts the CO–NO reaction, albeit positively influencing NO reduction in three-way catalytic reactions

Redox Dynamics of Rh Supported on ZrP₂O₇ and ZrO₂ Analyzed by Time-Resolved In Situ Optical Spectroscopy

In situ time-resolved diffuse reflectance spectroscopy was first applied to supported Rh catalysts (0.4 wt % Rh/ZrO₂ and Rh/ZrP₂O₇) under dynamic three-way catalysis conditions fluctuating between fuel-lean and fuel-rich gas atmospheres. The optical absorption at 650 nm was found to decrease upon lean-to-rich switching of the gas feed, which led to the reduction of Rh oxide (Rh³⁺) to metallic Rh (Rh⁰), followed by a reversible increase upon back switching rich-to-lean. The kinetic analysis suggested that the reduction of Rh³⁺ to Rh⁰ was faster than the reoxidation over Rh/ZrP₂O₇, whereas the reduction was comparable with or slower than the reoxidation over Rh/ZrO₂. The activation energy of Rh/ZrP₂O₇ for the reduction, 13.6 kJ mol^–1, was smaller than that for the oxidation, 48.7 kJ mol^–1, which contrasted with those of Rh/ZrO₂ (21.4 and 34.1 kJ mol^–1, respectively). These results were closely associated with the higher NO reduction activity of Rh/ZrP₂O₇ than Rh/ZrO₂ under a lean-gas atmosphere because Rh was more active in the metallic state than in the oxide state. Applying fast lean–rich perturbation of the gas feed with 1 s intervals led to an immediate and significant drop of the optical absorption intensity, suggesting that the reduction of Rh substantially penetrated to deeper layers under the surface. This study provided the first in situ evidence for the formation of active metallic Rh species under high-frequency lean–rich oscillations

<i>MiR-376c</i> Down-Regulation Accelerates EGF-Dependent Migration by Targeting <i>GRB2</i> in the HuCCT1 Human Intrahepatic Cholangiocarcinoma Cell Line

<div><p>MicroRNA <i>miR-376c</i> was expressed in normal intrahepatic biliary epithelial cells (HIBEpiC), but was significantly suppressed in the HuCCT1 intrahepatic cholangiocarcinoma (ICC) cell line. The biological significance of the down-regulation of <i>miR-376c</i> in HuCCT1 cells is unknown. We hypothesized that <i>miR-376c</i> could function as a tumor suppressor in these cells. To test this hypothesis, we sought the targets of <i>miR-376c</i>, and characterized the effect of its down-regulation on HuCCT1 cells. We performed proteomic analysis of <i>miR-376c</i>-overexpressing HuCCT1 cells to identify candidate targets of <i>miR-376c</i>, and validated these targets by 3′-UTR reporter assay. Transwell migration assays were performed to study the migratory response of HuCCT1 cells to <i>miR-376c</i> overexpression. Furthermore, microarrays were used to identify the signaling that were potentially involved in the <i>miR-376c</i>-modulated migration of HuCCT1. Finally, we assessed epigenetic changes within the potential promoter region of the <i>miR-376c</i> gene in these cells. Proteomic analysis and subsequent validation assays showed that <i>growth factor receptor-bound protein 2</i> (<i>GRB2</i>) was a direct target of <i>miR-376c</i>. The transwell migration assay revealed that <i>miR-376c</i> significantly reduced epidermal growth factor (EGF)-dependent cell migration in HuCCT1 cells. DNA microarray and subsequent pathway analysis showed that interleukin 1 beta and matrix metallopeptidase 9 were possible participants in EGF-dependent migration of HuCCT1 cells. Bisulfite sequencing showed higher methylation levels of CpG sites upstream of the <i>miR-376c</i> gene in HuCCT1 relative to HIBEpiC cells. Combined treatment with the DNA-demethylating agent 5-aza-2′-deoxycytidine and the histone deacetylase inhibitor trichostatin A significantly upregulated the expression of <i>miR-376c</i> in HuCCT1 cells. We revealed that epigenetic repression of <i>miR-376c</i> accelerated EGF-dependent cell migration through its target <i>GRB2</i> in HuCCT1 cells. These findings suggest that <i>miR-376c</i> functions as a tumor suppressor. Since metastasis is the major cause of death in ICC, microRNA manipulation could lead to the development of novel anti-cancer therapy strategies for ICC.</p></div

Unusual Redox Behavior of Rh/AlPO₄ and Its Impact on Three-Way Catalysis

The influence of the redox behavior of Rh/AlPO₄ on automotive three-way catalysis (TWC) was studied to correlate catalytic activity with thermal stability and metal–support interactions. Compared with a reference Rh/Al₂O₃ catalyst, Rh/AlPO₄ exhibited a much higher stability against thermal aging under an oxidizing atmosphere; further deactivation was induced by a high-temperature reduction treatment. In situ X-ray absorption fine structure experiments revealed a higher reducibility of Rh oxide (RhO_<i>x</i>) to Rh, and the metal showed a higher tolerance to reoxidation when supported on AlPO₄ compared with Al₂O₃. This unusual redox behavior is associated with an Rh–O–P interfacial linkage, which is preserved under oxidizing and reducing atmospheres. Another effect of the Rh–O–P interfacial linkage was observed for the metallic Rh with an electron-deficient character. This leads to the decreasing back-donation from Rh <i>d</i>-orbitals to the antibonding π* orbital of chemisorbed CO or NO, which is a possible reason for the deactivation by high-temperature reduction treatments. On the other hand, surface acid sites on AlPO₄ promoted oxidative adsorption of C₃H₆ as aldehyde, which showed a higher reactivity toward O₂, as well as NO, compared with carboxylate adsorbed on Al₂O₃. A precise control of the acid–base character of the metal phosphate supports is therefore a key to enhance the catalytic performance of supported Rh catalysts for TWC applications

Downregulation of <i>miR-376c</i> expression levels in bile duct carcinoma cell lines, and proteomic analysis of <i>miR-376c</i>-overexpressing HuCCT1.

<p>(<b>A</b>) Real-time PCR assay of <i>miR-376c</i> in HIBEpiC, HuCCT1, Huh28, IHGGK, TKKK, and TFK1. Expression levels were normalized to <i>RNU6B</i>, and the expression level in HIBEpiC cells was defined as 1. The significance of differences among cells was assessed by ANOVA followed by Tukey's test (*<i>P</i><0.05). (<b>B</b>) Representative 2D-DIGE images of <i>miR-376c</i>-overexpressing HuCCT1 cells. Cells were harvested 72 h after the initiation of transfection of Pre-miR-376c or the Pre-miR-negative control, and subjected to proteomic analysis. A spot downregulated by treatment with Pre-miR-376c is indicated by the arrow, which was later shown by mass spectrometry to be GRB2. (<b>C</b>) Quantitative analysis of the fluorescence intensity of the GRB2 protein spot shown in <b>B</b> (peak outlined in red).</p

The effect of Olig1 deficiency on T cell proliferation capability.

<p>(A) Proliferative responses of MOG-specific T cells isolated from WT and Olig1^−/− EAE mice (<i>n</i> = 4). (B) RT-PCR analysis of Olig1 expression in brain, spinal cord, lymph node, spleen and thymus of WT mice.</p

Quantification of histopathology of the spinal cords in EAE mice.

<p>Quantitative analysis of the extent of demyelination (A), GFAP-positive (B) and iba1-positive (C) cells in the spinal cord. The areas of demyelinated regions in the white matter were measured by ImageJ 1.43u and expressed as a percentage of the whole area of the white matter. GFAP- and iba1-positive cells were counted per unit area (0.143 mm²) in the middle region of the ventral horn. ***<i>P</i><0.001; **<i>P</i><0.01; *<i>P</i><0.05.</p

Validation of <i>GRB2</i> as a <i>miR-376c</i> Target.

<p>(<b>A</b>) Western blotting analysis of GRB2 protein levels in HuCCT1 cells transfected with Pre-miR-376c or the Pre-miR negative control (NC). ACTB was monitored as an internal control. Relative GRB2 expression levels were calculated and are indicated below the bands. (<b>B</b>) <i>GRB2</i> mRNA expression levels in HuCCT1 cells transfected with Pre-miR-376c or the Pre-miR negative control (NC). The <i>GRB2</i> expression level was normalized to <i>GAPDH</i>. The expression level of the NC sample was defined as 1. The significance of differences between means was determined by Student's <i>t</i>-test. (<b>C</b>) The sequences of the mature <i>miR-376c</i> and its putative target site in the 3'-UTR of <i>GRB2</i>. The target site corresponding to the seed sequence of <i>miR-376c</i> was converted via mutation; the mutation introduced into the <i>miR-376c</i> recognition site of <i>GRB2</i> 3'-UTR in the reporter plasmid is also shown. (<b>D</b>) <i>GRB2</i> 3'-UTR luciferase reporter assay. Reporter vector (pMIR-GRB2 [GRB2] or pMIR-GRB2mt [GRB2mt]) and Pre-miR molecule (Pre-miR-376c [376c] or Pre-miR negative control [NC]) were co-transfected into HuCCT1 cells. Renilla luciferase vector pRL-TK was used as an internal control. Luciferase expression levels of Pre-miR negative control (NC) were set to 1.0. The significance of differences between means was determined by Student's <i>t</i>-test.</p

Representative histopathology of the optic nerves in EAE mice.

<p>(A) Optic nerves were stained with luxol fast blue (LFB) and hematoxylin and eosin (HE) (upper two panels) or NF200 and toluidine blue for the semithin transverse sections (lower two panels). The arrows point to the degenerating axons. Scale bar: 100 µm for the first and third panels, 75 µm for the second panels and 15 µm for the lower panels. (B) Quantitative analysis of cell infiltrates in the longitudinal section of the optic nerve. (C) Quantitative analysis of degenerating axons in the transverse section of the optic nerve. *<i>P</i><0.01.</p