Two Branched Silicone Resins with Different Reactive Groups: A Comparative Evaluation

In this study, vinyl-terminated polysiloxane (abbreviated VISR) and allyl-terminated polysiloxane (abbreviated ALSR) were synthesized and characterized. The curing behaviors and viscoelastic and thermal properties of VISR/PHSR and ALSR/PHSR were comparatively investigated. DSC and in situ FT-IR spectroscopy can be adopted to study the influence of molecular structures on reactivity. The results prove that ALSR/PHSR shows higher reactivity including a higher reaction rate constant and cure degree than VISR/PHSR. Moreover, it is found that the Šesták-Berggren equation can adequately depict the cure kinetic model of silicone resin in hydrosilylation comparing the calculated results with experimental data. Additionally, DMA exhibits that the glass transition temperature and cross-linking density of ALSR/PHSR are much lower than those of VISR/PHSR, TGA data reveal that they have similar thermal stability as well as high char yield, and the decomposition energy ranges from 100 to 270 kJ/mol with increment of degree of mass conversion (α_d) (α_d = 0.15–0.85)

The overexpression of p300 regulates the expression of odontoblastic marker genes in HDPCs in normal growth medium or odontoblastic induction medium.

<p>(A) Real-time qPCR examination of the relative endogenous mRNA levels of <i>DMP-1, DSPP, DSP, OPN</i> and <i>OCN</i> in cells with overexpressed p300 and in negative control cells cultured under normal culture conditions. The mRNA levels of each product were normalized to GAPDH mRNA levels. (B) The overexpression of p300 increases the expression of odontoblastic marker genes in HDPCs induced to differentiate. Total RNA was extracted from the induced cells. The endogenous mRNA expression of <i>DMP-1, DSPP, DSP, OPN</i> and <i>OCN</i> was measured by real-time qPCR on days 7 and 14. GAPDH was used as an internal control. All results are presented as the means ± SD of three independent experiments. Procedures were performed as described in the text (n = 3). * Statistically significant difference relative to the control, <i>P</i><0.05.</p

The effect of p300 on the proliferation of HDPCs.

<p>(A) Cell growth curves of HDPC/p300, HDPC/p300-ΔHAT and HDPC/V cells were constructed with the results of the CCK8 assay. The growth curves showed that p300 does not have a significant effect on the proliferation of HDPCs. (B) The BrdU assay revealed no significant differences in the amount of DNA synthesized by HDPC/p300, HDPC/p300-ΔHAT and HDPC/V cells. Newly synthesized DNA is stained red by BrdU and nuclei are stained blue by DAPI. Procedures were performed as described in the text (n = 3). All results are presented as the means ± SD of three independent experiments.</p

The overexpression of p300 increases ALP activity and mineral formation in HDPCs.

<p>(A) HDPC/V, HDPC/p300 and HDPC/p300-ΔHAT cells were cultured for 3 days in normal growth medium or odontoblastic induction medium, and the ALP activity in these cells was measured. GM, normal growth medium; IM, odontoblastic induction medium. (B) The effect of p300 on the formation of mineralized nodules in HDPCs cultured in odontoblastic induction medium, as analyzed by alizarin red S staining on day 21(×100). a: HDPC/V; b: HDPC/p300; c: HDPC/p300-ΔHAT. Scale bar, 100 µm. d: The histogram shows the quantification of mineralization by densitometry and reveals that remarkable decreases in mineralization occurred in HDPC/p300 and HDPC/p300-ΔHAT cells relative to control cells. All results are presented as the means ± SD of three independent experiments. Procedures were performed as described in the text (n = 3). * Statistically significant difference relative to the control, <i>P</i><0.05.</p

The stable overexpression of p300 and p300-ΔHAT in HDPCs.

<p>(A) real-time qPCR was performed to measure the relative levels of p300 and p300-ΔHAT mRNA after the transduction with lentiviral vectors. The level of each product was normalized to GAPDH mRNA levels. (B) Protein expression levels of p300 and p300-ΔHAT were assessed by western blotting analysis (right panel) and densitometric evaluation (left panel; expressed as ratio to GAPDH). The expression of GAPDH served as a control. All results are presented as the means ± SD of three independent experiments. Procedures were performed as described in the text (n = 3). * Statistically significant differences relative to the control, <i>P</i><0.05.</p

Hierarchical Nanotubular Anatase/Rutile/TiO₂(B) Heterophase Junction with Oxygen Vacancies for Enhanced Photocatalytic H₂ Production

Oxygen vacancies have been demonstrated to enhance the interfacial charge separation in TiO₂-based photocatalysts. In this report, we explored a facile route to synthesize hierarchical nanotubular anatase/rutile/TiO₂(B) nanostructures with high surface area and defective electronic structure. The formation of oxygen vacancies in the heterophase junction was analyzed by UV–vis absorption spectra, electron spin resonance, and X-ray photoelectron spectroscopy. The enhanced interfacial charge separation and transportation ensured the excellent photoactivity of oxygen-deficient junctions for the photocatalytic production of hydrogen. As a result, the defective anatase/rutile/TiO₂(B) junction showed a high hydrogen evolution rate of 2.79 mmol/h, which was 19 times higher than blank TiO₂ nanotubes. The results demonstrate that defect modulation is a powerful tool to enhance the catalytic performances of TiO₂-based photocatalysts

p300 regulates the expression of OCT4, NANOG and SOX2, whereas HAT mutant p300 suppresses the expression of NANOG and SOX2.

<p>(A) Real-time qPCR estimation of the relative endogenous mRNA levels of <i>OCT4, NANOG</i> and <i>SOX2</i> in HDPC/p300 and HDPC/V cells. The mRNA levels of each product were normalized to the mRNA levels of GAPDH. (B) Western blotting analysis (right panel) and densitometric evaluation (left panel; expressed as the ratio of protein levels to GAPDH levels) measuring the levels of OCT4, NANOG and SOX2 proteins in HDPC/p300 and HDPC/V cells. The expression of GAPDH was used as an internal control. (C) Measurement of the relative endogenous mRNA levels of <i>NANOG</i> and <i>SOX2</i> in HDPC/V, HDPC/p300 and HDPC/p300-ΔHAT cells using real-time qPCR. The mRNA levels of each product were normalized to GAPDH mRNA levels. (D) The results were further confirmed by western blotting (right panel) and densitometric evaluation (left panel; expressed as ratio to GAPDH). GAPDH was used as an internal control. All results are expressed as the means ± SD of three independent experiments. Procedures were performed as described in the text (n = 3). * Statistically significant difference relative to the control, <i>P</i><0.05.</p

Tungsten-Assisted Phase Tuning of Molybdenum Carbide for Efficient Electrocatalytic Hydrogen Evolution

Phase tuning during crystal phase transformation is an important but challenging step toward the development of effective hydrogen evolution reaction (HER) catalysts. Herein, we report on a feasible approach to achieve effective polycrystalline molybdenum carbides during transformation from α-phase to β-phase through the regulation of additive (tungsten) amount. Benefiting from the optimal Mo–C bond lengths and abundant active sites, molybdenum carbide prepared with a moderate addition of tungsten enhanced electrocatalytic activity and stability compared with pure α-phase and β-phase Mo₂C in the HER, and only required an overpotential of 148 and 93 mV to drive 20 mA cm^–2 of current density in 0.5 M H₂SO₄ and 1.0 M KOH, respectively

CHIP assay shows that p300 binds to the promoter region of <i>OCN</i> and <i>DSPP</i> in HDPCs.

<p>(A, B) Cells were cross-linked with formaldehyde. Chromatin was immunoprecipitated with anti-p300 or anti-H3K9Ac antibodies. The chromatin was eluted, reverse cross-linked, and the eluted DNA was analyzed by PCR.</p

Pore Structure-Dependent Mass Transport in Flow-through Electrodes for Water Remediation

Hierarchical three-dimensional architectures of granphene-based materials with tailored microstructure and functionality exhibit unique mass transport behaviors and tunable active sites for various applications. The micro- /nanochannels in the porous structure can act as micro- /nano- reactors, which optimize the transport and conversion of contaminants. However, the size-effects of the micro- /nanochannels, which are directly related to its performance in electrochemical processes, have not been explored. Here, using lamellar-structured graphene films as electrodes, we demonstrate that the interlayer spacing (range from ∼84 nm to ∼2.44 μm) between graphene nanosheets governs the mass transport and electron transfer in electrochemical processes; subsequently influence the water decontamination performances. The microchannel (interlayer spacing = ∼2.44 μm) can provide higher active surface areas, but slow reaction kinetics. Densely packed graphene nanosheets (interlayer spacing = ∼280 nm), which possessed better electron conductivity and could provide higher surface-area-to-volume ratio in narrow nanochannels (7.14 μm^–1), achieved the highest reaction kinetics. However, the ion-accessible surface area was decreased in highly dense films (interlayer spacing = ∼84 nm) due to serious interlayer stacking of graphene nanosheets, thereby leading poor reaction kinetics. These results demonstrate the size-effect of nanochannels in porous materials and highlight the importance of controlling mass transport and electron transfer for optimal electrochemical performance, enabling a deep understanding of the benefits and utilization of these hierarchical three-dimensional architectures in water purification