Optical and Photocatalytic Properties of Three-Dimensionally Ordered Macroporous Ta2O5 and Ta3N5 Inverse Opals

Colloidal crystal templating is a simple yet remarkably versatile synthetic strategy toward inverse opal (IO) photonic crystals for optical sensing and catalytic applications. Herein, we report the successful fabrication of tantalum (V) oxide, Ta2O5, inverse opal thin films and powders using the colloidal crystal templating method, utilizing poly(methyl methacrylate) (PMMA) colloidal crystals as sacrificial templates and TaCl5 as the tantalum source. The Ta2O5 IO thin films and powders showed structural color at ultraviolet (UV) and visible wavelengths, with the photonic band gap (PBG) position along the [111] direction increasing linearly with the diameter of macropores (D) in the inverse opals and also the refractive index of the medium filling the macropores, in excellent accord with a modified Bragg’s law expression. Thermal ammonolysis of the Ta2O5 inverse opals at 700 °C yielded well-ordered Ta3N5 IO films and powders possessing high specific surface areas (37 m2 g–1) and a semiconductor band gap of 2.0–2.1 eV. A Pt/Ta3N5 IO photocatalyst delivered a H2 production rate of ∼300 μmol g–1 h–1 in aqueous methanol (10 vol % MeOH) under visible-light irradiation (300 W Xe lamp, λ ≥ 420 nm), approximately twice that achieved using conventional Pt/Ta3N5 powder photocatalysts (161 μmol g–1 h–1, 8.4 m2 g–1). Results demonstrate that inverse opal engineering is an effective approach for realizing Ta2O5 IO thin films for sensing applications and Ta3N5 IOs with enhanced photocatalyst performance

Surfactant-Mediated Ultrasonic-Assisted Extraction and Purification of Antioxidants from Chaenomeles speciosa (Sweet) Nakai for Chemical- and Cell-Based Antioxidant Capacity Evaluation

In this study, a surfactant-mediated ultrasonic-assisted process was used for the first time to produce an antioxidant-enriched extract from Chaenomeles speciosa (Sweet) Nakai (C. speciosa, a popular fruit grown widely in the temperate regions of China). Ultrasonic treatment at 51 °C and 200 W for 30 min with sodium dodecyl sulfate as the surfactant led to a phenolic yield of 32.42 mg/g from dried C. speciosa powder, based on single-factor experiments, the Plackett–Burman design and the Box–Behnken design. The phenolic content increased from 6.5% (the crude extract) to 57% (the purified extract) after the purification, using LSA-900C macroporous resin. Both the crude and purified extracts exhibited a significant total reducing power and DPPH/ABTS scavenging abilities, with the purified extract being more potent. The purified extract exerted significant antioxidant actions in the tert-butyl hydroperoxide-stimulated HepG2 cells, e.g., increasing the activities of superoxide dismutase and catalase, while decreasing the reactive oxygen species and malondialdehyde levels, through the regulation of the genes and proteins of the Nrf2/Keap1 signaling pathway. Therefore, the extract from C. speciosa is a desirable antioxidant agent for the oxidative damage of the body to meet the rising demand for natural therapeutics

Performance comparison of Ni/TiO2 and Au/TiO2 photocatalysts for H2 production in different alcohol-water mixtures

This study systematically compares the performance of 0.5¿wt% Ni/P25 TiO2 and 2¿wt% Au/P25 TiO2 photocatalysts for H2 production in alcohol-water mixtures under UV excitation. HRTEM, XANES and EXAFS confirmed the presence of 5–8¿nm Ni0 and Au0 nanoparticles on the surface of the photocatalysts. H2 production tests were conducted in various alcohol-water systems (0–100¿vol%), using methanol, ethanol, ethylene glycol and glycerol. The Ni/P25 TiO2 and Au/P25 TiO2 photocatalysts demonstrated remarkably similar performance for hydrogen production in all the alcohol-water systems tested. At low alcohol concentrations (15¿vol% or less), H2 production rates followed the order glycerol¿>¿ethylene glycol¿>¿methanol¿>¿ethanol, whilst at higher alcohol concentrations methanol (optimum 40¿vol%) and ethanol (optimum 80–90¿vol%) afforded the highest rates. Rates depended on the polarity and oxidation potential of the alcohol. Further, anatase-rutile heterojunctions in P25 TiO2 were found to greatly enhance H2 production.Peer ReviewedPostprint (author's final draft

Performance comparison of Ni/TiO2 and Au/TiO2 photocatalysts for H2 production in different alcohol-water mixtures

This study systematically compares the performance of 0.5¿wt% Ni/P25 TiO2 and 2¿wt% Au/P25 TiO2 photocatalysts for H2 production in alcohol-water mixtures under UV excitation. HRTEM, XANES and EXAFS confirmed the presence of 5–8¿nm Ni0 and Au0 nanoparticles on the surface of the photocatalysts. H2 production tests were conducted in various alcohol-water systems (0–100¿vol%), using methanol, ethanol, ethylene glycol and glycerol. The Ni/P25 TiO2 and Au/P25 TiO2 photocatalysts demonstrated remarkably similar performance for hydrogen production in all the alcohol-water systems tested. At low alcohol concentrations (15¿vol% or less), H2 production rates followed the order glycerol¿>¿ethylene glycol¿>¿methanol¿>¿ethanol, whilst at higher alcohol concentrations methanol (optimum 40¿vol%) and ethanol (optimum 80–90¿vol%) afforded the highest rates. Rates depended on the polarity and oxidation potential of the alcohol. Further, anatase-rutile heterojunctions in P25 TiO2 were found to greatly enhance H2 production.Peer Reviewe

Attenuation of Palmitic Acid-Induced Intestinal Epithelial Barrier Dysfunction by 6-Shogaol in Caco-2 Cells: The Role of MiR-216a-5p/TLR4/NF-κB Axis

Palmitic acid (PA) can lead to intestinal epithelial barrier dysfunction. In this study, the protective effects and working mechanisms of 6-shogaol against PA-induced intestinal barrier dysfunction were investigated in human intestinal epithelial Caco-2 cells. Transepithelial electrical resistance (TEER), paracellular flux, qRT-PCR, immunofluorescence, and Western blot experiments showed that the 24-h treatment with 400 μM PA damaged intestinal barrier integrity, as evidenced by a reduction of 48% in the TEER value, a 4.1-fold increase in the flux of fluorescein isothiocyanate-dextran 4000 (FD-4), and decreases in the mRNA and protein expression of tight junction (TJ)-associated proteins (claudin-1, occludin, and ZO-1), compared with the control. The PA treatment significantly (p < 0.05) increased the levels of pro-inflammatory cytokines (interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α)) in Caco-2 cells due to the upregulation of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), phosphorylated nuclear factor kappa-B (NF-κB) proteins, and downregulation of miR-216a-5p (which directly targeted TLR4). Co-treatment with PA and 6-shogaol (2.5 μM) significantly (p < 0.05) attenuated PA-induced changes through regulation of TJs via the miR-216a-5p/TLR4/NF-κB signaling pathway. This study provides insights into the functions and working mechanisms of 6-shogaol as a promising food-derived agent against PA-induced intestinal epithelial barrier dysfunction

Quercetin Induces Apoptosis in HepG2 Cells via Directly Interacting with YY1 to Disrupt YY1-p53 Interaction

Quercetin is a flavonol found in edible plants and possesses a significant anticancer activity. This study explored the mechanism by which quercetin prevented liver cancer via inducing apoptosis in HepG2 cells. Quercetin induced cell proliferation and apoptosis through inhibiting YY1 and facilitating p53 expression and subsequently increasing the Bax/Bcl-2 ratio. The results revealed that YY1 knockdown promoted apoptosis, whilst YY1 overexpression suppressed apoptosis via direct physical interaction between YY1 and p53 to regulate the p53 signaling pathway. Molecular docking using native and mutant YY1 proteins showed that quercetin could interact directly with YY1, and the binding of quercetin to YY1 significantly decreased the docking energy of YY1 with p53 protein. The interactions between quercetin and YY1 protein included direct binding and non-bonded indirect interactions, as confirmed by cellular thermal shift assay, UV-Vis absorption spectroscopy, fluorescence spectroscopy and circular dichroism spectroscopy. It was likely that quercetin directly bound to YY1 protein to compete with p53 for the binding sites of YY1 to disrupt the YY1-p53 interaction, thereby promoting p53 activation. This study provides insights into the mechanism underlying quercetin’s anticancer action and supports the development of quercetin as an anticancer therapeutic agent

Assessing the nutritional quality of lipid components in commercial meal replacement shakes using an in vitro digestion model

This study aimed to investigate the nutritional value of five commercial meal-replacement shakes, and mainly focused on the lipid digestion fates and fat-soluble vitamin bioavailability. Four out of five samples exhibited a low lipolysis level (37.33–61.42%), aligning with the intended objectives of these products. Although the remaining sample rich in diacylglycerol (DAG) had a higher lipolysis level (80.83%), the inherent low-calorie nature of DAG might compensate for this drawback. The release level of individual fatty acid was largely determined by the glycerolipid composition. Moreover, the strong positive correlation between lipid hydrolyzed products amounts and the fat-soluble vitamin bioavailability was observed. Surprisingly, one out of five samples can provide enough vitamin A and vitamin E for consumers as a total replacement of one or two regular meals. Consequently, the meal-replacement shakes hold the potential to emerge as healthy products for this fast-paced era if the composition and structure were carefully designed and calculated

Comparison of kokumi gamma-[Glu]((n > 1))-Val and gamma-[Glu]((n > 1))-Met synthesized through transpeptidation catalyzed by glutaminase from Bacillus amyloliquefaciens

A series of gamma-[Glu]((n= 2,3,4))-Val or gamma-[Glu]((n= 2,3,4))-Met were synthesized in the presence of donor (Gln) and corresponding acceptor (Val or Met) through transpeptidation catalyzed by the glutaminase from Bacillus amyloliquefaciens. Gln in excess significantly (p &lt;.05) improved the yield of gamma-[Glu]((n&gt; 1))-Val/Met except for gamma-Glu-Val/Met. The Km values for transpeptidase activity to yield gamma-[Glu]((n= 0,1,2,3))-Val increased with an elevated n, but remained essentially the same irrespective of n value for gamma-[Glu]((n= 0,1,2))-Met (which were 31-44% of that for gamma-[Glu] 3-Met). The highest Km value appearing when n= 3 (gamma-[Glu](3)-Val or gamma-[Glu](3)-Met) suggested the rising difficulty for synthesis when the number of donor increases. All the gamma-[Glu](n)-Val/Met substances exhibited kokumi properties and enhanced the continuity and umami taste of soy sauce as well as the thickness, mouthfulness and umaminess of model chicken broth. These results indicate the potential of the gamma-[Glu](n)-Val and gamma-[Glu](n)-Met as food flavor enhancers.</p

Structural, Optical, and Catalytic Support Properties of γ‑Al₂O₃ Inverse Opals

Colloidal crystal templating is a versatile and inexpensive method for the fabrication of 3-dimensional photonic crystals. Here we describe the successful use of the method to fabricate γ-alumina (γ-Al₂O₃) inverse opal thin films and powders, possessing pseudo photonic bandgaps (PBGs) along the [111] direction at visible wavelengths. The optical properties of γ-Al₂O₃ inverse opal films were investigated in detail for the first time and closely obeyed a modified Bragg’s law expression. The PBGs red-shifted on immersion in organic solvents, with the magnitude of the shift being directly proportional to the solvent refractive index. Calcination of the γ-Al₂O₃ inverse opals (BET area 250–275 m² g^–1) at temperatures from 550 to 1200 °C resulted in the stepwise transformation γ-Al₂O₃ → δ-Al₂O₃ → θ-Al₂O₃ → α-Al₂O_3. The onset temperatures for the latter polymorphic transitions were ca. 50–100 °C higher for Al₂O₃ inverse opals compared to a sol–gel alumina nanopowder, suggesting that the inverse opal architecture imparts sintering resistance. Au/γ-Al₂O₃ catalysts synthesized using γ-Al₂O₃ inverse opal supports demonstrated excellent activity for CO oxidation, with 69% CO conversion being achieved at 20 °C and near-complete conversion at 150 °C. The hierarchical porosity and high specific surface areas of γ-Al₂O₃ inverse opal powders make them near ideal supports for catalytic applications that traditionally utilize γ-alumina