In-Depth Understanding of the Oxidative Compatibility of Volatile Organic Compounds with Mn2O3 and Pt-Loaded Catalysts.

Designing suitable catalysts for efficiently degrading volatile organic compounds (VOCs) is a great challenge due to the distinct variety and nature of VOCs. Herein, the suitability of different typical VOCs (toluene and acetone) over Pt-based catalysts and Mn2O3 was investigated carefully. The activity of Mn2O3 was inferior to Pt-loaded catalysts in toluene oxidation but showed superior ability for destroying acetone, while Pt loading could boost the catalytic activity of Mn2O3 for both acetone and toluene. This suitability could be determined by the physicochemical properties of the catalysts and the structure of the VOC since toluene destruction activity is highly reliant on Pt0 in the metallic state and linearly correlated with the amount of surface reactive oxygen species (Oads), while the crucial factor that affects acetone oxidation is the mobility of lattice oxygen (Olat). The Pt/Mn2O3 catalyst shows highly active Pt-O-Mn interfacial sites, favoring the generation of Oads and promoting Mn-Olat mobility, leading to its excellent performance. Therefore, the design of abundant active sites is an effective means of developing highly adaptive catalysts for the oxidation of different VOCs.

Thermal Annealing Induced Surface Oxygen Vacancy Clusters in α-MnO2 Nanowires for Catalytic Ozonation of VOCs at Ambient Temperature.

Catalytic ozonation has gained considerable interest in volatile organic compound (VOC) elimination due to its mild reaction conditions. However, the low activity and mineralization rate of VOCs over catalysts hinder its practical application. Herein, a series of α-MnO2 nanowire catalysts were prepared via thermal annealing treatment at various temperatures to tailor defect species. Numerous characterization techniques were used and combined to investigate the relationship between activity and microstructure. PALS and XAFS indicated that more unsaturated manganese and oxygen vacancies, especially surface oxygen vacancy clusters, were produced in α-MnO2 under the optimal high calcination temperature. As a result, MnO2-600 was found to exhibit the best-ever performance in toluene conversion (95%) and mineralization rate (89.5%) at 20 °C, making it a promising candidate for practical use. The roles of these defects in manipulating the reactive oxygen species of α-MnO2 were clarified by quantifying the amounts of reactive oxygen species by quenching experiments and density functional theory calculations. 1O2 and ·OH species generated in the vicinity of oxygen vacancy clusters, especially the dimer oxygen vacancy cluster, were identified as key oxygen species in the abatement of toluene. This study provides a facile method to engineer the microstructure of MnO2 by means of the manipulation of oxygen vacancies and an in-depth understanding of their roles in the catalytic ozonation of VOC.

Synergistic Catalytic Oxidation of Typical Volatile Organic Compound Mixtures on Mn-Based Catalysts: Significant Promotion Effect and Reaction Mechanism.

The miscellaneous volatile organic compounds (VOCs) in industrial flue gas streams usually demonstrate significant mutual inhibition effects, and the behavior of a particular VOC in mixtures is not clear, which hinders the application of catalytic technology. This study examines the catalytic oxidation and mixing effects of representative VOCs in industrial exhausts, consisting of acetone (AC), ethyl acetate (EA), and toluene (Tol), on common Mn-based catalysts (e.g., MnO2, Mn2O3, LaMnO3, and Mn3O4) by means of intrinsic activity evaluation, coadsorption, VOC temperature-programmed oxidation, in situ diffuse reflectance infrared Fourier transform spectroscopy, and gas chromatography-mass spectrometry. The results showed no inhibiting effect on the conversion of these VOCs when combusted together; instead, a significant mutual promotion effect was found, especially on Tol destruction, with a sharp decrease in the Tol T50 from 214 to 158 °C on MnO2. It is proposed for the first time that the addition of AC/EA in Tol combustion leads to the generation of o/m-methyl phenol, which changes the rate-determining step of the ring-opening process, thus elevating the conversion of Tol together with AC and EA in the mixture at low temperatures.

Effective Toluene Ozonation over δ-MnO2: Oxygen Vacancy-Induced Reactive Oxygen Species.

To improve the reactivity and lifetime of catalysts in the catalytic ozonation of toluene, a simple strategy was provided to regulate the morphology and microstructure of δ-MnO2 via the hydrothermal reaction temperature. The effects of the reaction temperature and the ozone to toluene concentration ratio on the catalyst performance were investigated. The optimized MnO2-260 catalyst prepared at the limiting hydrothermal temperature (260 °C) showed high catalytic activity (XTol = 95%) and excellent stability (1200 min) at the approximately ambient temperature of 40 °C, which was superior to the results in previous studies. The structure and morphology of δ-MnO2 were characterized by extended X-ray absorption fine structure, X-ray diffraction, scanning electron microscopy, positron annihilation lifetime spectroscopy, electron spin resonance, and other techniques. Experimental results and density functional theory calculations were in agreement that surface oxygen vacancy clusters, especially surface oxygen dimer vacancies, are critical in ozone activation. Oxygen vacancies can facilitate the adsorption and activation of O3 to generate reactive oxygen species (ROS, including 1O2, O2-, and •OH), leading to superior ozonation activity to degrade toluene and intermediates. Meanwhile, free radical detection and scavenger tests indicated that •OH is the primary ROS during toluene ozonation rather than 1O2 or O2-.

Variations in Pedicel Structural Properties Among Four Pear Species (Pyrus): Insights Into the Relationship Between the Fruit Characteristics and the Pedicel Structure.

Fruit pedicel is the bridge linking the parent tree and the fruit, which is an important channel for water and nutrients transport to the fruit. The genetic specificity determines the characteristics of the pedicel and the fruit, but the relationship between the pedicel structure and the fruit characteristics is unexplored. Combining the investigation of fruit characteristics, the statistical analysis of the pedicel structural properties, and the 2D and 3D anatomical observation of the pedicel, this study found distinctive contributions of the pedicel elements to the fruit characteristics in four pear species. The European pear (Conference) showed distinct fruit shape index and pedicel structural properties compared with the oriental pears (Akizuki, Yali, and Nanguoli). The fruit size positively correlated with pedicel length, fiber area, pedicel diameter, the area percentage of the cortex, and the area percentage of phloem; however, fruit firmness and soluble solids concentration are showed a stronger positive correlation with xylem area, pith area, the area percentage of xylem, the area percentage of sieve tube, and the area percentage of pith. Pedicel elements, including pith, fiber, and cortex, likely play a certain role in the fruit growth due to the variations of their characteristics demonstrated in the four pear species. The porosity, the ratio of the surface area to the volume, and the spatial arrangement of the vessels showed significant variations across the pear species, indicating the distinction of the hydraulic conductance of the pedicels. Our findings provided direct evidence that pedicel structural elements contributed distinctively to the fruit characteristics among pear species.

HOXD8 inhibits the proliferation and migration of triple-negative breast cancer cells and induces apoptosis in them through regulation of AKT/mTOR pathway.

HOXD8 (Homeobox D8) functions as an apoptotic inducer to suppress tumor progression. However, the role of HOXD8 in triple-negative breast cancer (TNBC) has not been fully understood. Firstly, HOXD8 was found to be reduced in TNBC tissues based on the TCGA samples through Ualcan (http://ualcan.path.uab.edu/analysis.html) prediction. Moreover, data from qRT-PCR and western blot confirmed the lower expression of HOXD8 in the TNBC tissues or cells than that in paracancerous tissues or human mammary epithelial cell line (MCF10A), respectively. Secondly, pcDNA-mediated over-expression of HOXD8 were conducted in TNBC cells, and the gain-of functional assays showed that over-expression of HOXD8 promoted TNBC cell progression with repressed cell apoptosis and induced proliferation, migration and invasion. Moreover, xenografted mouse model was constructed by injection of tumor cell line with stable over-expression of HOXD8 to assess the in vivo tumor growth, and the results revealed that over-expression of HOXD8 inhibited tumor growth. Lastly, our results showed that AKT and mTOR phosphorylation were repressed by HOXD8 over-expression in TNBC cells. In conclusion, HOXD8 functioned as an apoptotic inducer to suppress TNBC cell growth and progression by inhibition of AKT/mTOR pathway.

Performance Improvement and Biofouling Mitigation in Osmotic Microbial Fuel Cells via In Situ Formation of Silver Nanoparticles on Forward Osmosis Membrane.

An osmotic microbial fuel cell (OsMFC) using a forward osmosis (FO) membrane to replace the proton exchange membrane in a typical MFC achieves superior electricity production and better effluent water quality during municipal wastewater treatment. However, inevitable FO membrane fouling, especially biofouling, has a significantly adverse impact on water flux and thus hinders the stable operation of the OsMFC. Here, we proposed a method for biofouling mitigation of the FO membrane and further improvement in current generation of the OsMFC by applying a silver nanoparticle (AgNP) modified FO membrane. The characteristic tests revealed that the AgNP modified thin film composite (TFC) polyamide FO membrane showed advanced hydrophilicity, more negative zeta potential and better antibacterial property. The biofouling of the FO membrane in OsMFC was effectively alleviated by using the AgNP modified membrane. This phenomenon could be attributed to the changes of TFC-FO membrane properties and the antibacterial property of AgNPs on the membrane surface. An increased hydrophilicity and a more negative zeta potential of the modified membrane enhanced the repulsion between foulants and membrane surface. In addition, AgNPs directly disturbed the functions of microorganisms deposited on the membrane surface. Owing to the biofouling mitigation of the AgNP modified membrane, the water flux and electricity generation of OsMFC were correspondingly improved.

In situ surface-enhanced Raman spectroscopy for detecting microplastics and nanoplastics in aquatic environments.

The detection of microplastics and nanoplastics in the environment, especially plastic particles in aquatic environments in situ, still faces challenges due to the limitations of current methods, instruments and size of plastic particles. This paper evaluates the potential of surface-enhanced Raman spectroscopy for the analysis of microplastics and nanoplastics. The condition of different tests including the volume ratio of sample to silver colloid, the concentrations of NaCl, and the concentrations of the samples, are assessed for the study of microplastics and nanoplastics (polystyrene (PS), polyethylene (PE) and polypropylene (PP)) in pure water and seawater. A method based on SERS, that uses silver colloid as the active substrate, is developed for the qualitative analysis of microplastics and nanoplastics in aquatic environments. The particle sizes of microplastics and nanoplastics include 100 nm, 500 nm and 10 µm. The Raman signals of microplastics and nanoplastics in pure water and seawater both show good enhancement efficiency. The optimal enhancement factor is 4 × 104. The SERS-based detection method overcomes the limitations of microplastics and nanoplastics in liquids and can detect 100 nm plastics down to 40 µg/mL. It provides more possibility for the rapid detection of microplastics and nanoplastics in aquatic environments in the future.

The Complex Toxicity of Tetracycline with Polystyrene Spheres on Gastric Cancer Cells.

Nowadays, microplastics (MPs) exist widely in the marine. The surface has strong adsorption capacity for antibiotics in natural environments, and the cytotoxicity of complex are poorly understood. In the study, 500 nm polystyrene (PS-MPs) and 60 nm nanoplastics (PS-NPs) were synthesized. The adsorption of PS to tetracycline (TC) was studied and their toxicity to gastric cancer cells (AGS) was researched. The adsorption experimental results show that PS absorbing capacity increased with increasing TC concentrations. The defense mechanism results show that 60 nm PS-NPs, 500 nm PS-MPs and their complex induce different damage to AGS cells. Furthermore, 600 mg/L PS-NPs and PS-MPs decline cell viability, induce oxidation stress and cause apoptosis. There is more serious damage of 60 nm PS-NPs than 500 nm PS-MPs in cell viability and intracellular reactive oxygen species (ROS). DNA are also damaged by 60 nm PS-NPs and PS-TC NPs, 500 nm PS-MPs and PS-TC MPs, and 60 nm PS-NPs damage DNA more serious than 500 nm PS-MPs. Moreover, 60 nm PS-NPs and PS-TC NPs seem to promote bcl-2 associated X protein (Bax) overexpression. All treatments provided us with evidence on how PS-NPs, PS-MPs and their compounds damaged AGS cells.

Coagulation mechanism of cellulose/metal nanohybrids through a simple one-step process and their interaction with Cr (VI).

In this work, the coagulation mechanism of the cellulose/metal nanohybrids and the binding mode with Cr (VI) are deeply described. Nanohybrids with 3D porous networks were prepared from cellulose/Fe2O3-SO3H solutions through a simple one-step coagulation process in NaCl aqueous solutions. The structure and properties of nanohybrids were characterized by SEM, EDS, XRD, FTIR, and XPS. The cellulose/metal nanohybrids have a langmuir maximum adsorption capacity of 11.46 mg/g. The dissolved metal nanoparticles could form strong hydrogen bonding with cellulose by breaking the intermolecular hydrogen bonds between the polymer molecules. The porous networks of cellulose/metal nanohybrids provided multiple adsorption sites for Cr2O72- anion through FeO…Cr interactions. The cooperation between cellulose and Fe2O3-SO3H nanoparticles makes the hybrids exhibiting a satisfactory selectivity and affinity for Cr (VI). The cellulose/metal nanohybrids selectively interacted with Cr2O72- via Fe atom from Fe2O3 and oxygen atom from SO3- groups. The Cr (VI) adsorption occurred via a two-step process, the first of them was the initial adsorption of Cr2O72- on cellulose/metal nanohybrids surface, followed by the rearrangement of Cr2O72- molecules and the consecutive growth of Cr2O72- aggregate layers.

Regenerable bagasse-based carbon activated by in situ formation of zero-valent zinc microparticles for high-performance degradation of amoxicillin in water.

Increasing degradation of amoxicillin in water by low-cost advanced functional activated carbon-based materials derived from bagasse is an effective and economic way to remove the antibiotic residue pollutant and for high-valued utilization and transformation of plant wastes. In this work, bagasse was pyrolyzed and Zn2+ was activated for designing a high-efficiency bagasse-based activated carbon, which was characterized by FTIR, XRD, XPS, SEM, EDS, and ζ potential analyses. These analyses illustrated the mechanism of amoxicillin degradation, and microscale zero-valent zinc in bagasse-based activated carbon has a key role in amoxicillin degradation. Amoxicillin was broken down by reductive degraded radicals, which were produced by microscale zero-valent zinc corrosion in water. After the amoxicillin degradation, the byproduct of zinc hydroxide being adsorbed onto the used bagasse-based activated carbon can provide possibility of sustainable regeneration. Mass spectra analysis illustrated the main degradation products of amoxicillin. The kinetic experiments were adopted to observe the process of amoxicillin degradation, followed by the pseudo-first-order kinetic model. The isotherm experiments demonstrated that the maximum amoxicillin degradation capacity of bagasse-based activated carbon was about 46 mg g-1. The bagasse wastes were used as carbon source to design potential advanced activated carbon materials for increasing degradation of amoxicillin in water.

Effect of chlorogenic acid covalent conjugation on the allergenicity, digestibility and functional properties of whey protein.

We investigated the allergenicity, digestibility and functional properties of whey protein isolate (WPI) after covalent conjugation with chlorogenic acid (CHA). The covalent conjugation of CHA may cause an unfolded protein structure. The WPI-CHA conjugate showed lower IgE binding capacity but higher intestinal digestibility than unmodified WPI. Furthermore, after digestion, the IgE binding capacity of ß-lactoglobulin and α-lactoalbumin was lower in the digested WPI-CHA conjugate than digested WPI. Moreover, the solubility, emulsifying activity, foaming properties and antioxidant capacity of WPI were enhanced by covalent conjugation of CHA. Covalent conjugation with CHA might reduce the allergenicity in vitro of WPI by improving the functional properties of the protein.

Characterization of binding interactions of anthraquinones and bovine ß-lactoglobulin.

Anthraquinones, a class of naturally occurring polyphenolic compounds, exhibit a wide range of bioactivities. However, most free anthraquinones are lipophilic bioactive compounds. Bovine ß-lactoglobulin (ßLG), a major whey protein, has a high affinity for small hydrophobic compounds. In this study, the interactions between anthraquinones (rhein, emodin, and chrysophanol) and ßLG were investigated by using fluorescence, circular dichroism (CD), Fourier-transform infrared spectroscopy (FTIR), and docking studies. These anthraquinones bound to the site near Trp19-Arg124 on ßLG with a binding constant (Ka) between 103 and 105 L mol-1 to form complexes, which changed the secondary structure of ßLG, inducing an α-helix to ß-sheet structure transition. The order of binding increased with an increasing polarity in the order of rhein > emodin > chrysophanol. In addition, the degree of radical scavenging capacity masking increased with an increasing binding affinity. Complexation with ßLG significantly increases the hydrosolubility of anthraquinones.

Effect of Covalent Interaction with Chlorogenic Acid on the Allergenic Capacity of Ovalbumin.

Ovalbumin (OVA) is a major allergen in avian egg white. Here, we investigated the conjugation of OVA and chlorogenic acid (CHA) to reduce the allergenic capacity of OVA. OVA-CHA conjugate was characterized by SDS-PAGE, MALDI-TOF-MS, differential scanning calorimetry, and multispectroscopic methods. Sites of the OVA-CHA conjugate were identified by LC-MS/MS. CHA possibly conjugated with Lys20 and Lys17 in OVA, which resulted in the unfolding of OVA. ELISA and Western blot assay indicated that the OVA-CHA conjugate reduced the IgE binding capacity of OVA. The results also indicated that the ability of the OVA-CHA conjugate to activate histamine release was reduced. The decreased allergenic capacity of OVA was attributed to changes in the protein structure. Moreover, the CHA binding site in OVA might directly shield the linear IgE epitope, thereby reducing the IgE binding ability. Also, the OVA-CHA conjugate showed high antioxidant activity. OVA conjugated with CHA may be a promising method of OVA hyposensitization.

[Effects of Conductivity on Performance of a Combined System of Anaerobic Acidification, Forward Osmosis, and a Microbial Fuel Cell].

In this study, a novel combined system for simultaneous recovery of bioelectricity and water from wastewater was developed by integrating anaerobic acidification and a forward osmosis (FO) membrane with a microbial fuel cell (AAFO-MFC). Conductivity was thought to be an important factor affecting the performance of the AAFO-MFC system. Thus, effects of conductivity on the performance of AAFO-MFC system in treating synthetic wastewater were investigated. The results indicated that a higher conductivity increased the bioelectricity production, owing to a reduction in the internal resistance. However, it resulted in a rapid decrease of FO water flux and a shorter operating time because of a severer membrane fouling. The conductivity had no impact on the water quality of the effluents. The total organic carbon (TOC) and total phosphorus (TP) concentrations in the FO permeate were less than 4 and 0.5 mg·L-1, respectively, at all conductivity levels. However, the rejection of the FO membrane for NH4+-N was lower at all conductivity levels. The optimal comprehensive performance of this system was obtained when the conductivity was maintained at 7-8 mS·cm-1. In this case, the AAFO-MFC system achieved continuous and relatively stable power generation, and the water flux of FO membrane was relatively stable during a long-term operation of approximately 29 days.

Reducing the allergenic capacity of ß-lactoglobulin by covalent conjugation with dietary polyphenols.

To help produce hypoallergenic food, this study investigated reducing the allergenicity and improving the functional properties of bovine ß-lactoglobulin (ßLG) by covalent conjugation with (-)-epigallo-catechin 3-gallate (EGCG) and chlorogenic acid (CA). The covalent bond between the polyphenols and the amino acid side-chains in ßLG was confirmed by MALDI-TOF-MS and SDS-PAGE. Structural analysis by fluorescence spectroscopy, circular dichroism (CD) and Fourier transform infrared (FTIR) indicated that the covalent conjugate of EGCG and CA led to the changed protein structure of ßLG. Western blot analysis and enzyme-linked immunosorbent assay indicated that conjugation of ßLG with these polyphenols was effective in reducing the IgE-binding capacity of ßLG. The conjugates maintained the retinol-binding activity without denaturation the protein and enhanced the thermal stability with high antioxidant activity. The study provides an innovative approach to producing hypoallergenic food.

Characterization of binding interactions between selected phenylpropanoid glycosides and trypsin.

Phenylpropanoid glycosides (PPGs) are important bioactive polyphenolic compounds that are widely distributed in plants. In this paper, the inhibitory effects of four selected PPGs against trypsin were investigated. The interactions between these PPGs and trypsin were further investigated by multiple spectroscopic methods and molecular docking studies. The results showed that the binding of each of these PPGs to trypsin induced changes in the natural conformation of trypsin, which inhibited the enzyme in the following order: acteoside>syringalide A 3'-α-l-rhamnopyranoside>lipedoside A-I>osmanthuside B. The binding constant (Ka) values followed the same trend. The hydrogen bond force played an important role in the interaction between each PPG and trypsin. Interestingly, the binding affinity and inhibitory effect increased as the number of phenolic hydroxyl groups increased. In addition, the effect of the phenolic hydroxyl group on the A ring had a greater effect than one on the B ring.

Acteoside and Acyl-Migrated Acteoside, Compounds in Chinese Kudingcha Tea, Inhibit α-Amylase In Vitro.

Acteoside, the predominant polyphenol of small-leaved kudingcha, the Chinese tea, has various biological activities. In this study, we examined the acyl migration of acteoside to isoacteoside with high-temperature treatment of acteoside. The inhibitory effects of acyl-migrated acteoside and acteoside on α-amylase were investigated, as were their binding interaction with α-amylase. The binding of acteoside and isoacteoside to α-amylase was investigated by using the fluorescence spectra assay, circular dichroism, and protein-ligand docking studies. Acteoside was more effective than preheated acteoside and isoacteoside in inhibiting α-amylase activity. Acteoside and isoacteoside binding to α-amylase may induce conformational changes to α-amylase, and the binding site of acteoside and isoacteoside being near the active site pocket of α-amylase may explain the decreased activity of α-amylase. The different affinities and binding sites of acteoside and isoacteoside for α-amylase resulted in different inhibition rates, which may be due to structural differences between acteoside and isoacteoside.

Integrating microbial fuel cells with anaerobic acidification and forward osmosis membrane for enhancing bio-electricity and water recovery from low-strength wastewater.

Microbial fuel cells (MFCs) and forward osmosis (FO) are two emerging technologies with great potential for energy-efficient wastewater treatment. In this study, anaerobic acidification and FO membrane were simultaneously integrated into an air-cathode MFC (AAFO-MFC) for enhancing bio-electricity and water recovery from low-strength wastewater. During a long-term operation of approximately 40 days, the AAFO-MFC system achieved a continuous and relatively stable power generation, and the maximum power density reached 4.38 W/m3. The higher bio-electricity production in the AAFO-MFC system was mainly due to the accumulation of ethanol resulted from anaerobic acidification process and the rejection of FO membrane. In addition, a proper salinity environment in the system controlled by the addition of MF membrane enhanced the electricity production. Furthermore, the AAFO-MFC system produced a high quality effluent, with the removal rates of organic matters and total phosphorus of more than 97%. However, the nitrogen removal was limited for the lower rejection of FO membrane. The combined biofouling and inorganic fouling were responsible for the lower water flux of FO membrane, and the Desulfuromonas sp. utilized the ethanol for bio-electricity production was observed in the anode. These results substantially improve the prospects for simultaneous wastewater treatment and energy recovery, and further studies are needed to optimize the system integration and operating parameters.

SIN1 promotes the proliferation and migration of breast cancer cells by Akt activation.

Stress-activated protein kinase (SAPK) interacting protein 1 (SIN1) is an essential TORC2 component and a key regulator of Akt pathway that plays an important role in various pathological conditions including cancer. Whereas its functional role in breast cancer has not been well characterized. In the present study, SIN1 is associated with the progression and survival of breast cancer patients, as well as human breast cancer cell proliferation and migration. SIN1 mRNA level was significantly up-regulated in human breast cancer samples compared with their corresponding paracancerous histological normal tissues. Furthermore, the expression levels of SIN1 were also increased in three human breast cancer cell lines compared with human breast epithelial cell MCF10A. Overexpression of SIN1 promoted cell proliferation, colony formation and migration of breast cancer cells. Knockdown of SIN1 in MDA-MB-468 cells inhibited cell proliferation, colony formation and migration. In addition, SIN1 overexpression increased phosphorylation of Akt and knockdown of SIN1 inhibited phosphorylation of Akt in MDA-MB-468 cells. In a tumour xenograft model, overexpression of SIN1 promoted tumour growth of MDA-MB-468 cells in vivo, whereas SIN1 knockdown inhibits the tumour growth. Taken together, our results reveal that SIN1 plays an important role in breast cancer and SIN1 is a potential biomarker and a promising target in the treatment of breast cancer.