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Montmorillonite (MMT), as a naturally sourced and FDA-approved biomaterial, has attracted considerable attention due to its extensive application in biomedical areas, such as intestinal ailments, drug delivery, and additive manufacturing. In this work, two-dimensional montmorillonite (2D-MMT) ultrathin nanosheets were successfully prepared from sodium montmorillonite (Na-MMT) by utilizing a freeze-drying assisted method. Possessing a large specific surface area and increased number of exposed hydroxyl groups, 2D-MMT nanosheets exhibited better antibacterial ability than the original Na-MMT. More strikingly, we found that both 2D-MMT nanosheets and Na-MMT could generate reactive oxygen species (ROS) upon visible light illumination, which could promote their antibacterial efficiency. As a result, 2D-MMT nanosheets showed efficient antibacterial performance in the presence of light towards Escherichia coli with a simultaneous enhancement of surface adsorption and photodynamic ablation. What's more, a possible mechanism for ROS generation by MMT upon light illumination was first proposed in this work. The combination of the increased physical adsorption capacity and ROS generation ability of 2D-MMT nanosheets would help inspire the development of MMT as a promising antimicrobial candidate in the future.

Calcium ions (Ca2+) are extremely important for efficiently improving the mechanical properties of alginate dual-crosslinked hydrogels through the synergy of crack bridging of covalent crosslinking and hysteresis of ionic crosslinking, but it is hard to achieve a high content of Ca2+ (>5 wt%) in these hydrogels for the following reasons. The low solubility and poor dispersion of CaSO4 in the gelling solution lead to a low Ca2+ content (

The substitution of noble metal platinum catalyst is one of the important research contents for sustainable development and is also the key to the practical application of photoelectrochemical (PEC) hydrogen production. In this work, we loaded the 1T-2H mixed phase MoS2 on the hydrogenated anatase/rutile heterophase TiO2 (A-H-RTNA) by hydrothermal method to prepare a new MoS2/A-H-RTNA electrode material. The prepared material exhibited higher carrier density, lower PL intensity and higher conductivity than Pt/A-H-RTNA because 1T-MoS2 has more active sites and lower charge transfer resistance than Pt. With the bias voltage of −0.4 V, the optimized 16MoS2/A-H-RTNA as photocathode shows the largest PEC hydrogen production rate of 1840 mmol m−2 h−1, which is 2.9 and 2.2 times higher than those of A-H-RTNA (625 mmol m−2 h−1) and Pt/A-H-RTNA (848 mmol m−2 h−1), respectively. We innovatively used the prepared 16MoS2/A-H-RTNA film as counter electrode instead of Pt electrode to construct a PEC system without any noble-metal. The result demonstrates that the noble-metal-free MoS2 loaded on TiO2 electrode as counter electrode has 75% PEC activity of noble metal Pt electrode. This study develops a PEC method for hydrogen evolution, which no longer depends on precious metal platinum as cathode.

Tree peony (Paeonia section Moutan DC.) has recently been recognised as an important woody oil plant of high economic value, with its seeds containing high levels of α-linolenic acids (ALA,...

Tree peony has been widely planted as an excellent oil crop with high proportion of α-linolenic acid (ALA) in its seeds. It was reported that pollen sources have clear effects on fatty acid (FA) composition of its kernels. Nevertheless, the molecular basis of this novel phenomenon is poorly understood. In this study, four Paeonia suffruticosa cultivars whose pollen caused significant differences in ALA content of Paeonia rockii were selected as pollen donors and grouped under high and low ALA groups. After pollination, total FAs content, composition and expression profiles of 10 genes involved in the FA and triacylglycerol (TAG) biosynthetic pathways were investigated during seed development. During the rapid oil accumulation in seeds, three desaturase genes (SAD, FAD2, FAD3) showed much higher expression in high ALA group, and their differential expression profiles corresponded well with the variations in ALA content among different pollen sources. Overall, pollen sources could affect the expression level of genes associated with fatty acid modification and subsequently affect the composition of FA in the kernels.

Lytic replication of Epstein-Barr virus (EBV) is not only essential for its cell–to–cell spread and host–to–host transmission, but it also contributes to EBV-induced oncogenesis. Thus, blocking EBV lytic replication could be a strategy for managing EBV-associated diseases. Previously, we identified a series of natural lignans isolated from the roots of Saururus chinensis (Asian lizard's tail) that efficiently block EBV lytic replication and virion production with low cytotoxicity. In this study, we attempted to elucidate the molecular mechanism by which these lignans inhibit EBV lytic replication. We found that a representative compound, CSC27 (manassantin B), inhibits EBV lytic replication by suppressing the expression of EBV immediate-early gene BZLF1 via disruption of AP-1 signal transduction. Further analysis revealed that manassantin B specifically blocks the mammalian target of rapamycin complex 2 (mTORC2)-mediated phosphorylation of AKT Ser/Thr protein kinase at Ser-473 and protein kinase Cα (PKCα) at Ser-657. Using phosphoinositide 3-kinase–AKT-specific inhibitors for kinase mapping and shRNA-mediated gene silencing, we validated that manassantin B abrogates EBV lytic replication by inhibiting mTORC2 activity and thereby blocking the mTORC2–PKC/AKT-signaling pathway. These results suggest that mTORC2 may have utility as an antiviral drug target against EBV infections and also reveal that manassantin B has potential therapeutic value for managing cancers that depend on mTORC2 signaling for survival.

In the past few years, anatase/rutile TiO2 heterophase junction structures with highly efficient photocatalytic performance have been explored widely, while their activities are still unsatisfactory in solar-to-hydrogen energy conversion. In this study, a novel anatase/rutile TiO2 photoelectrode with hydrogenated heterophase interface structures (A-H-RTNA) was successfully designed and synthesized for the first time via hydrothermal synthesis–hydrogenation–branching growth. Structure characterization indicated that the hydrogenated interfaces between anatase–branches and rutile–TiO2–nanorod hold appropriate oxygen vacancies and Ti3+ and inferred that new energy levels of oxygen vacancy and Ti–OH lie below the band edge positions of conduction band and valence band of rutile TiO2 nanorod, respectively. The matching energy levels between anatase–branches and hydrogenated rutile–nanorod obviously reduce the recombination of the photogenerated carriers, resulting in a superior photoelectrochemical (PEC) perfo...

The phytochemical investigation on the acetone extract of Euphorbia milii afforded thirteen new ent-rosane diterpenoids (1–13) through bioassay guided fractionation for evaluating its effect on Epstein–Barr virus (EBV) DNA lytic replication. Structures were determined by comprehensive spectroscopic analyses including 1D & 2D NMR techniques, chemical methods, and experimental and calculated electronic circular dichroism (ECD) data. The absolute configuration of euphominoid A (1) was established by single crystal X-ray diffraction analysis of its p-bromobenzoate derivative 1a. Compounds 1–3, and 10 displayed inhibitory activity with EC50 values ranging from 5.4 to 29.1 μM and selective index (SI) values varied from 4.5 to 9.3. Compound 2 showed the most potent inhibitory activity with an EC50 value of 5.4 μM comparing with the positive control (+)-rutamarin (EC50 = 5.4 μM). This is the first report of ent-rosane-type diterpenoids exhibiting significant inhibition of EBV lytic replication.

Tree peony (Paeonia section Moutan DC.) species are woody oil crops with high unsaturated fatty acid content, including &alpha, linolenic acid (ALA/18:3, &gt, 40% of the total fatty acid). Comparative transcriptome analyses were carried out to uncover the underlying mechanisms responsible for high and low ALA content in the developing seeds of P. rockii and P. lutea, respectively. Expression analysis of acyl lipid metabolism genes revealed upregulation of select genes involved in plastidial fatty acid synthesis, acyl editing, desaturation, and triacylglycerol assembly in seeds of P. rockii relative to P. lutea. Also, in association with ALA content in seeds, transcript levels for fatty acid desaturases (SAD, FAD2, and FAD3), which encode enzymes necessary for polyunsaturated fatty acid synthesis, were higher in P. rockii compared to P. lutea. Furthermore, the overexpression of PrFAD2 and PrFAD3 in Arabidopsis increased linoleic and ALA content, respectively, and modulated the final ratio 18:2/18:3 in the seed oil. In conclusion, we identified the key steps and validated the necessary desaturases that contribute to efficient ALA synthesis in a woody oil crop. Together, these results will aid to increase essential fatty acid content in seeds of tree peonies and other crops of agronomic interest.

A novel membrane-free electrodeionization (MFEDI) process has been proposed and tested successfully for high purity water production in our previous work. However, to prevent the ions backward migration, the electrode polarity had to be reversed during regeneration, which complicated the regeneration process, reduced the regeneration efficiency and shortened the electrode life. In order to avoid the electrode polarity reversal and enhance the regeneration efficiency, the resin layer structure and the types of mixed resins were changed in this work to form a MFEDI without electrode polarity reversal which was then tested by desalinating the synthetic two-pass RO permeate of seawater with a total of 40 operational cycles. Results demonstrated that the backward migration of Na + ions was prevented effectively; the weak-type resins facilitated the water dissociation and promoted the regeneration of strong-type resins significantly. Both good purification and effective regeneration were achieved. The conductivity of effluent was 0.060–0.063 μS/cm only. The energy consumption and the water recovery were 0.24 kW h/m 3 water and 96.1%, respectively. Repetitive experimental results showed this MFEDI system could work stably.

Electrodeionization (EDI) is widely used for removal and recovery of nickel from dilute wastewater due to its high efficiency and easy operation. However, the use of membranes in EDI causes problems such as membrane fouling, scaling and concentration polarization. In this work, the treatability of nickel containing wastewater by membrane-free electrodeionization (MFEDI) was experimentally investigated. The study concentrated on the effect of different resin bed configurations in MFEDI system in term of nickel removal, precipitation generation and water recovery, as well as energy consumption. The experiment results show that excellent purification and effective regeneration were achieved by MFEDI with a layered mixed bed. It was observed that, in the purification stage, with an inlet conductivity of 42.5 μS/cm and a nickel concentration of 10.0 mg/L, the effluent conductivity was 0.3–1.0 μS/cm and the nickel concentration of the effluent was below the detection limit; in the regeneration stage, the average nickel concentration of the concentrate was over 80.0 mg/L, the average pH of the concentrate was 7.4, thereby precipitation was prevented. The energy consumption and water recovery rate were 5.6 kWh/m 3 and 88%, respectively.

In some coastal areas, the primary freshwater obtained through seawater desalination has been widely used as the feed water in high purity-water production. Due to its high conductivity, however, further lowering ionic species load is needed before the final polishing process such as the mixed bed ion exchange and electrodeionization. In this work, a new process called as chemical-free ion exchange (CFIE) was proposed to replace the conventional two-bed (cation–anion) ion exchange for the purpose above. Results demonstrated that the mixed resin regeneration was achieved mainly by electrically enhancing water split. After regeneration, the resins could resume their ability to desalinate. The conductivities of purified water were 0.8–1.5 μS/cm, and the energy consumption and water recovery were 0.29–1.04 kWh/m3 water and 81.8–94.7%, respectively. The neutral concentrate collected during regeneration could be returned to a pretreatment unit for recovery. No chemical was needed and no wastewater was produced. Repetitive experimental results showed that the CFIE system could run stably.

A promising membrane-free electrodeionization (MFEDI) process has been proposed for high purity water (HPW) production in our previous work. However, the employ of a large number of weak-acid resins in MFEDI limits this process for purifying the reverse osmosis (RO) permeate of tap water with a pH value below 6.0. In this work, a MFEDI system filled only with mixed strong-acid and strong-base resins was tested to desalinate the synthetic acidic RO permeate. Results demonstrated that the resins regeneration was achieved mainly by electrically enhancing water dissociation after a high current density was imposed to the resin layer. Both good purification and effective regeneration were achieved. The conductivity of effluent was 0.060–0.062 μS/cm only. The energy consumption fluctuated in the range of 0.35–0.41 kW h/m 3 water and the water recovery reached 93.1%. The mixed concentrate collected during regeneration, with an average conductivity of 145 μS/cm and a pH value of 6.5, could be returned to a pretreatment unit for recovery. No chemical was needed and no wastewater was produced. Repetitive experimental results showed the MFEDI system could work stably.

Bi2WO6 nanoplates with thickness of about 100 nm had been successfully synthesized by sol-gel method using egg white proteins (albumin) as a biotemplate. On the basis of results of morphologies observation, it was found that albumin was critical for controlling the morphologies of the final products. Photocatalytic activities of the samples were evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. Due to the combined effects of high specific area, high light absorption and efficient separation of photogenerated electron-hole pairs, Bi2WO6 photocatalyst synthesized in the presence of albumin exhibited better photocatalytic activity than that Bi2WO6 synthesized without using albumin.

Purpose – The purpose of this study was to investigate the corrosion of rusted carbon steel in dilute NaCl solution, with the purpose of exploring the effect of the rust layer on metal corrosion and establishing a corrosion model for rusted iron. Design/methodology/approach – The corrosion behavior of rusted carbon steel in dilute NaCl solution was studied by means of weight-loss determinations, scanning electron microscopy, Raman spectrometry and electrochemical techniques. Findings – The results indicated that carbon steel had a similar corrosion behavior in all three NaCl solutions. The iron rust, which consisted of a thin γ-FeOOH layer and a thick Fe3O4 layer, can facilitate the corrosion process of carbon steel via reduction of γ-FeOOH and the large area cathode of Fe3O4. Hence, the corrosion rate of carbon steel was accelerated significantly and finally was determined by the limiting diffusion rate of oxygen. Originality/value – A corrosion model of rusted carbon steel was established, suggesting that iron rust formed in all slightly acidic waters with low alkalinity probably promotes the corrosion of carbon steel. Anti-corrosion measures for iron in this type of solution, such as desalination water, should be aimed to reduce the promotional effect of the rust layer on metal corrosion.

Purpose – The purpose of this investigation was to study the effects of sodium hexametaphosphate and zinc sulfate on the corrosion control of rusted iron in reverse osmosis (RO) product water of seawater. Design/methodology/approach – The synergistic effects and inhibition effects of corrosion inhibitors on rusted carbon steel were studied using the weight-loss method, electrochemical tests and surface analysis techniques. Findings – The results indicated that sodium hexametaphosphate could partly suppress the corrosion of rusted steel, but zinc sulfate used alone had no inhibition effect. Hexametaphosphate and zinc sulfate showed a strong synergistic effect and the optimal ratio of two chemicals was 1:1. The inhibition efficiency appeared to increase with increasing inhibitor concentration and the ideal dosage of inhibitors was set at 20 mg/L, when chemical cost and inhibition efficiency were taken into account. Surface analysis results proved that this compound inhibitor could make the rust layer much more compact. The inhibitive mechanism was to combine with rust and form a protective film, which consisted of iron oxide, polyphosphate and Zn(OH)2. Originality/value – It was found that the compound inhibitor consisting of sodium hexametaphosphate and zinc sulfate had a good inhibitive effect on rusted iron in RO product water. The research results can provide theoretical guidelines for corrosion control of rusted pipes in power plants.

In order to develop highly efficient visible-light-driven photocatalysts, bismuth tungstate (Bi2WO6) was incorporated with reduced graphene oxide (RGO) via an ionic liquid-assisted hydrothermal process. The photocatalytic activities of the as-prepared samples were evaluated by photocatalytic degradation of a rhodamine B aqueous solution under visible light irradiation. Compared with pure Bi2WO6, all the as-prepared RGO–Bi2WO6 composites exhibited significantly enhanced photocatalytic performances for the degradation of rhodamine B. Significantly, the optimum photocatalytic degradation efficiency of RGO–Bi2WO6 composites prepared in the presence of the ionic liquid was about 1.9 times higher than that of Bi2WO6–RGO composites prepared without using the ionic liquid. The excellent photocatalytic performances of RGO–Bi2WO6 composites were correlated with the surface area, light absorption and the separation efficiency of photoinduced electrons and holes. Moreover, the possible mechanism of the enhanced photocatalytic activity for the RGO–Bi2WO6 photocatalyst was proposed on the basis of the experimental results.

PurposeThe purpose of this paper is to explore the long‐term corrosion behavior of carbon steel in 3% NaCl solution and evaluate the effect of rust layer on the corrosion process.Design/methodology/approachThe corrosion behavior of rusted carbon steel in 3% NaCl solution was studied by means of infrared spectroscopy (IR) and electrochemical impedance spectroscopy (EIS).FindingsThe results indicated that the corrosion of carbon steel was affected by chloride ion in initial immersion and then controlled by the rust layer. The rust layer consisted of a thin outer layer (γ‐FeOOH layer) and a thick inner layer (Fe3O4 layer). The outer rust layer facilitated the cathodic process via reduction of γ‐FeOOH, while the inner rust layer provided a large cathode area and oxygen could be reduced on its surface. As a result, the corrosion rate of carbon steel was determined by the limiting diffusion rate of oxygen and stabilized at a high value.Originality/valueThe corrosion model of rusted carbon steel in 3% NaCl solution was established. It is probable that the iron rust in all slightly acidic water with low alkalinity can promote the corrosion process via reduction of γ‐FeOOH. Anti‐corrosion measures for iron in this type of solutions should be aimed to reduce the promoting effect of rust layer on the metal corrosion. The NaCl solution prepared from tap water is more suitable for the substitution of artificial water than that prepared from deionized water.

Summary Recent progress in single DNA manipulation with atomic force microscope has proved its potential in analysing genetic information at the molecular level instead of macro ensemble approach. However, current manipulation of DNA is mainly carried out by manual operations, which is labour-intensive and time-consuming, thus limits the further applications in other fields. In this paper, an optimized DNA manipulation method is successfully established. An image correlation technique is introduced to realize automatic thermal drift compensation. Combined with elaborately designed tip movement control for different manipulation purposes, accurate and efficient DNA manipulations such as dissection, folding and picking are realized. The efficiency has been improved for an order of magnitude compare to manual manipulations, whereas the performance is demonstrated to be the same. This newly developed method has shed light on high-efficiency nanomanipulation of small molecules with complex structures, and thus provides the possibility of deeply understanding the intrinsic properties of single biomolecules.