Hexagon MXene based heterojunction interface with high ion adsorption and electron transfer efficiency for soft-package potassium-ions aqueous supercapacitors.

Potassium-ion hybrid capacitors (PIHC) are considered as ideal large-scale rechargeable energy storage devices due to their low-cost, high-power density and environmental protection. However, a low energy density is the main factor restricting the practical application of PIHC. The interface is formed on the surface of electrode material of PIHC through strong correlation to construct heterojunction, which can significantly improve the performance of ion energy storage. However, how to reveal the influence of the interfacial state of the heterojunction on the adsorption and electron transmission of energy storage ions at the atomic level is still one of the key scientific problems in this field. In this work, metal ion intercalation and microwave-assisted in-situ etching are used to construct the Hexagon MXene Ti3C2 heterojunction with TiOHO strong correlation. At the interface of heterojunction, TiOHO highway for electron transmission is developed to improve the rate performance of PIHC. Through experimental and theoretical calculation, the optimum adsorption position and maximum adsorption amount of potassium-ion at the single interface of heterojunction are obtained, and the specific energy density of PIHC is increased. This lays a foundation for the practical application of high-performance soft-package PIHC.

Source-Sink Manipulation Affects Accumulation of Zinc and Other Nutrient Elements in Wheat Grains.

To better understand the source-sink flow and its relationships with zinc (Zn) and other nutrients in wheat (Triticum aestivum L.) plants for biofortification and improving grain nutritional quality, the effects of reducing the photoassimilate source (through the flag leaf removal and spike shading) or sink (through the removal of all spikelets from one side of the spike, i.e., 50% spikelets removal) in the field of the accumulation of Zn and other nutrients in grains of two wheat cultivars (Jimai 22 and Jimai 44) were investigated at two soil Zn application levels. The kernel number per spike (KNPS), single panicle weight (SPW), thousand kernel weight (TKW), total grain weight (TGW) sampled, concentrations and yields of various nutrient elements including Zn, iron (Fe), manganese (Mn), copper (Cu), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), phytate phosphorus (phytate-P), phytic acid (PA) and phytohormones (ABA: abscisic acid, and the ethylene precursor ACC: 1-aminocylopropane-1-carboxylic acid), and carbon/N ratios were determined. Soil Zn application significantly increased the concentrations of grain Zn, N and K. Cultivars showing higher grain yields had lower grain protein and micronutrient nutritional quality. SPW, KNPS, TKW (with the exception of TKW in the removal of half of the spikelets), TGW, and nutrient yields in wheat grains were most severely reduced by half spikelet removal, secondly by spike shading, and slightly by flag leaf removal. Grain concentrations of Zn, N and Mg consistently showed negative correlations with SPW, KNPS and TGW, but positive correlations with TKW. There were general positive correlations among grain concentrations of Zn, Fe, Mn, Cu, N and Mg, and the bioavailability of Zn and Fe (estimated by molar ratios of PA/Zn, PA/Fe, PA × Ca/Zn, or PA × Ca/Fe). Although Zn and Fe concentrations were increased and Ca was decreased in treatments of half spikelet removal and spike shading, the treatments simultaneously increased PA and limited the increase in bioavailability of Zn and Fe. In general, different nutrient elements interact with each other and are affected to different degrees by source-sink manipulation. Elevated endogenous ABA levels and ABA/ACC ratios were associated with increased TKW and grain-filling of Zn, Mn, Ca and Mg, and inhibited K in wheat grains. However, the effects of ACC were diametrically opposite. These results provide a basis for wheat grain biofortification to alleviate human malnutrition.

Rational Application of Fertilizer Nitrogen to Soil in Combination With Foliar Zn Spraying Improved Zn Nutritional Quality of Wheat Grains.

To alleviate human zinc (Zn) deficiency, it is worthy to develop rational agronomic managements to achieve high yielding and high resource-use efficiency wheat (Triticum aestivum L.) grains biofortified with Zn. Effects of application of three rates of nitrogen (N) fertilizer (75,200 and 275 kg·ha-1) to soil in combination with three foliar applications (deionized water, Zn alone, and a combination of Zn and sucrose) on grain yield, yield components, grain Zn concentration, protein, phytic acid (PA), phosphorus (P), calcium (Ca), and carbon (C), as well as on Zn bioavailability, were investigated in four wheat cultivars ("Jinan 17," "Jimai 20," "Jimai 22," and "Luyuan 502") under field conditions. Enhanced N increased Zn and protein concentrations as well as bioavailability; excessive N input did not result in further improvements. Zinc spraying was more effective than soil fertilizer N application, the spray of Zn (with or without sucrose) increased grain Zn concentrations by 11.1-15.6 mg·kg-1 (27.1-38.1%), and increased grain Zn bioavailability, estimated using total daily absorbed Zn (TAZ) and molar ratios of PA/Zn) and PA × Ca/Zn, by 0.4-0.6 mg d-1 (28.6-42.9%), 23.1-27.4% and 24.0-28.0%, respectively. Remarkably, increases caused by 'Zn + sucrose' were higher than spraying Zn alone. Grain Zn bioavailability was more sensitive to the selection of cultivar than Zn concentrations. Among cultivars, the higher the grain yields and concentrations of antinutritional compounds, the lower the grain Zn nutritional quality would be. 200 kg N ha-1 application rate in combination with foliar spraying of "Zn + sucrose" maximized grain Zn concentrations of "Jinan 17," "Jimai 20," "Jimai 22," and "Luyuan 502" to be 59.4, 56.9, 55.8, and 60.9 mg kg-1, respectively, achieving the target value for biofortification. Additionally, PA/Zn and PA × Ca/Zn of "Jinan 17," "Jimai 20," and "Luyuan 502" were <15 and 200, and TAZ was maximized to be 2.2, 2.0, and 2.1 mg d-1, respectively, indicating higher bioavailability. Therefore, optimal soil N and foliar Zn management together with suitable cultivars maintained high grain yield with lower N input and could substantially increase grain Zn nutritional quality simultaneously.

Evaluation on oxidative stability of walnut beverage emulsions.

Walnut beverage emulsions were prepared with walnut kernels, mixed nonionic emulsifiers and xanthan gum. The effects of food antioxidants on the physical stability and lipid oxidation of walnut beverage emulsions were investigated. The results showed that tea polyphenols could not only increase the droplet size of the emulsions, but also enhance physical stability during the thermal storage at 62 ± 1 °C. However, water-dispersed oil-soluble vitamin E and enzymatically modified isoquercitrin obviously decreased the physical stability of the emulsion system during the thermal storage. BHT and natural antioxidant extract had scarcely influenced on the physical stability of walnut beverage emulsions. Tea polyphenols and BHT could significantly retard lipid oxidation in walnut beverage emulsions against thermal and UV light exposure during the storage. Vitamin E exhibited the prooxidant effect during the thermal storage and the antioxidant attribute during UV light exposure. Other food antioxidants had no significant effect on retarding lipid oxidation during thermal or light storage.

Impact of pH, freeze-thaw and thermal sterilization on physicochemical stability of walnut beverage emulsion.

The effects of environment stresses on the stability of walnut emulsion were investigated. The physical stability of walnut emulsion was characterized by droplet size, zeta potential and chemical stability of walnut oil in the emulsion was evaluated by determining the peroxide concentration during the storage. The results showed that emulsion in the presence of xanthan gum and mixed emulsifiers exhibited better stability after 4 freeze-thaw cycles. At pH 3-10, the mixed emulsifiers could improve the stability through their absorption on the oil-water interface. However, xanthan gum couldn't protect the droplets against the aggregation in high acid environment, but greatly enhanced the physical stability at pH 6-10. During the thermal sterilization process, the physical stability of walnut emulsion was decreased with a rise of sterilization temperature and the extension of sterilization time. The sterilization temperature above 121 °C and time over 25 min led to the poor physical and oxidative stability.

Pyrolytic Characteristics and Kinetics of Phragmites australis.

The pyrolytic kinetics of Phragmites australis was investigated using thermogravimetric analysis (TGA) method with linear temperature programming process under an inert atmosphere. Kinetic expressions for the degradation rate in devolatilization and combustion steps have been obtained for P. australis with Dollimore method. The values of apparent activation energy, the most probable mechanism functions, and the corresponding preexponential factor were determined. The results show that the model agrees well with the experimental data and provide useful information for the design of pyrolytic processing system using P. australis as feedstock to produce biofuel.

[Main regulatory factors for differentiation, development and function of naturally occurred CD4+ CD25+ regulatory T cells].

Naturally occurred CD4(+)CD25(+) regulatory T cells derived from thymus. It plays an important role in self-tolerance and allograft-tolerance through cell-contact dependent mechanism. This review described the advances of study on the probable regulatory factors of the naturally occurring regulatory T cells, such as Foxp3, IL-2, TGF-beta(1), dendritic cells and CTLA-4. As a marker of Treg, the expression of Foxp3 could be used to identify regulatory T cells. The combination of interferon 2 and IL-2Ralpha would activate Treg and promote its proliferation through the phosphorylation of STAT5. TGF-beta(1) on the cell surface may influence the function of Treg, while the secretion type of TGF-beta may promote the proliferation of Treg. Dendritic cells can positively or negatively regulate Treg, which depends on the signal transduction pathway. CTLA-4 expressed on the surface of Treg might bind to the B7 molecule on the DC, effective cell or Treg itself directly or indirectly regulate Treg.