High Strength MXene/PBONF Heterogeneous Membrane with Excellent Ion Selectivity for Efficient Osmotic Energy Conversion.

Layered MXene nanofluidic membranes still face the problems of low mechanical property, poor ion selectivity, and low output power density. In this work, we successfully constructed heterostructured membranes with the combination of the layered channels of the MXene layer on the top and the nanoscale poly(p-phenylene-benzodioxazole) nanofiber (PBONF) layer on the bottom through a stepwise filtration method. The as-prepared MXene/PBONF-50 heterogeneous membrane exhibits high mechanical properties (strength of 221.6 MPa, strain of 3.2%), high ion selectivity of 0.87, and an excellent output power density of 15.7 W/m2 at 50-fold concentration gradient. Excitingly, the heterogeneous membrane presents a high power density of 6.8 W/m2 at a larger testing area of 0.79 mm2 and long-term stability. This heterogeneous membrane construction provides a viable strategy for the enhancement of mechanical properties and osmotic energy conversion of 2D materials.

Expression and immunogenicity of hepatitis E virus-like particles based on recombinant truncated ORF2 capsid protein.

Hepatitis E is an emerging zoonotic disease, posing a severe threat to public health in the world. Since there are no specific treatments available for HEV infection, it is crucial to develop vaccine to prevent this infection. In this study, the truncated ORF2 encoded protein of 439aa∼617aa (HEV3-179) from HEV CCJD-517 isolates was expressed as VLPs in E. coli with diameters of approximate 20 nm. HEV3-179 protein was immunized with mice, and the results showed that a higher titre of antibody was induced in NIH mice in comparison with that of KM mice (P < 0.01) and BALB/c mice (P < 0.01). The induced antibody titer is much higher in subcutaneous immunization mice than that in the mice inoculated via abdominal immunization (P < 0.05) and muscles immunization (P < 0.01). Mice immunized with 12 µg and 6 µg candidate vaccine induced higher level of antibody titer than that of 3 µg dosage group (P < 0.01, P < 0.05). Antibody change curve showed that HEV IgG antibody titer increased from 14 days post immunization (dpi) to 1:262144 and reached the peak level on 42 dpi before gradually retreated with the same level antibody titer with 1:131072 until 84 dpi. Mice inoculated with HEV3-179 produced higher titer of cytokines than the mock group, and the concentration of IL-1ß (P < 0.01) and IFN-γ (P < 0.01) further increased after stimulated by candidate vaccine. The result indicated that HEV3-179 possesses good immunogenicity, which could be used as a potential candidate for future HEV vaccine development.

Construction of A375·S2 Melanoma Cell Line with High Sensibility to IL-1 by Overexpressing IL-1 Receptor.

We described an operation that co-overexpress interleukin receptor 1 (IL-1R1) and its co-receptor (IL-1R1AcP) genes in wild-type A375·S2 cells in order to increase their sensibility to IL-1. Firstly, laser scanning confocal microscope observed that IL-1R1 could be expressed on the surface of A375·S2 cells. qPCR was performed to estimate the ratio of two genes and result showed the ratio was almost 4.57:1. Then two genes were linked to vectors and co-transfected into A375·S2 cells. qPCR and Western blotting showed the protein content improved markedly. Finally, MTS assay was executed and the sensitivity of A375·S2 cells that co-transfected receptors to IL-1ß increased significantly. Another MTS assay showed the cell activity variation changed significantly (P < 0.05) and the reliability of the experiment was high, indicating that cell line established in this study could be further used for the activity test of IL-1Ra. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01027-8.

[Determination of pesticide residues in substitutional tea by dispersive solid-phase extraction and gas chromatography-triple quadrupole mass spectrometry].

OBJECTIVE: The method was established for determination 14 kinds of psticide residues in substitutional tea using gas chromatography-triple quadrupole mass spectrometry( GC-MS/MS) for instrument method and dispersive solid-phase extraction( dSPE) for sample preparation. METHODS: The samples extracted with acetonitrile, and purified by N-propyl ethlene diamine( PSA), the extracts were separated on DB-5MS column( 30 m × 0. 25 mm, 0. 25 µm) with programmed temperature and determined by GCMS/MS in multi-reaction monitoring( MRM) model. The external standard method was applied to quantify the pesticides. RESULTS: The method showed a good linearity( r ≥0. 999) in certain ranges for 14 kinds of pesticides. The limits of quantification( LOQ)were 4-40 µg/kg. The average recoveries range were 65. 6%-116. 6% in three add levels of 20, 40 and 200 µg/kg, and relative standard deviations( RSD S) of 1. 5%-15. 7%( n = 6). CONCLUSION: This method is simple, fast, sensitive, selective and can satisfy the request of simultaneous analysis of multiple pesticide residues in substitutional tea.

Ultraviolet-Irradiated All-Organic Nanocomposites with Polymer Dots for High-Temperature Capacitive Energy Storage.

Polymer dielectrics capable of operating efficiently at high electric fields and elevated temperatures are urgently demanded by next-generation electronics and electrical power systems. While inorganic fillers have been extensively utilized to improved high-temperature capacitive performance of dielectric polymers, the presence of thermodynamically incompatible organic and inorganic components may lead to concern about the long-term stability and also complicate film processing. Herein, zero-dimensional polymer dots with high electron affinity are introduced into photoactive allyl-containing poly(aryl ether sulfone) to form the all-organic polymer composites for high-temperature capacitive energy storage. Upon ultraviolet irradiation, the crosslinked polymer composites with polymer dots are efficient in suppressing electrical conduction at high electric fields and elevated temperatures, which significantly reduces the high-field energy loss of the composites at 200 °C. Accordingly, the ultraviolet-irradiated composite film exhibits a discharged energy density of 4.2 J cm-3 at 200 °C. Along with outstanding cyclic stability of capacitive performance at 200 °C, this work provides a promising class of dielectric materials for robust high-performance all-organic dielectric nanocomposites.

Multilayer Dielectric Nanocomposites with Cross-Linked Dielectric Transition Interlayers for High-Temperature Applications.

In energy storage and transportation systems, polymer dielectrics are widely applied in smart grids, electric vehicles, and power conditioning owing to their incomparable power density and high reliability. However, the dielectric constant (ε) and breakdown strength (Eb) normally cannot be increased simultaneously, which results in insufficient discharged energy density especially at high temperatures. In this work, enhanced Eb and high energy density are archived in multilayer polymer nanocomposites by introducing cross-linked dielectric transition layers. Specifically, the sandwiched composite achieves a huge discharge energy density of 4.64 J cm-3 with a charged-discharged efficiency of 84% at 150 °C and 500 MV m-1. The formation of cross-linked dielectric transition layers between layers of the multilayer nanocomposite could effectively restrain the growth of the electrical tree and greatly increase the Eb. This work presents a strategy for designing high-performance multilayered dielectric polymer nanocomposites by introducing cross-linked dielectric transition layers to reduce the loss from interlayer interfaces.

[Nondestructive examination of tomato chilling injury by ultraweak luminescence].

Ultraweak luminescence (UWL) is an universal phenomenon of photons emission in living organism. It is intrinsically connected with biological processes, and it closely links with biochemical, physiological and pathological conditions in organisms under stress. UWL testing is widely used in clinical medicine, agriculture, environmental protection and food industry etc. But it was not applied in testing physiological disease of agricultural product in storage. This study used tomato fruit as material to find rule of UWL in fruits under chilling stress, which is the main problem in tomato fruit storage. To obtain fruits with different chilling injury degree, before cold storage a group of fruits were treated with cold shock, the effective method to decrease chilling injury, which showed alleviative chilling injury symptom compared with untreated fruits. It was found that UWL rose with the degree of chilling injury, furthermore UWL went up remarkably (P < 0.01) before symptom of chilling injury happening. Correlation analysis between UWL and chilling injury rate and chilling injury index showed that correlation coefficient was 0. 901 6 and 0.9577 (P < 0.01)respectively. In conclusion, UWL could factually reflect the degree of chilling injury.

Ethylene and cold participate in the regulation of LeCBF1 gene expression in postharvest tomato fruits.

C-repeat/dehydration-responsive element binding factor (CBF) is a transcription factor regulating cold response in plants, of which little is known in fruits. We showed a double-peak expression pattern of Lycopersicon esculentum putative transcriptional activator CBF1 (LeCBF1) in mature green fruit. The peaks appeared at 2 and 16 h after subjection to cold storage (2 degrees C). The second peak was coincident with, and thus caused by a peak in endogenous ethylene production. We showed that LeCBF1 expression was regulated by exogenous ethylene and 1-methylcyclopropene, and was not expressed without cold induction. LeCBF1 expression was different in the five maturation stages of fruits, but expression peaked at 2 h at all stages.