The ability to obtain a maximum loading of inorganic nanoparticles while maintaining uniform dispersion in the polymer is the key to the fabrication of mixed‐matrix membranes with high pervaporation ...performance in bioalcohol recovery from aqueous solution. Herein, we report the simultaneous spray self‐assembly of a zeolitic imidazolate framework (ZIF)–polymer suspension and a cross‐linker/catalyst solution as a method for the fabrication of a well‐dispersed ZIF‐8–PDMS nanohybrid membrane with an extremely high loading. The ZIF‐8–PDMS membrane showed excellent biobutanol‐permselective pervaporation performance. When the ZIF‐8 loading was increased to 40 wt %, the total flux and separation factor could reach 4846.2 g m−2 h−1 and 81.6, respectively, in the recovery of n‐butanol from 1.0 wt % aqueous solution (80 °C). This new method is expected to have serious implications for the preparation of defect‐free mixed‐matrix membranes for many applications.
Thin and functional: A ZIF‐8/polymer suspension and a cross‐linker/catalyst solution were simultaneously sprayed onto a polysulfone substrate (see picture). The nanoparticles of the zeolitic imidazolate framework ZIF‐8 were dispersed uniformly and separated from one another by the polymer chains. The resulting ZIF‐8/polymer nanohybrid membranes exhibited excellent biobutanol‐permselective pervaporation.
High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Although in the infant ...stage, the emerging of this new family of materials has brought new opportunities for material design and property tailoring. Distinct from metals, the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering. Aside from strengthening, hardening, and low thermal conductivity that have already been found in high-entropy alloys, new properties like colossal dielectric constant, super ionic conductivity, severe anisotropic thermal expansion coefficient, strong electromagnetic wave absorption, etc., have been discovered in HECs. As a response to the rapid development in this nascent field, this article gives a comprehensive review on the structure features, theoretical methods for stability and property prediction, processing routes, novel properties, and prospective applications of HECs. The challenges on processing, characterization, and property predictions are also emphasized. Finally, future directions for new material exploration, novel processing, fundamental understanding, in-depth characterization, and database assessments are given.
The stability of the membrane for pervaporation separation of aromatic/aliphatic mixtures is critical for industrial applications. To improve the stability of the membrane, a “pore-filling” membrane ...was prepared by dynamic pressure-driven assembly of a poly(vinyl alcohol)–graphene oxide (PVA–GO) nanohybrid layer onto an asymmetric polyacrylonitrile ultrafiltration membrane. The results of the swelling experiment suggest that the pore-filling structure could effectively reduce swelling of the nanohybrid membrane. Assembly of the nanohybrid membrane by molecular-level dispersion of GO in PVA led to enhanced affinity of the membrane to aromatic compounds and thus improved performance in the pervaporation of toluene/n-heptane mixtures. Moreover, the dynamic assembly process could easily be used to adjust the separation performance by controlling the pressure, filtration time, polymer, and GO concentration.
•GO and PVA nanohybrid membrane for pervaporation of toluene/n-heptane mixtures.•“Pore-filling” composite membranes prepared by dynamic pressure-driven assembly.•Improvements of PV performance and swelling resistance with the addition of GO.
The ripening of grape berry is generally regulated by abscisic acid (ABA), and has no relationship with ethylene function. However, functional interaction and synergism between ABA and ethylene ...during the beginning of grape berry ripening (véraison) has been found recently.
The expressions of VvNCED1 encoding 9-cis-epoxycarotenoid dioxygenase (NCED) and VvGT encoding ABA glucosyltransferase were all increased rapidly at the stage of véraison and reached the highest level at 9th week after full bloom. However, VvCYP1 encoding ABA 8'-hydroxylase and VvβG1 encoding berry β-glucosidase are different, whose expression peak appeared at the 10th week after full bloom and in especial VvβG1 remained at a high level till harvest. The VvACO1 encoding 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase, the VvETR2 (ethylene response 2) and VvCTR1 (constitutive triple response 1) had a transient expression peak at pre-véraison, while the VvEIN4 (ethylene insensitive 4) expression gradually increased from the véraison to one week before harvest stage. The above mentioned changes happened again in the berry after harvest. At one week before véraison, double block treatment with NiCl2 plus 1-methylcyclopropene (1-MCP) not only inhibited the release of ethylene and the expression of related genes but also suppressed the transcription of VvNCED1 and the synthesis of ABA which all might result in inhibiting the fruit ripening onset. Treatment with ABA could relieve the double block and restore fruit ripening course. However, after harvest, double block treatment with NiCl2 plus 1-MCP could not suppress the transcription of VvNCED1 and the accumulation of ABA, and also could not inhibit the start of fruit senescence.
The trace endogenous ethylene induces the transcription of VvNCED1 and then the generation of ABA followed. Both ethylene and ABA are likely to be important and their interplaying may be required to start the process of berry ripening. When the level of ABA reached the peak value, part of it will be stored in the form of ABA-GE. While after harvest, abiotic stresses principally (such as dehydration, harvest shock) could induce the transcription of VvNCED1 and the accumulation of ABA, thus starting the process of fruit senescence.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
When the lateral stiffness of the frame flat column is relatively small, the strength of the frame flat column is not enough to resist the large horizontal earthquake force and seriously deformed, ...which leads to the structure fail and could not work normally. In order to study the bearing capacity and the deformation capacity, experiments of three specimens of high axial compressive ratio under frequency cyclic loading were conducted, in which the failure process were observed in detail and the failure mechanism of the specimens were researched, the failure type, the hysteretic characteristic were studied, and the effect of the axial compressive ratio, the ties type and the stirrup ratio on the ductility of the members were analysed.
As a main inhibitory neurotransmitter in the central nervous system, γ-aminobutyric acid (GABA) activates chloride-permeable GABAa receptors (GABAa Rs) and induces chloride ion (Cl
) flow, which ...relies on the intracellular chloride concentration (Cl
) of the postsynaptic neuron. The Na-K-2Cl cotransporter isoform 1 (NKCC1) and the K-Cl cotransporter isoform 2 (KCC2) are two main cation-chloride cotransporters (CCCs) that have been implicated in human epilepsy. NKCC1 and KCC2 reset Cl
by accumulating and extruding Cl
, respectively. Previous studies have shown that the profile of NKCC1 and KCC2 in neonatal neurons may reappear in mature neurons under some pathophysiological conditions, such as epilepsy. Although increasing studies focusing on the expression of NKCC1 and KCC2 have suggested that impaired chloride plasticity may be closely related to epilepsy, additional neuroelectrophysiological research aimed at studying the functions of NKCC1 and KCC2 are needed to understand the exact mechanism by which they induce epileptogenesis. In this review, we aim to briefly summarize the current researches surrounding the expression and function of NKCC1 and KCC2 in epileptogenesis and its implications on the treatment of epilepsy. We will also explore the potential for NKCC1 and KCC2 to be therapeutic targets for the development of novel antiepileptic drugs.
Welding deformation and residual stress have negative influence on assembly accuracy and service performance. Thermal elastic plastic (TEP) and inherent strain finite element analysis (FEA) methods ...were used to study this challenge. Basic principle of these two methods was first introduced. The influence of welding process, constraints, solid phase transformation and multi-pass welding on deformation and residual stress was discussed, and computation accuracy and efficiency were summarised. Loading method of inherent strain in inherent strain FEA was analysed, interface element was introduced to simulate effects of the gap on deformation in assembly welding especially for large structures. The future work, including accurately multiscale TEP model, efficiently transient prediction method of large structures, and flexible evaluation software, was planned.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Machining performance of thin-walled components made by aeronautical difficult-to-process materials is a significant issue in the aviation manufacturing industry. Although wire electric discharge ...machining-low speed (WEDM-LS) is one of typical non-contact machining processes without macro cutting force, which does well in removing hardness and brittleness materials via pulsed discharge at high temperature, but few researchers have studied the thermal distortion behavior leading to a considerable geometric error in the WEDM-LS of thin-walled components. In this paper, a transverse magnetic field assisted method is applied for affecting the uniformity of discharge point distribution so as to reduce the distortion in WEDM-LS processing thin-wall component. First, the generation mechanism of this new distortion behavior and the impact mechanism of transverse magnetic field (TMF) on distortion are demonstrated by theoretical analysis. In order to further figure out the distortion behavior in the TMF-WEDM process, a new thermo-physical model considering the discharge point distribution is established to simulate temperature field, residual stress field and distortion profiles. Then a large number of Taguchi experiments are carried out to investigate the influences of process parameters including pulse discharge energy (pulse on time, pulse off time, and current) and magnetic field strength on distortion in WEDM-LS. To comparatively analyze simulated and experimental results, the accuracy of established thermo-physical model is verified within a relative error of 18.38 % in distortion. Moreover, it can be revealed that transverse magnetic field contribute to significantly improve the longitudinal distribution uniformity with maximum increase of 12.32% at magnetic field strength: 0.15 T, leading to significant reductions of 32.77% in distortion and 22.68% in recast layer. Eventually, we also presented the variation of residual stress and recast layer along thickness direction under different distortion behavior, which are in good agreement with that of distortion behavior.
The ultra-fine grained (UFG) CoCrFeMnNi alloy (Cantor alloy) exhibits high mechanical strength. As far as its real application is concerned, the corrosion behavior of the UFG Cantor alloy should also ...be taken into account, which, however, has not been reported so far. In this paper, the UFG Cantor alloy was prepared using Cryo-rolling followed by short time annealing, and its corrosion behavior was investigated by electrochemical test in 3.5 wt% NaCl aqueous solution at ambient temperature. Potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) indicated that an unstable passive layer formed more easily on the surface of the UFG Cantor alloy and made it show an enhanced corrosion rate, as compared with coarse grained (CG) sample. Detailed microstructural characterization showed that after the mechanical processing, the Cr-enriched region (σ phase) formed in the UFG Cantor alloy, resulting in the galvanic corrosion between the σ phase and its nearby matrix phase. Moreover, Cr-depleted passive layer formed on the surface of corroded specimen decreased the stability of the passive layer, and hence decreased the resistance to pitting corrosion.
•UFG Cantor alloy was prepared using cryo-rolling and short time annealing.•Mechanical processing led to the segregation of alloying elements in UFG specimen.•A Cr-depleted passive layer formed in the UFG alloy in corrosion media.•UFG Cantor alloy showed a lowed corrosion resistance compared with the CG sample.
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•The expression of LINC00665 was upregulated in NSCLC.•Downregulated LINC00665 suppressed cell proliferation and invasion of NSCLC cells.•LINC00665/miR-138-5p/E2F3 axis is probably a ...significant mechanism analyzing the involvement of LINC00665 in NSCLC.•LINC00665 exerts cancer promoting effects in NSCLC.
Non-small cell lung cancer (NSCLC) is a type of malignant tumor which threatens human health and life. Recently, some researches on long non-coding RNAs (lncRNAs) in NSCLC has elucidated critical regulatory roles in cell proliferation, migration, and invasion, the relative clinical significance and mechanisms of action are still unclear. This study focuses on the important role of a novel lncRNA LINC00665 in the development of NSCLC. Long intergenic non-protein coding RNA 665 gene (LINC00665) was found through microarray analysis and was measured by real-time quantitative PCR (RT-qPCR). The interactions between LINC00665 and miR-138-5p as well as the interactions between miR-138-5p and E2F3 (E2F transcription factor 3) were explored by bioinformatics analysis and dual-luciferase assays. CCK-8, transwell and mouse xenograft assays were performed to investigate the effects of LINC00665 and miR-138-5p on NSCLC proliferation and invasion. As a result, LINC00665 expression was upregulated in NSCLC lung tissues and cells. Downregulated LINC00665 could arrest A549 and H1299 cell proliferation and invasion in vitro, and this finding was recapitulated in vivo. LINC00665 directly regulated the expression of miR-138-5p. Additionally, E2F3 was one of the targets of miR-138-5p; E2F3 without 3′UTR could reverse the inhibitory effects of downregulated LINC00665 on proliferation and invasion in A549 and H1299 cells. In conclusion, dysregulation of LINC00665 plays a vital role in NSCLC progression, indicating that its downregulation may confer decreased cell proliferation and invasion via the miR-138-5p/E2F3 signaling pathway.
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